' WESSANALVSIS.‘ ' _ “0'“ f" 150 Demo 6! 8.13. jf‘ MICHIGAN STATE COLLEGE “ ;. RiChlrd W. Jones 194:, -.’- ' ' wv—‘v. D 3 . L. .I ' Q . q.‘ u . .,. ' ' .I . . ll I ‘0: . '5 v .- . - ' . ' I a ‘ q ' ‘ ’ '0 - 9 ~ . . ' ' r 0" . .. ‘ l . ‘ .9 _ I . I ' ‘ Or ‘ ‘ . ' ‘ n I I .- U. o .. .> ‘1‘, . 1 'i .I. f 0 .— ~ ‘ . ; _ I T ‘ ‘ '. u. _ x ‘ I u . . " 94?" ~ -‘. c ‘H I '. ‘ ‘ ‘ . . I ‘ .. V , . . . .. u, ‘9 . n. I _ "Q - ‘ ‘Q- | I ' | "*O‘v I ‘. _ -1; .. "I O. ’ __ ‘ ' ' ._ I: ‘ " . "fij I. z ‘ - AL’ 'I ' I I. .. I I ‘ , I . - . . .. . ' a ' Il . . .- .~ ' ' . u - A . ‘ ' 4 . ‘ u, so . ‘ " '1 ' c o r , ' , o n. . ,‘ ' 1'. . . . ' 4 : : . .“j: . ) . . > . ' l- ’ .1. I4 . I - I , . ' . .o‘. O: ' h z .’ i .. ' ._ " ‘. f . ..: v . . _ - __ ‘ ‘ $0 .. -. .. A 0’ ' . :5 ‘ " "' . . '.. ' f. . L “A . t .’ :0: 1- g h I l I ' . _ . f .; m 1.8 I." ’ .. .. .... n l -V\ - u. r , . ~ . . " , ;.- ' ' .I ..' . . ‘ . r : ~ . f ‘ ' 'I n O ' I _ > . . I V ' ‘. if, 1 ‘- I . .2 ‘u 'i ‘... - o . . 0' O 13' ‘ ’ Q . ' . T i' . - v . ‘ a n “I J‘ . II " I ' ' l ' i. . . '. O . - v:., . ' . a .' f I I ' .. ' l 9.. . .. -. .. ‘ 3 - ‘O- . Q THESIS /? , (“KC/fl/ 0 'FI.rIiIB Ihlv III-“Fl--- lltil' r._ ’I I} x I 4 . . I \. . . . o. in i . I . m I Q. L. \J- .t I. I . O . cl... . O r Ila-u . 4 II. . _ . . I . . . ‘ L I I . . I \ I. ‘ I u I . o I \ )I. . x .. . n I o I, . - I I I. I . . a . I I . . .I .I. I I Ir . . I ._ I ... I r . u . . . — . o . I . I ~ I o . . t \ § I. .. , I . . r \ u.I I. . | I... . . I. I . .l I v I ~ I III \ I u , . I ~ I ‘1 1 r. . . I II . u I . I ’ I . I I I I II n I . . . . a j I .l. u‘ I ‘l a h . . I .J. III: I 1- III.J l O r . . I I . I I _ I. . l o , .2 _ . u I .u . o . . I - II . u . . . ‘ .. . . . u . . . J x I . I . I o I x . . . . ‘ . . I 4 I f I I I .1 . . Ir IQ. l I p I ‘ _ . . I I . . I . , _ .I. .. .. a Stress Analysis. Steel Fire Tower A Thesis Submitted to The Faculty of MICHIGAN STATE COLLEGE of AGRICULTURE AND APPLIED SCIENCE BY Richard w. {9333 Candidate for the Degree of Bachelor of Science June 1941 THESIS Czar.) . / a 0U TLI FIE I. INTRODUCTION II. I-‘IETHOD OF ANALYSIS I II . LEIGH I TUBE CF LOADS A . DEAD LOA DS IV . E'PSRE’III‘IATICN OF STRESSES A. COLUZ-EN STRESTES B. DLIGCI‘EAL S' HESS-ES C. S‘I'PESSES IN HORIZONTAL SCRUTS D. STRESSISS IN HORIZONTAL GIRTS V. ALID‘W'ABLE STEBSSES A. COLUI—iNS B. DIAGCNALS C. HORIZONTAL STRUTS D. HORIZONTAL GIRI‘S VI . GONG LUSI ON 1.36099 IN ODUCT ON The need for steel observation towers, or fire towers, of the type which is analyzed in this thesis arose along with the need for the prevention and control of forest fires in the nations' timberlands. One of the most important factors in fire prevention and control is the detection of all fires while they are still in their early stages. Once a fire gets a good start, it is a difficult Job to arrest its progress and keep it from spreading farther. One man, armed with a pair of highppowered field glasses and situated in the cab of a fire tower one hund- red feet above the ground. can watch over a large area of forest and can immediately report any traces of smoke he may see. If two men in different towers can see the same smoke. the exact location of the fire can be determined and men and equipment can be rushed to the spot before the fire has a chance to become very large. . A large number of these steel fire towers have been erected. The United States Forest Service has built them in the National Forests, and most of the state conser- vation departments have erected them to guard over their state forests. The steel observation tower which is analyzed in this thesis is 109' high to the tap of the cab, and is the most modern type in use at the present. This type has been adep- ted as standard by the Michigan Department of Conservation. The tower is designed and