HE 2708 R3 A2 1920 U. S. Railroad Administration. Automatic Train Control Committee. Report. HE ^^ 210 g 1?^ ^^^ /qao ANNUAL REPORT OF WALKER D. HINES DIRECTOR GENERAL OF RAILROADS 1919 U V) . y ■ l^rrJ OJU^^^. 'A ' l-'J..- ll' AUTOMATIC TRAIN CONTROL COMMITTEE A. M. BURT, Chairman WASHINGTON GOVEENMENT PRINTING OFFICE 1920 C '^^ pehSonnel of the committee. A. M. BuET, Chairman Assistant Directoi-, Division of Operation, United States Railroad Administration. W. P. BoELAND Chief, Bureau of Safety, Interstate Commerce Commission. 0. E. Denney Assistant Federal Manager, New York, Chicago & St. Louis Railroad. H. S. BALtiET Assistant Terminal llanager. Grand Central Ter- minal, New York City. Henby Bartiett Chief Jlechanical Engineer, Boston & Maine Rail- road. J. H. GuMBES General Superintendent, Pennsylvania Railroad. R. W. Bell General Superintendent of Motive Power Illinois Central Railroad. Mr. C. A. Morse, chief engineer, Chicago, Rock Island & Pacific Railroad, who was, at the time of the creation of this committee. Assistant Director, Division of Operation, United States Railroad Administration, was appointed at that time chairman of the committee. On June 1, 1919, Mr. Morse resigned as Assistant Director and from th(j chairmanship of the committee, and Mr. A. M. Burt, his successor as Assistant Director, was appointed in his stead. 2 CONTENTS. Page. Letter of transmittal 4 Introduction 5 Outline of work done by the committee 6 General considerations ' s The train control problem , 11 Reliability in operation 11 Inspection, maintenance, and test to insure efficiency 12 Clearance — Relation between parts of a train and obstructions on the roadside or train 12 Capacity — ^The effect upon the traffic handled over a given section of railroad 13 Interchangeabillty as between different devices on track used by railroads jointly 14 Correlation with track circuit controlled block signaling and air-. brake apparatus 14 Analysis and description of the different types 15 Description of devices examined 22 General discussion 31 Conclusions and recommendations 34 Definitions 36 Appendixes. I. Alphabetical list of plans and devices examined 40 II. Bibliography _• 47 3 LETTER OF TRANSMITTAL. Washington, D. C, Deoember 31, 1919. Deaf Sir : I have the honor to submit herewith the report of the Automatic Train Control Committee of the United States Railroad Administration for the year 1919. Sincerely, A. M. Btjrt, Ghairmam,. To Walkek D. Hines, Birectw General of Railroads. ANNUAL REPORT AUTOMATIC TRAIN CONTROL COMMITTEE. INTRODUCTION. The Automatic Train Control Committee was created by Circular ~No. 25, dated January 14, 1919, issued by C. E. Gray, Director of the Division of Operation, United States Railroad Administration, with the approval of Walker D. Hines, Director General of Eail- roads. The committee's instructions, as given in the circular, were as fol- lows : "The committee will proceed at once to make a study of, and report upon, the automatic train control devices now undergoing test upon various lines of railroad or available for test, with their recommendations for the installation and further practical test of any devices now or during their investigation made available for that purpose, which they may consider practicable and reasonably conforming to the purposes to be accomplished. "The report of the committee will include their recommendations upon -the requisites of automatic train control and their conclusioni\ upon the mechanical or economic features of such of the devices as the committee may find available for practical use." OUTLINE OF WORK DONE BY THE COMMITTEE. The committee held its first meeting in Washington on January 23, 1919, and since that time 14 meetings of the full committee have been held. In addition to these meetings of the full committee, 17 subcommittee meetings have been held. To enable the committee to become familiar with train-control devices undergoing test it became necessary to arrange for inspec- tions of such devices wherever tests were being conducted. To ac- complish this end the committee has made mvestigations and in- spections of devices actually installed and operated, either as test installations or in actual service, at the following places : Baltimore, Md. ; Boston, Mass.; Charlottesville, Va.; Chicago, 111.; Danville, 111. ; Indianapolis, lud. ; Millbury, ^lass. ; New York, N. Y. ; Oroville, Calif. ; Philadelphia, Pa. ; Pottstown, Pa. ; San Francisco, Calif., Spokane, Wash.; Virginia, Minn.; Waltham, Mass. Train control devices not undergoing road test, but which were presented to the committee's notice in laboratory form, were ex- amined at the following points : Baltimore, Md. ; Chicago, 111. ; De- troit, Mich.; Indianapolis, Ind. ; Newark, N. J.; New York, N. Y. ; Philadelphia, Pa. ; Pittsburgh, Pa. ; Kochester, N. Y. ; Scranton, Pa. ; Spokane, Wash. ; Swissvale, Pa. Thirty-seven devices were inspected as above outlined. In addition to this work, plans and specifications of 300 train- control devices Avere examined by the committee. The relation of automatic train control to operating conditions has been very fully discussed and all the elements of the problem have been thoroughly considered. Th.e committee has been especially careful to give full consideration to all devices that have in any manner been brought to its attention, and has endeavored, through its inspections, the consideration of plans received and its discus- sions, to obtain a comprehensive knowledge of the state of the art as it at present exists in this country. The following definitions and requisites for automatic train con- trol were adopted by the committee : DEFINITION OF AUTOMATIC TRAIN CONTROL. An installation so arranged that its operation automatically re- sults in either one or the other or both of the following conditions : First. The application of the brakes until the train has been brought to a stop. 6 AUTOMATIC TEAIN CONTROL COMMITTEE. < Second. The application of the bx-akes when the speed of the train exceeds a presci'ibed rate and continued until the speed has been reduced to a predetermined rate. REQUISITES FOE THE DESIGN AND CONSTRUCTION OF AUTOMATIC TRAIN- CONTROL DEVICES. 1. The apparatus so constructed as to operate in connection with a system of fixed, block, or interlocking signals, and so interconnected with the fixed signal system as to perform its intended function : (a) In event of failure of the engineman to obey the fixed signal indications, and (h) So far as possible, when the fixed signal fails to indicate a condition requiring an application of the brakes. 2. The apparatus so constructed that it will perform its intended function if an essential part fails or is removed; or a break, cross, ground, or failure of energy occurs in electric circuits when used. 3. The apparatus so constructed as to make indications of the fixed signal depend upon the operation of the track element of the train-control device. 4. The apparatus so constructed that proper operative relation between those parts along the roadway and those on the train will be assured under all conditions of speed, weather, wear, oscillation, and shock. 5. The apparatus so constructed as to prevent the release of the brakes after automatic application until the train has been brought to a stop, or its speed has been reduced to a predetermined rate, or the obstruction or other condition that caused the brake application has been removed. 6. The train apparatus so constructed that, when operated, it will make an application of the brakes sufficient to stop the train or control its speed. 7. The apparatus so constructed as not to interfere with the appli- cation of the brakes by the cngineman's brake valve or to impair the efficiency of the air brake. 8. The apparatus so constructed that it may be "applied so as to be operative when the engine is running forward or backward. 9. The apparatus so constructed that when two or more engines are coupled together, or a pusher is used, it can be made operative only on the engine from which the brakes are controlled. 10. The apparatus so constructed that it will operate under all weather conditions which permit train movements. 11. The apparatus so constructed as to conform to established clearances for equipment and structures. 12. The apparatus so constructed and installed that it will not constitute a source of danger to trainmen, other employees, or pas- sengers. 8 ANNUAL EEPORT DIRECTOR GENERAL OF RAILROADS. GENERAL CONSIDERATIONS. The use of automatic train control has been generally advocated in the public press for the past decade or more, and especially after each collision involving serious injuries and loss of life, occurring on tracks protected by block signals, where employees have failed properly to perform their duties. It is obvious that on lines where all the generally accepted means for the protection of trains are in use, and collisions still occur due to the failure of the human element, additional safeguards must be provided if such accidents are to be avoided. In considering additional safeguards that may be adopted for the prevention of collisions it is necessary to analyze briefly the circumstances under which such accidents occur and undertake to arrive at a conclusion as to the possibilities and limitations of any preventive measures which may be available. The purpose of a block system generally is to provide a proper space interval between trains to protect against rear-end collisions in the assigned direction of traffic, and against both rear-end and head-on collisions on track signaled for movements in both direc- tions. On roads where track circuit controlled block signals are installed it is evident that, if the rules are obeyed and the indications of the fixed signals along the roadway are at all times observed, undei'stood and obeyed, accidents such as the signal system is de- signed to prevent can not occur, except in the unusual event of a signal failing to indicate an unsafe condition when such a condition exists. Generally speaking, therefore, on tracks fully equipped with mod- ern track circuit controlled block signals, train collisions can occur only as the result of one of the following causes : 1. Failure of brakes. 2. Failure of signals to perform their functions. 3. Failure of employees to comply with rules or orders. 4. Failure of employees to observe, understand, or obey signal indications. Train-control devices will not prevent collisions due to brake fail- ures which are infrequent and comprise only a small percentage of such accidents. Failure of signals to perform their functions is a comparatively rare occurrence. Track circuit controlled block signal systems are so designied that when any part fails the signal should display the stop indication. In some cases of failure, however, the signal indi- cates "proceed " even though it should indicate " caution " or " stop." Such failures, known as " false clear " failures, contain a se- rious element of danger, but their infrequency makes the possibility of collisions from this cause exceedingly remote. AUTOMATIC TRAIN CONTROL COMMITTEE. 9 Collisions due to failure of employees to comply with rules or orders are a large proportion of the total number reported and many of these could not have been prevented by an automatic train- control device. Automatic train-control devices may be expected to prevent only such accidents as are due to the failure of employees to observe, understand, and obey signal indications. Failure to see or under- stand signals may be due to smoke, fog, snow, absence of the night signal indications, complexity in the scheme of indication, unfa- miliarity of the engineman with the route over which the train is running, the diversion of his attention or his physical incapacity, etc. Failure to obey signal indications that are seen and under- stood are rare and include only those cases where enginemen in their anxiety to make time take chances, or where they use poor judgment in the interpretation of rules, which permit them to exer- cise some discretion. Statistics show that most of the collisions which have occurred on tracks protected by track circuit-controlled signals are due to the causes above enumerated. There appears to be a popular misconception as to the number of fatalities that might be prevented by automatic train-control devices. Statistics show that train collisions have been the cause of less than 6 per cent of the fatalities to persons, other than trespassers, occurring on the railroads of the United States in the five and one-half years ending December 31, 1918. Eecords of the Interstate Commerce Commission show the fatali- ties to nontrespassers on railroads of the United States from July 1, 1913, to December 31, 1918, inclusive, as follows : Year ending June 30— Six months ending Year ending Dec. 31— 1914 1916 1916 Dec. 31, 1916. 1917 1918 Num- ber. Per cent. Num- ber. Per cent. Num- ber. Per cent. Num- ber. Per cent. Num- ber. Per cent. Num- ber. Per cent. 271 262 18 3,871 409 5.61 5.42 .38 80.13 8.46 121 lao 21 2,872 343 3.42 5.08 .j30 81.20 9.70 233 194 38 3,566 486 5.16 4.29 .84 78.95 111. 76 141 91 IS 2,355 248 4.95 3.18 .64 82.54 8.69 .364 176 151 4,633 520 6.23 3.01 2.58 79.28 8.90 499 290 168 4,485 689 8.27 4.81 other train accidents Train service accidents (in- cluding highway crossing 2.78 74.37 Nohtrain service accidents (industrial, etc ) 9.77 Total 4,831 100.00 .?,537ll00.00 4,517 190.00 2,853 100.00 .'i,S-tt 100.00 e,03ijioo.oo Note.— On account of change in the ending of the fiscal year from June 30 to Dec. 31, in 1916, the figures for the last 6 months of 1916 are shown separately. The foregoing facts, however, should not be taken as minimizing the seriousness of the situation, and iii considering them weight should be given to the further fact that many of the victims of train 158525°— 20 2 10 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. collisions are passengers who do not contribute by their negligence to the accidents and are entitled to the largest measure of protec- tion that is reasonably possible; nevertheless, the limitations of au- tomatic train-control devices, e\en the most complete and dependable that may be developed, should be clenrly understood. All fatalities resulting from train collisions averaged per year from July 31, 1913, to December 31, 1918, inclusive, 296, or 5.6 per cent of the fatalities to nontrespassers on the railroads of the United States, and of this number many resulted from collisions occurring on yard tracks or at other places where they would not have been prevented by an automatic train-control device. The cost of an automatic train-control system is an undetermined item which involves not only the original expense of installation but also the cost of maintenance and the effect of its operation ui^on the capacity of existing facilities. If a device materially reduces the capacity of a railroad, its installation where heavy traffic is han- dled may necessitate further expenditure for additional running tracks. A device to satisfactorily meet such conditions must there- fore be one which will interfere as little as possible with the ca- pacity of a railroad, and this requirement may necessitate the addi- tion of speed-control apparatus at an increased cost for its installa- tion and maintenance. The question of installing automatic train-control systems in such a manner that the normal operation of trains will not be interfered with is one of the most difficult problems to be solved. The primary function of a block-signal system is to maintain a definite sj^ace inter- val between moving trains, but in addition thereto it enables trains to be moved safely without delay, as by giving an engineman in- formation that the track ahead of his train is clear for a definite dis- tance, he is enabled to proceed with confidence at the highest rate of speed which can be maintained with safety. Train movements are thus greatly facilitated, and this fact is so important and funda- mental that on multijile-track roads of heavy traffic it is well recog- nized that to handle the volume of traffic now being moved would be impossible without the use of automatic block signals, unless addi- tional running tracks were provided. Fundamentally, therefore, track circuit controlled automatic block signals, in addition to pro- viding greater safety of train operation, add to the capacity of a railroad as do additional running tracks. In imposing automatic train control upon such a systenj this fact nmst be clearly borne in mind and in correcting unsafe conditions due to the failure of the human element the fundamental feature of the signal system itself, as above outlined, must not be unnecessarily impaired. There are other problems in connection with this subject, some of the most important being those of reliability, clearance, and inter- AUTOMATIC TRAIN CONTROL COMMITTEE. 