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BOUGHT WITH THE INCOME 
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 1891 
 
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Cornell University Library 
 TF 420.S99 
 
 Evolution of the air-brake.A brief but c 
 
 3 1924 022 793 818 
 
The original of tliis book is in 
 tlie Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924022793818 
 
EVOLUTION 
 
 OF THE 
 
 JVir-Brakk 
 
 A BRIEF BUT, COMPREHENSIVE HISTORY 
 
 OF THE 
 
 DEVELOPMENT OF THE MODERN. RAILROAD BRAKE, FROM THE EARLIEST CONCEPTION 
 
 CONTAINED IN THE SIMPLE LEVER, UP TO, AND INCLUDING, THE 
 
 MOST APPROVED FORMS OP THE PRESENT DAY. 
 
 PAUL |YNNESTVEDT 
 
 Author of "Diseases of the Air Brake System.' 
 
 PUBLISHED BY 
 
 'LOCOMOTIVE ENGINEERING" 
 256 Broadway, New York 
 
 1895 
 
Copyright, 1895 
 
 By PAUIj SYNNESTVEDT 
 
 all rights reserved 
 
PREFACE. 
 
 Upwards of two years ago the author of this book began the 
 publication, in the "Railway Engineering and Mechanics," of a 
 series of articles treating of the history of the railroad brake. Favor- 
 able comment from many readers has encouraged him to believe that 
 the subject is of sufficient interest to warrant the preservation of the 
 matter contained in the articles referred to in a more permanent 
 form. It has therefore been revised and corrected; and, together 
 with some additional material, brought together to form the basis of 
 this work. 
 
 To the author himself, the labor involved in collecting and arrang- 
 ing the data contained in these pages, has proven of great benefit in 
 aiding him to secure a clear and comprehensive knowledge of the art 
 of which he treats; and it is his sincere hope, that, to the reader as 
 well, this record of the past will prove of practical value. 
 
 Paul Synnestvedt. 
 Chicago, 1895.-126. 
 
 (3) 
 
CONTENTS. 
 
 Page 
 
 Introductory : 7 
 
 Power Brakes in Generai, 12 
 
 Compressed Air Brake 26 
 
 Hose Coupling 31 
 
 Air Pump 37 
 
 Governor : 51 
 
 Engineer's Vai^vb 62 
 
 Equalizixg Discharge Valve 67 
 
 Triple Valve 75 
 
 Quick Action Brakes ' 83 
 
 Wenger Brake 91 
 
 Quick Action Brakes (Continued) . .' 98 
 
 (4) 
 
LIST OF ILLUSTRATIONS. 
 
 Pig. Page 
 
 1. Early Lever Brake 8 
 
 2. "Le Caan" Brake 8 
 
 3. Modified Lever Brake 9 
 
 4. Example of Improper Leverage. 9 
 
 5. Defective Lever Brake 10 
 
 G. Stevenson Driver Brake 11 
 
 7. Steam Driver Brake , 12 
 
 7'/. Loughridge Chain Brake 13 
 
 8. Hydraulic Brake ^ IG 
 
 9.. Eames Vacuum Brake 17 
 
 10. Eames Ejector 18 
 
 11. Eames Ejector 19 
 
 12. English Vacuum Brake 20 
 
 13. English Vacuum Brake 20 
 
 14. Sanders Vacuum Brake 22 
 
 15. Vacuum Brake used at Burlington 23 
 
 16. Vacuum Valve used at Burlington 24 
 
 17. Westinghouse Straight Air Brake 26 
 
 18. First Auxiliary Eeservoir 29 
 
 19. Automatic Brake with Triple Valve 29 
 
 20. First Westinghouse Triple Valve 29 
 
 21. Early Westinghouse Coupling 31 
 
 22. Modified Westinghouse Coupling 32 
 
 23. Original Form of Present Coupling 32 
 
 24. Flat Back Coupling 33 
 
 25. Jackson Coupling 33 
 
 26. Beery Coupling 34 
 
 27. Eames Vacuum Coupling 34 
 
 28. Welsh Coupling Cover 35 
 
 29. Westinghouse Combined Coupler and Valve 33 
 
 30. Modified Westinghouse Coupling and Valve 36 
 
 31. Harris Automatic Coupling 30 
 
 32. First Westinghouse Pump 37 
 
 33and34. Details of Westinghouse Pump 39 
 
 35. Improvement in Westinghouse Keversing Gear 40 
 
 36. Second Improvement in Westinghouse Eevqrsing Gear 41 
 
 37. Third Improvement in Westinghouse Reversing Gear 42 
 
 38. Westinghouse Old Style Standard Pump 43' 
 
 39. Westinghouse Latest Design Standard Pump 45 
 
 40. Barrett Valve Motion 45 
 
 41. Cameron Pump...". 45 
 
 42. Harlow Pump Head 46 
 
 43. Boyden Pump - 47 
 
 44. Lansberg Pump -. — 48 
 
 440. New York Pump 49 
 
 45. Breitenstein Pump 50 
 
 (5) 
 
Fig. Page 
 46 and 47. Illustrative Governor 52 
 
 48. First Westingliouse Governor 53 
 
 49. Second Westinghouse Governor 55 
 
 50. Third Westinghouse Governor 56 
 
 .'^1. Double 'Westinghouse Governor 57 
 
 52. Boyden Governor 58 
 
 53. New'York Governor 59 
 
 54. Westinghouse Improved Governor 60 
 
 55. Mason Eegulator 61 
 
 56. Three Way Coek V 62 
 
 57. Westinghouse 1879 Sngine Valve 63 
 
 58. Paradise Engineer's Valve 64 
 
 59. Independent Driver Brake Valve 65 
 
 60. Cosgrove Engineer's Valve ".. ; . . .66 
 
 61. First Westinghouse Equalizing Valve i 68 
 
 62. 1889 Westinghouse Eaualizing Valvo.... 69 
 
 63. Boyden Eau.alizing Valve 70 
 
 64. Massey Eqiializing Valve 71 
 
 65. New York Eaualizing Valve .' 72 
 
 66. Vaughn & MoKee Eaualizing Valve 73 
 
 67. Howard Eaualizing Valve ..! 74 
 
 68. 1873 Westinghouse Triple Valve 76 
 
 69. Perkins Triple Valve 77 
 
 70. Westinghouse 1875 Triple Valve 78 
 
 71. Prince Automatio Brake gO 
 
 72. Westinghouse Standard Plain Triple ' gi 
 
 73. Westinghouse '87 Quick-Action Triple 84 
 
 74. Ford & Welsh Belief Valve 86 
 
 75. Sanders Belief Valve 87 
 
 76. Westinghouse '79 Belief Valve .'. . . 88 
 
 77. Westinghouse '81 Belief Valve 88 
 
 78. Boyden 1883 Triple 89 
 
 79. Fives' Lille Brake 92 
 
 80. Duval Begulator ^4 
 
 81. Duval Begulator and Triple -. 96 
 
 82. Westinghouse Standard Quick Action Triple 98 
 
 83. Westinghouse Independent Quick Action Valve 99 
 
 84. New York Quick Action Valve No. 1 100 
 
 85. New York Quick Action Valve No. 2 101 
 
 86. New York Quick Action Valve No. 3 102 
 
 87. New York Quick Action Valve No. 4 ^ 102 
 
 88. Boyden Quick Action Valve No. 1. v ■ 103 
 
 89. Boyden Quick Action Valve No. 2 .io5 
 
 90. Crane Quick Action Valve 105 
 
 91. Lansberg Quick Action Valve No. 1 , 106 
 
 92. Lansberg Quick Action Valve No. 2 107 
 
 93. Haberkorn Quick Action Valve ~ 108 
 
 94. Dixon Quick Action Valve 109 
 
 95. Park Quick Action Valve 110 
 
 96. Howe Quick Action Valve Ill 
 
 (6) 
 
EVOLUTION or TME AIR 
 /BRAKE. 
 
 INTRODUCTORY. 
 
 It is easy to conceive that with the invention of wheeled vehicles, 
 there was felt the necessity of a brake to stop them in cases of en-er- 
 gency, and that this need became greater as the running gear of such 
 vehicles was perfected and friction eliminated. But with the intro- 
 duction of the tramway and steam railway the brake became an 
 absolute necessity, and its importance has grown with the develop- 
 ment of the railway and the increased speed arid weight of the trains 
 hauled, until at the present day there is hardly a part of the rolling 
 stock equipment which is deserving of more care and study than the 
 brake. The evolution of the railway brake therefor^ becomes a mat- 
 ter of unusual interest at the present day, and in the pages of this book 
 its progress and development will be briefly outlined. 
 
 In no place or manner has the early history of the railway brake 
 been more perfectly portrayed than in the " world's railway '.' exhibit 
 of the Baltimore & Ohio Railroad at the World's Columbian "Exposi- 
 tion. A long line of drawings, illustrative of the above subject, 
 proved an interesting and 'instructive collection to anyone at all 
 familiar with such things, and the author made free-hand sketches of a 
 number of them, a few of which are here reproduced. 
 
Evoi,u*ioN oi* THB Air BraKE. 
 
 FiG.l - EABIiY LBVEB BBAKE (1630). 
 
 Fig. 1 was the first one in the set and is about as simple a form of 
 brake as could possibly be designed. There is nothing to it in fact 
 except a single wooden lever, pivoted at one end to the body of the 
 car and supported at the other by a short chain-. This chain was 
 slipped off the end of the lever and a downward pressure exerted 
 when it was desired to bring the brake into action. Here is an excel- 
 lent lesson in simplicity for designers of brakes at the present day. 
 Shoe, beam, tie rod, lever and cylinder are all in one, and a little 
 muscle is all that is necessary to bring them into operation. Attention 
 is called to the fact that the lever, practically as it is used most gen- 
 erally to-day, was used in this brake of 1630, the fulcrum at one end, 
 the shoe in the middle, and the power at the other end. 
 
 Fig. 2— "Le Caan" Brake (1796.) 
 Fig. 2 shows what is called the " Le Caan" brake, which was used 
 in England about 1796. It was attached to a kind of road cart and 
 as will be clearly seen by a glance at the cut, was put into operation 
 
Evolution o? fHE Air Brake. 
 
 9 
 
 automatically. By merely droppirtg the shafts the point of the curved 
 arm wedged itself in between the wheel and the -ground. The author 
 must confess to not having had any experience with such a brake, but 
 is inclined to think it must have befen very -effective. 
 
 Fig. 3— MoDiriED Lbvek Bkake. 
 
 Fig. 3 shows what might be called a modified form of the device 
 shown in Fig. 1 , with the diflference that it has shoes applied to both 
 wheels instead of one. 
 
 Fig. 4— Example op Impkopek Letekage. 
 
 Fig. 4 shows a wooden lever brake used in England, but this lever 
 was not pivoted to the car at all, what might be called the fulcrum 
 
16 
 
 EvotuTiON OF THE Air Brake. 
 
 point bearing against one of the wheels and. the power point against 
 the other. , This is a very good sample of unequal braking power, or a 
 poorly equalized brake, as the wheel to the right in the cut evidently 
 has to stand more pressure than the other. It seems a remarkable 
 fact that this same mistake has been repeated hundreds, perhaps 
 thousands of times in designs made since this style of brake was in 
 use. Every brake which has no dead lever on one end of the truck is 
 just as faulty in construction as this one. 
 
 Fig. 5— Defective Fobm or,LEVEK Bkake. ' 
 
 Fig. 5 shows still another lever brake which, while it looks as if it 
 might be very effective, contains also a mistake which has been 
 repeated innumerable times in modern construction. It is that of 
 placing two weight points on the same lever, one on each side of the 
 fulcrum. If one shoe has a little more slack than the other the one 
 that has the least will receive nearly all the braking force while the 
 other gets little or nothing. Without compensating devices of some 
 kind (springs or equalizers) a lever can no more act properly with two 
 weight points than it can with two. fulcra. Any one can see that with 
 two fixed points in a lever any movement is impossible. 
 
 Fig. 6, the last cut shown, is jjerhaps to railroad men the most 
 interesting. It contains all the elements of the present driver 
 brake ; cylinder, toggle-joint and suspension links. This is the first 
 power brake shown in this set and was operated by steam from a valve 
 near the dome. Attention is called to the- fact that the method of 
 arranging the cylinder made it unnecessary to use any stuffing 
 box around the piston rod, one of the great points of the present push- 
 
Evolution of the Air Brake. 
 
 11 
 
 down brake. The fact that this brake was used on one side of the en- 
 gine only was of course a great objection, as it must have produced a 
 
 Fig. 6— Stephenson Dkivek Brake (1833). 
 
 very severe torsional strain on the driving axles. But there is much food 
 'for reflection in the fact that as early as 1833 Stephenson had in use a 
 driver brake so nearly like the best practice of the present day. 
 
12 
 
 Evolution of the Air ^RAk^. 
 
 POWER BRAKES IN GENERAL. 
 
 Stephenson's driver brake, shown in Fig. 6, serves very appropriately 
 to introduce the subject which, in a general way, we shall consider 
 next, namely, the early forms of the power brake. These were many 
 in number and of great variety. Among them may l)e mentioned 
 steam brakes, chain brakes, hydraulic brakes, vacuum brakes, and a 
 number of primitive air brakes 
 
 FiG.7— Steam Dbiveb Brake. 
 
Evoi,uTioN OF THE Air Brake. 
 
 13 
 
 STEAM BRAKES. 
 
 The steam brake for obvious reasons made practically no headway 
 at all beyond its use on the engine and tender. In this limited field, 
 however, it has been and is at present extensively used on account of 
 its simplicity, requiring only the cylinder and the operating valve. 
 One of the earlier arrangements of it is shown in Fig. 7. The objec- 
 tions to it are the liability to freeze, and the escape of steam from 
 leakage obscuring the view of the engineer in very cold weather. 
 
 BUFFER BRAKE. 
 
 There were a number of different forms of this brake designed 
 during the period when air was coming into general favor, all depend- 
 ent for their operation on the strains on the draw-bars, but as this 
 style of brake became most prominent at the Burlington brake tests 
 in 1886, we shall treat of it more fully in that connection. 
 
 ^•-fV. f B 
 
 H ^•C^./e-M^/y.»...n 
 
 . rf 
 
 *c 
 
 Fig. 7a— Loughkidge Chain Bbakb. 
 chain brakks. 
 
 One of the best known of these was the " Loughridge " which 
 was in actual use on, a number of roads for some time, just about 
 the period when " air " was in its infancy. This form of brake, or a. 
 modification of it, is still in service on some street car lines, on 
 trains jDf two or three cars (notably on some of the large cable 
 systems). 
 
 As the name indicates, a chain was utilized in the transfer of 
 power, there being chain connections between the cars. We illustrate 
 it in Fig. 7a, quoting a description written by W. de Sanno, of 
 Indianapolis. 
 
