Evening Star Newspaper, February 6, 1922, Page 4

(Continued From First Page.) leaking of melted snow onto the heads of the audience would have re- sulted. FINDS ELEMENTARY RULES |PRAWINGS BY THEODORE. L. In figure 1 the double lings indicate the six roof trusses, while the single lines indicate the steel I-beams or girders connecting with the trusses. Four of the trusses connected at one end of each to the main truss, No. 11. One truss, No. 16, extended from the east wall to column No; 5. The main trubs, No! 11, was at right angles to the other trusses, and its north end rested upon the curved wall on the Columbia road side of the building. Its 'south end was supported on the | CONDRON EXPLAINING KNICKERBOCKER COLLAPSE.|SNNOW FOUGHT . E FALLING UNDER PHIADELPHIA'S SYSTEM' Fleet of Speédy: Motor Plows. 4,390 Men, 1110, Teams and City's Sewers o i Kéep Stree BY COL. JAMES B. McCORD. S. Bureau of Public Roads, Former- 1y Engineer of Highways, Philadel- phia, Pa. The writer has read with a great deal of interest the efforts of The Evening Star to collect data from various citles oconcerning thelr ts Cleared. Subordinate Inspectors. FEach inspeo- tor in charge of a district was pro- vided, of course, with a set of plans and specifications and was required to keep in close touch with his con- tractor by telephone, to be familiar with the location of the plow truck garages and the addresses of t crews. The police precincts also ca- operated in making up and mobiliz- methods and organization for snow |ing contractors and city laborers for removal. It is thought that it might snow work. upper end of a column (No. 2), at the level of the ceiling. This column, un- like coluinn No. 3, did not .extend to the roof, but stopped at the level of the suspended ceiling, which was about six or seven feet below the roof. Supported by Vertleal Strut. The three roof girders meeting at}. the point over column No. 2 were supported by a vertical strut, com- | sisting of two small steel angles, which strut stood upon the bottom chord of truss No. 11, directly over the top of column No. 2. It showld be observed that there is no stedbimg:. ber extending west from tha ehd or. this strut. This strut was siipportea “cobhouse” fashion, not being rigid- 1y connected at its base and not con- nected directly to, the column below, contrary to accepted practice. Sece figure 8. Truss No. 12 is the one which ap- ‘pears in the various photographs of the interior taken since the collapse. It is eltogether, but has a bad break in its upper or compression flange. ‘This break is evidently due to tension developed by a tremendous side pull which probably came with the general collapse, rather than being the cause of the collapse. Pigure 2 is a sketch to larger scale, of the top of column No. 3 end shaws the relative positions of the four roof members connecting at this column. Perhaps it is well here to call atten- tion to the fact that all of these con- nections were made with loose fitting bolts instead of rivetss It may be permissible to make steel connections with bolts in = framework of short spans, but good practice dictates the use of field driven rivets in the con- nections for work of this character. Where bolts are used the number should always be greater than would suffice for rivets, which is not the case here. Figure 3 is an elevation or side view of a part of the connection shown in plan_in _figure his shows that the twelve-inch I beam “B-41" was, cannected in & most flimsy fashion to ite support, which was a short section channel twelve inches high and half an inch thick, standing on angle brackets, connected to the column. The upper flange of this channel was not fastened to the column in any way, so that a very slight movement of beam “B-41" would certainly cause the web of the channel to fold over, bending near its bottom flange, and this is just what did shappen te this channel support, as shown by dotted lines on fieure 3. . Figure 4 is a sketch of the connect- ing beams and the angle strut above lumn No. 2. The west end of beam -41” was connected by a bent plate bolted to the 10-inch channel. Figure 5 shows a side view of this connection to the west end of B-41 to the 10-inch channel. This connection was made by six bolts through. the bent plate and the web of thé chan- nel, and this connection is. still:jn~ tact in the wreckage. % Only Three Bolts Carry Load. . Figure 6 shows the connection of this same 10-inch channel to the ver- tidal 3-inch by 4-inch angle by s of three