11 changeability. These and other questions involved are considered later in this report. It must not be assumed that this brief statement of general con- siderations with regard to the use of automatic train-control devices is anything more than an attempt to indicate some of the difficulties of the subject. THE TRAIN-CONTROL PROBLEM. Automatic train control is popularly regarded as a penacea for railroad accidents. Persons who are not familiar with railroad operating requirements generally fail to understand fully the factors which must be taken into account in the practical use of train- control devices. On this account a comprehensive statement of the questions involved from the standpoints of construction, main-' tenance, and operation is desirable. Briefly stated, the problem is to provide some appliance to furnish protection against accidents when employees disregard signal indi- cations or, so far as possible, when signals improperly indicate proceed. The problem comprises two main elements, one of which consists in reproducing upon a moving train, either by mechanical or electrical means, a correct indication of the condition of the track ahead; the other requires proper means for controlling the train in obedience to the indication given. The first element necessitates the use of suitable mechanism along the roadside, while the second re- quires the use of suitable mechanism installed upon the train, both of which must properly correlate and function interdependently. Important factors entering into the problem are : (a) Eeliability in operation. (h) Inspection, maintenance, and test to insure efficiency. (e) Clearance — Eelation between parts of the device and obstruc- tions on the roadside or train. (d) Capacity — The effect upon the traffic handled over a given section of railroad. (e) Interchangeability as between different devices on track used by railroads jointly. (/) Correlation with track circuit controlled block signuling and air brake apparatus. EELIABILITY. It is obvious that an automatic train-control device must be reliable in operation ; that is, it must respond with certainty to all the con- ditions under which it should act, and should remain inert at all times when conditions are such that a train may proceed with safety. If the device fails to act when the danger it is. designed to guard against is present, its intended function can not be performed, and 12 ANNUAL EEPOET DIRECTOR GENERAL OF RAILROADS. if it acts frequently when there is no chinger the interference with operation becomes serious and the device itself becomes discredited, the device must of necessity be exposed to all climatic conditions and must function properly during the most severe weather. It must also be protected from damage, the roadside mechanism from being torn out by objects dragging from passing trains, and the train-car- ried mechanism from being struck by foreign obstacles on the road- side. INSPECTION, MAINTENANCE, AND TEST. Even the best designed apparatus, installed in the most substan- tial manner, will fail if not properly inspected and maintained. Proper inspection and maintenance of automatic train-control de- vices will be more difficult than the inspection and maintenance of track circuit controlled signals, for the reason that part of the apparatus will be located on the roadside and another part upon the train. The roadside apparatus will naturally be looked after by the maintainers who keep the signals in order, while the condition of the train-carried apparatus will be looked after by the mechanical forces in enginehouses and shops. While it is quite possible to have these two sets of maintainers subject to a single supervision, it will nevertheless be a difficult matter to correlate the results of the neces- sarily divided inspection and maintenance so as to determine with certainty the cause of failures which are reported to have occurred. This difficulty arises from the fact that it will often be imprac- ticable to bring the train apparatus and the roadside apparatus at a particular location into operative relation with one another for test purposes. To a certain extent also the amount of inspection and maintenance required by the signal system itself will be increased by the use of an automatic train-control device, as by its imposition upon the signal system certain elements will be added to the latter, and these will require careful attention. In view of the emergency nature of an automatic train-control device it may be assumed that under ordinary operating conditions it will very infrequently be called upon to perform its intended function. It is important, therefore, in order that the device may not become inoperative through disuse, that its condition be dis- closed by means of frequent and regular tests. CLEARANCE. The location of automatic train-control apparatus on train or roadside requires detailed study in an effort to secure satisfactory operation. Clearances are materially affected by tunnels, bridges, station platforms, track pans, grade and highway crossings, etc. AUTOMATIC TRAIN CONTROL COMMITTEE. 13 An analysis of train-control devices places them in two general classes : (a) Contact. — Those that depend for their operation on the physical contact of an element carried on the train with an element at a fixed location on the roadside. (6) N on'contact. — Those that depend for their operation on an electrical or magnetic impulse without physical contact between the roadside and train elements. A large part of the development has been in devices of the contact class. Many troublesome clearance problems enter into tlie solution of their application and use. If the roadside elements are located between the rails they are likely to be torn out by objects dragging from moving trains. The most practicable location appears to be a short distance outside of the rail and near its level, but even here there are some serious difficulties. Snowplows and ballast spreaders work to the level of the rails and a track element extending above the rail within their range will interfere with such equipment. These difficulties, while perhaps not insurmountable, will be, on some roads, quite serious and must be met. It is evident that part of the tfack element must be placed above the rail level, as it is impossible to operate any part of the train element below that level for the reason that in such location it would be torn off by coming in con- tact with switch rails, crossing jplanks, and other obstructions. With the noncontact devices the clearance difficulties are very materially reduced and evidently this fact has been one of the lead- ing causes for the development work that has been and is now being done with this class of devices. CAPACITY. As previously pointed out, a properly operated automatic block- signal system adds to the capacity of a railroad by increasing the freedom and flexibility of train movements over it. This condition should not be unduly interfered with by the use of an automatic train-control device. It is apparent, however, that if such a device is to act to stop a train only in the occurrence of those emergencies caused by the failure of employees to obey signal indications, the automatic brake application must be made a sufficient distance away from the actual point of danger to bring the train to a stop before reaching that point, under the most unfavorable conditions. This' involves the necessity of providing maximum braking distance for all trains equal to that required for any train on the road. This can not be done without decreasing the tracli capacity, and on congested railroads is therefore a matter for serious consideration. To overcome these difficulties permissive features have been installed to enable the engineman to nullify the brake application and speed- control apparatus is being developed. 14 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. INTERCHANGEABILITY. The joint use of a track by two or more railroads is frequent tliroughout the United States and essential in many cases to eco- nomical operation. This practice, as well as the joint use of terminal facilities, has been extended during the past two years, and will, without doubt, become more general. It is necessary, therefore, that train-control devices shall be so designed that the engine equip- ment of the various lines will properly function with the roadside apparatus on tracks used jointly. Detouring in case of accidents makes it necessary for the trains of one company to move over the tracks of another. Such move- ments are handled by a qualified employee of the owning road in connection with the crew of the detouring road. Due to the com- parative infrequency of and the safeguards thrown around such movements it would not appear necessary that the train-control apparatus should be so designed as to be operative in all cases on the engine of the detouring road, but the equipment detoured must conform with the clearance requirements on the road used. It is therefore highly desirable, and in certain localities necessary, that a train-control device for practical use shall not restrict the free operation of the trains of several roads over the same track. COEKELATION WITH ELECTRICALLY CONTROLLED BLOCK SIGNALIXG A:SD AIR-BRAKE APPARATUS. The use of electrically controlled block signals has resulted in ma- terially increasing the safety and efficiency of train operation and it is essential that train-control apparatus shall be so designed that it may be superimposed upon the block signal system and not interfere with the performance of the signals. It is also essential that the engine apparatus of automatic train- control devices shall be adapted to use with the present air brake system and shall not interfere with its practical operation. The committee, as a result of its investigations, has prepared the following classification of automatic train-control devices, based on the character of control, on the general method of communication between the roadside and train and on the type of device used in securing the desired result. Most devices readily fall into a single classification, although a few are found with characteristics of two types. In the present stage of development the dividing line be- tween the different types is not always well defined. The charac- teristics of the various types, with a brief description of their main distinguishing features, arc given as far as it is possible to state them from our knowledge of the art as it exists. AUTOMATIC TRAIN CONTROL COMMITTEE. 15 ANALYSIS AND DESCRIPTION OF THE DIFFERENT TYPES. CLASSIFICATIOISr OF TKAIN-CONTROL DEVICES. Character of control. Class of device. Types of device. I. Intermittent A. B. C. A B 1. Plain mechanical trip. Ground or overhead. 2. Electrically controlled meehaniealtrip. Ground or overhead. 3. lutcrmitterit electrical contact. 1. Insuhited truck with short track circuit section. Track rail contact II. Continuous . . . 2. Ineit roadside element. 3. Nonmagnetic rail. 1. Third rail or special conductor. 1. Induction. Noneoutact 2. Wireless. Speed control or cab signals may be applied to most of the above types. Iktermittent Charactek, Coxtact Class (I-A). The cUstinguisliing feature of automatic train-control devices of the intermittent cliaracter is that the indication is transmitted to the train from the roadside apparatus only at definite points. The indication thus received continues as the controlling factor in the operation of the train until the next indication point is reached, when it may be continued or changed, depending on the indications there received. Normally the indication on the train is not changed while it is between any two indication points. Control of the intermittent character may be either of the contact or noncontact class, depending on whether or not physical contact is required between the roadside and train apparatus. All intermittent contact types have the following characteristics in common : 1. ■ Control of the train apparatus by the roadside apparatus is through mechanical means. 2. Impact shocks between the train and roadside apparatus with trains moving at high speed are severe. 3. Where electrical energy is required for their operation the amount is relatively small. 4. If the train apparatus is not properly located the operation of the device is liable to be interfered with by oscillation. 0. Being composed largely of mechanical elements its maintenance is comparatively simple. 6. When electrical elements, are used they are similar to those generally found in signal installations. 7. Since effective contact requires an overlapping of train and roadside apparatus, clearance lines are interfered with, resulting in a possibility of the train apparatus being damaged or unnecessarily operated by obstructions along the right of way or the roadside apparatus being struck and deranged by train-carried obstructions. 16 ANNUAL EEPORT DIEECTOK GENERAL OF RAILROADS. Intermittent Character, Track Eail Contact Class (I-B). This class requires no special contact element on either the road- side or train, but uses the running rails of the track in lieu of a roadside contact element and wheels of the engine in lieu of a train- contact element. It has no characteristics common to other types of devices. Intermittent Character, Noncontact Class (I-C). Since the development of the intermittent noncontact types has been comparatively recent, the characteristics (which are largely ascertained by experience) are not as well determined as with the contact types. The following characteristics, however, are common : 1. Control of the train apparatus by the roadside apparatus be- comes effective when the two parts are in proper inductive or mag- netic relation. 2. Considerable " air gap " is necessary as compared with devices commonly used in railroad signaling. 3. There being no overlapping of train and roadside apparatus, the different elements can be kept within established clearance lines. 4. Improper operative conditions of roadside apparatus can not be readily detected. Continijous Character, Both Classes (II-A and II-B). Some effort has been made to develop train-control devices of the continuous character, both of the contact and noncontact class. These are designed to give an immediate indication on the train of any change in operating conditions. As only a few devices have reached the stage of practical development no common characteristics can be stated, and such individual characteristics as have been de- termined are given later in the consideration of the individual types. Pi.AiN Mechanical Trip Type (I-A-1). The plain mechanical trip type has a train element which func- tions with the contact element of the roadside apparatus. The road- side apparatus may be placed either at the track level or at some point above it. The train contacting element either directly con- trols the brake-application valve or is' mechanically connected thereto. The roadside contact element is movable so that it may be brought into range of the train element when a stop is to be produced. This operation is purely mechanical and the controlling mechanism is remote from the roadside element. The roadside contact element may be a movable trip making momentary contact with the train contact element or it may be a movable trip rail. AUTOMATIC TRAIN CONTROL COMMITTEE. 17 The characteristics of this type are well known, since it represents the earliest development in the art. Its limitations, however, have restricted its use. The chief characteristics of this type, in addi- tion to those previously noted as common to its character and class, are as follows: 1. Generally speaking, mechanical connections are positive in their action. 2. The removal of essential parts is not readily detected. 3. Long mechanical connections may be required. These are gen- erally impracticable. 4. With the roadside element located much above the track level there is danger of injury to passengers and to employees whose duties require them to ride on the sides or tops of cars. 5. The roadside apparatus and the train apparatus are only in operative relation when a stop is to be produced by the device. Electrically Controlled Mechanical Trip Type (I-A-2). In the electrically controlled mechanical trip type the roadside apparatus is controlled electrically, though the trip element itself may be operated bv some other power, such as comj)ressed air. The train apparatus may be of the same cliaracter as tliat used in the plain mechanical trip type and may be similarly located, or it may be electrically controlled so that when a circuit is broken by the contact of the train and the roadside apparatus the brakes are ajsplied. The chief characteristics, in addition to those already noted as common to its character and class, are as follows: 1. The power I)y which it is controlled permits the roadside ap- paratus to be placed a suitable distance from the point at which a stop is to be made. 2. The roadside apparatus may be readily interconnected with the signal system. 3. Electrical elements may be confined to the roadside apparatus where they can readily be maintained. 4. The breakage or removal of certain essential parts can not readily be detected. 