>. ^. .* .'.«|fe, \„^,.* ,^i^, ^. . <^ *'T;t« .0 .^ \ - ^^^/r?7^ ■• o A V • o, "-^ V^ *?.!oL'* <^ ^ov^ A"- 0°"'* '"^^ o « . -V <^ *'7V ■> o *' A^ -^^ ^. OM^ r ^S' -^, «^°^ ^\.':^^.\. ^^^•^i'% .^'^:^^%"- .^<-^iX c0^c;^^'^. . ^o-n^ ''^^^ V^^\/\. V^^'V'' "V^-^V^ \.-..o- .V, / \/^-\/ V^*/ \/^\/ v^-/ V^\/ ' C" * A^ 6 ° "0 « "^ = \<>^ :'»': *"-./ V- .iJ^TfCJ"-* <^ ^^..^^ . »" ^^ U . 4^^ 6 o "» * "^> .0^ t .0 "V *.,,• ^•^ 0? XV • X .c°Vi-:^-> ./.-^i-X. ./..•'-■•• •"<= '« 'o ^^ ^iy ov^^^i;^"-.. '-^^ ^^ " :^^^^\ '>i^ ^^ oV'^^ot'". ^%. rS ' "'^HM^r.^ ^^ A^ 1 » *tv «i ♦ ^»K(r- v^ .*j*:^'* o ■Ku^ \/ < V «2. - " - a" C" .' '^o\ "HO- ^0' '^^. •'.v.-' .^^- ^q,. '*.To'- ..0-- '^^ ''*^'^*' o.^" *ip.'%??r'* .o'> "^^ ^:^f^' ..^^ V>..i.^'.^'o ""^^c^' ^\. .coVi-i^.^o. .//^^%. .^'^^^'> .^<*^iA co^c^."°o '^6' .^^ 'bV^ ♦/ \/^f^\/ V^*/ \/^\/ v^-.o^ ■"-^^' /^^: '^"^-^^'^ «^1^^ "''^y '&'\^'^" «? V. oH/J|\F* aV 'S^ ■'©lis* «> "^ VWMW>' A^ "^ <./*: k'^ c.""". 0" *' - o - ,0' <^ aO • • * < IC 8998 Bureau of Mines Information Circular/1985 Inverted Pyramid-Shaped Plugs for Closing Abandoned Mine Shafts— Galena, KS, Demonstration Project By W. M. Dressel and John S. Volosin UNITED STATES DEPARTMENT OF THE INTERIOR 03 C 3J m > c Q 751 ' /^INES 75TH A^ Information Circular 8998 Inverted Pyramid-Shaped Plugs for Closing Abandoned Mine Shafts— Galena, KS, Demonstration Project By W. M. Dressel and John S. Volosin UNITED STATES DEPARTMENT OF THE INTERIOR William P. Clark, Secretary BUREAU OF MINES Robert C. Horton, Director Library of Congress Cataloging in Publication Data: Dressel, W. M. (W'aldemar M,) Inverted pyramid-shaped plugs for closing abandoned mine shafts- Galena, KS, demonstration site. (Bureau of Mines information circular ; 8998) Bibliography: p. 14. Supt. of Docs, no.: I 28.27:8998. 1. Mine filling. I. Volosin, John S. II. Title. III. Seriest In- formation circular (United States. Bureau of Mines) ; 8998. TN2»5iiM^ [TN292] 622s [622] 84-600227 CONTENTS Page Abstract 1 Introduction 2 Selection of shaft sites 3 Design of plug 6 Installation of plugs 9 Backfill 11 Installation of slab caps 12 Discussion 13 Conclusions 13 References 14 ILLUSTRATIONS 1 . Proj ect site location 3 2. Typical open shaft with timber still in place 4 3. Typical open shaft with enlarged surface opening 4 4. Typical shaft showing rotted timber and washout along timbers 5 5. Typical open shaft showing circular outline in slumping residuum 5 6. Installed plug 6 7. 8-ft form showing reinforcing grid 7 8. 10-foot form showing I-beam position and reinforcing grid 8 9. 12-ft form showing I-beams and position of horizontal and vertical re- inforcing bars 8 1 . Lowering form into opening 9 11. Form filled with concrete showing space between form and shaft wall 10 12. Poured plug with expanded metal edging resting on reinforcing bars 10 13. New concrete poured on expanded metal surrounding plug 11 14. 10-foot form showing spider-leg reinforcing over edge of form to support the expanded metal 12 TABLES 1 . Material requirements per plug 7 2. Material requirements per slab 12 UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT ft foot lb pound ft2 square foot yd^ cubic yard in inch INVERTED PYRAMID=SHAPED PLUGS FOR CLOSING ABANDONED MINE SHAFTS-GALENA, KS, DEMONSTRATION PROJECT By W. M. Dressel ^ and John S. Volosin ^ ABSTRACT This Bureau of Mines report describes a shaft closure demonstration project in which 11 inverted pyramid-shaped plugs were used to plug abandoned open mine shafts in Galena, KS. The inverted pyramid-shaped forms, fabricated from steelplate, were designed so that the inverted base would be larger, by 4 ft on a side, than the approximate size of the shaft opening at the surface residuum-solid rock interface. After the surface openings of the shafts were trimmed with a backhoe, the steel forms, complete with reinforcing, were lowered into the open- ings and filled with concrete; the remaining portions of the openings above the plugs were backfilled to slightly above the surrounding sur- face level with waste rock and soil. Location and elevation monuments were