boits. Notwithstand- ing-the fact that the load from B-41 wag delivered to this channel by si boits and that the channel was also called upon to earry in addition a considerable area of the roof, only three bolts were provided to trans- mit all of tkis load t6 the supporting angle. During the collapse this channel was torn away from the an- gle support and one bolt head was pulled clear through the thin steel web of the channel. Referring back to figure 1 it will be noted that in case any force tend- ed to disturb the equilibrium of the point of support over column No. 2, and cause a movement of B-ii, there was no member extending. westward- ¢ to resist such force, but the slight: est movement of B-41 ‘would tend to upset the lizght angle strut, whick rested so insecurely on top ef the truse below. - Flfure 7, drawn to scale, shows the relative positions and the unbraced condition above the balcony of col- umn_No. 2. and also o strut above it. When first there was no member in the plane of the ceiling between columns No. 2 and:No. 3. but this critical defect was discovered, doubtless because column No. 2 wouid not stand alone and had 1o he held. even temporarily. Conse- quently the ten-inch I beam strut wasg provided at the ceiling level as shown, This was not rigidly connected to the truss, byt simply connected by tw bolts to the flange of the trussi through a flat plate. P Splice Plates Inefeetive. Colimns No. 2 and ¥ were each spliced- above the balcony level to similar columns which extended from the foumdations up and through the balcony framing. These columns were more slender for their lengths than good practice warrants. The connéctions between the upper and lower columns was entirely inade- quate to develop the bending strength of these columns and when subjected to move their top mply broke away splice plates, just above the balcony. Figure € shows the manner which. the main truss was connected to the top of column No. 2. Sketch} (a) of figure 8 shows the top of column 2 as looked down upon, when it was in position. The four lug angles on this column were pre- sumably set level and flush with the top of the column section, which was cut square to the column axis. How- ever, it is practically impossible to rivet sfour lug angles onto a column in perfect slignment and one or more will be found a little too high or_a jittle ‘too low, or slightly out of level. Therefore, good practice re- uires that a cap plate be riveted to the top of such a column in order to ‘give a fair bearing surface and to distribute the load uniformly over the section of the umn. No such cap plate was used. Not less than seventy-five tons of load had to be * @elivered to this column at its top, and examination shows that a groove | . had been worn into the bottoms of the steel truss where it rested on e of the “H” colum: ‘This ndicate that the defiections changes in the truss had actually caused measurable mevement and corresponding’ wear at this peint, Sketch (b) of figure 8 is the elavation or side view of this connéction of the truss to the col umn, and sketch (c) shows the lug angle at the base of th angle strut, vl’\h t two bolts to fasten it tol and temperature the n truss. This is the strut that carries -three roof beams, in- cluding B-41. Only two holes were “provided for this lug connection. { - “'In 3 structure so poorly designed [ and detailed as this, gnd about which “ at this time only a limited knowledge | of the actual stresses is by the . writer, gfl{f' fieflu ;ov& evident rea- sons why fallups should -eccur Vinad - siand! s the angle| erected | 2 s Xhat their ures will ROL-Bd-t greement with recopded -giF X ever, it does not appear that the fallure was due to the pulling apart of any steel section and the writer would not ex- pect such to be_ the case. ‘Glaring ‘Faults Found. Some glaring faults in the sections of the trusses are found. The splic- ing of both the tension and compres. sion flanges of the several trusses was inadequate and improperly done, 80 that the stresses at the splices were nearly double the allowable safe stresses. However, failure did ?lot result’ from this cause, although it was tempting Providence to try such a reckless experiment over the heads of unsuspecting audiences. Evidently no thought was given the fact that truss No. 11 bolted to lug. angles on the top of column No. 2, caused large bepding stresses in -the- ¢olumn No. 2'due to -the deflection of (‘he truss jtself. This tall, slender. column ‘with inadequate connection at its base was unable