5. In exposed locations there is danger that the trip clement will be frozen in nonstop position. Intermittent Elsctkical Contact Type (I-A-3). The distinguishing feature of the intermittent electrical contact type, commonly known as the " ramp " type, consists in the train apparatus being put into operative condition at every indication point. This result may be attained by direct operation of the contact 158525°— 20 3 18 ANNTJAX, EEPOET DIRECTOR GENERAL OF RAILROADS. elements themselves oi- through electrical circuits controlled by the contact element. A necessary sequence is that the train apparatus must be retained in the proceed position, if the block is clear, by a circuit maintained through contact with the roadside element while ]5assing over it. The length of the ramp may vary . considerably, depending on the results to be accomplished while the train element is in contact with it. The ramp is generally placed outside of and parallel with the running rail. This type has received I'elatively the greatest development, and a number of devices haAc been installed and tested, two now being in service operation on steam roads. There is a very little difference between the devices of this type and this is chiefly in the design of details. In some devices the ramp is energized by a roadside bat- tery. The control is through circuits similar to those used in an auto- matic signal system. In other devices the ramp is not energized by a roadside battery but energy is supplied from a source on the train, the ramp in this case forming part of a circuit between the train apparatus and the signal controlling apparatus. The distinguish- ing feature of all these devices is a holding circuit for energizing the train element. This is a " stick " circuit so that when the train element is once deenergized it can not be again energized unless it be restored mechanically, or by means of a secondary circuit through the ramp or by a release switch. In all cases the train circuit will be broken when the contact shoe passes over a ramp. As extensive tests of this type have been made its characteristics are well defined. In addition to those before noted as common to its character and class, the following characteristics are known. 1. The train circuit is broken every time a ramp is passed ; a valu- able self-checking feature is thus provided. 2. Few electrical elements are required on the train. 3. Electrical contact between the ramp and the train element is subject to interference by snow, ice, sleet, frost, or other insulating- materials. 4. To secure effective electrical contact considerable pressure in required between the train contact element and the ramp. Insulated Teuck, avith Short Thack Circuit Section, Type (I-B-1). This type requires insulation between a truck and the engine or tender and short track circuit sections located at the indication points. In some devices the insulated joints in the two rails must be exactly opiaosite while in others one joint must be located a given distance ahead of the other. The circuit controlling the train relay is completed from the insulated truck through the wheels and run- ning rails to the other part of the engine. When an indication point AUTOMATIC TRAIN CONTEOL COMMITTJiiJi. 19 is reached the circuit through the rails is interrupted by the insu- lated joints unless the joint is electrically bridged by means of a loop circuit through the signal relay. No roadside battery is required for the operation of the engine apparatus. Some devices of this type have been tested to a limited extent. The principal chaiacter- istics are as follows: 1. No roadside apparatus involving clearance problems is required. 2. No contact element is required on the engine. 3. Check circuits are necessary to detect failures of insulation. 4. Insulations that are sufficient for track circuit purposes may not withstand voltages required on the engine. 5. A definite location of insulated joints is required. 0. Unbonded joints on sidings or in yards may produce a stop. 7. Poor contact between wheels and rails, due to sand or rust, will produce an unnecessary stop. 8. The short track circuit section must be incorporated in the signal control circuits. INDUCTION Type (I-C-1). In this type both permanent and electromagnets are used in the roadside apparatus. The field of the permanent magnet is present to cause the train apparatus to act except when conditions are proper for the train to proceed, in Avhich case the field of the permanent magnet is deflected or neutralized by the electromagnet. The elec- tromagnet is energized by a separate battery through one of the re- lays of the usual signal system. The magnets employed in the road- side apparatus are placed between the running rails of the track, as this location better meets the cleai'ance requirements of opera- tion. In princijile the train element may be either a duplicate of the track element or a receiving element of suitable form, through which the train controlling apparatus is made operative. As but one device of this type has been tested in service, compar- atively little information is available concerning the practicability of its operating features. The chief characteristics of this type, in addition to those already noted as common to its character and class, are as follows: 1. Safe operation depends on the reliability of permanent magnets. 2. Generally speaking, clearance conditions require the permanent magnets to be placed between the running rails of the track. 3. The electrical energy required to energize the electromagnet used as a neutralizing element may prove to be excessive. 4. With a normal clear scheme of automatic stop control short track circuit sections may be necessary at each indication point to conserve current. 20 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. 5. On account of the location of the roadside element between the rails, and the necessity for its protection against damage, the diffi- culty of track maintenance at roadside element locations will be increased. 6. Due to the small amount of energy transmitted through the necessary air gap between the roadside and train elements, any parts on the train that are to be operated by the magnetic field of the road- side magnets must possess low inertia. Induction Ttpe with Inert Roadside Element (I-C-2). This type employs a fixed and inert roadside element, which may be placed either between or outside of the running rails of th6 track, to reduce the flow of current in a coil on the train. This re- duction in the flow of current causes the brake controlling relay on. the train to open, tlius applying the train brakes. No extensive road tests of this type of device have thus far been conducted, and it is practically in the laboratory stage of development. In addition to those before noted as common to its character and class, the following characteristics are known: 1. No magnetic or electromagnetic energy is required at the 'road- side element location. 2. The roadside apparatus may be readily installed at desirable points. 3. The reduction of current flow produced on the train appa- ratus by the inert roadside element is similar in its action to a shunt circuit. 4. The train apparatus may be influenced by metals on the road- bed. 5. Where the track element is connected with the signal system it may be rendered inoperative by short circuit between connections. Induction Type, Nonmagnetic Eail (I-C-3). This type makes use of a rail of nonmagnetic material, such as manganese steel, inserted in the track at indication points. Only very limited tests of this type have been conducted and its charac- teristics have not been fully determined. In addition to those be- fore noted as common to its character and class, the following characteristics are known : 1. No roadside apparatus in which clearance problems are in- volved is required. 2. Interference may exist when passing over manganese frogs and crossings. 3. Introduction of rails of special material will be to some extent objectionable. automatic train control commit'i'ee. 21 Continuous Electrical Contact Type (II-A-1). This type employs -a continuous conductor. When placed at the track level the conductor is usually in the form of a rail of lightei section than the running rails of the track. In some devices of ■ this type the track rails are utilized as conductors. In normal operation the train contact element must remain in constant engage- ment with the roadside contact element. The train apparatus may be of the same kind as that used in the intermittent electrical contact type. The chief characteristics, in addition to those already noted as common to its character and class, are as follows : 1. The use of a continuous conductor renders it possible to use current at a higher voltage than is generally feasible with other contact -type devices. •2. Contact must be maintained with the roadside conductor. 3. Special construction will be required at highway and railway crossings, crossovers, turnouts, etc., to avoid breaks in the continuous conductor. 4. Frost and dirt may cause interference with contact. ■">. Introduction of special conductors along the roadside will be objectionable. Induction Ttpb (II-B-1). This type employs either the running rails of the track or special conductors on the roadside. Some of the roadside and train ele- ments I'equired are dissimilar to those used in other types, such as the alternating current track circuit and apparatus to amplify the current transmitted to the train. The following are the chief characteristics of the type so far as known : 1. Energy required in the roadside apparatus is comparativelj' small in amount. 2. No roadside apparatus which interferes with clearance require- ments is necessary. 3. Operation of the device is based directly on tiie track circuit. 4. The amplifying element proposed has not been subjected to service tests and its reliability for the purpose intended has, there- iore, not yet been determined. 5. So far as known, this type requires the use of alternating cur- rent in the track rails. 6. Its operation may be affected by location of insulated joints. Wireless Type (II-B-2). Some progress has been made in developing new methods of applying the wireless principle to the operation of an automatic train-control device. Practically all the work accomplished in this 22 ANNUAL REPORT DIRECT'OR GENERAL OF RAILROADS. lino has been of a laboratory nature and definite information as to the results attained is not available. The chief characteristics of this type are as follows : 1. A continuous conductor is required along the roadside. 2. Different frequencies are required for diiferent tracks or di- rections. 3. Special apparatus is required to produce current. DESCRIPTION OF DEVICES EXAMINED. The devices examined by the committee are briefly described below. The devices in this list ai-e arranged according to type, and those in service or tliat have been installed for test purposes are not separated from those that were examined by the committee in shop or laboratorJ^ Plain Mechanical Trip Type (I-A-1). Installed on the United Railways & Electric Co. of Baltimore. Inspected September 3, 1919. The contact is made above the roof of the car and the roadside apparatus is operated mechanically from levers in an interlocking plant. The only place where this stop is in use on this company's tracks is at a drawbridge, roadside appa- ratus being used on each side of the draw span. One hundred and fifty overhead trolley type cars, such as are commonly used on city lines, are equipped with train apparatus. The device has been in service since May, 1918, and is reported to have given good service. Electeically Conteolled Mechanical Tkip Type (I-A-2). automatic conteol company. Inspected July 11, 1919, in the office of the company at Indian- apolis, Ind. Apparatus of full size was used for demonstration purposes. The roadside apparatus includes a movable trip rail operated by an electric motor. The train contact element is operated by the roadftide element wiien a stop is to be produced, making a brake application. Contact elements are placed on each side of the rear end of the tender to provide for forward or backward move- ment. A proceed valve or release switch when operated manually permits the train to pass a trip rail in the stop position. No speed control elements are included. C'LiFrQED Automatic Train Stop Co. Inspected July 23, 1919, in the company's shop at Scranton, Pa. Apparatus of full size was used for demonstration purposes. The roadside apparatus included a movable trip rail, designed to be AUTOMATIC TEAIN CONTROL COMMITTEE. 23 operated by an electric motor, operating directly on a valve in the train contact member. Speed control features were included whereby brake applications would be made at approach signals unless neu- tralized by the engineman by proper operation of the brake valve. KEY ROUTE, OAKLAND, CALIF. Inspected May 5 and 7, 1919. This device is of the electrically controlled mechanical trip type. The contact is made above the roof of the car and the roadside apparatus is operated either by a sepa- rate motor or mechanical connection to the signal arm. Eoadside apparatus for 113 stops is in service on the terminal inteilocking plant and on 3.4 miles of double track on the pier leading to the feri-y terminal, 91 cars being equipped with the train apparatus. Xo speed control features are used. Provision is made so that the roadside trip arm may be moved from the stop to the proceed position by the train crew, from the ground, when necessary to pass a signal in the stop position, after this operation the trip arm assuming the stop position as soon as released. KINSMAN DEVICES. Six installations of this device were inspected as follows : New York Municipal Railway Corporation. , Interboroush Rapid Transit Co Hudson & Manhattan Railroad , Pennsylvania Tunnel & Terminal Co Philadelphia Rapid Transit Co Boston Elevated Railway Co Date of inspection. June 4, 1919 June 5, 1919 June 6,1919 do Sept. 4,1919 Sept. 8,1919 Number of stops. 569 1,813 290 52 136 207 Number of cars. 4,010 286 376 215 424 Mileage. 50.0 26.0 7.0 7.5 19.0 All of these installations have electrically controlled roadside ap- paratus, the trip arm being operated electrically or pneumatically. In some cases the trip arms are located between the running rails, but in most cases they are outside of the rails. On the New York Municipal, Interborough, and Hudson & Manhattan speed control features are used in connection with the signal installation, time limit relays being used to define the time allowed for a train to run a definite distance. Provision is made so that the roadside trip arm may be moved from the stop to the proceed position by the train crew, from the ground, when necessary to pass a signal in the stop position. After this operation the trip arm assumes the stop i^osition as soon as released. This type has given satisfaction under the special conditions existing in subways and on elevated lines. 24 ANNtTAL. REPOET DIEECTOE GENEEAL OF EAILEOADS. NEVENS-WALLACE TRAIN CONTROL 00. Inspected September 8, 1919. Eoadside apparatus was installed at one location at Waltham, Mass., on the Boston & Maine Railroad, and one engine equipped for development and demonstration pur- poses. The roadside trip arm is operated by an electric motor con- trolled through the automatic signal circuits. The train apparatus is operated by direct contact of the train trip arm with the roadside trip arm. Xo electrical circuits are used in connection with the train apparatus. A centrifugal governor controls the train apparatus so that when the speed is at or below a predetermined rate the en- gineman can prevent an automatic application of the brakes or re- lease them when they had been applied automatically. ^\'ILr,S0N-WKI0HT SAI-ETT APPLIANCE CO. Inspected JIuv 1, 1919. This device is of the electrically con- trolled mechanical trip type. The contact is made above the roof of the car by contact with a glass tube on the car, and the roadside ap- paratus is operated by mechanical connection to the signal arm. Eoadside apparatus is installed for 21 stops, on 29 miles of single li-ack of the ^Vasliington Water Power Co.'s electric lines, Spokane, \A'a.sh. No speed control is used. Provision is made so that the roadside trip arm may be moved from the stop to the proceed po- sition by the train crew from the ground when necessary to pass a signal in the stop position. After this operation the trip arm as- sumes the stop position as soon as released. Intermittent Electrical, Contact Ttpe (I-A-3). a5ier1can railway signals co. Inspected July 26, 1919, at the laboratory of Thomas E. Clark, Detroit, Mich. This is the device formerly known as the Julian- Beggs. The parts of the apparatus that were examined, with the exception of the engine relay, had been used experimentally on the Cincinnati, New Orleans & Texas Pacific Eailroad. Proceed, caution, or stop indications ^^'eve provided for by means of a three- position relay controlling the train apparatus. The three-position relay is controlled by the polarity of current on the ramp. A cen- trifugal governor was provided for speed control. A circuit reverser, operated in connection with the centrifugal governor, depends for reversal upon a specified movement of the engine and provides for change in circuits to permit engine running backward. Cab indi- cator lights were provided. AUTOMATIC TRAIN CONTROL COMMITTEE. 