built by the Aermotor Company, Chicago. Illinois. It consists mainly of structural steel . angles, and all parts are cut to size, drilled preperly, and galvanized at the factory. The members are shipped to the location.of the new tower. and all the parts are numbered so that the tower is ready to assemble. It can be erected by a crew of four or five men. being assembled by means of either bolts and lock nuts. or bolts. nuts and lock washers. The blueprint in the pocket in the back of the thesis shows an assembly view of the tower. the number of each piece. the size and number of all rolled sections. the size of bolts used.and assembly detafIs“wher§”needed. Also includ- ed in the back pocket is a checklist of all parts. giving the part number, quantity, name and description of each piece. All the information used in the analysis of the tower was taken from the assembly drawing and the checklist. The main purpose in choosing this subject for a thesis was to enable the author to become more familiar with the methods of design and analysis of steel structures in general, and to apply these methods to a problem which required.a technique different from the techniques that 'were used in the several design courses given in the civil engineering curriculum. METHOD F Ah? ALXF‘BIS The method used to analyze the steel fire tower is similar to that which is commonly used in the design and analysis of a water tower. There are. however, certain features of the fire tower which make the problem of analysis somewhat different, and.which require a slightly different procedure. The presence in the structure of numerous interior bracing members and additional members in the exterior framework makes the tower a statically indeterminate structure. Therefore it can not be solved by the ordinary methods of mechanics. In order that it may be analyzed by a method which is not too highly technical, but which is practical and usable, certain assumptions are made to simplify the analysis. These assumptions are: The principal members which take the stresses are the columns, the diagonal braces and the horizonp tal struts. as shown in Fig. l. The remaining members, with one exception, are not considered to take any stress, although their weight is included in the dead weight of the tower. The one exception consists of the horizontal girts to which the stairwaysare fastened. These girts are checked for stress caused by the weight of the stairways. These assumptions form the basis for the complete stress analysis of the tower. The analysis is divided .into three parts, each of which is followed through in detail on the following pages. The three parts are: (l) The determination of the magnitude of the loads acting on the tower. These con- sist of the dead load and the live load. (2) The determination of the total stresses and the unit stresses in the prin- cipal members, caused by the dead and live loads. (3) The determination of the allowable unit stresses in the principal members, and a comparison‘between the actual unit stresses as found in part (2) and the allowable unit stresses. DEAR AND LIE; LOADS D? D LOAD The dead load to be considered in the analysis consists of the weights of the individual members, the weight of the people and equipment in the cab, and the weight due to snow on the cab roof. In a symmetrical four-leg tower, the vertical dead load is commonly assumed to be divided equally between the four columns, and it is assumed that the struts and diagonals are not stressed by such.vertical loads. However, in this tower, each column is made up of six lengths of structural steel angle, varying in size from 3"x 3"x l/4" at the top of the tower to 5"): 5"x 3/8" at the bottom. Since the total weight on each column is not the same at different elevations, the maximum weight