14 EvoiiUTiON OF THE Air Brakb. 
 
 "There was a frictioH wheel or sheave like A, Figs. 1 and 2, on a 
 three inch shaft, B\ this shaft was hung in hangers, one of which 
 swung loose. This loose hanger was connected to a lever passing up 
 through the foot board and in such a position as to be easily handled 
 by the engineer. To apply the brake the lever was pulled back, 
 which brought the friction wheel A in contact with the driving 
 wheel flange on the right side of the engine; this would revolve the 
 shaft B and wind up the chain. Under the center of each car was 
 the frame D swinging on the pivot E. Running loose in the frame 
 D were the two sheaves F -F. The chain was the length of the 
 train, but the end of it was secured to the back end of the rear coach. 
 When the brake was applied, in winding around the shaft the 
 tendency of the chain was to assume a straight line, and in doing so 
 it would swing the frame D around in the direction of the arrows, 
 which in turn would pull on the two rods H H which were connected ■ 
 to the brake leverS. By the time the brakes were set (and it was 
 quick) about all the chain belonging to the first car would be wound 
 around the shaft. On the shaft B was a ratchet wheel and dog or 
 pawl that would hold the. brakes- set. The lever spoken of set the 
 brakes and the ratchet held them set; but the contact between the 
 friction wheel and flange was controlled by a weighted bell crank also 
 under the foot board. If the tension of the chain became too severe 
 it would pull the friction, wheel away from the flange by overcoming 
 the weight on the bell crank. To release the brake the engineefr 
 would raise the pawl from the ratchet and throw the lever forward, 
 when the chain would unwind. One great trouble with this brake 
 was the friction wheel would get flat spots cut in it by the flange." 
 
 The Clark chain brake was another form of this idea which was 
 tried very persistently in England. It was automatic, being arranged 
 so that it would apply in case of a separation of the train. 
 
 To accomplish this it was made so that a constant tension on the 
 chain held the brakes off and a relaxation of this tension caused them 
 to set from force stored in compressed springs. Concerning this 
 brake, Mr. Reynolds, in a work published in England in 1882, on 
 " Continuous Railway Brakes," makes th e following criticism: 
 
 "It has the great defects of all chain brakes: 1. That it can only 
 be used on short trains, or portions of trains, so that it is practically a 
 sectional brake rather than a continuous brake. 2. The action can- 
 not be controlled; that is to say, when applied, the action is in full 
 
Evoi,uTiON OF THE Air Brake. 15 
 
 force, because the friction between the pulleys cannot be graduated. 
 On account of this, chain brakes will at all times be very rough 
 brakes. 3. It is influenced by changes in the weather, and it very 
 commonly happens that drums and pulleys' become coated with ice in 
 winter. The friction pulleys, under such circumstances, lose their 
 grip entirely, and the brake is rendered powerless. 4. It not infre- 
 quently happens that in winter the chain gets frozen fast on its 
 guiding pulleys. In this'case, the brakes cannot be either applied to 
 or taken off the wheels. 
 
 " It may be added that the chain brake is very old, and that it has 
 been tried more than any other brake." 
 
 Hydraulic Brakes. 
 
 Classed under this head are all those brakes which were worked by 
 any liquid stored under pressure in an accumulator. One of the 
 forms is shown in part in Fig. 8. 
 
 Most of them were operated by a continuous pipe carried along 
 the train, with cylinders for applying the force under the cars. The 
 pressure was generally obtained by a direct acting steam pump on the 
 engine; and in the cases of those which were automatic water under 
 pressure was stored in receptacles under the cars. On a separation 
 of the train and consequent disconnection of the pipe, those of the 
 automatic class would set in a manner quite similar to the automatic 
 air brake, the stored water being forced into the brake cylinders by 
 springs. Several modifications, some of them very elaborate, were 
 made of this general principle, but none were ever perfected so as 
 to be satisfactory in practice. 
 
 Lack of compressibility, and susceptibility to cold are the charac- 
 teristics which form the main objections to the use of liquids in the 
 operation of train brakes. 
 
 VACUUM BRAKES. 
 
 There are two general forms of this brake, the plain vacuum, and 
 the automatic vacuum. Both have been and in some places are now 
 extensively used. In fact the vacuum brake is the only form of train 
 brake which can be considered in any sense a competitor of the com- 
 pressed air brake. The plain and the automatic vacuum have each a 
 distinct field of usefulness. In service similar to that on elevated 
 roads, where the trains are short and the stops frequent, the plain 
 
«, 
 
 Q 
 1 
 
 1^ 
 
EVOI.UTION OF THE Air Brakb. 
 
 17 
 
 brake has given great satisfaction, having the very strong recommen- 
 dation of simplicity, while on trains of moderate length and light 
 cars the automatic vacuum has had many admirers because of two 
 advantages which it possesses over the automatic air brake. There 
 are possibilities of accurately graduating the release as well as the 
 application, in other words making a partial release; and second, the 
 
 Fig. 9-Eames Vacuum Bkake, Engine and Tendeb. 
 
 fact that repeated applications in rapid succession do not reduce the 
 available braking force in the auxiliary reservoir, except of course 
 what little may be lost by leakage. 
 
 , Fig 9 shows the application of the Eames plain vacuum brake to 
 ?in engine and tender. It comprises the following parts: An ejector 
 
18 Evoi<uTioN OF THE -Air Brake. 
 
 ■for producing the vacuum; a continuous line of pipe; couplings 
 between the cars; and diaphragms, (generally substituted for cylinders 
 as a means of applying the force.) 
 
 Outside and sectional views of the ejector are given in figures 10 
 and 1 1 respectively. This is similar in construction to an injector, with 
 
 Fio; 10.— Eames Ejectok. 
 
 the difference that instead of the flow of the steajn through the cones 
 acting to draw water from the tank and force it into the boiler, it 
 operates to draw the air out of the train pipe, the-eby applying the 
 brake. By simply re-admitting the atmospheric pressure the brake 
 is released. 
 
Evolution of the Air Brake. 
 
 19 
 
 Fig. 11— Eames Ejeotok. 
 
 With this form of brake the parting of a train has no efifect and 
 the engine is the only place where it can be applied. When the 
 ejector is put into operation it must take air fi-om the entire train pipe 
 and all the diaphragms to set the brakes, This it does readily in 
 short trains, and this brake has a remarkable record of efficiency and 
 freedom from accident on the elevated roads of New York and 
 Brooklyn. 
 
 AUTOMATIC VACUUM BRAKE. 
 
 \ 
 
 This was a natural outgrowth from the plain vacuum, and most of 
 the earlier forms were exceedingly simple. Nearly all of them 
 
20 
 
 Evoi,uTiON OP THE Air Brake. 
 
 employed diaphragms or pistons having air tight chambers on both 
 sides and mechanism so arranged that when, the vacuum in the pipe 
 (which was maintained constantly while running ) was . destroyed by 
 the adinission of air from the atmosphere, this air so admitted entered 
 the chamber on one side of the diaphragm, but was prevented from 
 entering the chamber on the other side. This of course moved the 
 diaphragm, with the force of the atmospheric pressure admitted, 
 
 \Pvll roi' 
 
 Fig. 12— English Vacuum Beake.— Fig. 13. 
 
 towards the chamber in which the vacuum was still maintained, 
 and so applied the brakes. The pressure was removed by drawing 
 the air out of the pipes again with the ejector. 
 
 ENGLISH VACUUM. 
 
 One form of this general type of brake which is still extensively 
 used in England, was exhibited at the fair and is shown in Figs. 12 and 
 13. The train pipe is indicated by A, the cylinder by Z>, the piston by 
 C, and the piston rod by £. The piston rod is large in diameter, 
 hollow, and attached rigidly to the floor of the car. The cylinder £>, 
 is attached to the brake lever, jE, and moves up and down on the 
 piston as the brakes are operated. Both the cylinder and piston are 
 of pressed steel, and very light. A release valve, /^, is provided for 
 releasing the brakes by hand when necessary. The piston packing is 
 rubber and so attached to the piston that air pressure admitted above 
 the -piston forces the packing out in contact with the cylinder and 
 
Evoi,uTioN OF THE Air Brakb. 21 
 
 shuts off communication with the lower side of the piston. Air 
 admitted below the piston easily pushes past the packing and passes 
 to the upper side. When the train is running a vacuum exists in the 
 train pipe, and also on both sides of the piston; the cylinder of its 
 own weight takes the position shown in Fig. 12. When the brakes are 
 to be applied, atmospheric pressure is admitted to the train pipe, A, 
 whereupon it passes through the piston rod B, into the space above 
 the piston, C, "and forces the cylinder up into the position shown in 
 Fig. 13, applying the brakes through the lever E. Gages are placed 
 on the engine and also in the guards' compartments, and the instruc- 
 tions are that when the trains are running they shall show not less 
 than 20 nor more than 25 inches of vacuum. In order to apply the 
 brakes simultaneously on all wheels a valve or brake setter is pro- , 
 vided in each guards' compartment, so constructed that any sud- 
 den increase of pressure in the train pipe wil instantly cause the valve 
 to open automatically and admit a supply of air, after which it closes 
 again by its own weight. A handle is attached to this brake setter, 
 by the use of which the guard ,can, in case of emergency, apply the 
 brakes to the entire train. 
 
 The engine equipment comprises an air pump attached to the 
 cross-head for maintaining the vacuum while the train is in motion, 
 and a combined ejector and engineer's valve. This device has several 
 offices to perform, all controlled by one lever. One position of this 
 lever puts into operation a steam ejector which creates a vacuum in 
 the train pipe and cylinders before the train starts. Another position 
 of the lever admits air to the train pipe and at the same time admits 
 steam to the cylinders of the steam brake. When the brakes are to 
 be released, a movement of the handle will throw the ejector into 
 action if the train is at rest. If not, the vacuum is created by the air 
 pump. The cylinder of this pump is five inches in diameter, and the 
 stroke coincides with that of the locomotive piston. 
 
 SANDER'S Vacuum. 
 
 Fig. 14 illustrates an automatic vacuum brake patented in 1879. 
 It was very similar to the one just described, but embodies, in a form 
 better suited to purposes of illustration, the idea spoken of above, 
 that of making the application of the brakes throughout the train as 
 nearly simultaneous as possible, by the automatic opening of a local 
 admission valve under each car, whereby atmospheric pressure gained 
 
22 Evolution of the Air Brake. 
 
 entrance to the train pipe at or near each cylinder in turn, when a 
 quantity of air was admitted at the engineer's valve. 
 
 The operation of this device is aS'- follows: When the vacuum is 
 equal on both sides of the piston a, it is forced inwards into the posi- 
 tion represented, by the pressure of the atmosphere acting on the 
 closed and external end of the piston rod b. In this position the 
 brakes are held out of action. On the admission of air into the con- 
 tinuous pipe on the train and to the non-piston rod side of the piston 
 a, for the purpose of applying the brakes, the piston moves outwards 
 
 Fio. 14— Sandee's Vacuum (1879.) 
 
 and the valve e is opened by the action of the enlarged end g-2 of the 
 rod g on the lever e-z of the said valve e. A sudden inrush of air then 
 takes place and the brakes are rapidly applied by the vacuum, which 
 is retained on the other side of the piston and in the reservoir by the 
 check value p. 
 
 AUTOMATIC VACUUM BRAKE USED AT BURWNGTON. 
 
 Fig. 15 shows the general arrangement of the Eames automatic 
 vacuum brake tested at. Burlington in 1886. It required the use of a 
 
Evolution op the Air Brake. 
 
 23 
 
24 
 
 Evoi<uTioN OF THE Air Brakb. 
 
 double ejector, and in addition to the other parts used with the plain- 
 vacuum it comprised a storage reservoir of some kind under each car, 
 in which the force of a constant vacuum could be maintained, and a 
 valve, corresponding to the triple in the compressed air brake The 
 double ejector was simply a combination of a latge ejector for exhaust- 
 ing the air from the train rapidly, and a small ejector for maintaining 
 a constant vacuum throughout the apparatus while running. 
 
 Fig. 16 is a sectional view of the valve which takes the place of 
 
 Fig. 16.- 
 
 -AuTOMATiC Vacuum Conteolling VAiVE Used in Buklington 
 Tests in 1886T 
 
 the triple in the compressed air brake. The valve is placed between 
 the diaphragms and the reservoir, the reservoir being exhausted 
 through it. Its functions are to control the passage of air from the 
 bJake diaphragms to the reservoir, and partially or wholly apply the' 
 brakes; also to admit air to the brake diaphragms, and partially or 
 wholly release the brakes. This is accomplished by the valves M and 
 
Evoi,u*ioN OF THE Air Brake. ^5 
 
 L. These valves are moved by the bell crank levers shown in the cut, 
 which are controlled by the flexible diaphragms F and TV connected 
 with them by links. 
 
 Amongst other'kinds of vacuum brake maSe and tested at different 
 times may be mentioned Smith's, Hardy's and Aspinall's, but in spite 
 of the fact of there being so many different forms, the same general 
 principle obtains in them all. 
 
 None of them have been made to fully meet the requirements of 
 railway se.vice where very long trains and heavy cars are used. The 
 greatest force that can be c btained with a vacuum is necessarily limi- 
 ted to less than atmospheric pressure (abotit 15 pounds), so that to get 
 a total piston power equivalent to that of the compressed air brake 
 (which averages 70 pounds) necessitates the use of proportionately 
 larger apparatus in every part or an abnormal increase of power 
 through levers. The first alternative makes the vacuum brake fully 
 twice as heavy, and the second makes frequent adjustment of slack 
 necessary. The vacuum brake is also slower in application, and, as 
 will be seen in a subsequent chapter, produces in consequence very 
 violent shocks on the rear of long trains. 
 
26 
 
 Evolution of the Air Brake. 
 
 COMPRESSED AIR BRAKE. 
 
 From the manifest uncertainty or insufficiency of the apparatus 
 previously described, it would seem to us now sis if the whole railroad 
 world would have turned with eagerness to anything which promised 
 better sjrvice, and welcomed it with outstretched arms. Such was 
 not the case, however. The early days of the air brake afford a strik- 
 ing record of a hard struggle for recognition, and some roads did not 
 adopt it until years after it had been proven to be a pronounced 
 success. 
 
 The first form of air brake put into successful operation was what 
 is known as the " straight air " brake. In service the operation was 
 as follows: 
 
 Air compressed by the pump was stored in the reservoir under the 
 engine. When it was desired to set the brake, the engineer's valve 
 
 jh5 u-^^^j;^ h-i« 
 
 Fig. 17— Westinghouse Straight Aie Brake. 
 
 was turned so as to allow the air from the drum to go back through 
 the pipe and fill the cylinders under the cars, forcing out the pistons, 
 which through the levers and rods brought the shoes against the 
 wheels. To release the brake, the handle of the engineer's valve 
 was turned so as to cut off the supply of air from the drum to the train 
 pipe, and allow the pressure in the. train pipe and cylinders to escape 
 to the atmosphere. 
 
 WESTINGHOUSE STRAIGHT AIR BRAKE. 
 
 Mr. Geo. Westinghouse, Jr., was the first inventor to make this 
 brake a practical success. The foundation patent on it was issfied 
 
Evolution of the Air Brake. 27 
 
 April 13, 1869, and re-issued July 29, 1873. Fig. 17 is a general view 
 of the apparatus shown in this patent. The main drum is marked d, 
 the engineer's valve k, the train pipe i, and the cylinder under the car 
 m. The pump, c, it will be noticed, had three cylinders, one for 
 steam, one for pumping the air, and the third for supplying water to 
 the boiler. By this it will be seen that the air brake antedated the vise 
 of the injector. The specification of this patent dwells very emphat- 
 icallyon the advantages of being able to pump up the boiler without 
 the necssity of cutting the engine loose from the train and running it 
 back and forth. 
 