to resist bend- 'l)r,l_‘g’&lrhesle! a(rlld simply tended to tip ase and i c 7 AT ip fact at the collapse t is difficult to determine what the loads and stresses were in tl’:\z Ihnhl- cony framing. An addition was made to the balcony last summer, the de- tails of which the writer has not seen. A glance at figure 1 will show that any disturbance of the eguili- brium of the framing at either of the Supports over the two columns, NoE. 2 or 3, would be fatal. It is evident that beam B-i1 is the most seriously overloaded and 1 pooriy supported member of the 1o0f framing. This beam is Showp .ta be of the same size as other beams' in the roof, which had much. smaller areas to support. “Beam B-41is bent at present, which, while not surpris- ing. is confirmatory of the view that it “was bent out of line by severe overloading. Here is a case where the snow load was.a larger. factor. than in the case of the trusges and it caused probably more than 25 per cent increase to the decad load Stresses. i ' Would Unseat Main Girder, ..Thig beam_being sq serioysly over- loaded would tend to buckle sidewise, and if it started to buckle it would bring a pull upon the top flange of the vertical channel on which its east end rested, and that channel uld instantly collapse, witl the sult that the angl€ strut aboye ¢ol- uwmn No. 2 would be pulled toward the east.. Column No. .2 wauld. be restrained by the.strut directly undet{" B-41. from falling in thit direction, with the result that it would be car- ried south_and slightly east, as was the case. “This would instantly pull the main girder off of its wall sup- port and the entire roof would col- 1apse. The mute testimony of the posi- tions taken by the fallen trusses and columns that had supported the roof shows that the movement was toward the south, that §s away from, the stage. The~ north. end-of the main truss was pulted off of. u?u ring on tipping that twebty-inch beam ovor, whtich indicates ¥ yery sudden. i As this truss fell.'it.dld. not scrape down the inner face of the ‘wall"but{" cleared it entirely, showing that.the movement was not. toward the north, nor even straight. downward, but toward the south, . As mome of the beams or trusses were: attached to eir wall bearings, they readily moved off_of them when the collapse began and the unstable jeondition 3, offered no resistance to the first rippling force, which the writer be- lieves developed in the beam B-41 and because of the weak sup- ports under that beam the collapse followed the overstressing of beam B-41. The change in temperature of the roof slab from 80 degrees to 30 de- grees would result. in lengthering the distance between columns Nos. 2 and 3 'a quarter of an finch, if it'is assumed that the walls ca not be pulled in that much by the stresses in the roof construction. From this it is evident that even the temperature of the roof had an influence on the st the struct as no means were idopted to ‘care for these irresistible stresses. . Plans Need Much Study. 1t reqyires painstaking study of plans to® discover Wwhether or not eacin and every connmeétion Of 'steel in [work and each detail of any kind of construction is adequate; One may not grasp the facts in a hurried, cur- sory examination of plans.and if the publio is to depend absolutely on government supervision to discover of ! the two slender columns, Nos. 2 and | — H - s N 787 STREET 10BBY. §NG.1 ROOF PLAN- KNIGKERBOCKER THEATER. y 2 Single Lines- Beas or Channel Double Lines- Trusses Fig S Sechon at 8 of Fig 4. Jookingseuth " looking sovth,showing’ | ShowirgConnectionof’ Commection of 10" Chamie/ B-4la 12T bthe % angle strot over ro'channel Ths Cof. 2. The &p bott Comgectiore IS fread e Hhes Conreectzor— iufiui;a.d Aas was pulled throvgh- 6 bolfs. Upper: Figure 2—Pl. Lower: Figure 3—Side view of conmection of beam Bél—to cham at column three—only the bottom flange of chanmel comnected to the ?l -, Lhe web of channe/ /n the eollgpse.., There were 3 botts Lbte. Groowe 1sworn inbotiomof __ -~ - e and correct all errors of ignorance or |. - incompetence, it will be important to have appropriations or building per- mits fees sufficiently large to support building inspection department with large corpe of trained enginéers ind inspectors. Even then it will be as it is now, of major importance that the designing and supervision of all’ buildings except very simple resi dences and similar atructures shall be intrusted only to architects who will agree to retain compétent engineers to make their structural designs