installed for long-term evalua- tion of the success of the project. ^Supervisory metallurgist. ^Metallurgist. Rolla Research Center, Bureau of Mines, Rolla, MO. INTRODUCTION The Bureau of Mines operated a shaft closure demonstration project in Galena, KS, in which 11 inverted pyramid-shaped plugs were installed in abandoned open mine shafts. The primary purpose of the project, which was part of the Bureau's Conservation and Development Program for conserving land resources, was to provide alternative methods for closing some of the hundreds of open shafts in the area. The Galena field is in the Tri-State zinc-lead belt district of Kansas Missouri-Oklahoma, which was one of the largest zinc-lead mining districts in the country. The district produced over 11 million tons of zinc and 2.8 million tons of lead during its 122 years of operation. Mining began in the Tri-State district in 1848 with the discovery of lead ores in Joplin, MO. Increased mining activity developed in the 1870*s, coincident with the extension of the railroad into the area and the development of new milling and smelting techniques for zinc. By 1875, the Joplin field became the leading zinc producer in the Nation. Mining moved westward with the discovery of the Galena, KS, field in 1877; the Peoria, OK, field in 1891, and the Commerce, OK, field in 1905. Mining continued in the Missouri por- tion of the district until 1957 and in the Kansas-Oklahoma portion until 1970. Early mining leases were generally small with many leases being only 100 or 200 ft square ih-h) .^ The ore was mined by small crews of men using handtools and simple hoisting devices. Exploration was done by sinking a shaft, generally 50 to •^Underlined numbers in parentheses re- fer to items in the list of references at the end of this report. 100 ft deep, until ore was found and then drifting outward (_5). If drifts reached 300 ft in length or if ventilation became difficult, additional shafts were sunk. If ore was not encountered, the miner moved to new ground and sank another shaft. In 1892, Henrich (j6) reported that diamond drills were being used for prospecting deeper than 100 ft. The churn drill replaced shaft sinking as the principal exploration tool about 1900 O, The use of shafts as a means of explor- ation and the small lease and sublease mining plots resulted in a high density of mining shafts in the area. Many of these shafts remain open. They are con- stant safety and environmental hazards and limit the uses for the land. In preparing a series of reports for the Bureau, the State Geological Surveys of Kansas, Missouri, and Oklahoma located over 1,400 abandoned open mine shafts in the Tri-State district (8-10). In the Galena, KS, field alone, 377 open shafts were located within or adjacent to the city limits of Galena. All but 11 of these shafts showed surface enlargement because of cribbing removal or failure. Backfilling is a common method for filling shafts and is quite successful if done properly with graded material free of degradable trash and in a manner that avoids temporary bridging. Wood planking has been used with varying degrees of success but eventually decays, resulting in an unsafe closure. Although concrete caps have been successful in some in- stances, there are examples of failed concrete caps in the Galena area where the caps were improperly reinforced or where undercutting around the shaft caused the cap to tip on end, thus creat- ing a hazard from an open shaft. In the Picher field, at least one com- pany successfully used concrete cubes to close shafts when abandoning the field. The cubes, which were 6-1/2 ft on a side, were constructed on the surface next to the shaft and then rolled into the open- ing and wedged into place by undercutting and blasting. This report describes a method using an inverted pyramid-shaped plug that would be easy to install and would seal itself into the shaft. The weight would be dis- tributed to the edges and sides of the shaft. SELECTION OF SHAFT SITES Galena was picked as a site for demon- strating methods for closing abandoned shafts