 From a catalogue issued in 1872 I have taken the following inter- 
 esting items, testifying to the remarkable efficiency of this pioneer air 
 brake, though it is to be noted that the results given were taken from 
 trials with short trains. 
 
 At Chicago, November 26, 1869, tests were made on the C. & N. 
 W. Railway, with the following results: A train of six cars running 
 at the rate of 32 miles per hour was stopped in 19 seconds, or seven 
 car lengths. The same train at a speed of nearly 40 miles was stopped 
 in 10 seconds, running a distance of only 370 feet. 
 
 At Altoona a train of six cars was stopped in less than its own 
 length, in 1 1 seconds, from a speed of about 30 miles per hour. An- 
 other train on the P. R. R. running at a speed of 45 miles per hour, 
 was suddenly flagged and brought up in nine car lengths. 
 
 Although this brake was such a great step in advance over the 
 chain brakes and similar devices used in the early days, it lacked 
 several of the elements which are essential to a perfect brake. It was 
 still too slow, particularly in releasing, as all the air in both pipe and 
 cylinders had to "be exhausted through the engineer's valve. The 
 longer the train the slower it was, on account of the increased number 
 of cylinders and length of pipe. The storage capacity of the main 
 drum was necessarily limited, and this on long trains, reduced the 
 effective power on the pistons. To illustrate: With an initial pres- 
 sure in the main drum of 90 lbs. the braking force at full equalization 
 on one or two cars would probably be about 85 lbs., while on 10 cars 
 it might not be 70. 
 
 Another great objection to this brake was the fact that if a hose or 
 pipe burst the brake was thereby rendered useless on the entire train, 
 and if the train broke in two the brake on the rear portion was not 
 available, although the use of a valve in tlie coupling enabled the 
 
28 Evoi<uTioN OF The Air Brakb. 
 
 engineer to stop the forward section — something which was often done 
 with disastrous results, collisions between the divided sections being 
 not at all uncommon. 
 
 These defects or shortcomings were rendered all the more serious 
 and dangerous because of the fact that trouble was most liable to 
 occur just at the time when the brake was most badly needed, i. e., 
 when a very heavy pressure was put into the pipes to make an emer' 
 gency stop. 
 
 Experience with the straight air brake soon developed the fact 
 that a brake, in order to be satisfactory, should be adapted to be set , 
 from the train as well as from the engine, for occasions frequently 
 arose (as when passengers attempted to get on or off the train wliile 
 in motion), in which accidents could have been averted had the train- 
 men been able to Stop the train quickly without the loss of time 
 incident to signalling the engineer to apply the brake. 
 
 It also soon became apparent that a brake in order to be reliable 
 must be perfectly automatic, that is, it should be so constructed that 
 any defect -would operate to set it. Such action would necessitate 
 immediate investigation and repair of the defective part. 
 
 It finally became evident that, to secure such a result from the air 
 brake, the force for applying the brake must be stored on each car, 
 and held out of action by a constant pressure carried in the train pipe. 
 The most primitive conception of this idea was a design in which a 
 spring was used as the operative force, so arranged that it was held 
 vinder compression by the air in the pipe, and brought into action 
 when the air escaped. Many of the tminitiated at the present day 
 have the idea that such is the action of the modern air brake. 
 
 AUTOMATIC AIR BRAKE. 
 
 The first step towards a practical solution of the problem of storing 
 the braking po%er on the cars was to use a reservoir, auxiliary to that 
 on the engine. This idea was embodied in a patent issued to Mr. 
 Westinghouse, March 5, 1872, the principal cut of which is shown in 
 Fig. IS. Here the auxiliary reservoir is open to one train pipe and 
 hence in communication with the main reservoir, while by means of 
 the other pipe the brakes were applied as in regular straight air. But 
 if the train parted the brakes were to be set by the couplings pulling 
 apart and thereby turning the valves shown at diagonally opposite 
 
EVOI<UTION OF THE AlR BRAKE. 
 
 29 
 
 Fig. 18— First Auxiliary Kesekvoie (1872). 
 
 Fig. 19— Automatic Beake with Tbiple Yalve (1872), 
 
 Fig. ao— Fibst Wbstinghouse Teipie Vaivb. 
 
30 Evoi,uTiON OF THE Air Brake. 
 
 corners of the car, thus admitting the air from the auxiliary reservoir 
 into the cylinder. 
 
 The next move in this progressive march was to provide a mechan- 
 ism so arranged that the stored pressure in the auxiliary reservoir 
 would be automatically admitted to the brake cylindei" whenever the 
 pressure in the train pipe escaped. Such a device is shown in another 
 patent issued to Mr. Westinghouse on the same day as the preceding 
 one, and from it we have taken Figs. 19 and 20, Fig. 20 being a large 
 sectional view of the valve D of Fig. 19. 
 
 In Fig. 19 A-\ is the auxiliary reservoir, A the cylinder, and D 
 the triple valve, or what, to speak more accurately, formed the begin- 
 ning of the triple valve. We shall not endeavor to describe the opera- 
 tion of the parts in Fig. 20, for (as a glance at the cut will show) it 
 was a device so " fearfully and wonderfully made " that considerable 
 time and space would be required to make it clear. It will be 
 sufficient to say that it was for the purpose of opening communication 
 from the auxiliary reservoir A-\ to the cylinder .^, when the pressure 
 in the train pipe B-l escaped. 
 
Evolution of the Air Brake. 
 
 31 
 
 HOSE COUPLING. 
 
 As it was in the development of the straight air brake that the 
 hose coupling was perfected, and as that device has played a very 
 important part in the evolution of the air brake, before we proceed 
 further with the general subject, we shall here give a brief sketch 
 of the 
 
 HISTORY OF THE HOSE COUPLIXG. 
 
 Between the years 1867 and 1874 (the date of the invention of the 
 present well known form) tliere were ten different patents on hose 
 couplings taken out or assigned to the Westinghouse Air Brake Co. 
 
 Fig. 21— Eakly Westinghouse Coupling. 
 
 alone Many others were patented during the same period by other 
 inventois, and the total number issued to date is very large. 
 
 Fig. 21 shows a good specimen of what, for convenience, we shall 
 term the direct type, which was the general form of nearly all the 
 designs. They came together end for end, and were held in contact 
 by snap springs and lugs. Sometimes, as shown in the cut, they were 
 made with check valves, inserted in such a way as to close when they 
 were pulled apart; for in use with the straight air brake this was neces- 
 sary to keep the brakes on the first section of the divided train in 
 operative condition. From the very first, rubber rings or washers 
 were used to keep the joint g.t the point of contact air tight. 
 
 One great diflSculty with many of these direct couplers was that 
 they would not couple without alteration if the cars were turned end 
 for end. In other words, the couplers on the two ends o'f a car were 
 not duplicates. This necessitated placing two hose and half couplings 
 on each end of each car. As a step in the direction of overcoming 
 
32 
 
 Evolution op the Air Brake. 
 
 this difficulty the design shown in Fig. 22, having a male and female 
 part cast together in each half coupling, was made and tried for a 
 time. 
 
 These attempts were so iinsatisfactory, however, that an entirely 
 
 Fig. 22— Modified Westinghouse Coupling. 
 
 new departure was made by Mr. Westinghouse in 1874, when he 
 brought out the coupler shown in Fig. 23, with the passage at right 
 angles to the axis. It is safe to say that there have ,been very.few 
 mechanical contrivances ever designed which so completely and fully 
 met all the requirements of the case; interchangeability, simplicity,, 
 convenience, non-liability to leakage, and detachability in case of for- 
 cible separation of the train. The essential form of this last described 
 
 Fig. 23— Okiginal Foem of the Present Coupling (1874). 
 
 coupler is the same as that in geneial use to-day. The principal 
 'changes made in it have had reference to the method of retaining the 
 rubber gasket in place, or additions in the shape of auxiliary devices 
 of some kind which have not affected the general construction. Two 
 of the first mentioned modifications are shown in Figs. 24 and 35, the 
 
Evolution of the Air Brake. 33 
 
 first from a patent issued to T. W. Welsh, and the second from a 
 patent granted to A. W. Jackson, both improvements being of recent 
 date. / 
 
 In Fig. 24 the gasket is held in place simply by ils own elasticity 
 
 Fig. 24— Flat-Back Coupling (Recent). 
 
 causing the flange to bind in the groove, which is made of a taper 
 form for the purpose. 
 
 Fig. 25 shows the gasket held in place by an adjustable retainer, 
 which can be operated by a tool thrust through the opening. Both of 
 the above designs were made for the purpose of making it possible to 
 renew a worn or defective gasket without the necessity of removing 
 the hose from the car. 
 
 Fig. 25— Jackson Coupling. 
 
 One complaint made against the common form of coupling is that 
 the cup shape of the end forms a pocket in which dirt collects when 
 the hose is allowed to hang down. With this idea in mind Mr. S. M. 
 Beery designed the coupling shown in Fig. 26, making the casting of 
 such a form that the passage through it would be of practically the 
 same diameter at all points, and least liable to afford a lodgment for 
 dirt. This was patented in November, 1893. 
 
 The peculiar angular construction shown in Fig. 27 is illustrated in 
 a patent issued to Fames in 1877, and was designed for use with 
 vacuum brakes, the atmospheric pressure holding the two halves to- 
 
34 
 
 Evoi<uTioN OF THE Air Brake. 
 
 gether with sufficient force to keep the connection air tight. That 
 this form was a success is evidenced by the fact that it has been and is 
 still extensively used, practically without material modification. 
 
 In Fig. 28 we return again to the usual construction, -with the addi- 
 tion of a clapper or cover to keep out the dirt. This was patented by 
 
 Fig. 26— Beeby Coupling (1893). 
 
 T. W. Welsh in 1879. Others, to whom the same idea occurred later, 
 have been surprised to find that it was not novel, and we are forced to 
 confess that the author was one of the number. 
 
 The remaining cuts illustrate various schemes for doing away with 
 the " deadly" angle cock. 
 
 Those shown in Figs. 29 and 30 were patented by Westinghouse in 
 1879. Fig. 29 shows a semi- spherical rotary valve adapted to be 
 opened automatically by the lug H in the act of coupling. Fig. 30 
 shows an adaptation of the idea to the usual style of coupling, the 
 
 Fig. 27— Fames Vacuum Coupling (1877). 
 
 valve in this case being a rotary ported disc E, operated by engage- 
 ment of the outside arm G with a lug on the opposite half coupling. 
 In several devices in this line a plug cock is inserted in the back of 
 
Evolution of the Air Brake. 
 
 35 
 
 coupling and operated in some such manner as the disc valve in Fig. 
 30. Some of these are wholly impractical, while others possess more 
 or less merit, but none of them have seen extensive use. 
 
 Fio. 28 -Welsh Coupling Cover (IHTO). 
 
 Fig. 29— Westinghouse Combined Couplek and Valve (1879). 
 
 Many inventors have tried and are still trying to perfect a coupler 
 which will not need to be coupled by hand. Fig. 31 shows one of this 
 class patented by W. A. and h. S. H. Harris, Feb. 20, 1894. It pro- 
 
36 
 
 Evolution of the Air Brake. 
 
 vides for both brake and signal connections. Frequent attempts have 
 been made to combine the brake coupling with the signal and steam 
 connections, and even to combine it with the M. C. B. car coupler. 
 
 So far as our information goes, no automatic hose coupler, either 
 alone or in combination with other couplers, has proven satisfactory. 
 In fact, the great majority of them are entirely impracticable, and 
 even if one shall be designed which will meet all the requirements, its 
 introduction will be a matter of great difficulty because of the lack of 
 interchangeability. 
 
 Fig. 30— Westikghouse Coupling and Valve, Modified (1879.) 
 
 Fig. 31— Habkis Automatic Coupling (1894). 
 
Evolution of the Air Brake. 
 
 37 
 
 AIR PUMPS. 
 
 Having in the last chapter considered the development of the hose 
 coupling up to the present date, let us begin now the history of 
 another detail of the apparatus, 
 
 THE AIR PUMP. 
 
 Fig. 32 is an isometric view of the first Westinghouse pump, pat- 
 ented August 30, 1870. It will, no doubt, have a very familiar appear- 
 
 FiG. 32--PIBST Westinghouse Pump (1870). , 
 (Uppek Cylindeb Only Shown.) 
 
 ance to many of the older generation of railroad men, so many 
 of whom operated the " first one ever put on the X. X. & X. R. R." 
 
 The reversing cylinder on top, the outside crank and moving 
 piston, and the handle for starting it when stopped, are very clearly 
 shown. 
 
38 Evolution of the Air Brak^. 
 
 Many times the writer has heard stories of engineers operating the 
 pump for a round trip over the road by means of a string tied to the 
 reversing piston, giving it a pull every time the pump took a stroke; 
 for it is to be noted that this pump had a very peculiar habit, when- 
 ever it took a bad spell, of always stopping at one end of the stroke, 
 when a pull on the string would be necessary to get it to make 
 another move. All these old timers are agreed, however, that, for 
 those days, this pump vas a wonderful piece of mechanism, and it is 
 reported to have done very effectTve work as long as it was properly 
 adjusted and cared for. 
 
 In Fig. 32 the upper cylinder and head only is shown. Fig. 33 
 shows the whole pump, except the top head, in section, the section 
 being taken, however, too far back to show the main piston and rod. 
 In this cut we wish to call attention particularly to the air cylinder, 
 in which, it will be noted, the arrangement of air valves is practically 
 the same as that used in the standard 6-inch pump for many years 
 afterward. 
 
 The familiar stop pin above the lower discharge valve is . clearly 
 shown, as well as the both'ersome bushing in which the upper discharge 
 valve works. 
 
 The valve motion in the steam cylinder of this pump comprised a 
 main valve C, (Fig 34); a reversing piston, the rod and cross head Ei 
 of which are seen in Fig. 32; and a reversing valve and stem A, shown 
 in Fig. 34. The main valve C, Fig. 34, stood vertically, on the side of 
 the cylinder, with the crank arm sticking out through a packing nut 
 on the top, and the valves proper were in the shape of conical plugs, 
 one on the lower end of the stem, and the other a little above the mid- 
 dle, opposite the top end of the cylinder. This valve was adapted to 
 be adjusted vertically by means of two set screws /I in Fig. 33 and 
 /2 in Fig. £2. Of course, if the upper one of these got screwed down 
 too far it resulted in a binding of the valve in its bearing, making it 
 very hard to move at all, and if the lower set screw were set up too 
 tightly, the valves would leak. 
 
 The reversing piston was operated by steam admitted alternately 
 to the outer ends by the reversing valve A (Fig. 34). As shown, this 
 valve had a stem adapted to project into a hollow made in the upper 
 part of the main piston, through an oblong slot in the reversing plate, 
 shown as 5 (Fig. 84). The stem was twisted at its upper and lower 
 ends so that as the main piston moved to the top or bottom of the 
 
Evolution of the Air Brake. 
 
 39 
 
 cylinder a rotary motion was imparted to the conical reversing valve 
 g', the main piston rod itself being made square in cross section to pre- 
 vent it from turning. The stuffing boxes used for packing the piston 
 were set in horizontally, as shown in D (Tig. 34), and were ndnptcd to 
 te drawn to=;ether bv two set screws or bolts 
 
 Figs. 33 and 34— Details or Pikst Westinghouse Pump. 
 