25 AMERICAN TRAIN CONTROL CO. Inspected April 15 and 16, 1919, on the Chesapeake & Ohio Eail- road between Charlottesville and Gordonsville, Va. The device is in use on 21 miles of single track and 32 engines are equipped. Auto- matic block, color light signals, and train control were installed at the same time. Eamps are located in pairs in advance of the signal, the right-hand ramp being used for the stop and the left-hand for the approach indication for the next block. No speed-control fea- tures are used but approach indication is provided. CASALE SAFETY DEVICE CO. Inspected July 28, 1919, on the Chicago, Eock Island & Pacific Eailroad, near Blue Island, 111. One ramp was installed and one engine equipped. A three-position relay controls the train appa- ratus to pro^■ide proceed, caution, or stop indications. The three- position relay is controlled by the polarity of current on the ramp. A centrifugal governor provides speed control that prevents ex- ceeding a predetermined speed after receiving a brake application at the approach signal. GENERAL RAILWAY SIGNAL CO. Inspected July 24, 1919, at the shops of the company in Eochester, N. y. This apparatus was part of that used in an extensive test installation on the New York Municipal Eailways at Brooklyn, X. Y. Special ramps were used to regulate the speed control fea- ture. Depending on the local conditions existing, different speeds were permitted which were automatically adjusted by the ramps. A centrifugal governor operated the necessary circuit closers that control the circuits through the different devices. The device is designed so that no automatic application of the brakes will be pro- duced as long as the speed of the train is controlled in accordance with the signal indications, GENERAL SAFETY APPLIANCE CO. Inspected May 2, 1919. A temporary ramp and one engine was fitted up on the Spokane International Eailroad. The contact shoe was bow shaped and not of the vertical lifting type. No special features were exhibited which differed from the general type. No speed control features were provided. GOLLOS RAILWAY SIGNAL CO. OF AMERICA. Inspected March 21, 1919, in the office of the company at Chicago. This device was tested by the Bureau of Safety, Interstate Com- merce Commission, on the Chicago, Burlington & Quincy Eailroad, 158525°— 20 4 26 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. in 1916. Speed-control features were included and as exhibited re- quired two centrifugal governors. Two different voltages are used on the ramp to give proceed and caution indications. INTERNATIONAL SIGNAL CO. Inspected June 6, 1919, in the company's office at New York, N. Y. The apparatus examined had been used experimentally on the New York, New Plaven & Hartford Railroad. The air valve on the en- gine was worked by direct contact between the engine shoe and the ramp. Speed-control features were used that would permit the en- gineman to release the brake when the speed had been reduced to a predetermined rate. MILLER TRAIN CONTROL CORPORATION. Inspected March 17, 20, 21, and 22, 1919. Apparatus exhibited in Chicsigo was inspected and an inspection made of the installation on the Chicago & Eastern Illinois Railroad at Danville, 111. This installation is on 106 miles of automatic-signaled double track and 73 engines are equipped. The engine air valve is operated by direct contact between the shoe and the ramp. No speed control is pro- vided. OKCTJTT AUTOMATIC TRAIN CONTROL CO. Inspected September 9, 1919. This device was installed experi- mentally on the Millbury branch of the Boston & Albany Railroad. Multiple ramps on the roadside and a number of shoes on the engine were used. One rail only was divided into blocks, the other being continuous. The current was provided from the engine and the circuit was completed through the ramps, line wires, relays, and running mils. Cab indicators were used, but no speed-control fea- tures were provided. SHADLE AUTOJIATIC TRAIN SIGNAL CO. Inspected" July 11, 1919. Three ramps were installed on the Cin- cinnati, Indianapolis & Western Railroad near Indianapolis, Ind., and were connected with the automatic signal system. One engine was equipped. Speed-control features were included and were controlled by a specially wound generator driven from the axle, which was designed to close the circuit to the brake valve at a cer- tain speed, permitting a deenergized ramp to be passed, if circuit controllers were operated by the engineman and fireman at the same time. SIMMEN AUTOMATIC RAILWAY SIGNAL CO. Inspections were made of the installation on the Mesaba Railroad at Virginia, Minn., March 24, 1919, and on the Indianapolis & Cin- cinnati Traction Co., July 21, 1919. This device gives control of AUTOMATIC TRAIN CONTROL COMMITTEE. 27 trains from a central point by the use of cab signals. No stop fea- tures are iiicluded and no speed-control devices are used. Both in- stallations examined were on single-track electric lines. Eamps for one direction are energized with one polarity from a central bat- tery and ramps for the other direction by the opposite polarity, depending on the position of the control switch. Apparatus is also installed in the central station which automatically records the time of the passing of cars over the ramps. THAYER AUTOMATIC SIGNAL & TRAIN CONTROL CO. An examination was made of plans and some apparatus of this company at Spokane, Wash., on May 2, 1919. Speed-control appa- ratus and one of the air valves, all the apparatus constructed, were examined. TRAIN CONTROL APPLIANCE CO. This apparatus, known as the Bulla device, was inspected March 17 and 20, 1919, in the Coliseum at Chicago. The roadside apparatus consisted of a brush with which the engine shoe makes contact. The roadside circuits are so designed that when a stop is to be made the engine circuits are shunted when the shoe makes contact with the brush. No speed control features were included. B. p. AVOODING. Certain parts of this device were examined in New York, N. Y., on September 6, 1919. This device is of the same type as that tested on the Delaware, Lackawanna & Western Eailroad by the Bureau of Safety, Interstate Commerce Commission, in 1917. The ramp is of special design, having two hinged leaves that are forced apart by the shoe or knife contact on the engine. At the same time the shoe is forced downward in a vertical plane, operating the contacts of the engine. Speed control is provided by a special cam on the engine, operated in accordance with the speed of the train when the engine shoe engages the ramp. Insulated Truck, with Short Track Circuit Section, Ttpe (I-B-1). safett block signal CO. Inspected September 4, 1919, at Philadelphia, Pa. This apparatus had been installed experimentally on the Huntingdon & Broad Top Mountain Eailroad. The apparatus examined comprised only an air valve and a throttle-closing device which had been on an engine for about two years, although only in service six months. As in- stalled both tender trucks were insulated but no detector circuit was used to show a failure of the insulation. No speed control features were provided. 2s annual eepoet director general of railroads. Induction Ttpe (I-C-1). 3i-\- all-weather train controller co. Inspected November 1, 1919, at the company's shop in Newark, N. J. Electromagnets for the roadside apparatus are energized as the train approaclies and they act on the collecting coils of the train apparatus to allow the train to proceed. To provide time for the engine apparatus to act, a group of magnets must be placed at each indication point. A train occupying the block shunts the energizing battery of the roadside coils in the rear so that a following train would be stopped. Speed control is provided. NATIONAL SAFETY APPLLVNCE CO. Inspected ^lay 5 and 6, 1919, at the company's shop at San Fran- cisco, Calif., and at the road installation at Oroville, Calif. Three roadside magnets were installed at Oroville, on the Western Pacific RTvilroad, and one engine equipped. The roadside apparatus con- sists of a permanent magnet with neutralizing coils to give a pro- ceed indication. The train apparatus includes a permanent magnet that is influenced when it passes over the unneutralized field of the roadside apparatus. No speed control is provided. SI'R.UlUK SAIKTY CONTROL AND SIGNAL CORPORATION. Inspected June ;], July 7, and Se^jtember 10, 1919, at the company's laboratory in New York, N. Y. Permanent magnets are used on the roadside to produce approach and stop indications, and electro- magnets to reset the train apparatus. Neutralizing coils are used to deflect the magnetic field of the permanent magnets when condi- tions are proper to proceed. The train apparatus includes pole pieces th,at attract an armature to break the train holding circuit Avhen passing over the unneutralized field of a permanent magnet. Speed control, based upon the speed of the train and the braking effort, is provided. The device is designed so that no automatic ap- plication of the brakes will be produced as long as the speed of the train is controlled in accordance with the signal indications. Inert Eoadside Element Type (I-C-2). general eailwat signal co. Inspected July 23 and September 29, 1919, at the laboratory of the company in Eochester, N. Y. The roadside apparatus con- sists of coils arranged around a U-shaped laminated core. The terminals of the coils are joined through contact of relays in the signal circuit. The train apparatus consists of similar coils de- AUTOMATIC TKAIN CONTROL COMMITTEE, 29 signed to pass directly over the roadside coils. The current in the train coils is greatly reduced when the train coils come within range of the roadside coils, if the terminals of the latter are not joined. An electron amplifier is used to ^■ary the current in a circuit of the train apparatus to produce the results desired. No battery is re- quired for the roadside apparatus. No speed contiol features were • used. NoNMAcxETic Eail Typb (I-C-3). AUSTEN H. rOX. Inspected June 7, 1919, in the laboratory of the Fox-Lenderoth Co. in New York, N. Y. This apparatus is now in process of de- velopment. Only the engine collecting device was examined. This device uses nonmagnetic rails at indication points. No speed control was provided. Induction Type (II-B-1). pittsburgh train control co. Inspected July 10, 1919, at the company's laboratory in Pitts- burgh, Pa. The induced field aroimd the rails of an alternating cur- rent track circuit is used to produce the proceed indication. Train collecting coils are constantly within range of this field and are con- nected to an electron tube amplifier to control the train apparatus. The stop indication is produced by the absence of alternating current in the track circuit. This is accomplished between the approach and stop signals by changing the character of the track circuit from an alternating current to a direct current circuit and between the stop signal and the obstruction due to the absence of track circuit current. A manually operated valve is provided so that the engineman may assume cohtrol of the train at any time or may prevent an automatic application of the brakes. No speed control is provided. UNION SWITCH & SIGNAL CO. Inspected July 8, 1919, at the company's shop, Swissvale, Pa. The operation depends on induced fields around the running rails in which alternating current for the regular track circuit, and in addi- tion an alternating current in the same direction in both rails, with a line wire return, are used. Two pairs of collecting coils aie carried on the train so as to always be in range of the induced fields. One pair of coils picks up current due to the field created by the track circuit current and the other pair picks up current due to the field created by the rail-line wire circuit. Each pair of coils is connected to an electron tube amplifier, the secondary circuits of which control 30 ANNUAL KEPOET DIKECTOE GENEEAL OF EAILEOADS. a three position, two element, alternating current relay. The polarity of either of the two roadside circuits may be reversed to provide ap- proach and proceed indications. The absence of current in either er both ci-cuits produces a stop indication. The device is designed so that no automatic application of the brakes will be produced as long as the speed of the train is controlled in accordance with the signal indications. A centrifugal governor controls air valves to provide speed control. Wireless Ttpe (II-B-2). thomas e. clark. Inspected July 26, 1919, at his laboratory in Detroit, Mich. This wireless device is in the experimental stage. CoMBiNATiox Insulated Truck and Inert Roadside Element Types (I-B-1 and I-C-2). SCHWETER ELECTRIC & MANUFACTURING CO. Inspected September 5, 1919. A test installation was located on the Colebrookdale Branch of the PhiladeliDhia & Eeading Eailroad. Six indication points were installed. They were controlled in differ- ent ways through the track circuit, by switch in the station or by circuit controllers on signals. The roadside apparatus consisted of a laminated steel element to cooperate with the train apparatus to produce a stop, and a short track section, controlled through the signal circuits, to work in connection with insulated parts of the engine to give a proceed indication. The train apparatus consisted of a choke coil supplied with alternating curient from a generator on the train and also the necessary control relays and valves. Speed control was provided. Combination Plain Mechanical Trip and Induction Types (I-A-1 and I-C-1). RICHARDS-EORD TRAIN CONTROL CO. Insjiected September 3, 1919, at the office of the company, Balti- more, Md. A ramp is used to produce a stop by opening the circuit for the train apparatus. The circuit for controlling the train appa- ratus is maintained by the cooperation of the armature on the train relay and the roadside magnet, if the conditions are proper to pro- ceed. Two ramps, located different distances from the running rails, are used to give the approach and the stop indication. The only apparatus constructed was the train pick-up relay and the indica- tion magnet. No spesd control was provided. AUTOMATIC TKAIN CONTROL COMMITTEE. 31 GENERAL DISCUSSION. A congressional enactment in 1906 directed the Interstate Com- merce Commission to investigate and report upon the subject of automatic train control. In compliance with this legislation the commission on February 23, 1907, sulnnitted a report to Congress in which it was recommended that official tests of automatic appli- ances for the control of railway trains, conducted at Government expense, be authorized by Congress. This recommendation was favorably acted upon, and in the appropriation act of March 4, 1907, an item of $50,000 was provided for that purpose. Tliis authoriza- tion and the appropriation making it effective was extended and continued by the sundry civil act of May 27, 1908, since which date the commission has continuously conducted examinations and tests of train-control devices of various types and made reports setting forth the results thereof. Coincident with the work of the Interstate Commerce Commission, investigations and tests have been conducted by a number of railroad companies, and this committee has had the benefit of much of the information gained from both Government and railroad sources. The installation of automatic train control appears feasible — as- suming that a type to satisfactorily meet the operating conditions will be fully developed — ^to protect trains moving with the estab- lished direction traffic on main tracks, but it is doubtful if a device can be developed to protect all movements in the large terminals without restricting train movements to a prohibitive degree. The necessity for automatic train control must be developed in each indi- vidual case. As automatic train control is most necessary for the protection of high-speed trains, the apparatus must be suitable, with reasonable maintenance, to operate efficiently on such trains at the highest permissible speed and must not restrict the operation of the engine over any track which it may use. The brake application as made by the train-control device must be such as to safely bring the trains of various classes to a stop without endangering the controlled train or trains on adjacent tracks more than would occur if the brakes were applied by the engineman. The fact that automatic train-stop devices of the electrically con- trolled mechanical trip type are operated with a high degree of suc- cess on certain underground and elevated tracks ca;n not be regarded as conclusive evidence that such devices, or devices of other types in- tended to accomplish similar results, would be practical for use on tracks in the open country, subject to entirely dissimilar operating conditions. On