on each member of each.column must be found. This is done by passing a section horizontally through the tower at the lower end of each member of the column, as shown in Fig. 1. Section "A-A" passes through the lower end of part 0-900, section "B-B" through the lower end of part U-901, etc. The total vertical load above each section is found, and that load is divided equally between the four column members through which the section passes. I 111 DEAD LOAD ON COLUMNS fig-.1: _._. ,,_,____~ _. _——————_. — -q sags £2 The allowance for snow load depends on the pitch of the roof, the climate and the material of which the roof is made. Since these towers are used in so many locations, the maximum load for the given conditions is used. The computations for the snow load are as follows: Pitch = 2.122 3.2" = 21. . span 96" 4 Type of roof == metal Snow allowance =:25 lb. per sq. ft. of horizontal surface. (from Structural Theory, by Sutherland and Bowman, p.61) Horizontal projection of roof area = 7’x 7' ='- 49 sq. ft. Say 50 sq. ft. Snow load == 25 x 50 = 1250 lb. EngHE 9g; STAIRWAXQ" Before the weight of each stairway can be computed. its length must be found. The slaps or all the stairways is shown in the figure: L2 = 122+ 9&2 /2 A L‘2 = 144 + 85.56 I.2 -= 229.56 L = 15.15 9;— L = length of stairway == rise of stairway 1 €55— : rise of stairway x 1.26 Rise of stairway is shown in Fig. 10. L2: 6.75' x 1.26 = 8.5' = tan-6" L3: 9.0' x 1.26 = 11.35' = 11'4" L4 = 10.5' x 1.26 = 13.25' = 13'4" LJ.= 12.75 x 1.26 = 16.os'= 16'-1" L6=13.5' x 1.26 = 17.0' = 17'-o" L7= 17'-o" Ll: 17'-o" 1.5’ = 17 no" The following are the computations for the weights of the stairways. The first figure is the part number as shown on the assembly drawing in the back pocket. followed by the quantity, description. weight per lineal foot. and total weight or each part: STAIRWAY N0. 1: U-676 2 - 1 x l x 1/8 x 7‘-O" @ 1.23 17.2 lb. 0-677 2 «- 13 x I: I 1/8 x 8'4)" @ 1.23 3.9.6 16-2:2:1/8:1‘-"@1.65 26.4 16-212x1/81 " @1.65 20.4 8 Treads «- 2 x 10 x 2'43" @ 4.29 68.6 11-690 1 - 1 x 1' x 1/8 x 2'-2 7/8" @ 1.23 2.8 11-691 1 - l x l x 1/8 x 4'o6 3/8" a 1.23 5.6 U-698 1 - 2 x 2 x 1/8 x 4!-5 3/8" @ 1.65 7.4 m T0381 16800" 1b. STAIRWAY NO. 2: 0-678 H-679 # " 1313‘ X 1% 1: V8 X 8"‘5.’ @ 1.23 41.8 lb. 18 " 2 X 2 X V8 X 1.-0“ @ 1065 2907 18-2x2xl/819’;" 21.65 22.9 9 Treads - 2 x 10 I 2'-0" @ 4.29 77.3 U-692 2 - 1% x 1% x 1/8 x 8'-5 9/16" a 1.23 20.9 (Itfifi 3:33: 2 x 2 x ,1/8 x 16'4“ @ 1.65 27.0 Total 219.6 lb. STAIRWAY NO. 3: 0.680 0-581 4 - 1% x 12 x 1/8 x 11'-4" @ 1.23 24 - 2 x.2 x 1/8 x l’-O” @ 1.65 24 o 2 x 2 x 1/8 x 9%" @ 1.65 12 Treads @ 8.58 lb. each U-693 2 - 12 x 1% x 1/8 x 11'-3%" @ 1.23 U-949; 0-950 H-951; H-952 (Same 38 I10. 2) 3:;82 2 " 2 X 2 x 1/8 X 7‘..11%.~* @ 1.55 Total 0r STAIRdAY NO. 4: U-682 3,683 4 - 1% x 1% x 1/8 x 13'-3" 2.1.23 28 - 2 x 2 21/8 x 1’70" 2 1.65 28 - 2 x 2 I L/B x 9%" @ 1.65 U-694 2 - 1% x 1% x 1/8 x 13*~2§" @ 1.23 0-949; 0-950 0-951: 0-952 0‘70} 0-704 (Same as no. 2) (Same as no. 3) Total Or 55.? lb. ‘70.2 103.0 27.7 27.0 13.1 296.7 lb. 300.0 lb. 65.3 lb. 81.8 120.2 32.5 27.0 13.1 m 339.9 lb. 340.0 lb. vases 0-685 0-695 0-949; 11-950 0-951; U-952 U¥703 U~704 0-686 0-687 U-696 11-949; 11-950 ' U—951; 0-952 U670} 0-704 STAIRHAY NO. 5: 4 - 1% x 1% x 1/8 x 16'-1" @;1.23 32-2x2xi/sx1'-o"ei.65 36 - 2 x 2 x 1/8 x 92" @ 1-55 17 Treads @ 8.58 2.- 1% x 12‘: 1/8 x 16’-0&“ @ 1.23 (Same as no. 2) (same as no. 3) Total STAIR‘;‘¥AY3 1‘70. 6' 7. 8. 9: 8 - 1% x 1%‘8 1/8 x 17'-O“ @ 1.23 36 - 2 x 2 x 1/8 x 1’-O” @ 1.65 ‘36-2x231/8x 92'? 