 Anyone at all familiar with the operation of air pumps will see at 
 once that there were, in this design of valve motion, two very weak 
 points, certain to give trouble. One of them was the square piston 
 rod which it was impossible to keep tightly packed, and the other 
 
40 
 
 Evolution op the Air SrakS. 
 
 was the reversing valve arrangement. Imagine the amount of fric- 
 tional resistance that would be encountered in moving the conical 
 valve g; and how far the main piston would have to travel to secure 
 full movement, or, in other words, how far from the end of the stroke 
 the pump would have to begin to reverse. We can imagine, also, how 
 rapid would be the wear of the rod, and the oblong slot in the revers- 
 ing plate in which it worked. 
 
 The patent itself was valuable, because it contained a broad claim 
 to the combination of a reversing rod operating in a hollow piston, 
 but that the mechanism was unsatisfactory in practical operation is 
 shown by the fact that this patent had not been issued a year before 
 
 Pig. 35— Impkovement in Westikghouse Bevebsing Geae (1870). 
 
 application was made by Mr. Westinghouse for another on an improve- 
 ment in the reversing valve gear. 
 
 This improvement is shown in Fig. 35, which is a sectional view 
 taken through the center of the reversing piston cylinder and revers- 
 ing valves. In place of the conical rotary valve with its twisted stem 
 there were substituted two poppet valves e and c which were held to 
 their seats by the pressure of steam in the chamber between them. 
 The lower one was unseated by being struck by the reversing plate 
 when the main_piston reached the upper end of its stroke. The up- 
 per one was unseated by the plate striking the bottom on the lower 
 end of -the rod when the main piston reached the lower end of its 
 stroke. These valves had two large double concentric seats and gave 
 
Evolution of the Air Brake. 
 
 41 
 
 considerable trouble in service because of the difficulty of keeping 
 these seats tight. An endeavor was made to compensate for slight 
 leakage by drilling a small leak port into the exhaust, but this was ft 
 sort of makeshift and did not full}- overcome the objections. In this 
 pump, as will be readily seen, it was possible to do away with the 
 square piston rod, and this was a great step in advance. The revers- 
 ing movement was still imperfect, however, and another alteration was 
 made in it inside of a year, as shown by a patent issued in 1872, from 
 which we have taken Fig. 3G. 
 
 In this design a return was made to the rotary conical plug of the 
 first construction, but it was set in a vertical position, with its axis hor- 
 izontal, and operated by a rod similar to the one used in the form 
 
 Fig. 3G— Second Impeovement in Westinghouse Keveksing 
 Gear (1872). 
 
 shown in Fig. 35. The cut (Fig. 33) shows only the valve, the bush- 
 ing and the top of the rod, but the manner in which the rotary mo- 
 tion was imparted to the valve, is clearly illustrated in the elevation 
 on the left. 
 
 Although this seemed to meet the requirements a little better, it 
 was superseded by another form brought out in 1873. 
 
 In this arrangement, shown in Fig. 37, the rotary valve was still 
 retained, but a kind of crank shaft, or rockpr arm, was substituted for 
 the direct connection of valve and stem of the preceding figure, and 
 the upper end of the rod was slotted, or made with a slotted eye, 
 shown in the main part of the figure, this eye being adapted to slip 
 over the pin ii of the crank shaft ,^1 , shown at the top of the figure. 
 By this time there were a great number of air brakes in use and quite 
 a large number of the pumps last described above were kept in service 
 for several years, although it was only a little over a year after this 
 that Mr. Westinghouse practically abandoned the old construction ex- 
 
4^ 
 
 ^VOI,UTION OF THE AlR BrAKB. 
 
 cept the hollow piston rod, and adopted the design shown in Fig. 38, 
 which is taken from a patent issued in 1875. The construction shown 
 is practically the same as that used in all the 6-inch pumps and later 
 in the standard 8-inch pump and at the present day in service on thou- 
 sands of locomotives all over the world. 
 
 Such differences as exist are matters of detail only. Instead of two 
 packing rings in each valve piston head a single broad ring is shown. 
 The bushings are inserted in exactly the same manner and position. 
 
 a 
 
 \^ 
 
 Fig. 37— Third Impkovement in Westinghouse Keveesing 
 Geak (1873). 
 
 The reversing valve, rod and plate are substantially identical, except 
 that the upper end of the rod projects through a stuffing-box at the 
 top. This was probably designed to obviate the difficulty sometimes 
 caused by inadvertent movement of the reversing valve, which results 
 in what is generally called ' ' giggling. " or ' ' fluttering." 
 
 In concluding this chapter the writer desires to call attention to a 
 very interesting fact that is revealed by one of the patents to which 
 we have referred. It will be noted that most of the changes above 
 
EvotDTiON OF THE Air Brake. 
 
 43 
 
 described had relation to the reversing valve mechanism; all of the 
 designs shown up to Fig. 33 evidently having been vinsatisfactory. 
 First a horizontal rotary valve was used, then a double poppet valve, 
 then a vertical rotary valve, and finally a simple slide valve; and yet 
 there is a suggestion as to the use of a slide valve contained in the 
 very first patent, which is as follows: "A sliding valve of short 
 throw might be made to do the same work (as the rotary valve used) 
 
 Fig. 38— Westinohouse Standabd (Old Style) (1875). 
 
 by means of the valve stem entering the hollow of the piston head and 
 stem, and the two being so constructed that at any desired part of the 
 stroke of the piston head it shall engage somp fixed point in, or part 
 of, the valve stem. " With our knowledge of the experience of the 
 past and of what actually has proven suitable in air pump construc- 
 tion, it certainly seems as if it was a strange error in mechanical judg- 
 ment to adopt a rotary or plug valve in a mechanism for which a slide 
 valve was manifestly superior, and especially so when, as shown 
 
44 :6voi<u'i?iON OF *HE Air Brake. 
 
 by the quotation above cited, the use of a slide valve had been con- 
 sidered. 
 
 From the iigure last above illustrated (which shows the valve 
 motion used in the Westinghouse 6 and 8-inch pumps) we naturally 
 pass to the latest design furnished by that company, two sectional 
 views of the upper head being given in Fig. 39. But little explanation 
 of its operation will be necessary, as it is already pretty well known 
 among air brake men. There are two important points to be noted, in 
 which it differs from the one shown in Fig. 38. 
 
 First — instead of the piston valve shown in the latter, a slide valve 
 (23) is used to control the main ports, the movement of the slide valve 
 being effected by a differential piston. 
 
 Second — All the valve motion is on the top head, so that if it be- 
 comes necessary a new head can be substituted while the old one is 
 being repaired. 
 
 The outer end of the smaller one of the valve piston heads (28) is 
 in constant communication with the exhaust, and the outer end of the 
 larger head (29) is connected alternately with live steam and exhaust 
 by means of a slide valve (8) operated by a reversing rod (7), a mech- 
 anism practically identical with that formerly used. 
 
 The advantages of such construction are obvious. It embodies, in 
 combination, features shown in various prior devices found in what 
 might be called the " ancient history " of the art. 
 
 In 1858 Mr. E. D. Barrett secured a patent on the pump shown in 
 Fig. 40, this being one of the earliest patents in this class of direct 
 acting steam valves. 
 
 The main valve B was similar to the slide valve on any ordinary 
 engine. It received its motion, however, from a double headed piston, 
 controlled in its movements by a smaller slide valve, supplementary 
 to the main valve. This supplementary valve was actuated by the 
 rocker shaft F, whenever the main piston reached either end of its 
 stroke, the arrangement of the parts being clearly illustrated in the 
 cut. 
 
 In 1865, a patent was issued to A. S. Cameron for a " steam slide 
 valve," the essential features of which are still used in the well known 
 ■ Cameron water pump. From this patent we have taken Fig. 41. 
 
 This is perhaps the simplest direct acting valve motion ever 
 designed, and is a model which may be very profitably studied by any 
 ambitious mechanical designer. The main valve ( C) is adapted to be 
 
Evoi,uTioN OF THB Air Brake. 
 
 45 
 
 I'lG, 39— Wesi?inghouse Latest Design. 
 
 Fig. 40— Bakkett Valve Motion (1858). 
 
 Fig. 41— Cameron Pump (1865). 
 
46 
 
 Evolution op the Air Brakb. 
 
 moved back and forth by a double-headed piston {FFi) whenever the 
 main, piston B, at either end of its stroke, unseats the exhaust valve 
 (/.or /r) and thus relieves the pressure from the corresponding end 
 of the valve piston. As leak ports {d di) are provided to*allov\r live 
 steam to equalize on both ends of the double piston, it 13 very mani- 
 fest that it is not necessary to have the piston heads a tight fit; in 
 other wOrds, no packing rings are necessary. All the parts in the 
 design illustrated are readily accessible, a very desirable feature in any 
 mechanical contrivance. In the figure shown the exhaust valves are 
 held to their seats by springs {h hi), but this waA changed some time 
 after the issue of the patent, by the substitution of an arrangement 
 
 Fig. 42— Haelow Pump Head (1884). 
 
 whereby live steam pressure was used in place of these springs, mak- 
 ing the apparatus even simpler than that shown. 
 
 In 1884 a patent was issued to M. S. Harlow for a valve mechanism 
 of this same general class (having a slide valve and double piston), but . 
 in which all the operative mechanism was placed in the top head. 
 
 This we have illustrated in Fig. 42. 
 
 In 1888, Mr. G. A. Boyden patented a pump in which a doiible pis- 
 ton and slide valve ate used, but having their functions reversed 
 
Evolution of the Air Brake. 
 
 47 
 
 That is, the piston is used for the main valve, and the slide valve for 
 reversing. This arrangement is shown in Fig. 43. 
 
 The double piston is really a quadruple one, for it has four heads, 
 the upper two being larger than the others. The movement of the 
 main piston is imparted to the reversing valve (28) through the instru- 
 mentality of the tappet rods (34). This mechanism while not arranged 
 
 Fig. 43— Boyden Pump (1888). 
 
 in the top head, is still so designed that ti can be completely removed 
 from the cylinder in case it becomes necessary to do any work upon it. 
 
 In 1889 Mr. F. Lansberg patented the valve mechanism shown in 
 Fig. 44. 
 
 This differs from prior constructions in the fact that, in place of a 
 valve piston with two heads of the same size, a differential piston is 
 
48 
 
 Evolution of the Air Brake. 
 
 used to move the main slide valve, this part of the construction being 
 practically identical with the one first above described. It differs 
 from that, however, in the form of reversing gear used. When live 
 steam first enters at (7) it forces the valve to the' position shown, be- 
 cause the upper piston is larger than the lower one. This admits 
 steam to the under side of the main piston (3), and the upper side, be- 
 ing open to the exhaust, through passage (8a and 9), forces the main 
 piston to the top of the cylinder. When it strikes the tappet (25) the 
 
 Fig. 44-Lansisekg Pump (1889). 
 
 rotary valve (23) opens a passage to admit live steam to the upper side 
 of the piston (12), and, forcing it down, reverses the pump. 
 
 At the bottom of the stroke the tappet (21) reverses the mcyement 
 by turning valve (23) soar, to exhaust the steam from above piston 
 ( 12). The under side of the piston (13) is at all times connected with 
 the exhaust through the port (35). 
 
 As shown, this arrangement was not as readily accessible as some 
 of the others, being placed at the side of the cylinder, instead of in 
 the top head . 
 
Evoi<uTiON OF THE Air Brake. 
 
 49 
 
 The New York pump, shown in Fig. 44a, seems to have been the 
 first attempt of any moment to- utilize the duplex principle in air 
 brake construction. Some years ago the Westinghouse company 
 made extensive experiments with a four cylinder compound pump, 
 and it was our privilege at that time to witness some tests made with 
 
 Pig. 4*1— New Yokk Pump. 
 
 that pump at their shops at \Yilmerding. We have no record of the 
 results, though it is our recollection that high efficiency and great 
 economy were obtained. The design was finally abandoned, however, 
 in favor of the 9j4 inch type, because of excessive liability to heat, 
 and unwarranted complication of parts. What resembles in some 
 respects a combination of the 9J^-inch pump with the New York 
 
50 
 
 Evolution of the Air Brake. 
 
 duplex, is shown in Fig. 45, taken from a patent issued to H. Brei- 
 tenstein, November 21, 1893. 
 
 As will be seen by reference to the drawing, the opposite ends of 
 the cylinder are connected in such a way that both pistons will move 
 
 Fig. 45. 
 
 at the same time, but in opposite directions, this being an evident 
 attempt to overcome the objection incident to any construction in 
 which one piston has to stand still until the other has completed its 
 stroke. What the operation of the device illustrated would be in 
 practice is problematical. 
 
EV0I,UTI0N OF THE AlR BRAKE. 51 
 
 GOVERNOR. 
 
 Shortly after the introduction of the automatic brake it became 
 manifest that to secure the most satisfactory results in the operation of 
 the appEiratus, some means must be devised whereby the air in the 
 train could be maintained at a uniform pressure without attention 
 from the engineer. In the use of the straight air brake it was not so 
 essential to keep the stored pressure uniform, and little difficulty was 
 experienced by the engineer in satisfactorily regulating the supply by 
 occasional manipulations of the pump throttle. 
 
 In itself the problem was a simple one. There was a valve to be 
 moved and pressure to do it. A plug cock might do for a valve and a 
 piston as a means for supplying the force. As the movement had to 
 take place when the pressure reached a certain predetermined amount 
 some yielding resistance to the movement of the piston had to be pro- 
 vided, which would permit action only when such predetermined 
 pressure had been reached. At first glance the solution seemed easy 
 enough. L,et us demonstrate-by illustration. 
 
 In Figs. 46 and 47 is shown, in simple form, what seemed to meet 
 the requirements. It was, as far as the general plan was concerned, 
 nearly identical with many that have been sketched out by aspiring 
 inventors who have endeavored to simplify the form in use. Air 
 entered the cylinder A at the air inlet, pressed the piston B to the 
 left against the spring C and thus through the lever D turned the 
 valve E until, when a sufficient number of pounds had accumulated, 
 the passage F was completely clcsed (as s'hown in Fig. 47) shutting 
 off the steam from the pump. As the pressure reduced the spring C 
 forced back the piston B, reopened the passage F, and allowed the 
 pump to start again. 
 
 It will be evident on a moment's reflection, that when the passage 
 F was nearly closed, the pump would run so slowly that the accumu- 
 lation of sufficient pressure to move the piston B further would require 
 some time. Herein lay the defect of this device. Just as the pres- 
 sure increased, the speed of the pump reduced, in consequence of 
 
52 
 
 Evoi,TJTiON OF THE Air Brake. 
 
 which the accumulation of the last five or ten pounds below the limit 
 was prolonged almost indefinitely It, therefore, became mahifest 
 that some auxiliary or supplementary device would have to be added 
 to overcome this defect. A diaphragm valve held shut by a spring 
 under adjustable tension, and adapted when opened to admit pressure 
 to the piston, so as to effect full closure of the steam valve when the 
 desired limit was reached, seemed best suited to the purpose. Such 
 
 From. 
 Boiler 
 
 u y y y uu 
 
 ^SSSSSSSSSXsSNSSSSNSSSS'j;; 
 
 kNNS\VNV^VNNV^\V^S.WvVWt 
 
 Figs. 46 and 47— Illusteative Governoiv. 
 
 an arrangement also permitted the steam supply passage to remain 
 unobstructed until the full pressure was obtained. 
 