because over 350 open shafts were readily accessible in a populated area. Before a location was selected for the demonstration, the Bureau contacted the Galena city government for its view as to which areas within the city limits were in the most need of shaft plugging. From the locations the city officials listed, the Bureau selected a site in NE1/4SW1/4 sec. 14, T 34 S, R 25 E at the west end of Front, First, and Second Streets. Virtually all of the open mine shafts in Galena are on privately owned land. A search of the county land records was made to determine the ownership of the lands, and the owners were contacted to obtain grants of easement that would per- mit the Bureau to carry on the demonstra- tion project. Figure 1 shows location of the site and the location of the shafts closed during the demonstration; the breaks in the shaft numbering sequence resulted from changes in the original closure plan, brought about in one case because considerable construction debris had been dumped in the opening and in other cases because the locations were out of the area covered under the grants of easement. Four of the open shafts selected for plugging are shown in figures 2 through 5, Contract 50/34005 was let to Goodson and Associates, Inc., Denver, CO, in 1982 to obtain the shaft dimensions, assess the conditions of shaft side walls, and obtain an estimated contact between over- burden and solid rock. These measure- ments were used in preparing bid specifi- cations for the plug installations re- ported herein. Eleven shafts were plugged, two were capped, and one was backfilled during the demonstration. <7m ^^ 14 ■ ■ ■ -..,0 '■ 2a ^a 6 ■» ■l9 ^ \ \ FIGURE 1. - Project site location. FIGURE 2. ° Typical open shaft with timber still in place. FIGURE 3. = Typical open shaft with enlarged surface opening. FIGURE 4. ° Typical shaft showing rotted timber and washout along timbers. FIGURE 5. - Typical open shaft showing circular outline in slumping residuum. DESIGN OF PLUG Pyramidal-shaped plugs designed for the project consisted of prefabricated steel forms with installed reinforcing, which were lowered into the prepared shaft opening and filled with concrete. The shafts were roughly square and ranged in size from 4 to 8 ft. The forms for the plugs were designed so that the tops of the plugs were approximately 4 ft larger on a side than the size of the shaft opening. The shape of the form was that of an inverted 45° pyramid, A sketch of an installed plug is shown in figure 6, Of the 11 forms required for the demonstration, 3 were 8 by 8 ft, 6 were 10 by 10 ft, and 2 were 12 by 12 ft. The 8- by 8-ft and the 10- by 10-ft forms were constructed of 3/16-in hot-rolled low-carbon steelplate welded at the seams. The 12- by 12-ft forms were con- structed of 1/4-in hot rolled low-carbon steel. The external edges of the seams were reinforced by the addition of a fab- ricated angle, approximately 3 in on an edge, welded to the seam. This rein- forced edge proved very beneficial since much of the weight of the plug rested on the corners before seating, A horizontal reinforcing rod grid was placed 1 ft from the top in the 8- ft-square pyramid forms, 1,25 ft from the top in the 10-ft forms, and 1.5 ft from the top in the 12-ft forms, A 12-in grid spacing was used for both east-west and north-south positions (fig, 7), Grade 60, No, 7 reinforcing bars were used in each instance. In the 10-ft form, 0.326-in web thicknes long were welded to which was welded to form. The beams we to each other and equidistant from the and from each other ( two S4 I-beams with s approximately 6 ft a 1/4-in footplate the sides of the re arranged parallel spaced approximately parallel side walls fig 8), 12 P L A N Pier Surface residuum ^■''°'Q'iTc<^'^'"->'^ s E C T I N FIGURE 6. ■ Installed plug. To brace the side walls of the 12-ft form, two S4 I-beams , approximately 8 ft long with a 0,326-in web thickness, were welded to the form at right angles to each other. The ends of these beams were welded to a 1/2-in plate at least 1 ft square, which in turn was welded to a 1/2-in