61.65 18 Treads @=8.58 2 - 1% x 1% x 1/8 x 17‘-0" @ 1.23 (Same as no. 2) (Same 8.3 no. 3) Total 0r 79.1 99.4 146.0 39.6 27.0 13.1 404.0 83.8 105.0 154.7 41.8 27.0 13.1 I“ 425.4 426.0 1b. 1b. 1b. 1b. 1b. A” ”b.0241 RAILINGS AT 6th, 7th a 8th LANDINGS: U-955 2 - 2 x 2 x 1/8 x 3'-7%" @ 1.65 11.9 lb. 0-961 '1 - 16 x 1%.: 1/8 x 5'-1%“ a 1.23 6.3 3:323 2 - 1% x 1% x 1/8 x 2'-1o" @ 1.23 - 7.0 Total 25.2 lb. WEIGHTS OF LANDINGS: (Weights or 2" wooden planks = 7 lb. per sq. ft.) . landing No. 1: (35345) x 2 x 7 49 lb. Landing No. 2: (—é—é—ad x 7 63 1b. landing No. 3: (Jig—‘1} x 7' 6311:. Landing he. #: (liéfgé) x 7 112 lb. Landing No. 5: (fig—2i) x 2.5 x 7 100“ lb. landing No. 6: (6 x 2.5) x 7 105 1b. Landing No. 7: ” _ " " 105,,1b. Landing No. 8: " " " 105 1b. { 0-956 U-67o 0-947 0-661 0-662 0-655 0-663 0-664 0-919 U-920 0-667 U-666 0-587 0-669 U-588 0-589 0-590 U‘591 0-592 0-593 “YEIGHT OF CAB- 1 4 .p- H HH HHN DEAQ LOAD ABOVE SECTION A-A: Ventilator and.base Roof sectionp #20 ga. galv. 17 sq. rt. @ 1.5 1b./aq. ft. Roof flaehi - #20 53. galv. 6“ x 7.-n§ '1; 105 Roof angles- 2 x 2 x 1/8 x 4'-1o§" @ 65 Cap plate- 12" x 12" x 3/16" with 6%" diam. hole Gusset plate for roof angles- 4" x 6" x.i" Roof girt angles- 3 x 3 x i x 6'-11§” @ 4.9 Roof girt o11ps- 3 x 3 x t x 5%" 0 4.9 Sash clipe- 1" x 1 3/4” x 3/16" Fenestra metal sash with.glasa and 0-668 clips- Window 21115- 3 x 3 x i x 6'-11" @ 4.9 Siding- #20 ga. 331v. 7' x 4' 2 1.5 1b./2q. ft. Cab girta- 3 x 3 x i x 6'-11" @ 4.9 Cab girts- 3 x 3 x i x 6'oll" @ 4.9 Cab girt- h 3 x 3 x t x 2'-10§“ @ 4.9 10 1b. 102 21 65 13 137 10 300 136 168 136 69 15 1189 lb. Weight forwarded— 1189 lb. Equipment in oab- 100 Maximum of fiva men@ 160 1b. each- 800 Floor of cab and trapdoor- 50 sq. ft. @‘7 1b. /sq. ft. 350 Snow load! 1250 Nuts. bolta. etc.- 100 '31.":171’1 qHT 0F STAIRWAYS- ‘Weight of ataxrway no. 1- - 168 One half weight of stairway no. 2- 110 WEIGHT OF COLUHH“- 0-900 4 No. 1 corner posh 3 x 3 x t x 19'-10" @ 4.9 388 WEIGHT BE1NEEN CAB LANDIRG & let LANDING- U-546 8 No. 1 angle brace- 2 x2 x 1/8 x 9' ~7" @.1.65 126 0-596 ' 8 No. 1 girt- 2 x 2 x 1/8 x 3'~92" @ 1.65 50 [1-562 4‘ NO. 1 tie“ 2 x 2 x 1/8 x 3'-9" 2 1.65 25 U-571 8 Gusset plate. no. 2 girt- 10"x 2" x 62' 37 U-756x 2 No. 2 girt- 11-598 1 22 x 22 x 3/16 x 7'62“" “ 3. 07 92 U-599 1 U-921 1 Girt lat Landing- 32 X 32 X i I 7'-12" @ 5.8 41 0-601 1 Girt 1st.é Lanai 22 x 22 x 5/1; 2' -1o2" @ 3.07 9 0-602 2 Girt, lat Landing- _ 2 x 2 x 1/8 x 5'o1"0 * 1.65 17 4852 lb. WEIGHT BET-.‘JEEN 181‘. LANDING 6:: 2nd LANDING- Weight forwarded- 4852 lb. U-527 8 No. 2 angle brace- 2 x 2 x 1/8 x 9'-112" 2 1.65 132 11-604 8 NO. 3 81". 2 x 2 x 1/8 x 4’-32" @ 1.65 57 [1-563 # NO. 2 tie- 2 x 2 x 1/8 x 5’-1o" 2 1.65 25 Landing no. 1-' 49 T011212. WEIGHT ON SECTION A-A 5115 lb. 0222 1,922 22012 sagTIog B-B: ¥EIGHT BETWEEN 2nd LANDING & 5rd LANDING- Weight above section.A-A - 5115 lb. {1.605 2 NC. # girt- 2 x 2 x 1/8 x 8'-42" @ 1.65 28 0-606 1 No. 4 girt- 0-607 1 22 x 22 x 5/16 x 8'-42" 2 3.07 52 0-914 No. 1 Splice angle- 3 x 3 x i x 0'-10" @ 4.9 17 0-572 8 Guaset p1ate, no. 4 girt- 8" x 2" x 11 3/4" 54 0-901 4 No. 2 corner post- }2 x 3‘2 x z x 16"-0" C 5.8 371 0-548 8 No. 3 angle brace- 2 x 2 x 1/8 x 12’-5" 2 1.65 165 0-609 3 Girt, 2nd landing- 2 x 2 x 1/8 x 6'-2" 2 1.65 31 0-922 1 Girt 2nd landing- 32 x 52 x 2 x 6'-22" 2 5.8 36 0-610 8 No. 5 girt- w 2.: 2 x 1/8 x 4'-102” 2 1.65 65 0-564 4' NO. 3 tie" 2 x 2 x 1/8 x 5'-O&" @ 1.65 54 WEIGHT BEiWEEN 3rd LANDING & 4th LANDING- 0-611 2 No. 6 girt- . 0-612 1 22 x 22 x 5/16 x 9'-92" ® 3.07 120 0-613 1 0-923 1 Girt, 3rd lanai - 4x4xtx6-5"@6.6 43 6131 lb. Weight forwarded- 0-615 2 Glrt 3rd landing- 2 X 2% x 1/8 x 7'-6" @ 2.08 0-616 1 Girt 3rd landing- 2- x 2% x 1/8 x 7'-1%" Q 2.08 0-617 8 No. 7 girt- 2 x 2 x 1/8 x 5'-7%" @ 1.65 0-573 8 Gusset plate no. 6 girt- 8" x 1" £11 3/“ 0-549 8 No. 4 angle brace- 2 x 2 x 1/8 x 14'-6%" @ 1.65 0-565 6 No. 4 tie- ‘ 2 x 2 x 1/8 x 5'-1o" 6 1.65 One half weight of stairway no. 2 - Weight of stairway no. 3 - One half weight of stairway no. # - Landing no. 2 - Landing no. 3 - TOTAL WEIGHT ON SECTION 3-3 6131 lb. 32 15 75 54 192 39 110 300 170 63 63 7244 lb. QEAD LOAD ABQEE SEQTIOy Q-C: WEIGHT BETWEEN 4th LANDING & 5th LANDING- Weight above section.B-B - 0-915 0-574 0-618 0-619 U-62O 0-924 0-622 U-902 U-BSO 0-624 0-566 4 (I) +4 142”» No. 2 splice angle- 32 X 3% x i x 1'-O%“ @ 5.8 Gusset! plate. n9. 