 As a plug cock was not as well adapted to the purpose as a com- 
 mon poppet valve, the latter was substituted for the former in 
 all th; constructions which have been used in practical service. 
 
 Various different modifications of this general idea have been or 
 are now in use, and we shall next proceed to consider th^m in d^- 
 
EV01,UTI0N OF THE AlR BRAKE. 
 
 53 
 
 Fig. 48-Fibst Westinghouse Govebnok (1881). 
 
54 Evoi<uTioN OF THE Air BrakS. 
 
 The pioneer is shown in Fig. 48. It was patented by Mr. Westing- 
 house in 1881, and may be found in the earlier catalogues issued by 
 the Westinghouse Company. 
 
 B^ is the connection from the boiler, B^ leads to the pump, and a 
 balanced steam valve of the usual construction controls the flow of 
 steam from the former to the latter. This steam valve is held open 
 by the spring which bears against the piston D, until sufficient pres- 
 sure has accumulated in the train pipe or receptacle connected at 
 B'^ to unseat the diaphragm valve v, when the air pressure flows 
 through the passage ji to the upper side of the piston D, moving it 
 downwards, and allowing the spring fl3 to seat the balanced valve and 
 cut off further supply of steam to the pump. The method of operation 
 of this governor was very little different from the best ones now in 
 use, but the details of construction were too complicated and delicate 
 to be satisfactory in the long run. These objections resulted in an 
 altered form, brought out in 1883, in which what might be called a 
 more negative principle of operation was adopted. Fig. 49 is a sec- 
 tional view of this device. 
 
 In this construction steam entered at B from the boiler; the pump 
 was connected at B^ and the valve C controlled the passage from one 
 to the other. When the hand wheel on the spindle R was unscrewed 
 the steam that leaked around the cup piston c-' and through leakage 
 groove fli caused an accumulation of pressure at a (valve d^ being 
 normally closed), and operated to open free passage to the pump. As 
 soon, however, as the accumulated pressure in the train pipe or drum 
 (connected at H'^ ) became sufficient to move the diaphragm e against 
 the resistance of spring 1, the small valve rfl unseated and permitting 
 the escape of the accumulated pressure that was holding the valve C 
 open, allowed the back pressure on the pump side of the valve C to 
 close it. In the last clause of the sentence just above is the key note 
 to the failure of this device. The ' ' back pressure ' ' was a varying and 
 uncertain quantity, and could not be depended on to seat the valve as 
 described, and the consequence was that of the large number of these 
 governors put into service very few were of any account. 
 
 The need of a good governor finally became so urgent that in 1889 
 Mr. Westinghouse brought out another form, more nearly resembling 
 the one patented in 1881, and which forms the basis of the construc- 
 tion that company is now using. It is shown in Fig. 50, in which 2 
 is the connection from the boiler, 3 to the pump, and the passage be- 
 
Evolution of the Air Brake. 
 
 55 
 
 Via. 49— Second Westikghouse Goveenok (1883). 
 
56 
 
 Evolution of the Air Brake. 
 
 tween them is controlled by a single valve 4, held open by the steam 
 pressure until the air unseats the diaphragm \alve and flowing in on 
 
 Fig. 50— Thikd Westinghouse Govebnok (1889). 
 
 top of piston 8, which is of larger area than the steam valve, forces 
 valve 4 to its seat. A modification of this construction, taken from 
 the same patent, is shown in Fig. 51, the design being simply a dupli- 
 
EV0I,UTI0N OP THE AlR BRAKE. 
 
 57 
 
 cation of the upper or diaphragm part, in order to provide independent 
 regulation for both the drum and train pipe. 
 
 Fig. 51— Double Gotbenob. 
 
 In 1891 Mr. G. A. Boyden designed a governor which differed 
 from that shown in Fig. 50, principally in having, instead of a dia- 
 
58 
 
 EVOI.UTION OF THE Air Brake. 
 
 phragm, a kind of a safety valve, the construction being clearly shown 
 in Fig. 52. 
 
 In 1893 Mr. Massey of the New York Company secured a patent on 
 the style of governor shown in Fig. 53, which, while on the same 
 general plan as those shown in Figs. 50 and 52, contained several 
 
 Fig. 52— Boyden Goveknok (1891). 
 
 modifications in detail. A small spring was introduced for the pur- 
 pose of unseating the diaphragm valve, in order to insure more sensi- 
 tive action, for without such a provision the least amount of lost 
 motion between the diaphragm and its valve interfered considerably 
 with the certainty of always securing prompt starting of the pump 
 when the pressure was slightly reduced. 
 
Evolution of the Air Brake. 
 
 59 
 
 Finding the construction shown in Fig. 50 a little too light, the 
 Westinghouse Company introduced an improved form, now known as 
 
 OF^ f^ESEf^i 
 
 BDILCR^ 
 
 Fig. 53— New Yokk Goveenok (1893). 
 
 their standard, and which is shown in Fig. 54, but which is too well 
 known to require further description. 
 
 In addition to the various ones already described we call attention 
 to the one shown in Pig; 55. It is the Mason regulator, which began 
 
60 
 
 Evolution .op the Air Brake. 
 
 to be very generally known quite a number of years ago, but as to the 
 exact date of the first introduction of which we are vincertain. 
 
 In this device steam from the boiler passing through passages X 
 and Z (valve 8 being held normally open by the tension of spring 5) 
 
 Fig. 54— Westinghouse Impeoved Goveknoe. 
 
 acts on the under side of piston 19, moving it upward and holding 
 main valve 21 open ; until the air pressure accumulated in the train 
 pipe or drum (connected at O with the cavity under the diaphragm 
 24) reaches the limit at which spring 5 is set, when valve 8 seats, the 
 steam under piston 19 escapes by leakage and allows valve 21 to seat 
 from the action of the spring 22 and steam pressure above it. 
 
Evolution op the Air Brake. 
 
 61 
 
 Fig. 55— Mason BbgumtQB- 
 
62 
 
 Evolution oif the Air Brake. 
 
 ENGINEER'S VAlvVE. 
 
 The first form of engineer's valve used witli an air brake was 
 nothing more or less than a plain three-way cock, i. e., a valve with 
 three openings controlled by one rotary plug, conical in shape. It 
 was illustrated in the 1872 catalogue of the Westinghouse Air Brake 
 Company, from which we take figure 56 This, the foundation idea, 
 (having three connections controlled by one valve) has been retained 
 in all of the engineer's valves since designed. The complications 
 found in later constructions are merely additions to this general 
 
 Fig. 56— Three- Way Cock (1870). 
 
 scheme. The valve shown in the cut was the form used with the 
 straight air brake, but it is to be noted that when the automatic brake 
 was first introduced, the same valves were use4 for a time simply by 
 reversing the motion, something which was made possible by the fact 
 that the position of the handle that would apply a straight air brake 
 would release an automatic brake, and vice versa. 
 
 With the straight air brake, and also with the automatic brake, as 
 long as it was limited to short trains, the operation of such a plain 
 valve was quite satisfactory, but as soon as the number of brake equip- 
 
Evoi,uTiON OF THE Air Brake. 
 
 63 
 
 ments increased materially difficulty began to be experienced in get- 
 ting the brakes to release properly, because of the insufficiency of the 
 air supply carried in the main drums. In order to overcome this 
 difficulty it became apparent that, either the size of the drum must be 
 increased, or else the air stored in it must be maintained at a higher 
 pressure than that jn the train pipe. This was the beginning of " ex- 
 cess ' ' pressure. It seemsto have been first put into practical u.'se in 
 
 the valve shown in Fig. 57 on which what is known as the 
 
 running 
 
 position" first appeared. In this construction (patented in 1879) a 
 
 Fig. 57— Westinghouse Engineee's Valve of 1879. 
 
 rotary valve C was substituted for the former plug valve and in the 
 center of the casting forming this rotary valve was arranged a small 
 poppet valvey held shut by a spring of just sufficient strength to hold 
 back the desired surplus pressure in the main reservoir, the ports in 
 the rotary valve being so arranged as to shut off, in running position, 
 all passage of air from the drum to the train, except such as forced its 
 way by this excess pressure valve and through the small port L. 
 
 In order to make it possible to more accurately gage the amount of 
 train pipe reduction made in applying the brakes an exhaust or dis- 
 charge valve E, held shut by a spring, was arranged in such a manner 
 as to permit the escape of train pipe pressure when the handle D was 
 
64 
 
 Evoi,uTiON OF THE Air. Brake. 
 
 moved so as to lighten the tension on the spring. This was also 
 designed to assist in closing the exhaust easily, which, as we shall see 
 presently, was quite a desirable feature. 
 
 Although this valve was very extensively introduced, experience 
 developed defects in its construction which frequently caused much 
 inconvenience. The spring on top of the discharge valve E would 
 some times weaken so as to permit the escape of air from the train 
 while the handle was still in the running position, which of course 
 made it impossible to carry it anywhere except in the position for full 
 release of the brakes, under which circumstances no excess pressure 
 could be carried. The spring on top of the excess pressure valve J 
 
 Fig. 58— Paradise EngineeiS's Talve (1882). 
 
 also caused frequent trouble, and the small port L above this valve 
 often became obstructed with gum so as to prevent entirely the passage 
 of air, which of course cut off all feed to the train, allowed the train 
 pressure to reduce, sometimes dragging the brakes, and at the same 
 time causing the accumulation of an abnormal pressure in the main 
 reservoir, the amount of this being only limited under such conditions 
 by the capacity of the pump. 
 
 In Fig. 58 is shown an arrangement in which the excess pressure 
 valve of Fig. 57 is combined with a common three-way cock. The 
 cut is taken from a patent issued to Mr. N. J. Paradise in 1882 and is 
 practically the same as the valve which was once used quite exten- 
 Sivelj' on the Chicago, Burlington & Quincy Railway. 
 
Evolution of thb Air Brake. 
 
 65 
 
 The next idea which seemed to develop in the improvement of 
 engineer's valves had relation to the driver brake. In some cases, 
 especially on mountain roads, it was condsidered advisable to arrange 
 the driver brake so it could be operated independently of the brakes 
 on the train. Fig. 59 shows an independent engineer's valve provided 
 for this purpose, the arrangement shown being a modification of a 
 
 ORESERVOm 
 
 Fig. 30— Independent Deivek Brake Engineek's Valve (1879). 
 
 device which was patented in 1879. The idea was that by setting the 
 handle at a certain point, a predetermined amount of pressure could 
 be maintained in the driver cylinders through the operation of the 
 piston \ 9) and valve (12) in a manner that will be clear from examina- 
 tion of the drawing. 
 
 In Fig. GO, from a patent issued to E. J. Cosgrove in 1885, we illus- 
 trate an attempt to combine th^ driver brake valve with the regular 
 
66 
 
 EV0I,UTI0N OF THE AlR BRAKE. 
 
 brake valve. It was so arranged as to bring the former into operation 
 only in case of emergency, the position of the handle marked 3 
 being the position for emergency applications in which it will be 
 noted the handle strikes the added valve, and, by connections not 
 clearly shown, admits air from the main reservoir to the driver 
 cylinders. 
 
 Shortly after the date of the last named patent conditions began to 
 develop which resulted in the introduction of what is known as the 
 equalizing discharge valve, but consideration of this we must defer 
 until the next chapter. 
 
 Fig. 60— Cosgkove Combination Engineeb's Dkiveb Beake 
 Valve (1885). 
 
Evoi,uTiON OF THE Air Brake. 67 
 
 EQUAIvIZING DISCHARGE VAI^VE- 
 
 In the operation of all the engineer's valves previously described, 
 difficulty was experienced on long trains from the brakes on the head 
 qars releasing when they should remain set, because of a violent re- 
 coil of the air in the train pipe, which resulted from any sudden clos- 
 ure of the exhaust opeping. As long as the number of air brake cars 
 in a train was limited to a few, this difficulty was of little moment, 
 but with the large increase i n the number of equipments that took 
 place about 188> or 1886 it becane evident that some automatic means 
 would have to be provided to overcome this objection) or the loss of 
 braking power through such a release on extremely long trains would 
 largely reduce the benefits to be derived from investments in contin- 
 uous brakes. An idea prevails with many that the equalizing valve 
 was an outgrowth of the quick action triple, adopted for the purpose of 
 preventing unnecessary emergency application through definite limita- 
 tion of the size of the service discharge opening, but this is a mistake. 
 The equalizing valve antedates the celebrated Biirlington brake tests, 
 besides which, if all that was wanted was a limited discharge opening, 
 a smaller hole in the regular rotary valve would have answered every 
 purpose. 
 
 Fig. 61, taken from a catalogue issued by Westinghouse in 1886, is 
 the earliest form of equalizing valve the writer has been able to find. 
 It seems to have all the elements of the present construction, but con- 
 tains in addition some springs, the use of which is not very clearly 
 defined. Possibly they were considered necessary to aid in moving 
 the slide valve. Briefly described the operation was as follows: A 
 slight quantity of air being exhausted from the cavity above the pis- 
 ton 18, allowed the pressure in the train pipe underneath to raise the 
 piston and hold the valve on the bottom of stem 22 open until the 
 same degree of reduction had taken place throughout the train, when 
 the valve would gradually close the exhaust as the pressure below the 
 piston became slightly less than that above. The valve as shown is in 
 the release position, and it is to be noted that in this position air from 
 the main drum passed directly through the equalizing piston by un- 
 
68 
 
 Evolution of the Air Brake. 
 
 Fig. 61— Fikst Westinghouse Equalizikg Disohakge 
 Valve (1886). 
 
 seating valve 20, and thence to the train pipe (as shown by the arrows), 
 an arrangement which might have been more satisfactorj' if it had 
 been possible to make the valve 20 in some way such as would insure 
 its seating absolutely tight at all times.' It is apparent that any lodg- 
 
Evoi,uTioN OF The Air Brakb. 
 
 69 
 
 ment of dirt on this seat which would hold the valve open would en- 
 tirely destroy its equalizing function, because the preliminary exhaust 
 port through which air was exhausted f oni the small cavity above the 
 piston being of necessity quite small, could not discharge pressure 
 sufficiently fast to raise the piston, if air from the train pipe were at 
 the same time flowing into the ca.vity past the valve 20. 
 
 Fig. 62— Westinghouse Equalizing Valvb op 1889. 
 
 In Fig. 63 we have illustrated a modification of the primitive valve 
 shown in Fig. 62, the cut having been taken from a patent issued to 
 Westinghouse & Moore in 1839. The principle of operation of the 
 two was almost identical, but the latter form was considerably sim- 
 pler and is now, with the addition of a feed valve, the standard of the 
 Westinghouse Company. The discharge valve 21 is formed on the end 
 of the piston 19, and the train pipe exhaust is in the shape of an elbow, 
 marked 23. 
 
10 
 
 Evoi,uYiON oif The Air BrakA. 
 
 A short time after the issue of this patent Mr. George A. Boydetl 
 devised an invention shown in Fig. 6S, in which the same end was 
 accomplished , /. e : the cushioning of the exhaust closure, by means 
 of an overflow reservoir substituted for the piston. The principle of 
 operation of this valve is well described by the second claim of the 
 patent, which was issued in January of 1891. It is as follows : "A 
 device to gradually stop the forward movement of compressed air in 
 the train pipe, comprising the combination of a trainpipe {//), an 
 engineer's brake valve {A), an air receiver (_/), and means to dis- 
 charge the train pipe air into the air receiver when the discharge from 
 the train pipe to the atmosphere is cut off." The cut shows a brake 
 
 Fig. 63— Boyden Equalizing Engineek's Valve (1891). 
 
 valveof the form of the old three-way cock, but the same equalizing 
 arrangement was subsequently used by Mr. Boyden in conjunction 
 with an improved valve of the rotary type. 
 