plate at least 1 ft sq which, in turn, was welded to the inside of the form approximately 2 ft from the top (fig. 9), Vertical reinforcing bars were placed 6 in from each of the sloping sides of the pyramidal form. They were spaced 1 ft apart at the top of the form and ta- pered down to a few inches near the bot- tom. The top end of the rebars extended to within 6 in of the top of the form, A spacer was welded approximately 1 ft from the tip of each form to hold the rods 6 in from the side walls (fig, 9), Material requirements per plug are tab- ulated in table 1, TABLE 1. - Material requirements per plug Approximate shaft size 4 ft 6 ft 8 ft Pyramid form size ft.. Metal preform, f t^ . . Weight of metal preform lb.. Estimated rebars per shaft: Linear ft... Weight lb. . I-beam: Length ft. . Weight lb . . Edge angle: Length ft.. Weight lb. . Total weight of steel lb.. Concrete yd-^ . . '3/16-in cold-rolled , low-carbon ^1/4-in cold-rolled, low-carbon 8x8x4 '90.51 693 327 660 27.7 260 1,613 3.2 10x10x5 '141.2 1,083 495 1,020 12 89 34.6 325 2,517 6.2 12x12x6 2203.6 2,079 698 1,420 16 118 41.6 391 4,008 10.7 steel plate, steel plate. FIGURE 7. - 8-ft form showing reinforcing grid. FIGURE 8. - 10-ft form showing I-beam position and reinforcing grid. FIGURE 9. - 12-ft form showing I-beams and position of horizontal and vertical reinforcing bars. INSTALLATION OF PLUGS The contractor, using a backhoe, trimmed sufficient material from around the surface of each open shaft to provide a reasonably level contact between the surface residuum and the bedrock. In several cases rock ledges or boulders needed to be trimmed to provide a suita- ble bearing surface for setting the forms. Trimming was done with a jackham- mer bit fitted to the backhoe. The prefabricated forms we to the site on a flatbed trai unloaded from the truck and rectly in the hole using a (fig. 10). In several cases sidewall trimming using the or jackhammer was required level position for the forms. re delivered ler and were placed di- 1 7-ton crane , additional backhoe and/ to obtain a A 4-in pipe was positioned in the cen- ter of each plug and was long enough to extend above the surface level of the ground after backfilling. These pipes were designed to remain as reference markers for followup evaluation. Class A concrete was delivered to the site from a local batch plant and poured into the forms. The 8-ft forms each required 3.2 yd^ of concrete, the 10- ft forms 6.2 yd^ , and the 12-ft forms 10.7 yd3. After the first three plugs were placed, it was noted that since the mine openings were only roughly square, there were noticeable gaps between the form and the sidewalls at some places (fig. 11). In these areas, reinforcing bars were positioned over the edge of the form and extended to the side of the prepared opening. This was covered with a 2-ft width of expanded metal, and 4 in of con- crete was poured on this expanded metal (fig. 12). Figure 13 shows the same hole after the completion of the edge pour. FIGURE 10. - Lowering form into opening. 10 FIGURE 11. - Form filled with concrete showing space between form and shaft wall. FIGURE 12. - Poured plug with expanded metal edging resting on reinforcing bars. 11 FIGURE 13. - New concrete poured on expanded metal surrounding plug, Before pouring concrete in the last eight forms , steel reinforcing rod was bent and fastened to the installed hori- zontal reinforcing grid and extended in spider-leg fashion several feet over the edge of the form. The 2-ft-wide expanded metal was positioned over these reinforc- ing rods, and concrete was poured over this when the form was filled. Figure 14 shows the positioning of the spider legs and expanded metal. An additional 1 to 1-1/2 yd^ of con- crete was required for each shaft because of these modifications. In the installation of one 12-ft and one 10-ft plug, the center reinforcing bars were left unwelded to the sides of the form to allow the form to bulge along the edges to better fill the gaps. This appeared to be an effective measure. BACKFILL After a concrete curing period of at least 7 days, the holes were backfilled with waste rock available near the shafts. The backfill at each site was mounded so that the center of the fill was approximately 2 ft above the sur- rounding ground surface. The 4-in pipe extending from the center o.f each plug was trimmed so that it extended 6 in above the fill; it was filled with con- crete and will remain as a marker for evaluation purposes. These markers have been located, and elevations of their tops have been determined. 