8 girt" 8" x in x 122" No. 8 girt- 3 x 3 x i x 11’-3%" 6 4.9 Girt, 4th landing- 5 x 3% x 7/16 x 7'-9" @ 12.0 Glrt, 4th landi - 3 x 3 x 2 x 8 -2" ® 4.9 No. 3 corner post- 6 x 4 x i x 16'-2i“ 2 6.6 No. 5 angle brace- 2 x 2 x 1/8 x 17'-3%“ @ 1.65 NO. 9 girt- 2 x 2 x 1/8 x 6'-6" @ 1.65 NO. 5 tile. 2 x 2 x 1/8 x 7'-1" @ 1.65 One half weight of stairway no. 4 - One half weight of stairway no. 5 - Landing no. 4 - TOTAL WEIGHT ON SECTION 0-0 724# lb. 25 56 222 93 120 428 229 86 47 170 202 112 9034 lb. (.1 DEAD LOAQ ABOVE SE TION D-D: WEIGHT BETWEEN 5th LANDING & 6th LANDING- Weight above section C-C - 9034 lb. 0-916 4 No. 3 sglioe angle- 4 x x i x 1'-3" @ 5.6 33 0-575 8 Gusset plate, no. 10 girt- 8“ x i" x 12 3/16" 56 0-625 2 No..10 girt- 0-626 1 3 x 3 x i x 13'-2%" @ 4.9 259 0-627 1 0-925 1 Girt, 5th landing- 5 x 3% x 7/16 x 7'-10" @ 12.0 94 0-629 1 Girt 5th11an - 2~ x 22 x 3/1 x 3'-4%" e 3.07 11 0-630 2 Girt, 50b landing- 3 x 3 x i x 10'-4%" @ 4.9 98 u-631 1 Girt. 5th lanai - i 3 x 3 x i x 9 -62” @ 4.9 47 U-903 4 No. 4 corner ost- - 4 x 4 x 5 16 x 13'-62“ @ 8.2 444 0-551 8 No. 6 angle brace- 2 x 2 x 1/8 x 19'-3" @ 1.65 255 0-632 8 No. 11 girt- 2%~x 2% x 1/8 x 7’-6" e 2.08 125 U-567 4 No. 5 tie- 2 x 2 x 1/8 x 7'-5" @ 1.65 49 One half weight of stairway no. 5 - 202 One half weight of stairway no. 6 - 213 Landing no. 5 - 100 TOTAL WEIGHT ON SECTION D-D 11029 ID. QEAD LOAD ABOVE gmcwxou gzg; Height above section D-D - 11029 1b. 0-917 4 No. 4 s lice angle- 4 x E x 5/16 x 1'-5%" @ 8.2 48 0-576 8 Gusset plate, no. 12 girt- 8" x 2" x 13 3/8“ 62 0-633 2 No. 12 girt- 0-634 1 3% x 32 x 2 x 15'-3" 2 5.8 354 0-635 1 0-927 1 Girt 6th landing- 5.x 3% x 7/16 x 12'-2" 2 12.0 146 {3-928 1 DO o 2% x 2% x 3/16 x 5'-7" 8 3.07 18 0-638 2 Do. 3% x 3% x i x 10‘-4" @ 5.8 120 U-639 1 DO. 3% x 32 x 2 x 10'-11&" 64 0‘67} 1 DO 0 0-674 1 2% x 2% x 3/16 x 3'-52" 2 3.07 22 0-904 No. 5 corner ost- 4 4 x 4 x 7 16 x 19'-9%" 2 11.3 895 0-552 4 No. angle brace- 21 x 22 x 1/8 x 12'-9%" @.2.08 0.553 # D0 0 2% x 22 x 1/8 x 11'-4" [1-554 4 DO 0 2% x 2% x 1/8 x 14'-9%" [1‘555 4 D00 . 22 x 23 x 1/8 x 13'-4" #35 0-640 4 No. 13 girt- 22 x 2% x 1/8 x 16'-9%" 140 11.568 4 N 0 0 t1 8- 2 x 2% x 1/8 x 4'-6" 38 13362 ID. Weight forwarded- 13362 1b. U-642 2 No. 16 girt- u-543 1 3 x 3 x i x 17'-1o" @ 4.9 349 U-644 1 U-931 1 Girt, 7th landing- 6 x 4 x 3/8 x 13'-7%" @ 12.3 168 ”-6468 1 DO 0 U-646L 1 2% x 2% x 3/16 x 4'-2i" @ 3.07 26 U-928 1 Do. 2% x 2% x 3/16 x 5'-7" 18 One half weight of stairway no. 6 - 213 Weight of stairway no. 7 - 426 One half weight of stairway no. 8 - 213 Landing no. 6 - 105 Landing no. 7 - 105 . Railing at Landing no. 6 & no. 7 - 50 TOTAL‘WEIGHT 0N SECTION E-E 15035 1b. REAR Weight above section E-E - U-918 U-579 U-651 U-556 U-557 U-558 u-559_ U-905 U-569 U-562 U-654 U-655 U-656 U-94O U-658L U-GSBR U-928 2 8 .p r4 revue No. 5 silica angle- 4 x x 7/16 x 2'-1" @ 11.3 94 Gusset plate. no. 15 girt- 11" x i“ x 18" 112 No. 15 irt- 4 x x i x 18'-1%" 8 6.6 478 No. 8 angle brace- 22‘.