the tracks where these devices are in successful use trains run are for passenger service and their equipment is uniform 32 A^'XXJAL EEPOKT DIKECTOE GENERAL OF EAILROADS. in character; they are moved at comparatively moderate speeds; clearance conditions are uniform, and there are no weather condi- tions present to interfere with proper operation. On roads in the open county, on the other hand, the equipment of trains is not uni- form, and the variation in train speeds is great; there is also great variation in the length and weight of trains, so that the breaking effort required varies widely between trains of different make-up. Clearance and weather conditions on tracks in the open country also present difficult problems which are not present on underground and elevated tracks. TJie committee believes that any comprehensive study of automatic train control must begin with the block system, as the principle of the bloclv system is fundamental to the subject and must be the f omidation of any automatic train-control system. The term ''• block system "' covers any means for maintaining an interval of space between trains as distinguished from establishing an interval of "time between trains at specified iDoints. The signals used in the block system on the railroads of this country indicate the condition of the blocks governed and convey certain information to employees respon- sible for the safe movement of trains. An automatic train-control device is not a substitute for the block system, but is merely a means for compelling observance of the rules and practices prescribed for its operation, thus insuring that the block system, or space-interval method of train operation, Avill be observed. The superiority of the block system as compared with other methods of train operation is generally recognized. It is in use on practically one hundred thousand miles of railroad line, including the busiest railroads or the busiest parts of practically all railroads in this country. Notwithstanding the fact that accidents occur on block signaled roads, the use of the block system is beyond question attended by a material increase in the safety of train operation and travel. The first step, therefore, which should be taken on lines which are not operated undei' the block system, in order to meet the need for more complete train protection, is not experimentation with or the adoption of some form of train-control device but the adoption of the block system itself, concerning which the results of years of experience in practical service on thousands of miles of railroad are available, firmly establishing its functions and value. The amount of apparatus required and the rules and practices necessary to be followed to render the block system adequate for any railroad depend upon traffic and operating conditions. On many lines where traffic is light a simple form of manual block system with the enforcement of proper rules is adequate ; on busy lines an auto- matic block signal system, together with the enforcement of proper rules and practices, is necessary to economically provide protection AUTOMATIC TRAIN CONTROL COMMITTEE. 33 for train movements, and the proper field for the use of automatic train-control devices is in connection with this latter class. The con- sideration of automatic train-control devices should be confined to this field, and any pressure or clamor for the introduction and use of such devices should not be permitted to divert attention from or ob- struct progress in the vastly more impoi'tant field of extending the use of the block system and instituting improvements in block signal apparatus and practices already in use. Constant progress and de- velopment is required to keep pace with traffic needs. Limiting the consideration of automatic train-control devices to their proper field of usefulness in connection with automatic signals, however, should not be construed as minimizing the importance of possible value of such devices. The practical development of auto- matic train-control devices and their use to supplement existing automatic block signals for the purpose of compelling obedience to signal indications is highly desirable. The use of train-stopping devices on lines- where trains are run on close headway will require the use of some form of speed-control ap- paratus in order to maintain the required capacity. The need of speed control is recognized, but little progress has been made in meet- ing the requirements. Some of the conditions under which speed control may be used are the following: 1. To prevent a predetermined speed being exceeded regardless of track conditions. 2. To permit a train to proceed at a predetermined low speed after having been stopped by an automatic brake application. 3. To permit a train to pass a brake application point at a pi-e- determined speed without receiving an automatic brake application. 4. To permit a train to pass an approach indication point without an automatic brake application providing the engineman properly observes the approach indication. 5. To permit a train to proceed without an automatic applica- tion of the brakes as long as the speed of the train is controlled in accordance with the signal indications. In a considerable number of the tests of automatic train-control devices which have been conducted during the past several years the apparatus tested has been far less substantial and rugged in con- struction than modern signal and interlocking apparatus in common use, notwithstanding that the operating conditions and require- ments are, generally spealring, more severe for train " control than for signal devices. In some cases also the installations tested were only temporary, and the apparatus was not so constructed and in- stalled that successful operation for a considerable period of time could reasonably be expected. Many of these devices have been de- 34 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. veloped and tested by persons who were not familiar with sigiial apparatus in common use nor with many of the problems which are encountered in the application of these devices to railroad operating conditions. The development of signal apparatus and interlocking devices has been comparatively slow process, during which countless devices have been proposed, many of them tested and used in actual service, and a comparatively small percentage retained in their original form. It follows that the development of automatic train- control devices will probably be along similar lines. Generally speaking, it may be said that the tests which have thus far been conducted have demonstrated that the functions of auto- matic train-control devices are possible of accomplishment under actual service conditions. But Avhile these functions may be ac- complished under the conditions existing at comparatively isolated locations, with the high degree of maintenance ordinarily given to test installations of this character, it is an entirely different prob- lem, and a far more complex one, to apply these devices to the various operating conditions encountered in railroad service, and to accom- plish these functions day and night, year in and year out, on a large number of trains and on several hundred miles of a busy railroad. From a practical standpoint, automatic train-control devices are still in the development stage, and many problems in connection with their practical application remain to be solved. Development of automatic train-control devices by individual en- terprises must of necessity be extremely slow, and it is believed that the time has come when more active cooperation should be undertaken by the railroads. To accomplish this task a systematic study of the problem must be continued, available engineering talent must be utilized to design and construct apparatus suitable for the purpose intended, apply it to meet various operating conditions, and conduct experiments on a more comprehensive scale than has been done in the past. CONCLUSIONS. The committee has reached the following conclusions : 1. That the relative merits of the various types of automatic train control can not be determined until further tests have been made. 2. That more extended service tests, including complete records of performance are necessary before a decision can be reached on the availability for general practical use of any of the devices that have been brought to the attention of the committee. 3. That on a large part of the railroad mileage in the United States, with a given amount of money available for protection pur- poses, a greater degree of safety can be obtained by installing block signals than by installing automatic train control devices. AUTOMATIC TEAIN CONTROL COMMITTEE. 35 i. That &n lines of heavy traffic, fully equipped with automatic block signals, the use of train control devices is desirable. 5. That complying with its instructions and without implying in- dorsement, the committee finds the following devices available for further test: American Railway Signals Co Intei-mittent electrical contact type. American Train Control Go Do. Automatic Control Go Electrically controlled mechanical trip type. Casale Safety Device Go Intermittent electrical contact type. Clifford Automatic Train Stop Co Electrically controlled mechanical trip type. General Railway Signal Co Intermittent electrical contact type. Do Inert road,side element. International Signal Co Intermittent electrical contact type. Miller Train Control Corporation Do. National Safety Appliance Go Induction type. Nevens-Wallaee Train Control Co Electrically controlled mechanical trip type. Schweyer Electric & Mfg. Go Inert roadside element. Shadle Automatic Train Signal Go Intermittent electrical contact type. Sprague Safety Control & Signal Corporation Induction type. Union Switch & Signal Go Continuous induction type. Wooding, B. F Intermittent electrical contact type. Willson-Wright Safety Appliance Go_Electrically controlled mechanical trip type. _ 6. That it does not appear necessary to make tests of all of the devices of a type to determine the availability of that type for gen- eral practical use. 7. That a committee on automatic train control should be con- tinued. RECOMMENDATIONS. The committee therefore submits the following recommendations: 1. That this or a similai' committee be continued to the end of Federal control, extending the present provisions for the employ- ment of a permanent staff. 2. That at the termination of Federal control the work of this committee be continued under the American Eailroad Association. On account of the importance of the subject the work should be done by a special committee, having the same standing as a section of the association. The Bureau of Safety of the Interstate Commerce Commission should, as now, have representation on this committee. This committee should include in its work : (a) Analysis of the reports of train accidents now made to tlie Interstate Commerce Commission. 36 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. (6) Authorization of tests to be undertaken and sucli supervision of them, in cooperation with the Interstate Commerce Commission, as may be necessary. 3. That arrangements be made by the Eailroad Administration or after the termination of Federal control by the American Kail- road Association, for the further practical test, under rules that may be adopted by the committee, of such devices as may be available for that purpose. Such tests should include in form prescribed by the committee: (a) Eecord of performance. (6) Eecord of installation cost, separated between roadside and train apparatus, and into unit costs. (c) Eecord of cost of modifications of the existing signal system to accommodate the test installation. (d) Eecord of direct operation and maintenance costs. The committee has been efficiently aided in its work by its secre- tary, Mr. G. E. Ellis, and its signal engineer, Mr. E. L. Adams. It also wishes to express its appreciation of the hearty cooperation re- ceived from railroad officers and the proprietors and inventors of the devices examined. Eespectfully submitted : A. M. Burt, Chairman. H. S. Balliet, E. W. Bell, W. P. BOELAKD, C. E. Dexney, J. H. GCJIBES. XoVEMBER 29. 1919. Mr. Bartlett, being absent in Europe, was unable to sign this report. To Mr. W. T. Tylek, Director of Operation. DEFINITIONS OP TERMS USED IN THIS REPORT. Advance (in advance of) : The space beyond the point referred to relative to an ap- proaching train. Amplifier (see Audion) : A device in which the current in one circuit is increased by the change in characteristics in another circuit connected to the device. Apparatus : The gi'oup of elements carried on the train or placed on the roadside. Audion (see Pliotron) : A glass tube or bulb resembling an incandescent lamp from which the air has been exhausted. The tube contains three ele- ments, a filament, a plate, and a grid with terminals for con- nection to outside circuits. The device is intended to change the amount, or characteristic, of a current flowing through the plate filament circuit as the potential of the grid is changed. The filament must be heated to incandescence before current will flow in plate-filament circuit. The potential on the grid is supplied from another source and as this potential changes the current in tlie plate-filament circuit changes. Circuit, holding (see Holding circuit). Circuit, normal closed : A circuit arranged so that its continuity is normally unbroken or so that a condition, such as a break, a cross, or a failure of source of power that would prevent the proper operation of the controlled device, would be self-evident by producing the result for which the apparatus was designed. Circuit, normal open : A circuit arranged so that its continuity is noiuially broken at one or more points, and so that a condition, such as a break, a cross, or a failure of source of power that would prevent the proper operation of the controlled device, would not be self- evident by producing the result for which the apparatus was designed. Circuit, pick-up: A circuit that is completed either by the closing of a manu- ally operated circuit controller or by cooperation between a train element and roadside element to restore the train apparatus to the proceed position or to hold it in the proceed position when passing a signaling point. 37 £8 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. Circuit, " stick " (see Stick relay) : Tlie control circuit for a stick relay. Collecting coils: Coils of wire carried as a part of the train apparatus and in wliicli current is induced by currents or magnetism in the road- side element. Device : The combination of tlie apparatus on the train and that on the roadside necessary to produce an automatic stop at one lo- cation. Electron amplifier (see Amplifier). Element : One of the parts that make up the train or roadside apparatus. Holding circuit : The circuit that holds the train apparatus in the " proceed " position. Main reservoir cut-off (see Xonrelease valve). Mechanism : An element, either of the roadside or train apparatus, having moving parts. Non release valve: A valve designed to shut off the supply if air from the main reservoir to the train brake pipe when an automatic apj^lica- tion of the brakes is made, thereby preventing the release of brakes through the engineman's brake valve until the purpose of the automatic application has been accomplished. Pliotron (see Audi on) : A device having practically the same characteristics as the Audion and used for similar purposes. Polarized relay: A relay having an armature that moves or rotates in one di- rection or the other, dependent on the direction of current in its coils. The relay may be operated by either direct or alter- nating current. A three-position relay is a polarized relay. A permanent magnet in pro]Der relation to an electromagnet may be used in direct current types. Eamp : A metal bar with an inclined upper surface fixed on the road- side in permanent relation to the track to lift the vertically mov- ing part of the shoe and, when necessary, to form a part of the pick-up circuit. Bear (in rear of) : The space before passing the point referred to relative to an approaching train. AUTOMATIC TRAIN CONTROL COMMITTEE. 