12 FIGURE 14. - 10=ft form showing spider-leg reinforcing over edge of form to support the expanded metal. INSTALLATION OF SLAB CAPS In some Instances, solid rock exposed at the surface was competent enough so that there was virtually no cratering or shaft enlargement at the surface. In these cases, it was found expedient to trim away loose surface rock reinforced concrete slabs, openings, approximately 4.5 were closed by this method completion of the project. and install Two mine by 4.5 ft, during the The slabs were designed to extend ap- proximately 5 ft over each edge of the open mine shafts. A reinforcing grid of No. 7 rebars spaced 1 ft apart at the edges, 1/2 ft apart in the area over the opening, and 1/2 ft from the bottom was specified. Eighteen inches of class A concrete were poured. A 4-in pipe was set into the center of each grid to serve as a marker for future evaluation of the project. The material requirements for each poured slab are shown in table 2. TABLE 2. - Material requirements per slab Size of shaft Dimension of slab Number of No. 7 rebars Total length of rebars Total weight of rebars Thickness of concrete. Volume of concrete.... • • • X u • • • • • X u • • • • • X u • • • • .lb* • • • • X u • • ..yd^.. 4.5x4.5 15x15x1.5 46 690 1,420 1.5 12.5 These slabs were of sufficient size and sufficiently reinforced to remain indefi- nitely without breaking or flipping over in the event of washout under part of the cap. They were also designed to with- stand loads from automobile or truck traffic which may occur in the area fol- lowing closure of the shafts. DISCUSSION 13 Working around abandoned mine shafts in areas where the extent of the abandoned underground mine working and the stabil- ity of the surface material around the shafts is not known is potentially haz- ardous. The contractor and suppliers were aware of the possible hazards and proceeded with due caution and regard for personal safety. A minimum of installation problems were involved, and only a few changes were necessary in completing the planned dem- onstration program. Most of the material trimmed from the shaft openings was allowed to fall into the open shafts, since sufficient waste rock was available on the nearby surface to backfill the openings over the in- stalled plugs. In at least one instance, temporary bridging of a shaft occurred during the trimming operation. This was to be expected because the material was ungraded, but it pointed out the neces- sity for using graded material when clos- ing small shafts by backfilling. In preparing hole 14 for plug installa- tion, the hole was found to be larger than original surface measurement had in- dicated, and it was difficult to obtain a stable bedrock surface. It became ap- parent that the alternatives were a plug at least 16 ft in diameter, a cap 22 ft in diameter, or completely backfilling the hole; backfilling was chosen, and ap- proximately 350 yd-^ of backfill were re- quired to close the opening. A 4-in pipe was also used as a marker for this closure. It also became obvious that the shaft dimension measurements made from the sur- face in these old hand-dug shafts before they were prepared for plugging were not the most reliable measurements that could be made. In several instances, measure- ments made after the holes were prepared required changes in plug size from origi- nal specifications. For example, the plug put in open shaft 19 was the plug meant to be placed in shaft 14. The original specification required that cross-reinforcing bars be welded near the top of each form to be used for attaching cables for