- x 2% x 1/8 x 12'-5" @ 2.08 D00 2:; x 2%,- x 1/8 x 13'-8" Do. 2%; x 2%; x 1/8 x 14'-9" Do. 2% x 2% x 1/8 x 16'-0" 473 No. 6 corner ost- 5 x 5 x 3 8 x 22'-3" @ 12.3 1100 NO. 8 tie- 3 x 3 x i x 9'-7" 8 4.9 188 Girt, section.E-E - 4 x 4 x i x 12'-11%" @ 6.6 542 NO. 16 girt- ‘ 3 x 3 x i x 19'-102" 8 4.9 388 Girt, 8th lending- 6 x I; x 7/16 x 18'-O" :2 14.3 258 Do. 23:: x 2%; x 3/16 x 6'48" 0 3.07 39 DO. 23;.» x 2%. x 3/16 x 5'-7" 18 18525 1b. 15035 1b. Weight forwarded- U-623 4 No. 17 girt- 3 x 3 x i x 20'-10%" @ 4.9 U-580 8 Gusset plate. base- 1010 x in x 9 5/8" One half weight of stairway no. 8 - One half weight of stairway no. 9 - Landing no. 8 - Railing at Landing no. 8 - TOTAL WEIGHT 0N BASE 18525 1b. 409 55 213 213 105 25 M 19545 1b. ELIE LOAD The only live load which is considered to act on the tower is the wind load. Since the tower is quite likely to be located in.an.srea where the wind attains a high velocity and in addition is a fairly high structure in itself (100'), maximum.values for wind pressure are used. The maximum value for the unit wind.pressure must be found first. According to the principles of aerodynamics, the value for most structural shapes is as follows: pl= cq , where p = unit wind pressure. But where and p:= 2(o.00256 v2) p = 0.00512 v2 c = a coefficient, and q = velocity pressure. q_= 0.00256'V2 , VW= wind velocity in M. P. H., c = 2.0 (ave. value) Assume maximum V = 75 M. P. H. p = 0.00512 x 752 p = 2808 Ibo/BQO ft. Use 30 lb./sq. ft. The unit wind pressure used in the computations is 30 lb. per sq. ft. on the surface of the cab normal to the wind direction.and on the projected area, normal to the wind direction, of the structural steel members. Since the members are relatively small and spaced far apart, it is assumed that there is no shielding effect of members in the same line of wind direction. The major compressive wind stress in,a column occurs when the wind blows in a diagonal direction; that is. when the direction of the wind makes an angle of 45 degrees with the sides of the tower. The wind load per foot of height is 170 lb. per ft. on.a section near the base, as computed in Fig. 2. The value of this distributed load is assumed to be the same over the entire height of the tower. The total wind load on the cab is computed thus: P:= p x A P=30x9091705 P = 2230 lb. (See Fig. 6) i K ‘1 ‘1 ? R‘— E‘s/125x311 / \- ,5" 5. 0:52; cO/bxvn F #840690 ‘1 "—"—.57A #3} VA Y 5 L L. .J __J HOE/Z O/V 7x41 5fC7/Q/V A/E/Le 5A 5 f F/(i. 2 0:5 54.0045": 207” Z7 25' sec 45°: 354" 25 07/7 45°=/.77" ; 0.- 5 5m 45%354" f '3 ll A854 , A/JF/L #41. 7 0 ; py/v0, #52 F007 0F hit’76/17'3 ”M0 49/02 P6? £007 0F ; 5253;.- Z//ZA 35¢) —- a5 54 m, #5527.- ; “I z {/21 229/) c / 70 .. ,. ' 35141214194‘2/31/[7/"j = 55 .. - p: 22,4555 E .I 4/}21354): /70 - /6 ’15:)? l Jffl/k’M/HK' /Z/'( 24’ = 2‘75 .. . ~ 0‘ /f/_‘ g 1 707744 = 700 5.; m. = .5755 59». fl haw, -___ _._,_.__,_. .______.___ _ -...._____ _._-____ _._____ ________._fi-_______..._..__..l The maximum wind stress in.a diagonal occurs when the wind direction is parallel to one side of the tower. The wind load in this case is 145 lb. per ft. of height, figured at a section near the base, as shown in Fig. 3. This value is assumed over the entire height of the tower. The uniformly distributed load is assumed to be concentrated at the Joints, as shown in Fig. 4. The values for the concentrated loads are: g,=-30 x 7 x 7.5 = 1575. say 1600 lb. 2,: @4351: 145: 490 1b. 1;: (égi+é;£5, 145 = 980 lb. if; = (ég5+§) 145 = 1140 lb. 1; = (3+ 31-35) 145 = 1420 lb. Pf: (LEE-13?) 145 = 1690 lb. P. = (—lg-gLr-lgi) 145 = 1910 lb. 1:72 (1354—89-35) 145 = 2450 1b. 3; z (22§§+%5) 145 = 2940 lb. lllli 3111114 \. 3 f ~ \—5A 5x5- 4' 00/0/77” I r' '11:: I f } I 3 57/4 /EW/47 VV/A/Z) r ‘- ‘ <———~-—--— —-————————— f ‘ Dx'BECAf/d/V I I L. t .J L. L. .1 _.l HOE/ZONVM ééfCI/Q/L/ 13/545. 5.6.5.5: £16. .5..- 70 7242'. AEEfl , A/OEMfi/L 7‘0 W/A/Z), P52 F00 7 0; H'E/GH r : 5155 : 4//Zx 5) = 240 5.7. In 25’ x 25’ 23 .- 4 (/51 235) : /z0 57/4/E'W/4Yf /Zx/7 - 204 .. .. 707741- 654 552 //7. = 47.5250 ,4? W/ND A 000, are FOOf 0F HEM/0”.- P‘px/I 30x 475 /4Z.:~’ ”:92; .4 _ 4 fl A 4. _____. 0/5 73/51/2222 4040 or /45 25. p5,? Ff /5 cows/05250 A 5 CONCENfP/J 7:50 A 7 THE JO/A/TS, A5 JHOI/ V/V. W/NO LOAD FOE MAX/MUM D/AQQ/VAZ. 572555 5.7.6.... 