 The next equalizing valve to make its appearance was designed by 
 Mr. A. P. Massey, of the New York Air Brake Company, in 1892, and 
 this we have illustrated in Fig. G4. In this also the main controlling 
 valve was of the- plug type, marked 5 in the cut. The principle of 
 operation of the valve in closing was similar to that of Figs. 61 and 62, 
 but it was opened by a positive mechanical pressure of the lever 15 in- 
 stead of a reduction of the pressure on the upper side of the diaphragm. 
 
Bvoi,utiON OP Yhk Air Brake. 71 
 
 In other words, when it was desired to ap^jly the brake lightly the 
 handle and controlling valve were moved to such a position as 
 would (through a cam on the lower edge of the plug 5) push down on 
 the lever 15 and thereby raise the diaphragm 13 and discharge valve 
 12, permitting the escape of not only train pipe pressure but also the 
 pressure in the cavity on top of the diaphragm, for in the application 
 position ports 8 and 11 were open, as shown in the cut, and the pres- 
 sure in cavity 10 reduced coincidently with that in the train until such 
 time as the handle was moved to the lap position, when the opening 
 from the cavity was closed and the air remaining in it would begin to 
 ..exert a downward pressure on the diaphragm and close the discharge 
 as soon as the pressure in the train became equalized. 
 
 Pig. 64— Masset Equamzing Engineeb's Valve (1892). 
 
 Another valve was made by the New York Company, and designed, 
 we believe, by A. P. Massey, about the same time as the preceding one, 
 is shown in Fig 65. It is practically the same as the one now fur- 
 nished by them as standard. The cut given shows the equalizing part 
 of the valve, combined with their arrangement of excess pressure 
 valve as designed by H. G. Manning. In this equalizing mechanism 
 the automatic closure of the discharge opening from the train pipe 
 was accomplished by a balance between, or rather an opposition, of 
 the pressures in train pipe and main drum exerted on opposite sides 
 of a piston 19. To make an application, the handle was moved to 
 such a position as would cause the lever 17 to open the valve 27 by 
 
72 
 
 Evolution of the Air BrakB. 
 
 means of the eccentric 13, then as the pressure in the train pipe, which 
 is on the upper side of the piston, became reduced the air in the maii 
 drum, which acts on the under side of the piston, would raise the pis)- 
 ton and permit the valve 27 to close. The bell crank lever 21, witl^ 
 its co-acting spring 24, was for the purpose of exerting a retarding, 
 
 V jSt,\SSSXsS^/-'i ^ 
 
 Fig. 65— New Yobk Enoineee's Valve. 
 
 force against the too sudden closure of the discharge valve, such as 
 might take place without some such provision, in case the piston 
 moved a little stiffly. 
 
 Fig. 60 shows an equalizing discharge valve patented by Messrs. 
 Vaughn & McKee, of St. Paul, in August, 1893. The distinctive 
 feature of this device lay in the use of an expansion cavity whicli had 
 a certain proportionate size as compared to the cylinder in which the 
 
BvoLuTioN OF THE Air fiRAKlt. 73 
 
 equalizing piston operated. Referring to the cut, it will be seen that 
 a slight movement of the handle to the right would move the slide 
 valve, b, to a position which would allow air to' escape from the train 
 pipe out of the exhaust. This escape of air reduced the pressure on 
 the train pipe side of the piston and through the lever c- (as the air 
 in the cavity «- expanded), caused a return movement of the small 
 slide valve c which automaticall}- closed the exhaust as the train 
 
 Fig. 66-Vaughn & McKee, Equalizing Engineee's 
 Valve (1893). 
 
 pressure became equalized. The notches in the quadrant marked 
 "service positions " represent various degrees of reduction, as the 
 further the lever is moved the greater must be the reduction in the 
 trai'i pipe before the valve c will be closed. 
 
 In Fig. 67 is shown an equalizing valve patented hy L. E. Howard 
 in July, 1894. This construction seems to be exactly the reverse of 
 the device shown in Figs. 61 and 62. That is, instead of opening the 
 equalizing valve by reducing the pressure on the upper side of the 
 
74' 
 
 fivoi<uTioN OF THE Air BrakB. 
 
 piston, the valve is opened by putting pressure underneath it. To 
 accomplish this result it was necessary to use two pistons, the lower 
 one to open the valve and the upper one to close it. In applying the 
 brake, the handle is moved to admit train pipe pressure underneath 
 the lower piston. The upper piston at this time being in equilibrium 
 of course, offers no resistance to the unseating of the discharge valve 
 8, and this, when open, allows train pipe pressure to escape out of the 
 port 1.3 from the under side of piston 6. To illustrate, if five pounds 
 
 Tof/Catn. j 
 .Fig. 67— Howard Equalizing Engineeb's Yalve (1894). 
 
 To Ttatn Ttjt^ 
 
 of air is admitted below the piston 7, valve 8 -will open and stay open 
 until a little more than five pounds has been exhausted from the under 
 side of piston 6 (the train pipe side) and then the pre^ure on the 
 upper side of the upper piston will begin to exert a downward pressure 
 on the valve 8, which will close it as soon as the pressure throughout 
 the train is equalized. 
 
 When we contemplate the array of devices shown above, all de- 
 signed to accpmplisji the same result, we cannot help feeling very 
 strongly the force of the teaching that the fact that we know of but 
 one way to do a thing is no reason to suppose that some one else may 
 not discover another method. 
 
HVOLUTION OF THE AlR BRAKE. 75 
 
 TRIPLE VALVE. 
 
 In the last few chapters we have considered the development of 
 the pump, engineer's valve, governor and auxiliary parts. Let us now 
 return to the subject of the triple valve, the consideration of which we 
 left sometime ago at the point where the " triple valve " first appeared 
 on the scene. 
 
 The form of " triple valve ' ' device, shown in Fig, 21, was not (as 
 can be easily imagined when reference is had to the cut) a very suc- 
 c .'ssful one. It did not take long to discover that to be satisfactory in 
 all the conditions of practical railroad service something much better 
 would have to be designed. The problem engaged the attention of a 
 number of invL-ntors, but Mr. George Westinghouse, Jr , seems to 
 have been the first to get one which came an)'where near doing what 
 necessity demanded of it. His invention, like nearly all inventions 
 of a mechanical nature, passed through several stages, embodying 
 numerous minor changes in detail of construction, but the main ele- 
 ments ofit are shown in a patent issued to him May 13, 1873, from 
 which we have taken' the view shown in Fig. 68. 
 
 Referring to the cut, it will be seen that the casing had three pipe 
 connections, and these I have marked -to indicate the parts of the 
 apparatus to which they are attached. The exhaust is also marked on 
 the cut. 
 
 In operation, air enters the valve at D, feeds through the ports x-l 
 to the reservoir, and by pressure on the upper side of the diaphragm 
 m-l holds shut the valve b leading to the cylinder, and the exhaust or 
 escape to the atmosphere open, the yalve c, which controls the ex- 
 haust, being, as shown, raised from its seat. To apply the brakes a 
 reduction is made in the train pipe. This closes the opening from 
 the reservoir to the train pipe arid from the cylinder to the atmos- 
 phere, and then opens the communication from the reservoir to the 
 cylinder. Reservoir pressure then flows into the cylinder and sets the 
 brakes. To let the brakes ( ff all that is necessary is to increase the 
 pressure again in the train pipe, which returns all the parts to the po- 
 sition shown. If a partial or service application is desired, only a 
 
76 
 
 Evoi:,uTiON OF THE Air BrakS. 
 
 slight reduction is made in the train pipe, this in turn only allows a 
 small quantity of air to flow from the reservoir to the cylinder, the 
 communication being cut off by the return of the valve b to its seat 
 when the reservoir pressure reduces a trifle below that in the train pipe. 
 
 f,TKAII/ PlF£. 
 
 ro Tj 
 
 'fxHfiuST 
 
 Fig. 63— Westinghouse Teiple Yalvb or 1873. 
 
 In Fig. 69 (taken from a patent to C. H. Perkins, iss ed in 1875) 
 we have illustrated an interesting modification of a device embodying 
 the same general .ideas, but using very different mechanical construc- 
 tions. The parts as shown are in the release position. As the names 
 
Evoi,uTioN OF THE Air Brake. 
 
 77 
 
 of the different connections are marked, no further explanation will 
 be necessary. 
 
 In Fig. 70 is illustrated what may be called the father of almost all 
 of the triple valves of the present day. The cut is taken from a patent 
 issued to Mr. George Westinghouse, Jr., October 5, 1875. Crude 
 though the device be in appearance, it marks the beginning of the 
 remarkable advance made in the brake business since that date. This 
 patent introduced two valuable and important improvements over 
 that shown in Fig. 68, i. e., a four-way cock (marked B^ ), provided 
 for the purpose of changing the brakes from straight air to automatic 
 or vice versa, and a slide valve JI is substituted for the poppet valves 
 
 CfiiniD^it 
 
 TRiiiv Pipe. 
 
 Fig. 69-Peekins Triple Valve (1875). 
 
 of the earlier form. The necessity which compelled the introduction 
 of the four-way cock arope from the fact that at the time this triple 
 valve was invented quite a large number of cars had already been 
 equipped with the straight air brake. As the principle on which this 
 operated was directly opposite to that on which the automatic ope- 
 rated, it was of course impossible to use the two conjointly. The 
 whole train had to be either straight air or automatic. Letting air 
 out of the pipe would set the automatic and release the straight air; 
 and restoring the pressure resulted in the release of the automatic and 
 the application of the straight air. 
 
 During the transition period much confusion arose as the result of 
 a misunderstanding on the part of many of t^'s teakemen as to the 
 
78 
 
 Evolution of The Air Brake. 
 
 Fig. 70.— Westinghouse Tbiple Valve of 1875. 
 
 proper position in which to place the triple valve handle. However 
 the four-way cock was a necessary evil, for it is obvious that all the 
 equipment could not be changed at once, and it is also obvious that it 
 would not do to abandon the use of the brakes entirely pending the 
 completion of the change. Even up to a very recent date the foxir- 
 way cock continued to fill a use on mountain roads, for until the intro- 
 
Evoi,uTiON OF THE Air Brake. 79 
 
 duction of the pressure retaining valve it was not considered safe to 
 use the automatic brake on very heavy grades, because of the danger 
 of the stored air in the reservoirs under the train becoming exhausted 
 through repeated applications of the bra:ke without proper recharging 
 On such lines it was customary to use the automatic brake going 
 up hill and then change to straight air before beginning the 
 descent. 
 
 On this drawing also (Fig. 70), the connections have been marked 
 for convenience of reference. The piston and slide valve are shown 
 in the release position. Air from the train pipe is feeding into the 
 reservoir through the small port j, and the cylinder is open to the 
 atmosphere through the recessed cavity k- in the seat of the slide 
 valve H. \\ hen the pressure in the train pipe is reduced the piston 
 G moves down, closing the port s from the train pipe to the reservoir, 
 cutting off communication between the cylinder and the exhaust, and 
 (the slide valve H continuing its downward movement), uncovering 
 the port f , leading from the reservoir to the cylinder, thus applying 
 the brakes. Restoration of the pressure in the train pipe moves the 
 parts back to the position shown, and thus releases the brakes 
 
 Up to this point we have confined our consideration of the auto- 
 matic brake almost entirely to those forms which use a triple valve. 
 Another form which should not be passed without some mention be- 
 longs to a class which was so constructed that no triple valve was 
 necessary. One of these is embodied in a patent issued to S. F. 
 Prince, Jr., iii June, 1878, and as this is one of the earliest ones of the 
 kind, we hav€ selected from that patent the illustration marked 
 Fig. 71. 
 
 In apparatus of this class a reservoir and cylinder were generally 
 used, but the piston in the cylinder was so arranged that it was 
 balanced between train pipe and reservoir pressures, the reservoir 
 being charged through a small port or passage through or around the 
 piston and as generally arranged, covered by a non-returning check 
 valve. In Fig. 71 this valve is marked K. To apply the brake 
 the pressure was reduced in the train pipe /, which caused a move- 
 ment of the piston to the left because of the expansion of the air in 
 the reservoir F and the seating of the check valve K. When pressure 
 was restored in the train pipe the piston was forced back to the posi- 
 tion shown, and thus the brakes were released. 
 
 This arrangement, or some modification of it, has been patented in 
 
80 
 
 Evolution of the Air Brake. 
 
 several countries, and times almost without number, and came into 
 quite extensive use in several of the foreign countries under various 
 different names. It is open to several serious objections, however, 
 especially in service on long trains, and on this account has in the 
 last few years been largely superseded by more modern forms. 
 
 In Fig. 72 is illu-strated the last of this series of plaiti triple valves, 
 for in that device the development reaches its greatest perfection. 
 The valve shown in that cut was designed by Mr. George Westing- 
 house, Jr., in the year 1879, and in all essential particulars forms the 
 basis of nearly all the triple valves since made. It is made on the 
 same general plan as the valve shown in Fig. 70, but contains in addi- 
 
 FiG. 71— Pkince Automatic Bkake (1878). 
 
 tion, the small graduating valve e-/, which makes the engineer's con- 
 trol of his brake so perfect in all classes of service application.. 
 
 A careful study of the sketch will be neceissary to thoroughly 
 understand the operation of this additional feature. In Fig. 70, as 
 stated, the brakes are applied by the slide valve moving down and 
 uncovering the port leading to the cylinder, and the flow of air to the 
 cylinder is cut off by a slight backward movement of the slide valve 
 (just sufficient to close the opening) caused by the reservoir pressure 
 reducing to a point a little below the pressure in the train pipe. Now 
 
Evoi,uiiON OF THE Air. Brake. 
 
 81 
 
 TO CYLINDtK 
 
 Fici. 72— Westinghouse Standaed Plain Triple 
 
 Valve (1879). 
 
 in practice it was soon discovered that with the device as shown in 
 Fig. 71 there was a tendencj; for the sliJe valve to move clear back to 
 the release position instead of stopping just at the point where the 
 graduating port was covered, but the e5chaust not yet open. This was 
 due in part to the fact that the amount of force necessary to start the 
 valve upward was more than enough to carry it to the end of its. 
 
82 Evolution of the Air Brake. ■ 
 
 stroke after it started. It is a general and well known law that it 
 takes more force to start a bddy, in motion than it r'equires to keep it 
 moving after it is Started, and this case was but one instance of that 
 law. To overcome this, then, the slide valve was given a slight 
 range of motion independent. of the piston stem, and the small grad- 
 uating valve was so inserted that after the slide-valve had uncovered 
 the port to the cylinder, d slight upward movement of the piston 
 would seat the small valve e-l, and without moving the slide valve cut 
 off communication from the reservoir to the brake cylinder, the 
 resistance afforded by the friction of the slide valve itself acting to 
 stop the upward movement of the piston and prevent any uninten- 
 tional release dviring the service application. 
 
 The extreme nicety with which this device operates must be seen 
 to be appreciated. 
 