or thfi: owners flhfi.llbodlrectly engage ngineers to collaborate with architects. e Architects generally do not wish to pay. out of their fees adequate compensation to competent engineers for designing and supervi: serv- jces. Therefore they are too often inclined to economize and omit em- ploying competent structural engin- ’::: as designers for what is afterall ‘most vital part of the building. It should be borne in mind that ltni‘s human \nature mnot to spend more than one can avoid for what does :fi lho;v and :—‘:l'“k:l‘;d“ the e eer is generally Einca ; en :out of. . L. Condron, Born.in.0..C., Looked Uron as Leader’ +* In"Engineering Circles ‘Theodore L. Condron, C. ] :g, has:been engaged in ‘practice im ' Fig.7 Showing that (ol and the Strut ing r00f beams were not ‘braced on the East side — ; Polytechnic Institute, where he was|Genmeral' Electric ‘Company, Sears. a classmate of George R. Putnam, | Roebuck & Co., Ford Motor &-my, now United States commissioner of | Wagner Electric Manufact: Com- Z { Iighthoyses, : Goodyear @l*Z 3 During the past twenty-ome years - . as a consulting and design- Navy Department 3 ing structural. . Among -his | ya; nts . "finu for. bridges and similar|jess wi structures have been a number of| Tn 1917 rafiroads, including the Chicago. and|Mr; Cond: Eastern - Illinois, Iilinois Central, M. K. and T., and Mobile and Ohio. A jon of his work has betn in rtant - buildings | Co: lar, oo, T et ke uhtry. - e Condron Gomnection of (]"2and Truas*11 s om e S AT 4 sz "% e Fig.6 SectunatAsfiy P 8?15‘.22;7;;151'5371&7&( ‘ be of interest to your readers to ‘l,muson;eug.ng of the system in on - b sy n the nearby city of Phila. As engineer of highways of Phila- delphia for five years between 1912 and 1917 the writer was in charge of the removal of snow from the city streets during that time, and therefore had more or less to do with the inaugu- ration of a new idea. in handling| snow. Philadelphia was the first city to r snow removal as an en- gineering problem amendable to solu- tion by the application of ordinary engineering rules. Prior to 1912 snow removal, in Philadelphia and in other American cities, had been con- sidered an emergency duty 1o be per- formed after the snowfall had ceased rather than a routine function which | became operative as soon as the snowfall has started and should con- tinue throughout its progress. On Christmas eve, 1912, Phila- delphia was visited by a very severe snowstorm, quite like the recent one in Washington. After the storm be- gan the writer was placed in charge of the removal of the snow from the streets. Neither he mor any of his engineer colleagues in the recently installed city government had had any experience in such work. There- fore, following the custom of 150 vears, the storm was allowed to com- | plete its damage before any work of | removal wss begun. The next morn- ing the snow had reached 2 depth of | nearly two feet and, with the excep- tion of a very small amount of re- moval with the few men and teams the officials were able to induce to work for emergency prices, the $n0w remained in the strests until it.melt- ed and Philadelphia floundered eround for over a week in about the same | kind of a mess as Washington has! experienced during the past mnine | days. There was simply no snow or- | ganization worthy of the name. H Begin When Snow Starts. This ome experience with time- honored methods of - snow removal quite enough for the engineers in hfi; of the work, and tkey im began to put into effcct an y _new practice, namely, that of fighting the storm and beginning the fight shortly after the snow had commenced to fall. It was realized that the fundamental problem was o maintain norma! traffic conditions as nearly as possible during and The city telephone bureau in City Hall was on duty day and night and was required to notify the writer by telephone at the first sign of snow during the night. It was then his duty to determine whether it would be necessary to order out the snow’ plows. If so, he notified his two principal assistants by telephone. They in turn each called their i spectors-in-charge of districts. These inspectors notified the plow contra removal en, trucks and teams word went forth to that effect by teicphone to the contractors and then very quickly to the laborers. through th 1s. Usually morning _of - upward of 4,000 men und 1.6600 trucks and teams were at work. The plows, working during the night. had cleared the main traveled way of the streets and traffic conditions were