39 Release button or switch : A manually operated button or switch, the operation of which will permit the release of the brakes after an automatic stop has been made. Shoe: The element of the train apparatus that includes the contact piece, circuit controllers, air valves, etc., that control the train apparatus when in contact with, or within the influence of, the roadside element. The shoe is generally carried on the frame of the engine or tender truck. Speed control: A device to control the automatic application of the brakes, dependent on the speed of the engine. It may or may not require the cooperation of the engineman to make it effective. Stick relay: A relay that is held energized through one of its own contacts so that when its holding circuit is opened an auxiliary pick-up circuit must be closed to restore the normal opieration. System, train control: A number of installations of the device to provide control over a certam section of track, the different groups of apparatus being properly interconnected, mechanically or electrically, to produce the desired result. Three-position relay (see Polarized relay). Trip arm: A movable rod or arm carried on the train or located on the roadside and intended to cooperate with a corresponding ele- ment on the roadside or the train, respectively, to produce a stop when conditions require it. Trip rail : A movable rail or ramp located on the roadside and capable of being moved into or out of position to engage the proper element of the train apparatus, dependent on whether a stop is to be produced or not. APPENDIX I. Plans and Devices Examined. The committee examined 37 devices in various stages of develop- ment as described in the body of the report. All types except one were repi'esented and these vrere distributed among the various types as follows: Plain meclianical trip 1 Electrically controlled mechanical trip 10 Intermittent electrical contact 15 Insulated truck witli short track circuit section 1 Intermittent induction 3 Inert roadside element 1 Nonmagnetic rail 1 Continuous electrical contact Continuous induction 2 Wireless 1 Combined insulated engine and inert roadside element 1 Combined plain mechanical trip and intermittent induction 1 Of the above list, 1-i possessed some speed control features as part of the device and 23 were without such features. Defects, classed as " open circuit," due to either the requirement of the application of energy to produce a brake application or to the possibility that essential parts might be removed or broken without producing a stop, existed in 6 devices. Generally the governor.^ used in those devices exhibiting speed control features have been of the centrifugal ball type, driven from an axle of the engine by belts of various kinds or by rigid connec- tions. The method of transmission is obviously an important part of such a device and presents difficulties, some of which are due to the limited space available for the location of the speed control apparatus. One device examined took into consideration, in its speed control apparatus, the braking effect which would be pro- duced by the engineman's handling of the train. Some purely electrical speed control appai-atus has been examined, but none which has been subjected to any extensive tests. One device de- pended for its speed control on the impact between the engine con- tact element and the roadside contact element, as related to the speed of the train in reference to the rate of inclination of the roadside contact element to the track. The use of amplifiers in the form of audions or pliotrons, designed to increase or modify the electrical energy in the train apparatus by the influence of the roadside element in noncontact types, is indicated in three devices. In each of the devices the amplifier is used in a different manner but they are all in the experimental stage and no tests under operating conditions have been made. 40 AUTOMATIC TRAIN CONTROL COMMITTEE. ' 41 As stated in the report, more or less complete plans of 300 devices have been examined in addition to the plans of those that were in- spected. These were divided among the various types as follows :, Plain mechanical trip 135 Electrically controlled nie.-liank-ul trip 31 Intermittent electrical contact--. 63 Insulated truck with short trade circuit section 9 Intermittent induction 4 Inert roadside element Nonmagnetic rail 2 Continuous electrical contact : 40 Continuous induction 2 Wireless L 1 Combined intermittent induction and intermittent electrical contact 1 C-ombined nonmagnetic rail and intermittent electrical con- tact 1 1 Unclassified 11 The following is a list of all devices, plans of which were exam- ined, arranged alphabetically : Adkins, ^\'. H Continuous electrical contact. Adler, Charles Do. Aird, W. S Plain mechanical trip. Allard, Andrew J Intermittent electrical contact. Allen, Dwight Do. American Railway Signals Co Do. American Signal Co Insulated truck with short track circuit section. Arderican Train Control Go Intermittent electrical contact. Amick, P. A Do. Anderson, .To.seph E Continuous induction. Amnendt, .T. C Intermittent electrical contact. Austin, AVilliam Plain mechanical trip. Automatic Conti'Ol Co Electrically controlled mechanical trip. Automatic Electric Railway Block /Plain mechanical trip. Signal Co. ■ 1 Intermittent electi'ical contact.^ Automatic Railway Appliance Co Plain mechanical trip. Backus, William E Intermittent electrical contact. Baldwin, C. W Plain mechanical trip. Barry, Garrett 3 Do. Battagliuo, Joseph Intermittent electrical contact. Baum, F. .1 Special. Beaver. Thomas Continuous electrical contact. Bedrossian, Archie Plain mechanical trip. Begin, A. F Insulated truck with short track circuit section. Benedict, G. W Plain mechanical trip. Berger, A. C Intermittent electrical contact. Bess. Elijah Plain mechanical trip. Betz, Plarry D ^■Wireless. Bogart, Harry Plain mechanical trip. Bond, Harry M Do. Bostwick, F. F See National Safety Appliance Co. Bouillet, E Continuous electrical contact. Bouladft, .lean Intermittent electrical contact. Bower, A. L : Plain mechanical trip. D,i Intermittent electrical contact. Bowersock, H. T Plain mechanical trip. 42 ANlv^UAL REPORT . DIEECTOE GENEEAL OF RAILROADS. Brew, T. A Contiuuous electriciil contact. Bi-inson, Joseph G Plain mechanical trip. Brooklns, Andrew J Intermittent electrical contact. Brosey, A. .T .- > Do. Brosvik, B. B Special. Brothers, George .J L Plain mechanical trip. Brownell, George W Do. Brubaker, J. L Do. Buck, J. G Do. Buell Signal & Train Control Co., Inc— Insulated truck with short track circuit .section. Buhl, C. R. H Intermittent electrical contact. Bulla, M. B .SVr Train Control Appliance Co. Burbridge, H. J Plain mechanical trip. Button, F. E Intermittent electrical contact. Cabrera, Jose Continuous electrical contact. Carlisle, Bert Special. Carlisle, Howard Continuous electrical contact. Casale Safety Device Co Intermittent electrical contact. Casselman, J. B Electrically controlled mechanical trip. Cave, Elmore Plain mechanical trip. Chaloner, T. T Do. (.'handler, J. L Continuous electrical contact. Clapp, Clark E Plain mechanical trip. Clark, Irving L Do. Clarke, Lee R Do. Clark, Thomas E "Wireless. Clifford Automatic Train Stop Co Electrically controlled mechanical trip. Codire, I'. F Plain mechanical trip. Ooker, J. R Intermittent electrical contact. Conte, A. M Plain mechanical trip. Cooper, Bernard Do. Cornet, A. E Do. Coulombe, Arthur Do. Coulombe, O. J Do. Courtright, ^y. R Do. Crawford, John S Do. Crossland, D. W Do. Crossley, AVilliain Do. Currier, W. S Do. Curtis, C. J Special. Custer, John Continuous electrical contact. Dally, AV. P ,_- Insulated truck with short track circuit section. Dansberry, William H Plain mechanical trip. r)a Silva, Raul Ribeiro Do. Do Electrically controlled mechanical trip. Dawson, J. V Plain mechanical trip. De Ford, .T. W Do. Dennette, Frederick Electrically controlled mechanical trip. Dettmer, J Plain mechanical trip. Devos, Charles '-— Do. D'Narvarte, Juan Do. Dodge, A. Y Intermittent electrical contact. Doran, J. J Plain mechanical trip. Drake, George Alexander Continuous electrical contact. Drawbaugh, I. P Plain mechanical trip. Dungan, Ernest E Continuous electrical contact. Do Intermittent electrical contact. Eickhoff, Fred H _ Do. Electrical Automatic Railroad' Safety Do. Signal Co. English, A. J Plain mechanical trip. Esworthy, J. W Intermittent electrical contact. Faufata, Namaka L Do. Fay, Bernard Plain mechanical trip. Filiberto, Nicola Continuous electrical contact. Do , Electrically controlled mechanical trip. AUTOMATIC TEAIN CONTROL COMMITTEE. 43 Finnigan, George P Intennittent induction. Fish, Edwin A Plain mechanical trip. Fockerynsld, .Joseph V Continuous electrical contiict . Fox, Austen H Nonmagnetic rail. Frame, .Tohn Plain mechanical trip. Friedly, E. R Do. Fry. Walter Do. Fulks, M. R Do. Fuller, R. E. Co Do. Do Do. Do Continuous electrical contact (Jadeholt. Bjorn Special. Gainer, A. L Plain mechanical trip. Garrison, G. B Do. General Railway Signal Co Intermittent electrical contact. Do Inert roadside element. General Safety Appliance Co Combined intermittent inductiou >xnd la- termittent electrical contact. Gerlach, George W Intermittent -electrical contact. Ghent & Webler Plain mechanical trip. Gibbons, W. A Do. Giles, William E Insulated truck with short traclt circuit section. Gilkeson & James Plain meclianicai trip. Gladish, W. J Electrically controlled mechanicar trip. Golliis Railway Signal Co. of Intermittent electrical contact. America. Goodpasture, Charles H Plain mechanical trip. Gorsuch, E. W Intermittent electrical contact. Goveia, Ervin M Plain mechanical trip. Gramm, John A Do. Gray-Thurber See Pittsburgh Train Control Co. Gumm, G. J Plain mechanical trip. Guthner, Albert L Do. Hanna, Jacob .Continuous electrical contact. Hardy, J. O Plain mechanical trip. Hawkins, Hubert C Electrically controlled mechanical trip. Heald, Leonard Special. Heales, George Plain mechanical trip. Heath, Frank Electrically controlled mechanical trip. Hedges, I. W. and R. F Plain mechanical trip. Hellman, Lui F Do. Hennessy, D. E Intermittent electrical contact. Henry. F. G Continuous electrical contact. Herniance JIachine Co Intermittent electrical contact. Hickman, Harry Do. Higgins, Vf. J Intermittent induction. Hitselbergei-, L_ Plain mechanical trip. Hochstein, A. P Do. Hoffman, James L Continuous electrical contact. Hole, 0. C Electrically controlled mechanical trip. Hollinger, A Continuous electrical contact. Holt, John Do. Horchler, William Pliiin mechanical trip. Home,- L. W Nonmagnetic rail. Howard, C. L Plain mechanical trip. Huber-Willianison iS'cc Pittsburgh Train Control Co. Hudson, Frederick F Intermittent electrical contact. Hudson' Signal Sales Co Continuous electrical contact. Industrial Appliances, Ltd Plain mechanical trip. Inman E. R Continuous electrical contact. International Automatic Signal Co_-Insulation truck with short track circuit section. International Signal Co Intermittent electrical contact. .Tenke, Carl F Plain mechanical trip. Jensen S ^o. Johnson, Arnold O Continuous electrical contact. 44 ANKXJAL EEPOKT DIRECTOR GENERAL OF RAILROADS. Johnson, Jeremiah Intermittent electrical contact. Johnson, W. H Plain mechanical trip. Joly, Cezaire Do. Josepl-.5on, A Intermittent induction. Julien-Beggs Signal Co See American Railway Signals Co. Kamiske, C. G Plain mechanical trip. Karl, William, and Karl H Intermittent electrical contact. Kern. John D Do. Khouhesserian, Hagop H Do. Knight Brothers . Plain mechanical trip. Koch, George Do. Kogler, Peter J Do. Kohlback, Henry F. AV ' Special. Krummel, William E Plain mechanical trip. Labit, G. E Do. Lawsdi!, Clarence Do. Leach, F. I Do. Lenz, Charles S Electrical controlled mechanical trip. Leon, F Plain mechanical trip. Littleton, A. S Continuous electrical contact. Lodge, H Insulated truck with short track circuit section. Loughridge, M. H Intermittent electrical control. Lumb, Charles F Plain mechanical trip. Lntschg, Fred M Intermittent electrical contact. Macfariane Communications Corpo- Continuous electrical contact, ration. Mahoad, Homer F Intermittent electrical contact. Mainardi Brothers Continuous electrical contact. Mansfield, W. Thomas Plain mechanical trip. Martell, Stephen Electrically controlled mechanical trip. Slathis, Paul Neree Plain mechanical trip. Matthias, B. F Do. Maxey, John Do. JIcArlhur, T. W Continuous electrical contact. McCollom, William R 1— Electrically controlled mechanical trip. Mclntyre, M. J Plain mechanical trip. McKay, Richard F Intermittent electrical contact. Mendonca, J. C Special. Merry weather, James Plain mechanical trip. Milde, Franz Do. Miller, R. L Electrically controlled mechanical trip. Miller Train Control Corp Intermittent electrical contact. Miner, J. R Plain mechanical trip. ilitchener. John Edward Do. Moore, John M Do. Jlorgan, C. W Do. Jlorgan, D. L Intermittent electrical contact. Morgan, J. A Do. Morgan, W. D. L Plain mechanical trip. Moulton, Richard L Do. Murphy, Albert Do. Murphy, James P Intermittent electrical contact. Musy, Felix M Electrically controlled mechanical trip. Do Intermittent electrical contact. M-Y All-Weather Train Controller Co_ Intermittent induction. National Safety Appliance Co Do. Nead, AVllliam S Intermittent electrical contact. Neely, S. L Continuous electrical contact. Nein, W. C Intermittent induction. Nelson, Buell C Continuous electrical contact. Nevens-Wallace Train Control Co — Electrically controlled mechanical trip. Newton, D. C : Intermittent electrical contact. NvCton & Lindeman Do. Do Do. O'Connor, Charles J Plain mechanical trip. AUTOMATIC TRAIN CONTROL COMMITTEE. 45 Getting, O. W. A Nonmagnetic rail. Oliver, Nathan A Plain uu^clianiral trip. Orcutt Automatic Train Control Co_ Intermittent electrical contact. Pate, M. M Electrically controlled mechanical trip. Patterson, W. C Intermittent electrical contact. Patterson, Warren Plain mechaiileal trip. Pilger, George J Do. Pittsburgh Train Control Co Insulated truck with short track circuit section. Do Intermittent electrical contact. Do Continuous induction. Poud, Albert D Electriially controlled mechanical trip. Powell, .John H Do. Prouty, E Plain mechanical trip. Putnam, A. G Electrically controlled mechanical trip. Quackenbush, William C Intermittent electrical contact. Query, Joseph O Plain mechanical trip. Quinn, P. J • Intermittent electrical contact. Ramapo Iron Works Electrically controlled mechanical trip. Raymond Manufacturing Co Intermittent electrical contact. Reedy, M. W Plain mechanical trip. Reger, Kent Special. Reichman Bros Intermittent electrical contact. Reliostop See Industrial Appliances (Ltd.). Richards-Ford Train Control Co Combined plain mechanical trip and in- termittent induction. Rideout, William A Intermittent electrical contact. Roberts, C. H Continuous electrical contact. Robinson, Peter J Intermittent electrical contact. Robinson, William Continuous electrical contact. Rockefeller, Arthur A Plain mechanical trip. Rodehaver, H. B Continuous electrical contact. Ruf, Henry C Intermittent electrical contact. Russ, Frank A Plain mechanical trip. Safety Block Signal Co Insulated truck with short track circuit section. Safety Signal Co Electrically controlled mechanical trip. Sammons, Thomas Contiiiuous electrical contact. Samuels, John Intermittent electrical contact. Schaefer, John Electrically controlled mechanical trip. Scheldt. Henry C, jr Plain mechanical trip. Schmidtke, C. W Do. Schneider, George Do. Schneider, Peter Electrically controlled mechanical trip. Schneider, William Do. Schultz, Emil H Continuous electrical contact. Schutte, Frederick A Do. Schweyer Electric & Manufacturing Combined Inert roadside element and in- Co. sulated truck with short track circuit section. Scott, J. .7 Plain mechanical trip. Seeley, Enridge P Do. Shadle Automatic Train Signal Co Intermittent electrical contact. Shelton, R. M Continuous electrical contact. SUvene, Tony Intermittent electrical contact. Simmen Automatic Railway Signal Co. Do. Simms, Amos Hoffman Electrically controlled mechanical trip. Sindeband, M. L Continuous induction. Slfetchley, F. A Electrically controlled mechanical trip. Skinner,", T. H Continuous electrical contact. Slattery. Martin F Plain mechanical trip. Slingland, Leonard Do. Smith, A. E Do. Smith, Sidney Guy ...Continuous electrical contact. Sparhawk, Frank O Plain mechanical trip. Sparks, John G Do. 46 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. Sprague Safety Control and Signal Intermittent induction. Corporation. Stafford, E. C Intermittent electrical contact. St. Clair, Frank Plain mechanical trip. Stebbins, H. O Intermittent electrical contact. Steele, Franklin, .ir Plain mechanical trip. Stiegelmeyer, Edward See Automatic Control Co. Streit, Jlelville V Continuous electrical- contact. Sullivan, J. Herbert Intermittent electrical contact. Taylor, A. G Continuous electrical contact. Thayer Automatic Signal & Train Intermittent electrical contact. Control Co. Thomas, C. P Do. Thomas, Charles P Plain mechanical trip. Do Electrically controlled mechanical trip. Thomas, M. E Do. Thempson Automatic Signal Co Insulated truck with short track circuit section? Todd, Kobert H Continuous electrical contact. Toxey, Elliott Intermittent electrical contact. Do Electrically controlled mechanical trip. Train Control Appliance Co Intermittent electrical contact. Troyer & Hochstetler Plain mechanical trip. Tubman, S. A ,__. Electrically controlled mechanical trip. Turner, C. C Intermittent electrical contact. I.'nion Switch & Signal Co Continuous induction. Vigliano, Joseph Intermittent electrical contact. ^^■adp, Frank K Do. AValker, James L Plain mechanical trip. Walsh, William E Do. V\'alliin, Frank A Intermittent electrical contact. ■\Varni3, Alfred Ernest Plain mechanical trip. V\'nrthen Automatic Stop and Cab Intermittent electrical contact. Signal Co. Welch, AV. H