Evolution of the Air Brake. 83 
 
 QUICK ACTION BRAKES. 
 
 What constitutes a quick action brake is, just at this particular 
 time, a much disputed point. The pending litigation, arising from 
 actions brought by the Westinghouse Company against a number of 
 competitors for alleged infringement of quick -action patents held by 
 that company, has jjiven to" the subject extended prominence and 
 great interest. 
 
 In I S86, a committee appointed by the Master Car-Builders' Asso- 
 ciation, conducted a number of exhaustive tests at Uurlington, for the 
 purpose of determining, if possible, which of the several different con- 
 tinuous brakes then on the market was best suited to use on long 
 freight trains. I'rior to the date above mentioned, the plain auto- 
 matic brake had proven quite sufficient, .for the reason that only short 
 trains were commonly used. As the motive power was constantly 
 being made heavier, the number of cars which could be used in a 
 train was correspondingly increased. 
 
 Amongst the brakes entered for trial in 1SS6, were momentum or 
 buffer brakes and compressed air brakes. All were tested on trains of 
 50 cars. All failed to meet the requirements. The momentum or 
 buffer brakes proved erratic, unreliable and insufficient, and the 
 vacuum and compressed air brakes produced too great shocks in the 
 rear of the trains, caused by the cars behind crowding into thqse 
 ahead because the head brakes set some time before those in the rear.. 
 
 In May, 1887, the tests were repeated, the competing designs com- 
 prising an electric brake, an electric air brake, a vacuum brake, and 
 what is known as the Westinghouse, 1837, quick actipn brake. In 
 these tests the electric air brake patented by J. F. Carpenter made the 
 . quickest stops and with practically no shock. The vacuum brake was 
 unsatisfactory and the Westinghouse new valve, while it made much 
 quicker stops than was made the year before, produced at first such 
 severe shocks that it was deemed unsafe to use it except in combina- 
 tion with electric relief valves. Subsequent investigation revealed the 
 fact that this result was due partly to the emergency port in the valve . 
 
84 
 
 Evolution of the Air Brake. 
 
 being too small, but mainly to an improper proportioning of the acces- 
 sory parts, such as the train pipe, hose cocks, etc. 
 
 This invention was patented by Mr. Westinghouse in March, 1887, 
 and as it clearly exemplifies the class to Which it belongs, we repr - 
 duce a sectional view of it (Fig. 73) as introductory to this article. 
 
 As to tjie part of the mechanism which is for use in ordinary or 
 service stops, the construction is practically identical with the older, 
 plain triple valve (shown in Fig. 72 in our last article). The ad- 
 ditional parts, which were used for emergency applications only, 
 included a slide. valve 41, a check valve 40, and a passage 46, the 
 valves in the cut being shown in open position the better to illustrate 
 their functions. The train pipe connection, marked on the figure, is 
 at all times in open communication (through a passage parallel with 
 passage 46, but not shown in the cut) with the drain cup chamber in 
 
 Fig. 73— Westinghouse '87 Quick Action (patent 360,070). 
 
 which Fig. 39 stands and should therefore be considered the same as 
 if the pipe connection were made directly into the drain cup itself. 
 
 In ordinary or graduation applications of the brakes, the piston 12 
 travels just far enough to touch the stem of the valve 41, but not 
 sufficient to move the valve itself, the spring 39 stopping it at that 
 point. On a sudden and extreme reduction in the train pipe pressure, 
 all parts move to the position shown, and then port 42, being uncov- 
 ered, air from the train pipe passes by the check valve 40, and through 
 passage 46 directly to the brake cylinder, at the same time' that reser- 
 voir pressure is flowing into the cylinder through ports 85, 33 and '11 
 This local venting of the pressure in the pipe under the first car 
 
Evolution of the Air Brake. 85 
 
 served to hasten the application of the brake on the next succeeding 
 car, and so on in turn throughout the train. In the first experimental 
 devices of this kind made by Mr. Westinghouse these vents discharged 
 directly to the atmosphere. This resulted in considerable waste of 
 air, in view of which fact they were subsequently connected to the 
 brake cylinder. 
 
 Examination of the state of the art prior to the date of this 
 patent reveals a number of devices which show the use of a local vent 
 as a m&ns of quickening the discharge from a long pipe. One of the 
 first is shown in a patent (No. 102,565) issued in 1875 to Ford, ,Westing- 
 house and Welsh, from which we have taken Fig. 74. 
 
 It was arranged to be put in the main train pipe, at such intervals 
 as were deemed desirable. The passages marked a' opening to th.e 
 atmosphere were adapted to be closed by valve c when air was admit- 
 ted to the train pipe. When the pressure in the pipe was reduced, the 
 air with which the reservoir B had been charged, reacted against the 
 diaphragm b, and unseating the valve c, opened the vent fropi the 
 train pipe, discharging the air locally to the atmosphere. This patent 
 was set up by the New York Air Brake Co. in their defense in the 
 suit recently decided, but was declared by the court to fail £is an 
 anticipation, because it was used for hastening the release of a straight 
 air brake, and not for quickening the action of an automatic brake. 
 
 Following this invention, a patent was taken out in England in 
 1S79, by a man named Sanders, for a device of a similar nature, but 
 used as an emergency relief valve in an automatic brake. From this 
 (British patent 980 of 1879) we have taken Fig. 7.1. 
 
 Several variations are illustrated and described in the patent, but 
 we shall confine our remarks here to this one. The pipe connection 
 shown, leading into the bottom, is for the train pipe attachment. The 
 emergency valve a is normally held shut by the air pressure and 
 spring d. A movable diaphragm b, with a small feed port through it 
 at c, is so balanced between air in the train pipe, and in the small 
 reservoir above, that in case of any sudden and extreme reduction in 
 the train pipe pressure the diaphragm will be moved down by the air 
 in the reservoir above, unseating the emergency valve, and creating a 
 local discharge from the train pipe to the atmosphere. During ser- 
 vice applications of the brake, the device described remains inopera- 
 tive (the graduating and release of the brakes being accomplished by 
 any other mechanism which may be provided for that purpose) 
 
86 
 
 Evolution of the Air Brake. 
 
 Fig. 74— Foed, Westinghouse & Welsh Eeliep Valve (1875). 
 Patent 162,565. , 
 
 because of the heavy pressure and spring d holding the emergency 
 valve to its seat. 
 
 About four months after the issue of the Sanders patent, Mr. Geo. 
 Westinghouse took out a patent (No. 217,838) on the automatic relief 
 valve shown in Fig. 76. 
 
 'f his was adapted to be put in the main pipe at intervals through- 
 out the train, a sufficient number being used to serve the desired pur- 
 pose. The one show;i in Fig. 76 is encased in one of the halves of a 
 
Evoi,utlON OF The Air Brake. 
 
 87 
 
 hose coupling. C is the exhaust port, F'Cas emergency valve, and D 
 the piston used to open the valve. On the unseating of the valve E, 
 air p sses freely to the rear portions of the train, through passages B' 
 and B. When a reduction is made at the head end of the pipe, the 
 air at the rear attempts to flow back and equalize, but, as it is stopped 
 by the seating of the valve E, pressure is exerted downward on the 
 
 Pig. 75— Sandeks' Quick Action (British Pat. 980 of 1879.) 
 
 piston D to open the valve F, and thus discharge the train pipe 
 pressure Jocally to the atmosphere. 
 
 In 1S81 a modification of this valve was patented by Mr. Geo. 
 and H. H. Westinghouse jointly. This we illustrate in Fig. 77. 
 
 In charging the train, air from the engine enters at the end 
 towards the left and moving the diaphragm away from the valve v,. 
 passes through to the rear of the train. A slight reduction forward of 
 
88 
 
 Fig. 76— Westinghouse Belief Value of 1879 (Pat. 217,838), 
 
 Pig. 77— Westinghouse Belief Valve of 1881 (Patent 245,110). 
 
Evolution of the Air Brake. 
 
 89 
 
 the device produces no effect on cars back of it, but a sudden and 
 extreme reduction on the head end, produces, by reaction of the air 
 behind the diaphragm, the unseating of the valve e, and consequent 
 opening of valve b to the atmosphere. This is called a " cut-off and 
 
 Fig. 78— Boyden Valve. (Patent 280,285—1883). 
 relief valve " for the reason that, when placed in the main line of the 
 train pipe, it prevents any service application of the brakes back of it, 
 but opens to "relieve " the pressure and hasten the application of all 
 the brakes in cases of emergency. 
 
90 ■ Evoi,uTioN oP THE Air fiRAitS. 
 
 lu }b83, Mr. Geo. A. Boyden secured a patent (No. 280,285), from 
 which we reproduce the section shown in Fig. 78. 
 
 This valve was designed for the purpose of providing means 
 whereby pressure in the cylinders conld be restored or replenished, 
 without releasing the brakes, if, on descending a long grade, the 
 braking power became reduced from leakage. Some lime subsequent 
 to the issue of this patent, Mr. Boyden discovered in this mechanism 
 the possibility of quick action, for jn 1889 he had the patent reissued, 
 inserting in the reissue claims so worded as to cover such an invention. 
 
 Referring now to the drawing, it will be seen that the piston is 
 made with two, heads, the space between them constituting the slide 
 valve chamber. Into this chamber there are two openings, one from 
 the reservoir, and one from the train pipe, the latter being controlled 
 by a check valve d. Above the upper piston is a reservoir or chamber 
 in which is stored the air which moves the valve. 
 
 On a reduction of pressure in the train pipe, the slide valve H 
 moves down, uncovers the port C vents the pressure from the slide 
 valve chamber, and thus permits air from both the reservoir and train- 
 pipe to flow into the brake cylinder. 
 
Evolution of the Air Brake. 01 
 
 WENGER BRAKE. 
 
 In the last preceding chapter we took up the subject of the 
 " quick action brake," and considered it as far as the beginning of 
 the development arising from the Burlington tests of 18S7. Before 
 proceeding to follow that line further, let us stop for a time and 
 turn our attention to something of interest that was being done 
 abroad. 
 
 As we have seen, the first Burlington tests demonstrated very 
 clearly the fact that the plain automatic brake was not suitable for 
 very long trains, primarily because in cases of emergency action, the 
 shocl( occasioned to the cars on the rear end of the train was dis- 
 astrous. In one of the designs which we illustrated in our last issue, 
 combined with certain improvements, covered by subsequent patents 
 of Which we shall treat later, Mr. Westinghouse eliminated this shock 
 by the use of means which quickened the action of the brakes on the 
 rear end of the train. 
 
 The tests of the Carpenter electric brake had shown clearly that 
 brakes which set simultaneously operated without-shock. Other tests 
 had shown that brakes which did not apply on the rear cars until 
 after the slack had run in produced violent shocks. It was found that 
 the time required for all the slack to run in was for a 50-car train, on 
 an average, somewhere in the neighborhood of 4 or 5 seconds. As 
 soon as the time of the application of the brake was shortened so as to 
 be materially less than the length of time required for the slack to run 
 in, the amount of shock decreased, the improvement becoming more 
 and more noticeable the more nearly the time of application ap- 
 proached to the simultaneous action of the electrical devices. 
 
 As a result of the widespread intere.st in the subject, incited by the 
 Burlington tests, the government of France, by a Ministerial, resolu- 
 tion passed Dec. 14th, 1888, appointed a commission to investigate the 
 air brake problem in that country. Various tests were made under 
 the comm ssion, concluding with some made in May, 1890, the results 
 of which are given in an annexed table. 
 
92 
 
 Evolution of the Air Brake. 
 
 Two points in the action of the Wenger brake which' attracted par- 
 ticular attention, because of the excellence of the results shown, are: 
 First, the ease with which the engineer handling it was enabled to. 
 make accurate stops for water or coal, the position when the train 
 came to rest varying in some instances but a few inches, and this it is 
 to be remembered, with trains of f cars, and' second, the quickness 
 and certainty of release after emergency applications , the brakes in 
 
 Fig. 79— Fives Lili.e Bka:5j:— (Genebal Abeangement). 
 
 some cases being all oflf before the speed of the train had been reduced 
 below 10 miles an hour, thus saving considerable time by permitting 
 the train to proceed' without coming to a stop, something practically 
 impossible with the devices we are using. The utility of this can be 
 better appreaated when viewed in connection with the fact that it 
 is common practice to run trains in several sections, and if one sec- 
 
Evoi,uTiON OF THE AiR Brake;. 
 
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.94 
 
 EVOI,UTIOTSr OF THE AlR BRAKE. 
 
 tioli is followed very closely by another, and after making an emer- 
 gency application, is delayed in releasing the brakes and getting out 
 of the way, the danger of collision is more imminent. The writer 
 recollects an actual experience which came under his notice some 
 years ago, where the engineer of an ait brake train of some length 
 
 Fig. 80 - Duval Regulatok. 
 
 sighted a. freight coming against it on the same track, and failing 
 after making an emergency stop, to get his brakes released, was 
 unable to back up and let the opposing train (which had no air) have 
 more room to stop, although the time was sufficient to permit him 
 
Evoi,uTioN OF THK Air Brake. 95 
 
 easily to get all his things out of his seat box before leaving his 
 engine. 
 
 We are not in possession of positive, information as to jtist what 
 form of apparatus was used by the Wenger Co. in the above tests. 
 
 The commission after the conclusion of the experiments, reported 
 in fa\or of the Wenger brake and against the quick action brake of 
 tin Westinghouse Co., although the latter made, in cases of emer- 
 gency-application, much quicker stops. 
 
 Some years after the completion of the 1887 tests another French- 
 man named M. L. E. Duval, hit upon the idea of overcoming, the 
 shock (which Mr. Westinghouse eliminated by quickening the 
 operation of the brakes on the rear cars) by automatically retarding 
 the operation of the brakes on the head cars. To accomplish this 
 purpose he designed a valve, which we here show in section in Fig. 
 80, the cut being taken from a U. S. patent issued in December, 1893. 
 This device was designed to be placed between the main train pipe 
 and the triple valve, as shown in Fig. 79 which we have taken from a 
 patent issued in 1892. Fig. 81 shows it combined, with a plain triple 
 valve in one casing, and as the principle on which it operates is the 
 same in either case we shall for convenience of reference use Fig. 81 
 to illustrate our more detailed description. The diaphragm and slide 
 valve, shown in the upper half of the casing, is substantially identical 
 with the plain triple valves in common use, and any preferred form 
 could be substituted in place of the one shown. The reservoir is 
 charged through the small tube a;;d check valve passage on the right 
 of the drawing. The diaphragm and slide valve shown in the lower 
 half of the casing, called by the inventor a "regulator," are means 
 by which the opening which connects the train pipe with the air 
 chamber on the lower side of the main diaphragm may be increased 
 or decreased in size. 
 
 Briefly stated, these parts perform the function of preventing the 
 sudden or extreme variations in the train pipe pressure (such as must 
 of necessity be made to secure emergency action) from producing 
 violent action of the head triple valves, or in fact any of the triple 
 valves, while still permitting the rapid venting of the train pipe at 
 the point of discharge and thus a quick as well as practically simul- 
 taneous application of all the brakes in the train. Operating on such 
 a principle it is of course not possible to make as quick or short an 
 emergency stop as with the quick actipn brake with which thi§ 
 
96 
 
 Evolution op ths Air Brake. 
 