moving the forms. The fabricator preferred to weld a plate with an eye in each corner. Figure 10 shows this to be a preferable method and allowed for easy handling and positioning of the forms. The crossbars in the orig- inal design were omitted in the later- constructed forms. The reinforcing rods were welded into position at crosspoints, and the ends were welded to the sides of the forms. This tended to make very rigid form. The welding of the reinforcing rod ends at the center of the sides was omitted in several of the forms installed near the end of the demonstration. This enabled the form to bow out when filled with con- crete to more nearly take the shape of the opening. However, when this happens, there are no reinforcing bars in the bowed-out part of the plug. A modified design that allowed the center reinforc- ing bars to extend through the plug walls might eliminate this problem. Four plug forms were set in their re- spective shafts prior to a 7-in rainfall. As a result, the forms were filled with water and had to be pumped out before the concrete was poured. Small drain holes were left in the last three plugs in- stalled; however, the plugs were filled with concrete before the next rain. CONCLUSIONS The 11 plugs and 2 caps installed and the shaft that was backfilled appear to be effective methods for closure in the Galena area. Long-range evaluation of the closures will be necessary to prove the stability of the inverted pyramid plugs . 14 REFERENCES 1. Hay, R. Geology and Mineral Re- sources of Kansas. KS State Bd. Agri,, Biennial Rep. 8, pt. 2, 1893, pp. 99-162. 2. Clerc, F. L. The Ore Deposits of the Joplin Region, Mo. Trans. AIME, V. 38, 1907, pp. 320-343. 3. Plyn, J. The Joplin District. Mines and Miner., v. 24, Feb. 1904, pp. 329-330. Kansas, and Oklahoma. 1972, 362 pp. Univ. OK Press, 4. Norris, J. D. AZn: A the American Zinc Company. Soc. WI, 1968, 244 pp. History of State Hist. 5. Crane, W. R. Methods of Prospect- ing, Mining and Milling in Kansas Lead and Zinc District. KS Geol. Surv. , v. 8, 1901, pp. 177-387. 6. Henri ch, C. Zinc-Blende Mines and Mining Near Webb City, Mo. Trans. AIME, V. 21, 1892-93, pp. 3-24. 7. Gibson, A. M. Wilderness Bonanza - The Tri-State District of Missouri, 8. McCauley, J. R. , L. L. Brady, and F. W. Wilson. A Study of Stability Problems and Hazard Evaluation of the Kansas Portion of the Tri-State Min- ing Area (contract J0100131, KS Geol. Surv. -Univ. KS). BuMines OFR 75-83, 1983, 193 pp. 9. McFarland, M. C, and J. C. Brovm. Study of Stability Problems and Hazard Evaluation in the Missouri Portion of the Tri-State Mining Area (contract J0100132, MO Dept. Nat. Resour. , Div. Geol. and Land Surv.). BuMines OFR 97-83, 1983, 141 pp. 10. Luza, K. V. A Study of Stability Problems and Hazard Evaluation of the Oklahoma Portion of the Tri-State Mining Area (contract J0100133, OK Geol. Surv.- Univ. OK.). BuMines OFR 76-83, 1983, 147 pp. H 3U^ 85 INT.-BU.OF MIN ES,PGH.,P A. 27773 D DD 2 Q_ O ^ Q- 3 a (/> n _. 3- n n a • o « ^ c -► 3 3- w n 2 --^ (V o Q -I 1- -< Tl -< -n ■n 3) > TJ t- 3) tD < C > -1 CO m z c m to C/) m w Cfl CD xgon O o c T3§> m S c ■7 OD f mo < m z > z m zc« O m 13 > 33 ii Hm 00 "n 03 -5 _ m zco H m O 3} m D c > O T3 T3 O D -< m O < m c o> go 2 Z > i o o 01 "n 11 -« m I m tn O a o 31 .^°<. •-•■ ^"■^ \'"^^*./* V^'^'^o''* \'''^^*\**'* '^V'^^V*' '\"'- .- ./.>¥/;•.%. .,.^.-^»i-.\. ..*''...:l-i:-/V .,<.^S^-.V ./..r...% •■' v< v^^ ^^..c."^' ■ 4<^:V/;-/^. ..^\^^i^^^\. .^^v^v.."-^ ^..^' »*A\M/A-o -^^,^- o'Biie^ ■^^..<=>'^ ^9- V-^^ ■J^^. * ^^ -.pc,- ^V ^^ oWJOh* aV^ -^ •wis* «? "% oWMW* aV -^^ . % '^^^-f^* o.^^ o. <► *'7Vi* ,0 ■^ A^^ « V .*r^v <^ ^^ ^^-^^^ ' . ** A ' « • 5 ^^"^^ « rlOft » ^ •. ^^-c,^ .^% ^' -,-1°^ C, vP .<' '\./ v5^ 'o . » * A A c "0 <> *',.«* .0 <^ *'.. ^ 5> » aN ' S"* ^* '^. ' ^^o< ^ \ \v '^__ "'"' A-* "^ "'• ^^J-^ 'o . (. • A • <^ * .-Jfe-v \/ .-iiK^i'. %.*' .• ♦ aV •5\, . <> *'..«* .0 ■0.*' ^i* ."^^"i ^ ^ -^ -^W^^T* ^L** *ti. - C)VP A°^ 0^ olV' ^> <> *'••'' aO -w. <^ vP (. «^^<>Tfe .^^-v. A' ^>. -*?7.T^\^o^' "^o. -o.. * A^ ^t«v • WHK* * «? «> o^ : S • • A . *^0