Electrically controlled mechanical trip. Whalen, E. V Plain mechanical trip. Wilbur, J. F Do. Williams, H. J Intermittent electrical contact. Wililams, William L Special. AVilliams, William ^ Plain mechanical trip. Willson-Wright Safety Appliance Co_Electrically controlled mechanical trip. Wilson, George Plain mechanical trip. Wilson, Henry AV Do. AA'intsch, Blax Th Combined intermittent electrical contact and nonmagnetic rail. Do Intermittent electrical contact. AVooding, B. F Do. AVorden, Aden M Special. WulflC, E. H Plain mechanical trip. Youngen, S. I Do. Zettel, Louie A Do. Zwickle, John Do. APPENDIX II. Bibliography. American Railway Association : Report on Automatic Train Stpps — Railway and Engineering Review, July 19, 1913. Railway Age Gazette, May 20, 1914. Reports of Joint Committee on Auto- matic Train Stops: April 21, 1913; October 20, 1013; April 20, 1914; NoTcmber 10, 1914 — Proceedings of the American Railway Association 1913-1915. American RaUway Engineering Association : Automatic Train Control. American Railway Engineering Asso- ciation Bulletin, February, 1919. Angus, A. R. : New System of Automatic Signaling and Automatic Train Stop, by O. O. Burge — Railway and Engineering Review, Au- gust 17, 1912. Bailey, Henry E. : Automatic Train Stops — Railway and Engineering Review, February 27, 1909. Block Signals and Safety Stops — Railway and Engineering Review, February 19, 1910. Belnap, II. W. : Report on Automatic Train Control — Railway Review, .lanuary 13, 1917. Biddle : Riddle's Automatic Train Control — Railway Gazette, June 22, 1917. Blair, H. Avery : The Perry-Prentice Wireless Signaling System — International Railway Congress Bulle- tin, August, 1909. Blocl^ Signal and Train- Control Board : Rowell-Potter Safety Stop — Second Annual Report, 1909. Harrington Train Control and Alarm — Third Annual Report, 1910. Lacroix Train Control System — Fourth Annuni Report, 1911. Block Signals and Automatic Control — Railway Library, 1911. Conclusions and Recommendations, De- cember 6, 1911. Final Report, June 29, 1912 — Annual Reports of the Interstate Com- merce Commission. Bostwick, F. F. : Cab Signals and Automatic Stops at Oro- ville — Railway Age Gazette, November 26, 1915. BrowDcll : Brownell's Automatic Stop — Railway Age Gazette, October 1, 1915, A New Type of Automatic Railroad Stop — Scientific American, August 28, 1915. Buell, Joseph W. : Anajysis of Railway Signaling and Pres- entation of a Plan for Better Safe- guarding Railwajy Travel. (Washing- ton, D. C. 1907.) The Buell Cab Signal System. (Wash- ington, D. C, 1905.) Buoli's Cab Signal and Automatic Train Stop — Railway Age Gazette, November 12, 1915. Burge, O. O. ; Now System of Automatic Signaling and Automatic Train Stop Invented by A. R. Augus — Railway and Engineering Review, Au- gust 17, 1912. Canadian Engineer, February 23, 1911 : I'rentice Wireless Train Control. Illus- tration of devices recently tried on the Canadian Pacific Railroad. Carlyle, S. S. : Making Collisions Impossible — Technical World, October, 1909. Carson-Burgess : Carson-Burgess Cab Signal and Auto- matic Train Stop — Railway and Engineering Review, March 3.0, 1012. Carter, Charles F. : When the Engineer Forgets — Technical World, March, 1913. Cary, Harold : Hands Off the Throttle — Technical World, October, 1915. Cassier's Magazine : May, 1911— The Harrington Safety Stop. Central R.nilway Club Proceedings : May, 1912— Prentice Wireless Train Control. Chatfleld, C. E. : Cost of Automatic Train Control — Railway Review, October 21, 1916. Coleman, F. C. : Automatic Wireless Train Control — Scientific American, December 5, 1913. Dammond, William H. : Cab Signals and Train Stops — Railway News, March 7 and 21, 1914. Dayton. Thaddeus S. : The Wrcckless Railroad — Harper's Weekly, February 22, 1912. Dearden, W. II. : Safety in Railroads — Harper's Weekly, October 18, 1913. Incentive to Invention — Outlook, July 26, 1913. Detroit : The Detroit Automatic Train Control — Railway Gazette, September 26, 1913. Edison Monthly : May, 1913— Train Control — The MacDonald Sys- tem. Electric Journal : October, 1913 — Automatic Control of Trains, by L. V. Lewis. Electric Review and Western Electrician : February 7, 1914 — Electric Automatic Railway Signaling System Used in England. Electric Traction : November, 191G — Norfolk Automatic Car Stop Installa- tion. Elliott, W. H. : An Expert's Experience With Automatic Stops — Railroad Gazette, March 6, 1903 Automatic Train Control. Railway and Engineering Review, No- vember 28, 1908. 47 48 AN^VAL, REPORT DIRECTOR GENERAL RAILROADS. Engineer (London) : January 16, 1914 — Automatic Train Control on tlie Great Western Railway. August 29, 191.S — Automatic Wireless Train Control. (Prentice System.) March 0, 191T — Railway Collisions at Wigan and Kirle- bridge. July 20, 1917— Description of the General Electric Railway System of Automatic Train Control for Westinghouse Brake. Engineering. July 13. 190G— The Raymond Phillips System of Train Control. Engineering News. Vol. 71, 1914 — Automatic Train Stop or Train Con- trol Systems. January 30, 1913 — British Opinion on Railway Automatic Stops, by II. Raynor Wilson. March G, 1913 — Collision in a London Subway. Fail- ure of an Automatic Stop. October S, 1914— Train Stops on the Chicago & Eastern Illinois Railroad. Farnsworth, F. L. : Mechanical Brains for Engines. Railroad Man's Magazine. October, 1917. Gollos : Developments in the Gollos Automatic Train Control. Railway Age Gazette, March 21, 1916. Gc^los Automatic Stop. Railway Age Gazette. August 6, 1915. Test of Automatic Stop Sy.stem. Railway Review, August 7. 1915. Test of Gollos Automatic Train Stop, Chicago Great Western Railroad. Railway and Engineering Review, Oc- tober 26, 1912. Report on Automatic Train Control Sys- tem by Interstate Commerce Commis- sion. House Document 1192, G4th Congress, 1st Session. Gradenwitz, Alfred : An Automatic Railway Stop — Scientific American. January 8, 1910. Gray-Thurber : Gray-Thurber System of Automatic Train Control as Applied to an Aiitomatic Signal System — Railway Engineering and Mainte- nance of Way, November, 1914. Illustrated Lecture on Train Control de- livered before Brotherhood of Loco- motive Firemen and Enginemen, ,Tune 18, 1913, at Washington, D. C, by Guy P. Thurber. The Conservation of Human Life in Steam and Electric Railroad Travel — Official Proceedings of Railway Club of Pittsburgh, February 24, 1911. Track Insulation Stops the Trains in this Automatic Control System — Popular Science Monthly, March, 1918. Report of the Chief of the Division of Safety, Interstate Commerce Commis- sion, for 1914 — House Document 1482, 63d Congress, 3d Session. Report of the Chief of the Division of Safety, Interstate Commerce Commis- sion, for 1915. Harper's Weekly : February 22, 1912 — The Wreckless Railroad, by Thaddeus S. Dayton. October 18, 1913— Safety in Railroads, by W. H. Dearden. Harrington ; Automatic Train Stopping Devices — Cassier's Magazine, May, 1911. The Harrington Safety Stop — Harrington Automatic Train Stop. Railway Age Gazette, May 5, 1911. Mechanical Trip Automatic Stops — Railway Age Gazette, May 19, 1911. The Harrington Train Control and Alarm — Third Annual Report of the Block Signal and Train Control Board, 1910. Hendrick, Calvin W. : A Railroad Adopts the Automatic Stop. Adoption of the Jones System by the Maryland & Pennsylvania Railroad — Scientific American, September 20, 1913. Home & Crane : Home & Crane's Automatic Stop — Railway Age Gazette, October 9, 1914. Hudson & Manhattan Tunnel Signals and Automatic Train Stops : Railroad Gazette, March 0, 1908. Hunting, Gardner : Railroad Trains Guard Each Other. Mac Donald System of Train Control — Technical World, September, 1913. Illustrated World : December, 1915 — Stopping Trains from the Dispatcher's Office, by Stanley B. Lowe. International Railway Congress Bulletin : August, 1909 — The Perry-Prentice Wireless Signaling System, by II. Avery Blair. ^Interstate Commerce Commission : Report on Block Signal Systems and Ap- pliances for the Automatic Control of Railway Trains. Washington, 1907. 59th Congress, 2d Session, Senate Doc. 342. Report of the Chief of the Division of Safety, 1914— Report of Test of the Automatic Train Control System of the American Train Control Company, Baltimore, Maryland — 63d Congress, 3d Session, House Doc. 1541. Report of the Chief of the Division of ■ Safety, 1915— Report on Test of the Automatic Train Control System of the Gollos Rail- way Signal Company, which was con- ducted from August 10 to October 1, 1915, and from February 26 to March 31, 1916 — 64th Congress, 1st Session, House Doc. 1192. Report of Tests of the Wooding Train Control System Conducted by the Division of Safety, on the Delaware, Lackawanna & Western Railroad, January to April, 1917 — 05th Congress, 1st Session, House Doc. 251. Annual Report on Automatic Train Con- trol- Railway Gazette, May 25, 1917. Iron Trail : November, 1905 — A Remedy for Railroad Accidents, by B, C, Eowell. Rowell-Potter Safety Stop. Jones, E. E. : Automatic Signal and Automatic Stops on High Speed Electric Railways — Pacific Railway Club Proceedings, Au- gust, 1917. A Railroad Adops the Automatic Stop, by Calvin W. Hendriclc — • Scientific American, September 20, 1913. The Jones System of Automatic Train Control — Railway and Engineering Review March 1, 1913. AUTOMATIC TKAIN CONTEOL COMMITTEE. 49 Jones, E. E. — Continued. Interstate Commerce Commission Report of Test of the Automatic Train Con- trol System of the American Train Control Co., Baltimore, Mil. — G3a Congress, 3d session. House Doc. 1541. Julian-Beggs : Automatic Speed Control. The Julian- Beggs Automatic Speed Control Ap- paratus — Hallway Age Gazette, March 16, 1913. Improved Jullan-Beggs Train Control — Railway Age Gazette, March 21, 1916. The Julian-Beggs Automatic Stop and Train Control System — Railway Review, May 26, 1917. Julian Train Control and Automatic Stop — Railway Gazette, November 12, 1915. The .Julian Train Control and Automatic Stop. A description of the demon- stration made on the Queen & Cres- cent and of the equipment required — Railway Age Gazette, June 25, 1915. Cab Signals and Automatic Stops, by Stephen Smith — Richmond Railroad Club Proceedings, May 15, 1916. Julian-Beggs System — Address and Explanation of Julian- Beggs Automatic Stop and Train Control System. Cincinnati Railway Club Proceed- ings, FebruaiT, 1917. Test of the Julian-Beggs Train Control Signal System — Railway Review, May 27, 1916. Kinsman : The Kinsman Block System — Railroad Gazette, June 8, 1894. Signals and Automatic Train Stops in the Hudson & Manhattan Tunnel — Railroad Gazette, March 6, 1908. The Kinsman System — Signals and Automatic Train Stops in the Hudson Tunnels — Railway and Engineering Review, March 14, 1908. Laeroix System : Making Collisions Impossible, by S. S. Carlyle — Technical World. October. 1909. To Prevent Train Wrecks, by Robert H. Moulton — Technical World, January, 1913. Seeking an Invention to Prevent Rail- road Collisions. Interstate Com- merce Commission makes test on Staten Island of Young Texan's De- vice — New York Times, April 23. 1911. Laeroix Train Control System — Block Signal and Train Control Board, Fourth Annual Report, 1911. Lewis, L. V. : , „ . ,, The Automatic Control of Trains. Ex- plains the problem of automatic train control and reviews the de- vices brought into use, discussing features of the automatic stop — Electric Journal, October, 1913. Literary Digest (editorial) : *Mr"^^ellen's $10,000 prize. (OfCercd for a perfect automatic train con- trol.) September 20, 1913 — The Necessary Engineer. January 2, 1915 — „ . ^ • Comment under title "A Tram hU,p that Works." April 28, 1917— . ^ ^. ,^,^ The Coming of the Automatic btop. From an editorial in the Railway Age Gazette, March 9, 1917, on the Mount Union collision. Locomotive Firemen and Englnemen's Mag- azine : December, 1911 — Demonstration of the Miller Train Con- trol System. July, 1916 — The Miller Train Control, by 0. G. Tripp. Lowe, Stanley B. : Stopping Trains from the Dispatcher's Office — Illustrated World, December, 1915. MacDonald System : Railroad Trains Guard Each Other, by Gardner Hunting — Technical World, September, 1913. Train Control — Edison Monthly, May, 1913. Macintosh, J. : Is the Safety Stop Practicable? Wireless System Successfully Tested on Cana- dian Pacific — Railroad Man's Magazine, April, 1913. McChord, C. C. : Commissioner McChord on Westport De- railment. Long crossovers demanded for all high speed trains. Railway called to account for neglecting auto- matic stop — Railway Age Gazette, December 13, 1913. McHenry, F. : The Automatic Railroad Stop — Scientific American, August 23, 1913. Mellen, Charles S. : The Truth, No. 3. (The Interstate Com- merce Commission and Automatic Train Stops) — Wall Street Journal, December 16, 1912. Mr. Mellen's $10,000 Prize. (Offered for a perfect automatic train control.) — Literary Digest, January 18, 1913. Mellen's Price. (Offered for an automatic safety stop.)— New York, New Haven & Hartford Railroad News, July, 1913. Miller Train Control : An Automatic Train Control — Railroad Man's Magazine, July, 1916. Automatic Train Stops on the Chicago & Eastern Illinois — Railway Age Gazette, November 27, 1914. A Train Stop That Works — Literary Digest, January 2, 1915. A Train Control That Works, by Joe Mitchell Chappie — National Magazine, July, 1916, Demonstration of the Miller Train Con- trol System — Locomotive Firemen and Enginemen's Magazine, December, 1911. The Most Important Invention of the Times, by Elbert Hubbard — Bast Aurora, N. Y., 1894. The Miller Automatic Train Stop — Railway Age Gazette, June 5, 1914, The Miller Train Control. What it Is and What it is Doing. The Train Control Securities Co. — Washington, D. C, 1916. MiUer : Recent Developments in the Miller Train Control — Railway Gazette, July 28, 1916. Train Stops on the Chicago & Eastern Illinois Railroad — Engineering News, October 8, 1914. The Miller Train Control, by O. G. Tripp — Locomotive Firemen and Enginemen's Magazine, July, 1910. Moulton, Robert H. : To Prevent Train Wrecks — Technical World, January, 1913. 60 ANNUAL REPORT DIEEGTOR GENERAL OF RAILROADS. National Magazine : July, 191G— A Train Control That Works, by Joe Mitchell Chappie. Now York, New Haven & Hartford Kail- road's Automatic Stop Prize — Conditions That Must Be Observed in the Competition for the $10,000 Award — Scientific American, January 18, 1913. Automatic Stop Competition — Scientific American, March 29, 1913. New York, New Haven & Hartford Rail- road Company's Automate Stop — Scientific American, July 19, 1913. New York, New Haven & Hartford Railroad News : July, 1913— President Mellen's Prize. (Offered for an automatic safety stop.) New York Times ; , April 23, 1911— Seeking an Invention to Prevent Rail- road Collisions. Interstate Com- merce Commission Makes Test on Staten Island of Young Texan's Device. Outlook : July 2G, 1913 — Incentive to Invention, by W. H. Dearden. Pacific Railway Club Proceedings : August, 1917 — Automatic Signaling and Automatic Stops on High Speed Electric Rail- ways, by E. E. Jones. Patterson : System of Electric Cab Signals and Auto- matic Stop, Patented by Frederick Patterson to Prevent Collisions — South African Railway Magazine, July, 1912. Poabody, J. A. : Automatic Control of Trains. Showing particularly the effect of automatic devices on the capacity o£ a road — Signal Engineer, 1913. Phillips : Phillips Automatic Train Stop — Railroad Gazette, May 31, 1907. The Raymond Phillips System of Train Control. Brief illustrated descrip- tion of this automatic train control system — Engineering, July 13, 1906. Prentice : Automatic Wireless Train Control. Dia- gram and description of the Prentice System — Engineer (London) August 29, 1913. The Perry-Prentice Wireless Signaling System, by H. Avery Blair — International Railway Congress Bulle- tin, August, 1909. Automatic Wireless Train Control, by F. C. Coleman. Prentice System — Scientific American, December 5, 1913. Is the Safety Stop Practicable ? Wireless system successfully tested on Cana- dian Pacific. By J. Macintosh — Railroadman's Magazine, April, 1913. Wireless Train Control, by Frank W. Prentice — Central Railway Club Official Proceed- ings, May, 1912. Prentice System of Wireless Train Con- trol on the Canadian Pacific Rail- road — Railway and Locomotive Engineering, February, 1911. The Prentice Wireless System of Auto- matic Train Control — Railwav News, August 23, 1913. Prentice Wireless Train Control. Illus- trated description of this invention for the automatic control of trains which has recently been tried on the Canadian Pacific Railroad — Canadian Engineer, February 23, 1911. Prentice Wireless Train Control — Railwav Age Gazette, June 23, 1911. Railroadman's Magazine : April, 1913 — „. Is the Safety Stop Practicable? Wire- less system successfully tested on Canadian Pacific, by J. Macintosh. October, 1917 — Mechanical Brains for Engines, by F. L. Farnsworth. July, 1916— An Automatic Train Control. The Mil- ler Train Control. Railroad Trainman : July, 1913— The Automatic Stop. Railroad Gazette : June 8, 1894 — The Kinsman Block System. August 10, 1894 — Rowell-Potter Automatic Signals on the Chicago & South Side. March 6, 1903 — A Discussion of the Inherent Difficul- ties in the Working of the Automatic Stop That Make Its Use Objection- able, by W. H. Elliott. May 31. 