9!. o DETERMINATION g§_ssssssms C CLUE-IN S THY-3133233 S The stresses in the members making up the columns are compressive stresses. due to the dead load (weight) and the live load (wind). The compressive stress due to dead load in any member is found by dividing the total weight.above the section through that member by four, since it is a four-post tower. The results are shown in Table 1 below. The section numbers and column numbers refer to Fig. 1. TABLE SECTION COLUMN wEIGn ABOVE V-COHPONENT NO. SECTION COLUMN STRESS 1.1 U-900 5115 lb. 1279 lb. B-B U-901 7244 1811 0-0 U-902 9034 2259 0-0 U-903 11020 2755 E-E . U-904 15035 3759 Base U-905 19545 4886 ,0- 2230 4“ 11!- WNW Mxlrmwww A II‘I 5 \ New 7 WeQQk\ C .K‘MV C ”FA .. 0 . tNGV 1.885% W/ND LOAD ["019 [KAI/MUM (ULUMA 57' f 5 F/G. 6. fillllllll’ , ur’lukl T4815} 2 SECTION y (99.75-y) .2065 x x Y2 (99.75-—yl .. A-A 12.28 87.47 18.06 12.44 150.80 B-B 28.22 71.53 14.77 15.73 796.37 0-0 44.35 55.40 11.44 19.06 1966.92 D-D 57.82 41.93 8.66 21.84 3343.15 E-E 77.56 22.19 4.58 25.92 6015.55 Base 99.75 0 0 30.50 9950.06 SECTION 8;;2 (y443.75) 2286 x (A)vL(B) E. .. (y+3.75) A-A 12,818.00 16.03 35.746.90 48,564.90 3904 B-B 67,691.45 31.97 71,293.10 138,984.60 8836 0-0 167,188.20 48.10 107,263.00 274,451.20 14400 D-D 284,167.75 61.57 137.301.10 421,468.90 19298 E-E 511,321.75 81.31 181,321.30 692,643.10 26722 Base 845,755.10 103.50 230,805.00 1,076,560.10 35297 The total vertical component of the compression in the column members equals the vertical component due to the dead load plus the vertical component due to the live 1084. The axial compressive stress is feund from the vert- ical component as follows: Hf: if “ T311 fl =3 01°32 15 = 5°~54' £122.11 ' V- on COB ¢ ' a so - 0 Stress cos 6 ' _ - m n Stress — cos - - nt TABLE 1 COR UTATIONS FOR TOTAL GGEPRESSIVE STRESS AND UNIT CCMPRESSIVE STRESS SECTION V-COMPONENT V-COMPONENT V-COMPCNEHT COK‘RESSION MLOAD LIVE LOAD TOTAL 3: IviEI-iBER A-A 1.279 3.904 5.183 5.211 B-B 1,811 8.836 10.647 10,704 C-C 2,259 14,400 16,659 16,748 D-D 2.755 19.298 22,053 22,170 E-E 3.759 26,722 30,481 30,643 Base 4,886 35,297 40.183" 40.397 'SECTION COLUMN SIZE OF COLUMN AREA UNIT srnsss w N0. (SQ. gs.) (COMEBESSION A-A u-9oo 3 x 3 x 1/A 1.44 3.620 lb/sq 1n B-B U-901 3% x 3% x 1/4 1-59 5.335 " c-c U-902 4 x 4 x 1/4 1.94 8,633 " p.13 [1-903 4 x 4 x 5/16 2.40 9.238 " E-E (1.904 4 x 4 x 7/16 3.31 9.258 " Base U-905 5 x 5 x 3/8 3.61 11.190 " QIAGCNAL and“‘v‘>LS The wind load which causes the maximum stress in the diagonals is shown in Figure 4. If the tower is considered as being made up of four bents. then the wind force will be resisted by the two bents whose planes are parallel to the wind direction. Therefore each bent will take one half of the concentrated.wind loads. The loading on one bent is shown in Figure 10. Before the stresses in the diagonals can be couputed. the lengths of the horizontal and diagonal struts must be determined. This is done on the following pages in Tables 4 and 5. COMPUTATIONS FOR LENGTH OF HORIZONTAL STRUTS- Decrease in length in 99.75' = 21.56'-—6.72' a 14.84. Decrease in length in 1.0"= %%f%%‘=-.l488' *' x = 21.56 —.1488y FIG: 8. TABLE 4 STRUT y .1488y x pr 20.25 3.01 18.55 no 90.50 5.03 15.53 km 54.00 8.04 13.52 11 66.75 9.93 11.63 8h 77.25 11.49 10.07 9f 86025 12083 8073 0d 93.00 13.84 7.72 ab 99.75 14.84 6.72 COIvIPUTATIONS FOR LENGTH OF DIAGONAL STRUTS- The equations which are used for finding the lengths of the diagonal struts are derived in Fig. 9 below, and the computations are tabulated in Table 5. k -H-.—-_ 7..