almost normal. And after the plows had finished the central streets they werr sent to outlyingrsections, even, in fact, on maih country roads. where they operated in pairs or batteries Formed Within Thrée Weeks. The snow organization described @hove wag completed and put into eftect in Ehiladelphia Within _thre 8 of the snow: = Weks of the, snowstorms of Christ The city cagineers made their snow orgmnization successful in spite of the very heavy handicaps of having practically no funds, for, although 1hé cost of snow removal in Phila- ‘delphia sometimes emounted to sev- eral hundreds of thousands of dol- lars per annum, the annual appro- priations available before the work was done was never over $2,500— hardly enough to pay for a few hours’ work. ~The balance had to he met during the spring by a deficiency appropriation. Not v has the tem been successful from the start but many cities have based their snow force reorganization more or less on the Philadelphia plan. Of course, the scope of the work varies in different cities. For instance, while Philadelphia undertakes to clean fifty miles of streets, New York city s a program embracing over 500 miles, but the practice is the same in both after the storm. This czn only be accomplished by fighting the storm. The actual disposal of the snow is. of course, important, but it is of scc- ondary importance. Almost all snowstorms in Philafiel- phia begin in the afternoon or at|) night, and as it was found almost impossible to induce many men to shovel and haul snow during the stormy weather at night, it wag de- cided that the main night work must, be done with some kind of plow machines to keep the traveled w in the streets clear as the snow fell. Horse-drawn roadscrapers were tried out and found inadequate. They were too light and moved too slowly. What was needed was speed combined with efficiency. Several contractors o’ ing large five and tem ton moter trucks were persuaded to equip thir- ty of them with adjustable plow bladgg, fastened on: the . front of the tr and arrangements were made whereby these tfucks with their crews were available day and night. They were paid by the truck-hour. The tremendous value of these pewerful plow' trucks during a snow storm is quite apparent when it is realized that they can plow. 1o a depth of six inches of fresh snow at a speed of from twenty to twenty five miles an hour. The street r way company at the city’s request also equipped eight cars with front and side plows to supplement their sweepers. Divided Inte Districtw. ‘The central business portion of the city was divided into nineteen snow districts, comprising about thirty miles of strects. Detailed plans of these districts were prepared show- ing the sewer manholes which might be used for dumping the snow. Where it was found that there was in- sufficient flow of water in the sewers, the manholes were fitted with water connection to increase the flow. Bils were received by the city from team- ing contractors for the removal of snow within the nineteen snow dis- tricts. Not more than two districts were awarded to ahy one contractor. The basis of payment was per cubic yard of snow disposed of in a man- hole or other dumping place indicated on the plans. The contractors were subject to call, and wers rtequired under penalty to have a certain num. ber of men and teams at work within their respective snow dlistricts within one hour after notification to begin work. The total force required for the nineteen districts was 2,000 men cities, and every northern city should r of Philadelphia invited northern cities to . Snow which was held in that city April 16-17, 1914. Representa- ives of sixteén cities were present and their report was presented at the mecting of the Americ ciety of Municipal Engineers cember, 1814. 1t might be noted that one of the enost active delegates t the snow conference and one wh made some very valuahle suggestion as to possible improvements in =now- removal practice was a former t cleaning Commissioner of the city of Washington, D. Cont of Plows Slight. In conclusion, it is sugge: the recent snowstorm in Washing would not have caused anvthing 1 the inconvenience it did if There forty heav: various conference turday, y throughout the might and follo: day. 1t costs comparatively litle to equip a_ motor truc! with @ plow blade. It might readily be done at the Army, Navy or Post Office garages or machine shops in Wash ington quite cheaply with surplus war materials, of which the War D« partment has sueh large