 Fig. 81 Combined Teiple and Eegulatok, 
 
Evoi,uxioN OF THE Air Brake. 97 
 
 country is familiar, but that this design would successfully eliminate 
 shock on long trains -would seem a reasonable conclusion. 
 
 It may be of interest to investigate, now more in detail, the 
 mechanism used by Mr. Duval, or more properly speating, invented 
 by Mr. Duval, and assigned to and controlled by the well known 
 Fives Lille Co., of Paris. 
 
 Referring particularly to Fig. 81, it is to be noted that the parts as 
 shown are in the normal or release position. Air enters from the 
 train pipe at the point marked "train pipe," and flows through the 
 passage in the centei of the stem D, and past the slide valye E, which 
 covers the opening out of the stem into the cavity below the main 
 diaphragm. Jf, in charging the train, a heavy pressure is let into the 
 train pipe from the main drum suddenly, the diaphragm B will be 
 moved upward partially closing the opening/?, and preventing any 
 sudden increase of the pressure below the main diaphragm, thus 
 retardffig the release of the brakes on the first cars, until the pressure 
 at the car is about equal to that in the head end when all the valves 
 release together. 
 
 In making emergency applications a sudden and extreme reduc- 
 tion is made in the train pipe pressure. This causes the " regulator " 
 diaphragm B to move down war i again partially or wholly closing 
 the opening which connects the train pipe with the cavity below the 
 main diaphragm, and thus retarding the application of the head brakes 
 until the pressure in the rear end of the train pipe has had an oppor- 
 tunity to become reduced to about the same extent, when all the 
 brakes will set at the same time. 
 
 To one familiar with our method of operating things, this schetne 
 appears at first glance to be objectionable, the disadvantages appear- 
 ing before the advantages. A little careful thought will, however, 
 soon serve to convince the mind that the advantages this system pos- 
 sesses are by no means so inconsiderable as we had been inclined to 
 think them at first, but are on the contrary of considerable import- 
 ance. Prominent among the desirable results which it aims to obtain 
 may be mentioned the entire ^elimination of shock, not only in 
 emergency applications, but also to a large extent in service applica- 
 tions. 
 
98 
 
 Evoi,uTiON OF THE Air Brake. 
 
 QUICK ACTION BRAKES (Continued). 
 
 We shall now return to a subject introduced in a previous chapter, 
 i. e., " Quick Action Brakes " Our previous investigation of this 
 extended up to the tests made at Burlington, in 1887, with the form 
 of valve shown in Fig 73, and which we designated the Westinghouse 
 '87 Valve. 
 
 WESTINGHOUSE BRAKE. 
 
 To secure greater reliability ih release, this construction was 
 altered in the latter part of 1887 and a separate piston introduced to 
 operate the quick action valve, the resultant design forming at the 
 present day the standard construction of the Westinghouse Company. 
 We illustrate it in Fig. 82. 
 
 .BCSCnvSiR 
 
 Fig. 82— ^VESTINGlIOUBs; Teiple Valve. 
 
Evolution of the Air Brake;. 
 
 99 
 
 In service applications the operation of this valve is the same as 
 that of Fig. 73. In emergency applications the main piston travels 
 back until it compresses the ^ring to the left of stem C, when air is 
 admitted by the slide valve from the auxiliary reservoir to the top of 
 the piston D, as shown by the arrows, and the piston D is forced 
 down until the valve E is opened. Air from the train pipe then flows 
 to the brake cylinder past the check valve F. 
 
 J^Zet 
 
 Pig. 83— Westinghouse Independent Quick Action Valve 
 (Patent No. 448,827). 
 
 Fig. 83 is taken from a patent issued to Westinghouse in 1891, but 
 which was declared by the New York court to be really included in 
 the 1888 patent. The figure shows an emergency valve alone, it being 
 designed particularly for use in conjunction with apparatus already 
 in service, and operating independently of the triple valve itself. 
 
 The Burlington tests and the rapid introduction of the device 
 above described soon resulted in the development of competing forms 
 
100 
 
 Evolution of the Air Brake. 
 
 of apparatus by rival companies and the exercise of great activity on 
 _ the part of a large number of inventors. 
 
 The designs produced were so numerous that we have not the space 
 to illustrate . them all, but will confine ourselves to those which are 
 best known or which serve best to exemplify the class to which they 
 belong. 
 
 NEW YORK BRAKE. 
 
 The New York Air Brake Company first entered the field with the 
 valve shown in Fig. 84. 
 
 TP 
 
 ^u.f..7i 
 
 i'lG. S4— New Yoke Triple Valve No. 1. 
 
 This employed a similar form of graduating valve and emergency 
 valve proper to that shown in Fig. 82, but the emergency piston y-was 
 arranged to secure its actuating force from the train pipe air, through 
 the operation of a valve H which in turn was operated by air in the 
 reservoir. Soon after the first introduction of this device it was dis- 
 covered that its operation in emergency was not active enough to 
 
Evolution of the Air Brake. 
 
 101 
 
 travel through a long train, but gradually weakened as it receded 
 from the engine. As soon as this became manifest the manufacturer 
 substituted a new de-.ice in which only one emergency piston was 
 used, and this in u somewhat modified form (as tested by a committee 
 of the M. C. B. Association at Altoona), we here illustrate in Fig. i^'j. 
 
 Fig. 8.5— New Yobk Tbiple Valye No. 2. 
 
 With this valve, when there is a rapid reduction of pressure in the ' 
 train pipe, the auxiliary reservoir pressure, acting upon the top of the 
 piston C, as shown by the arrow, forces the valve Z) from its seat, by 
 means of the stem J^, and permits air to enter under the check valve 
 E and pass to the brake cylinder, as shown by the ar, ows. 
 
 Receiving an adverse decision from the court on these two forms 
 of apparatus the New York Co. next introduced the device shown in 
 Fig. 86. 
 
 In this construction the emergency piston is actuated by a reduc- 
 tion of the pressure on its upper side through a pr rt in the main slide 
 valve whicli on an extreme movement of the main piston opened com- 
 municaton from the upper side of the emergency piston to tie atmos- 
 phere. This valve was decided by the court on injunctional proceed- 
 ings to be an infringement of Westinghouse claims, so another inven- 
 
102 
 
 EV0r,TJTI0N OP THE AlR BRAKE. 
 
 
 JraAc' , 
 
 Pig, 86-New Yokk Triple Valve No. 3. 
 
 Fig. 87— New Yobs TAple Valve No. 4. 
 
EvoluTioN oif THE Air Brakr. 
 
 103 
 
 tion was substituted for it whicli vented the train pipe to the atmos- 
 phere instead of to the cylinder. This we illustrate in Fig. 87. 
 
 In this valve the emergency piston moves within the main piston , 
 and, because of the restricted size of the opening A, operates to open 
 the emergency valve C whenever the reduction in the train pipe pres- 
 sure is made with great rapidity, remaining inactive however as long 
 as nothing but gradual or service reductions are made. When the 
 valve C unseats, the air vented from the train pipe strikes another 
 piston which in turn opens a. large passage from the reservoir to the 
 cylinder, the train pipe air escapirfg to the atmosphere through the 
 port D. 
 
 BOYDEN BRAKE. 
 
 Fig. 88 illustrates the first or earlier form of valve made by the 
 Boyden Brake Co., and patented by Mr. Geo. A. Boyden something 
 
 Rcac"-oiB 
 
 Fig. 88— Boyden Triple Valve No 1. 
 
104 Evolution op the Air Brake. 
 
 over a couple of years ago. In this device, which was one of those 
 tested at Altoona by the ' M. C. B. Committee bsfore mentioned, the 
 ctnergeucy passage is made directly through the center of the main 
 valve chamber. Graduation \vith this device is accomplished through 
 tlie hollowstem A, the emergency valve C remaining seated except in 
 emergency applications. 
 
 When a rapid reduction is made in the train pipe pressure the 
 piston y moves forcibly outward until the collar D comes against the 
 valve C and unseating it admits train pipe pressure directly to the 
 brake cylinder. 
 
 A later form of valve designed by Mr. Boyden is shown in Fig. 89. 
 In this construction the main slide valve itself performs both 
 graduation and emergency functions, the extreme traverse of the main 
 piston in cases of emergency uncovering the large port leading to the 
 brake cylinder and allowing the train pipe pressure to flow past the 
 check valve C around the port above the main piston chamber and 
 down through the main "Valve chamber into the brake cylinder. The 
 operation of the parts in service applications is the same as those pre- 
 viously described. . 
 
 CRANE BRAKE. 
 
 Another valve which was tested at Altoona in November, 1893, was 
 the one made by the' Crane Company. It is shown in Fig. 90. 
 
 With this ' valve any sudden and extreme reduction iri train pipe 
 pressure moves the piston E downward, unseating the small valve D, 
 and, by venting the pressure below the piston to the brake cylinder, 
 allows the train pipe air to flow in above the piston and by a continua- 
 tion of the downward movement of the same, unseating the valve F, 
 permits the train pipe pressure to discharge into the cylinder., ir is a 
 check valve of usual construction provided for the purpose of pre- 
 venting any return of cylinder pressure to the train pipe. 
 
 tANSBERG BRAKE. 
 
 A number of different forms of valve have been made by the Lans- 
 berg Co., of St. Louis, one of the first being shown in Fig. 91. 
 
 In this construction the emergency valve was in the shape of a slide 
 valve, moving on the surface of the main piston chamber as a seat and 
 controlling an opening (29) leading to the brake cylinder. This 
 (Fig. 91), as nearly as we can determine, is about the form of valve 
 
Evolution qf the Air Brake. 
 
 105 
 
 
 to 
 I 
 w 
 
 o 
 
 h! 
 
 O 
 
 1^ 
 
 s 
 
106 
 
 Evoi<uTioN OF The Air Brake. 
 
 which was found to be so unsatisfactory in service that some of the 
 roads refused to accept cars equipped with it. The makers soon began 
 to make improvements in their equipment, however, and now offer 
 4iie iorm cf construction which we iUustrate in Fig. 92, this being 
 substantially the same as the device subtnitted by them at Altoona, 
 but embodying a number of later improvements 
 
 Fig. 91— Lansbeeg Triple Valve No. 1. 
 
 As will be seen by reference to the cut, cup leather valves are used 
 both for exhaust, graduation and emergency, the arrangement being 
 such that the air pressures upon them are balanced, thus reducing the 
 force necessary to move them to a minimum. A careful' study of the 
 drawing will suffice to make the operation clear; provided it be under- 
 stood that the emergency passage from the valve leads directly to the 
 
Evo;,UTioN OF THE Air BaAKE". 
 
 107 
 
 Fig. 92— Lansbbbg Triple Valve No. 2. 
 
 chamber marked " to cylinder;", but being on a plane beyond that of 
 the section could only be shown by dotted lines. 
 
 HABBREORN BRAKE. 
 
 Another brake which has attracted considerable attention in the 
 air brake world is that invented by Mr. T. H. Haberkorn, of Fort 
 Wayne, Ind. From this patent, issued in November, 1893, we take 
 the cut Fig. 93. 
 
 In this'device the graduation is controlled by a piston C having a 
 stem of graduated size C-4 which, on being drawn out of the seat a-^, 
 allowed reservoir pressure to flow to the cylinder, connected at JV. 
 P is the emergency valve and o-i the piston which, on a sudden re- 
 
♦ 108 
 
 BvottJTloisr ^OF The Air BrakB. 
 
 Fig. 93— Haeekkobn Teiple Valve. 
 
 duction in train pipe pressure, caused the vajve P to open and dis- 
 charge the train pipe pressure to the atmosphere through the port b-4. 
 
 DIXON BRAKE. 
 
 A number of patents have been issued to Mr. T. S. E. Dixon, of 
 Chicago, for triple valves which vent train pipe pressure to the atmos- 
 phere. One of these we illustrate in Fig. 94. 
 
 A careful study of the drawing will serve to make the operation of 
 this device clear. 
 
 JPARK BRAKE. 
 
 In Fig. 95 we illustrate the triple valve, the patent for which, issued 
 to H. S. Park, formed one of those used by the Westinghouse Co. 
 against the New York Company in the litigation noted. This was 
 one of the devices which used train pipe pressure to actuate the emer- 
 
EvOI,UTION OF THE AIR BRAKE. 
 
 109 
 
 Fig. 94— Dixon Tbiplb Valve. 
 
110 
 
 Evolution of the AIr Brake. 
 
 Fig. 95— Pabk Triple Valve. 
 
Bvoi,uTioN OF THE Air Brake. 
 
 Ill 
 
 Fig. 96— Howe Teiple Valve. 
 
 gerjcy valve, and the patent contains a claim to this method, of 
 operation. 
 
 HOWE BRAKE. 
 
 In the latter part of 1893 a number of patents vifere issued to H.L. 
 Howe for a form of triple valve in which the main slide valve per- 
 formed the emergency functions, We have selected the one illus- 
 
112 Evoi,uTioN OF THE Air Brake. 
 
 trated (Fig. 96) merely as an illustration of the general idea. The 
 principle of its operation will be easily understood without explanation. 
 
 Within the last couple of years the number of patents on quick 
 action brakes, issued during each month, seems to be steadily increas- 
 ing. A complete collection would more than iill a volume. Many 
 disclose original, not to say startling ideas, but as we have already 
 illustrated and described a suflScient number of them to gi e the 
 reader a fairly good general idea of the state of the art, we shall leave 
 the subject here. 
 
 What the brake of the future will be, no man knows, for none can 
 know. Many indicatipns point to a complete revolution in the not 
 very distant future of the whole transportation system, and this, of 
 course, would necessitate a corresponding revolution in the means 
 employed as a braking force. 
 
 l-'INIS, 
 
Both the First and Second Editions exhausted inside 
 
 r^—^- --y;^jr--T,f-7.---^Mim; " ;■ ?■;.,, y^asing. What 
 
 s 
 
 
 OF THE 
 
 Air= Brake System 
 
 CAUSES-SYMPTONS-CURE 
 
 BY 
 
 PAUL SYNNESTVEDT 
 
 COVERS A FIELD ENTIRELY DISTINCT FROM THAT COV- 
 ERED BY ANY OTHER PUBLICATION. 
 
 SEE WHAT THE CRITICS SAY. 
 
 From Mr. S. D. Hutchins, President Association of Rail- 
 road Air Brake Men. 
 
 " Presents the disease and remedy in such a plain, practical 
 manner that there is no excuse for not understanding it." 
 
 From Mr. C. B. Conger, President Traveling Engineets' 
 Association. 
 
 " No one who is learning how to operate, or maintain the 
 air brake in good order, can afford to be without a copy. The 
 information is given in plain language so it can be clearly 
 understood even by beginners." 
 
 From a letter written by Mr. G. W. Rhodes, Superintendent 
 of Motive Poper C, B. & Q. Ry. ; Chairman of the Comm,Htee 
 on Air Brakes of the M. C. B. Association. 
 Mr. Paul Synnestvedt : 
 
 ' ' I think the information you have given will be invaluable 
 to those who must necessarily give the points you mention 
 attention in the future if the railroad companies in this country 
 expect to have safe and effective brakes. 
 
 " Your instructions to use reason first and hands afterward 
 is the keynote of the situation." 
 
 Price. ONE DOLLAR 
 
 PUBLISHED BY 
 
 THE W. F. HALL PRINTING COMPANY 
 
 21 to 25 Plymouth Place, CHICAQO