1907— Phillips Automatic Train Stop. Slarch 6, 1908— Signals and Automatic Train Stops in the Hudson & Manhattan Tunnel. Railroad Age Gazette : October 9, 1908 — Automatic Stops and Cab Signals. Railway Age Gazette : January 28, 1910 — The Rowell-Potter Safety Stop. May 5, 1911— Harrington Automatic Train Stop. May 19, 1911 — Mechanical Trip Automatic Stops. June 16, 1911— Waldron's Automatic Stop, by J. M. Waldron. A paper read before the Railway Signal Association, New York, June 14, 1911. June 23, 1911— Prentice Wireless Train Control. August 30, 1912 — . Automatic Train Control. September 20, 1912 — Summary of information concerning the principal automatic stops in use, with notes on some of the more re- cent experiments. September 27, 1912 — Automatic Stop or Cab Signal. December 27, 1912 — Automatic Stop Experiment on the Lackawanna. March 7, 1913— The Effect of Block Signals and Auto- matic Stops on Accidents, by A. G. Shaver. June 6, 1913 — The Automatic Train Control Problem. Some of the difficulties encountered in adapting automatic devices to miscellaneous railroad service, by A. H. Rudd. April 11, 1913 — October 10, 1913 — Automatic Stops and Audible Signals. December 13, 1913 — ■ Commissioner McChord on Westport Derailment. Lon^ crossovers de- manded for all high speed trains. Railway called to account for neglecting automatic stop. May 29, 1914— A. R. A. Report on Automatic Train Stops. June 5, 1914 — The Miller Automatic Train Stop. July 10, 17, 24, 1914— The Automatic Train Stop, I, II, III. October 9, 1914— Home & Crane's Automatic Stop. November 27, 1914 — Automatic Train Stops on the Chicago & Eastern Illinois. AUTOMATIC TRAIN CONTROL COMMITTEE. 51 Railway Age Gazette — Continued. Marcli 16, 191a — Tbe Juliau-Beggs Automatic Speed Control Apparatus. April 30, 1015— Two recent accidents at Devon and Ilford, and the necessity for auto- matic train control. June 25, 1915— The Julian Train Control and Auto- matic Stop. A description of the demonstration made on the Queen & Crescent and of the equipment re- quired. August 6, 1915 — The GoUos Automatic Stop. October 1. 1915 — Brownell's Automatic Stop. October 8, 1915 — Cab Signals and Automatic Stops on the Western Pacific. October 29, 1915 — Signal System and Automatic Stop on the Western Pacific at Oroville, Calif., criticized by M. Tainer. November 12, 1915 — Bupll's Cab Signal and Automatic Train Stop, by Joseph W. Buell. November 26, 1915 — The Cab Signals and Automatic Stops at Oroville, by F. F. Bostwiclc. March 21, 1916— Developments in the GoUos Automatic Train Control. March 21, 1916 — Improved Julian-Beggs Train Control. April 13, 1917— The Webb Automatic Train Stop. An automatic stop wliich tests its own integrity at every contact point and reports audiWy to enginemen. September 14, 1917— Wooding's Automatic Train Stop. A spring-supported contact rail, made movable to breals ice. November 9, 1917 — Wooding's Automatic Stop. July 19, 1918 — The Automatic Stop. Railway Gazette (London) : September 26, 1913 — The Detroit Automatic Train Control. November 12, 1915 — Julian Train Control and Automatic Stop. July 28, 191G— Recent Developments In the Miller Train Control. October 6, 1916 — Car Signals and Automatic Stops on the Western Pacific Railroad. November 17, 1916 — The Warmineter Collision and Auto- matic Train Control. March 30. 1917 — The Board of Trade and Automatic Train Control. May 18, 1917— More Thoughts on Automatic Train Control. May 25. 1917— Interstate Commerce Commission's An- nual Report on Automatic Train Control, 1917. June 22, 1917 — Biddle's Automatic Train Control. January 26, 1917 — Automatic Train Control Again. August 3, 1917— „ ^ „ . Automatic Train Control, Great East- ern Railway. November 2, 1917 — Wooding's Automatic Train Stop. Railway and Engineering Review. March 15. 1902— , ^, , Rowell-Potter Safety Stop and Block Signals on the Chicago, Milwaulcee & St. Paul Railway. Railway and Engineering Review — Contd. April 7, 1906— Address on Safety Appliances,, by B. C, Rowell. January 18, 1908 — Automatic Stops and Cab Signals. March 14, 1908— Signals and Automatic Train Stops in the Hudson Tunnels. October 17, 1908— Report of Railway Signal Association Committee VI for year 1908 — Auto- matic Stops and Cab Signals. November 7, 1908 — December 19, 1908 — Automatic Train Control, by George W. Ristine. November 28, 1908 — Automatic Train Control, by W. H. El- liott. December 26, 1908 — Trial of the Rowell-Potter Block Sig- nals and Automatic Stop. February 27, 1909— Automatic Train Stops, by Henry E. Bailey. May 1, 1909 — Official Inspection of Rowell-Potter Au- tomatic Train Control Apparatus. October 16, 1909 — 1909 Report of Railway Signal Asso- ciation Committee VI — Automatic Stops and Cab Signals. February 19, 1910— Block Signals and Safety Stops, by Henry E. Bailey. October 15, 1910 — 1910 Report of Railway Signal Asso- ciation Committee VI — Automatic Stops and Cab Signals. June 17, 1911 — Automatic Train Control. June 24, 1911 — Automatic Stop Device,- Interborough Rapid Transt Co., by J. M. Waldron. July 22, 1911— Automatic Safety Device Effective. October 28, 1911 — 1911 Report of Railway Signal Asso- ciation Committee VI — Automatic Stops and Cab Signals. March 30, 1912 — Carson-Burgess Cab Signal and Auto- matic Train Stop. August 17, 1912 — New System of Automatic Signaling and Automatic Train Stop, by O. O. Burge. Invention of A. R. Angus. October 26, 1912 — Test of the Gollos Automatic Train Stop, Chicago Great Western Rail- , way. January 4, 1913 — Automatic Control of Trains, by B. C. Rowell. February 8, 1913 — The Automatic Stop. Arguments Based on False Assumption. March 1, 191.3 — The Jones System of Automatic Train Control. Failure of an Automatic Stop on an English Railway. July 19, 1913— A. R. A. Report on Automatic Train Stops. Railway and Locomotive Engineering . February, 1911 — Prentice System of Wireless Train Control on the Canadian Pacific Railroad. May, 1917— Wooding Automatic Stop Signal and Speed Control. Description of the Apparatus. December, 1917 — Automatic Signals and the Automatic Stop. 52 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. Hallway Engineer : June, 1915 — General Discussion and Review oi: Auto- matic Train Control. Railway Engineering and Maintenance of Way: Novenvber, 1914 — Gray-Thurber System of Automatic Train Control as Applied to an Auto- matic Signal System. February, 1916 — Principles and Operation of Speed Con- trol Mechanism. Automatic Brake Application if Stop Indication is Overrun. Railway Master Mechanic : November, 1915 — The Automatic Stop Signal. Railway News : August 23, 1913 — The Prentice " Wireless " System of Automatic Train Control. March 7, 1914— March 21, 1914 — Cab Signals and Train Stops, by Wil- liam H. Dammond. .Tanuary 2, 1915 — ■ Signaling on Railway Trains in Mo- tion, by W. Wmox. Railway Record : November 23, 1912 — Automatic Train Control Safety Stop. Sketch of Development of Appliance. Estimated Cost of Equipping Exist- ing Railway with this Device. Railway Review: August 7, 1915 — Test of Gollos Automatic Stop System. April 22, 1916 — Automatic Stops. May 27, 1916— Test of the Jullan-Beggs Train Control Signal System. July 1, 1916- Progress with Automatic Train Control. September 9, 1916— Cost of Installation of Automatic Train Control in Connection with Auto- matic Block Signals, by A. G. Shaver. October 21, 1916 — Cost of Automatic Train Control, by C. E. Chatfield. February 17, 1917 — The Future of the Automatic Stop. April 14, 1917— British Report on Automatic Train Control. April 21, 1917— Trials of Automatic Train Control. Jlay 20, 1917 — Tlie Julian-Beggs Automatic Stop and Train Control System. March 9, 1918 — The Ruthven Electromagnetic Control System. October 5, 1918 — Automatic Stops Again Recommended. July 13, 1918— The Need of Development of Automatic Train Stops. January 18, 1919 — Train Control and Automatic Stop, by W. . I. Steel. Opinion of an En- gineer on the Chesapeake & Ohio. January IS, 1919— A National Automatic Train Control Board, Railway Signal Association : 1908 Report of Committee Yl — Auto- matic Stops and Cab Signals — Proceedings of the Railway Signal As- sociation, 1908. Railway and Engineering Review, Oc- tober 17, 1908. Railway Age Gazette, October 23, 1908. 1909 Report of Committee TI — Auto- matic. Stops and Cab Signals — Proceedings of the Railway Signal As- sociation, 1909. Railway Signal Association — Continued. 1909 Railway and Engineering Review, October 16, 1909. 1910 Report of Committee VI — Automatic Stops and Cab Signals — Proceedings of the Railway Signal As- sociation, 1910. Railway and Engineering Review, Oc- tober 15, 1910. 1911 Report of Committee VI — Automatic Stops and Cab Signals — Proceedings of the Railway Signal As- sociation, 1911. Railway and Engineering Review, Oc- tober 28, 1911. Developments of Automatic Train Con- trol Devices — Journal of the Railway Signal Associa- tion, twenty-third year, March, 1918. Railway Signal Engineer : May, 1917 — New Haven Tests Webb Automatic Stop. December, 1918 — The Shadle Automatic Train Signal and Stop. May, 1917 — The High Cost of Stopping Trains. Ristine. George W. : Attitude of Railroads to the Automatic Stop — Scientific American. January 25, 1913. Automatic Train Control — Railway and Engineering Review No- vember 7, 1908. Railway and Engineering Review, De- cember 19, 1908. Rowell-Potter Safety Stop : Block Signals and Safety Stops, by Henry E. Bailey. Railway and Engineering Review, February 19, 1910. Official Inspection of Rowell-Potter Auto- matic Train Control Apparatus. Railway and Engineering Review, May 1. 1909. The Rowell-Potter Safety Stop — Railway Age Gazette, January 28, 1910. Rowell-Potter Automatic Signals on the Chicago & South Side — Railroad Gazette, August 10, 1894. Rowell-Potter Safety Stop and Block Sig- nals on the C. M. & St. P. Railway — Railway and Engineering Review, March 15, 1002. Trial of the Rowell-Potter Block Signals and Automatic Stop^ Railway and Engineering Review, De- cember 26, 1908. The Rowell-Potter Safety Stop — 2nd Annual Report of the Block Sig- nal and Train Control Board, 1909. Rowel!, B. C. : Automatic Control of Trains — Railway and Engineering Review, January 4, 1913. The Automatic Stop. Arguments Based on False Assumption — Railway and Engineering Review, Feb- ruary 8. 1913. A Remedy for Railroad Accidents. Rowell-Potter Safety Stop — Iron Trail, November, 1905. Address on Safety Appliances — Railway and Engineering Review April 7, 1906. Rudd, A. H. : The Automatic Train Control Problem. Some of the difficulties encountered in adapting automatic devices to miscellaneous railroad service. Train Dispatcher's Bulletin, July, 1913. Railway Age Gazette, June 6, 1913. Truth Concerning Automatic Stops — Signal Engineer, June, 1913. A Safety Automatic Train Stop — Scientific American, May 3, 1913. AUTOMATIC TRAIN CONTROL COMMITTEE. 53 Huda, A. H. — Continued. Discussion of the Fourth Annual Report of the Board on Automatic Train Control — Scientific American, .Tanuary 18, 191.'1 The Need of an Automatic Stop — Scientific American, June 21, 1913. Kiithven : The Euthven Electromagnetic Control System — Railway Review, March 9, 1918. Schweyer ; Schweyer's Automatic Train Stop — Railway Age, June 21, 1918. Scientific American : Januai-y 8. 1910 — An Automatic Railway Stop adopted provisionally by the German Rail- road Administration. By Alfred Gradenwitz. July 20, 1912 — Human Fallibility and the Automatic Stop. December 28, 1912 — The Automatic Railroad Stop. January 18, 1913 — A Successful .Automatic Train Stop. A device which saves the train, reports disregard of signals, thereby stiffens discipline. January 18, 1913 — Discussion of the Fourth Annual Re- port of the Block Signal and Train Control Board. January 18, 1913 — Conditions that Must Be Observed in the Competition for the New York New Haven & Hartford Railway's Automatic Stop Prize. January 25, 1913^ Attitude of Railroads to the Automatic _ Stop, by George W. Rlstine. February 15, 1913 — Ideal Automatic Train Control, by Maximilian Weis. March 29. 1913 : New Haven Railroad Automatic Stop Competition. May 3, 1913 — A Safety Automatic Train Stop. June 21, 1913— The Need of an Automatic Stop. July 19, 1913— The Competition for the New York, New Haven & Hartford Railroad Company's Automatic Stop. August 23. 1913 — The Automatic Railroad Stop, by F. McHenry. September 20, 1913 — Adoption of the Jones System by the Maryland & Pennsylvania Railroad, by Calvin W. Hendrick. December 5, 1913 — Automatic Wireless Train Control, by F. C. Coleman. Prentice System. February 28, 1914 — Requirements of the Automatic Train Stop. August 28, 1915 — A New Type of Automatic Railroad Stop. (Brownell.) December 29, 1917 — Train Control ; Automatic Brake Oper- ation. Shaver, A. G. : The Effect of Block Signals and Auto- matic Stops on Accidents — Railway Age Gazette, March 7, 1913. Cost of Installation of Automatic Train Control in Connection with Auto- matic Block Signals — Railway Review, September 9, 1916. Shadle : The Shadle Automatic Train Signal and Stop — Railway Signal Engineer, December, 1918. Signal Engineer : 1913. Vol. 6 — Truth Concerning Automatic Stops, by A. H. Rudd. June, 1913 — Automatic Control of Trains, Dy J. A. Peabody. Showing particularly the effect of automatic devices on the capacity of a road. September, 1914 — Automatic Train Stops in France. May, 1915— 1915 Report of the Chief of the Divi- sion of Safety, Interstate Commerce Commission. Smith, Stephen : Cab Signals and Automatic Stops. Julian- Beggs System — Richmond Railroad Club Proceedings, May 15, 1916. Address and Explanation of Julian-Beggs Automatic Stop and Train Control System — Cincinnati Railway Club Proceedings, February, 1917. South African Railway Magazine : July, 1912— System of Electric Cab Signals and Automatic Stops to Prevent Colli- sions, patented by Frederick Patter- son. Technical World : October, 1909 — Making Collisions Impossible, by S. S. Carlyle. The Lacroix Cab Signal and Automatic Stop. January, 1913 — To Prevent Train Wrecks, by Robert H. Moulton. March, 1913- When the Engineer Forgets, by Charles F. Carter. September, 1913 — Railroad Trains Guard Each Other. MacDonald System of Train Con- trol. By Gardner Hunting. October, 1915— Hands Off the Throttle, by Harold Cary. Tainer M. ; Signal System and Automatic Stop on, the Western Pacific at Oroville, Calif., Criticised — Railway Age Gazette, October 29, 1915. The Train Control Securities Company : The Miller Train Control — what It Is and what it Is doing — Washington, D. C, 1916. Times Engineering Supplement : March 30, 1917 — Automatic Train Control. Tripp, O. G. : The Miller Train Control. — ■ Locomotive Firemen and Enginemen's Magazine, July, 1916. Waldron, J. M. : Waldron's Automatic Stop. A paper read before the Railway Signal As- sociation, New York, June 14, 1911 — Railway Age Gazette, June 16, 1911. Automatic Stop Device, Interborough Rapid Transit Company — Railway and Engineering Review, June 24, 1911. Wall Street Journal : December 16. 1912 — The Truth No. 3. (The Interstate Commerce Commission and Auto- matic Train Stops.) By Charles S. Mellen. Webb : New Haven Teats Webb Automatic Stop — Railway Signal Engineer, May, 191'7 The Webb Automatic Train Stop. An automatic stop which tests its own integrity at every contact point and reports audibly to enginemen — Railway Age Gazette, April 13, 1917. 54 ANNUAL REPORT DIRECTOR GENERAL OF RAILROADS. Weis, Maxmilian : Ideal Automatic Train Control — Scientific American, February 15, 1913. Willox, W. : Signaling on Railway Trains in Motion — Railway News, January 2, 1915. Wilson, I-I. Raynor : British Opinion on Railway Automatic Stops — Engineering News, January 30;-1913. Collision in a London Subway. Failure of an Automatic Stop. Railway and Engineering Review, February 22, 1913— Engineering News, March 6, 1913. Wooding ; Report of tests of the Wooding train control system conducted by the Dl- ylslon of Safety, on the Delaware, Lackawanna & Western Railroad, January to April, 1917. House Document 251, 65th Congress, 1st Session. Wooding — Continued. Report of tests of the Wooding ti-aln control system, etc. — Continued. Railway Signal Engineer, October, 1917. Wooding's Automatic Stop : Railway Age Gazette, November 9, 1917. Wooding's Automatic Stop Signal and Speed Control. Description of the Apparatus — ■ Railway and Locomotive Engineering, May, 1917. Wooding's Automatic Train Stop. A sprmg-supported contact rail made movable to break Ice — Railway Age Gazette, September 14, 1917. Wooding's Automatic Train Stop- Railway Gazette, November 2, 1917. Work, Leonard : The Future of the Automatic Stoi) — Railway Review, February 17, 1917, o Date Due m PRINTED IN U. S. A. CORNELL UNIVERSITY LIBRA Y 3 1924 062 246 040 2.708 .R3