stores. The Fovernment trucks are operating in Washington in large numbers and are under the control of the-engince Commissioner, having been receny placed under his jurisdiction hs ehief co-ordinator of motor tran port by the director of the budget. Tt should, therefore, be within the power of the District officials to pre- pare almost immediately the snow- fenting motor plow eguipment, which most cities find has solved the most important factor of the problem. —_— LOWER COURT UPHELD. Mandamus Sought by Foster Father of Soldier. The District Court of Appeals an opinion by ef Justice Smyth. ustained the action of the District Suprema Court in denying a m damus sought by John F. Norris, fox father of illiam_Ricketts. soldier, against Charles R. Forbe: director of the bureau of war risk insurance, and Andrew W. Mellon. Secretary of the Treasury. After the death of TRicketts Congress amended the war risk act ®o as to make the term in and 800 teams and trucks. In addition, the regular street cleaning force was also organized snow work. This force included 1.280 men and 200 teams and trucks. They were required to clean the crossings in the central part of the city and to remove snow in the outlying sectious. The municipal repair and sewer gangs consisting of 1.110 men and 110 teams and trucks, were an extra force avai able for snow ‘work in severe storms, thereby making a grand total of the snow force of 4,390 men and 1.110 teams and trucks, thirty heavy auto- mobile plow trucks and eight trolley plows. 140 in Supervision Work. To control this force the work was done under the supervision of the Writer, who had an engineering and inspection outfit of about 140 men, who were available day and night, working, however, in two shifts of twelve hours each. Each man had a definite assignment. The organization was-as follow: Two division engineers—one in charge of teA of the mnineteen snow districts and of fifteen automobile plows and one in.charge of nine of the districts and fifteen. of the motor plows. To each of these division en- gineers was assigned a chief inspec- tor, who assisted him in general sup- ervision. To each of the nineteen snow districts w assigned an in- spector-in-charge, assisted by six ica, involving' a property .loss of over $200,000. The Condron Com- pany. has sirce been -retaimed: to ‘make a new design for the structural fea- tures of .this temple,” which is esti- mated t6 cost one million dollars. K;Acnng:::l tl; ln:!l;lb!ar '?( the ‘American el “Engineers, the American mfl:‘qgsu‘lmers' A umerous other -techr sociation ) socl Mr. Condron was en ontc Temple Assg- x" o5 1o fuvesd ;] Ala., recently sent to the Hous: 7 father include persons standing in relation to the deccased. an jrris claimed under that provision. he burcau denied that he was en- titled and the petitioner sought a mandamus. The bureau ati: tion of the local acked the. jurisdic- court and asserted that a suit over such disagreement frust be heard in the district coutt Where the petitioner resides and as Norris is a resident of Maryland. pro- Seedings must be had in that state. The lower court sustained that claim and the Appellate Court has upheld the ruling. WILL CONSULT HOOVER. New England Chamber of Com- merce Officials Arrive. Fifty seoretaries and president chambers-‘of commerce of thirty towns and’ cities in. New England have arrived . in Washington for a two-. day ~_conference with Secretary, ‘Hoover. s of -five . The conference is to be held today 3 and tomerrow. Kecretary Will _describe the work being done fhe bureau of - forefgn and fe: - - commerce - in _promotinz: ign trade. The present oconomic situation with respect to foreign trade also will be_ discussed. —— WILL DISCUSS FORD OFFER" e Secretary Weeks to Appear Before House Military Committee. etary Weeks announc d to- da?f‘?l‘ul he would appear before the Hoase - military _affairs - committee Wednesday at 10:50 o'clock to supple- ment orally, his report on the con- act roposal Putchase and operation of the niira 2nd power projects at Muscle Shoz —— GEN. HARBORD ENDS TRIP. Maj. Gen. James G. Harbord, dep- uty chief of staff, who accompanied ‘Wainwright, assistant -secretary r, on an ;extensive. tour. of in- jon of military posts and .sta # in the south and west. returned i h:ra 'this morning and resumed his _ at the War_ Department. JAs- dutle: sistand Secrétary- Walnwright, pxtend his trip to St. Paul ‘und oth ints, in_the northwest, A séted\ to return to this city lulP 2y. - 7 of Henry Ford for ° Hoover » e, W i e