“ -. -77-. .V. V l... Equations: 13:3‘3 (1) (2) TAB LE STRUT “c" ”a" "c-—a” "b" "h” ad 7.72 6.72 1.00 0.50 6.75 or 8.73 7.72 1.01 0.51 6.75 eh 10.07 8.73 1.3a 0.67 9.00 gJ 11.63 10.07 1.56 0.78 10.50 in 13.52 11.63 1.89 0.95 12.75 kc 15.53 13.52 2.01 1.01 13.50 nr 18.55 15.53 3.02 1.51 20.25 pt 21.56 18.55 3.01 1.51 20.25 Strut "If" "a+b"' (e +11)? h2+(a+b)a "d" ad 45.56 7.22 52.13 97.69 9.88 of 45.56 8.23 67.73 115.29 10.64 eh 81.00 9.40 88.36 169.36 13.01 g3 110.25 10.85 117.72 227.97 15.10 in 162.56 12.58 158.26 320.82 17.91 ko 182.25 14.53 211.12 393.37 19.8} nr 410.06 17.04 290.36 700.42 26.47 pt 410.06 20.06 402.40 812.46 28.50 _‘ 9975’_ W/NO 49.42. QNflO/YEWEENI ONL Y 75/V5LQ/LL .223 6.0444 4.? ._ EHQWM [71614 'lfil—‘J' COMPUTATICNS FOR STRESSES IN THE DIAGONAL SYRUTS- The method used for computing the diagonal stresses is as follows: First the method of sections is used and horizontal sections are passed through the tower at each horizontal strut. Moments are taken about the Joints in the right-hand column (Joints b-d-f. etc.) to determine the upward.vertical thrust (V) in the corresponding Joints in.the left-hand column. Then, by using the method of. Joints, the vertical component of the stress in each diagonal can be found. Since the slepe of each strut is known, the axial tensile stress in each diagonal can be determined. The following sample computations show the procedure used in determining the diagonal stresses. The completed computations are tabulated in Tables 6 and 7. 2%: 03 V, X ab = ”a .. V, 7‘ 5~72 = 3.75 x 800 (k .. ,, V, x 6.72 = 3000 [i 'W = 446.4 ' <flk=m @xcd=Md ‘“ V2 1 00. = Mb+ZI§ x Ay :31“ {1. Va 2: 7.72 = 3000 + 1045 x 6.75 I; __;:. V2 1 7.72 = 10,053.75 72 =—- 1302.3 r..\-. .1.» I 214;: 0 At Jgint "a": At Joint ”0": EV —‘ -—-— 0 .0 e 9 x f = M; 1;: of = Md+zg x Ay x 10,053.75+ 1535 x 6.75 1;, x 8.73 = 20.415.0 03 e 0‘: UI II adv = 1302c} _ 446.4 ad, 3 8550 9 U 7 ad -_-_: 855.9 1 £225.91}. .0 . ad = 1253 11). cm: 11;le Orv: 2338.5 “1302.3 Cf, ‘—'—' 1036.2 of = 1036 2 1: 1913.831 4 t ‘ V-proj. ! cf = 1036.2 2: Aging-25*- g ‘ V-pI'OJ o f \xt‘ ad = 855.9 x ;$3 6' TABLE 6 ABOVE 211; Ay x 1401th v ‘sgggggm M __ ab 800 3.75 6.72 3,000.0 446.4 cd 1045 6.75 7.72 10,053.75 1302.3 of 1535 6.75 8.73 20,415.0 2338.5 gh 2105 9.00 10.07 39.360.0 3908.6 13 2815 10.50 11.63 68,917o5 5925.8 km 3660 12.75 13.52 115.582.5 8549.0 no 4615 13.50 15.53 177.885.0 11454.3 pr 5840 20.25 18.55 296.145.0 15964.7 8t 7310 20.25 21.55 444.172.5 20601.7 ABLE JOINT DIAGONAL ‘V-COMP. LENGTH V-PRCJ. TENSION 1 _;N MEMBER a ad 855.9 9.88 6.75 1253 c of 1036.2 10.64 6.75 1633 e eh 1570.1 13.01 9.00 2270 g 31 2017.2 15.10 10.50 2901 1 in 2633.2 17.91 12.75 3685 k k0 2905.3 19.83 13.50 4268 n nr 4510.4 26.47 20.25 5896 p pt 4637.0 28.50 20.25 6526 COMPUTATIONS FOR UNIT STRESS IN DIAGONAL STRUTS TABLE 8 014001141.w TENSION BOLT EFFECTIVE UNIT “1 DIAMETER NET.AREA 532555 ad 1253 5/8" 0.29 4320 lb/sq in of 1633 5/8" 0.29 5640 " eh 2270 5/8" 0.29 7830 " 63 2901 5/ " 0.29 10000 " in 3685 5/8" 0.29 12700 " Re 4268 5/8" 0.29 14700 " nr 5896 3/4" 0.39 15100 " pt 6526 3/4“ 0.39 16730 " EFFECTIVE NET AREA AT SECTION 1-1: (SEE FIG. 11) Area of angle-—two holes Net area Net area = Area of angle —— (d+l/8) 1: 2t For 2 x 2 x 1/8 angle and 5/8" bolt; Net area = 0.48-(5/87‘l/8) x 2 x 1/8 = 0.29 sq in For 2% x 2% x 1/8 angle and 3/4" bolt; Net area = 0.61-—(3/4le/8) x 2 x 1/8 = 0.39 sq in A h - - “-3—“! COMPUTATIONS FOR STRESSES IN THIS HORIZONTAL S’RUTS- The stresses in the horizontal struts are determined by the method of Joints. The Joints in the left-hand column are used, as before. The following sample computations show the procedure used to determine the stresses. The complete computations are tabulated in Table 9. At Joint "s": .2H = 0; ab== ad” _ - ro . \ “"21": ab ad x ength \\ \ \ But. H-pl‘OJ.= 3+1) (F180 9) \\ /. aasb ab = ad 1: m ab = 1253 x 9% = 916 113 At Joint ”c": 2H : 0; 00. = (if/5 H c‘ ~r———“—— Cfi/ __ -QrOfle cd —— of 1: length _ av‘b Cd - 0f 1 m \ . \‘ I cd = 1633 x 18%; = 1263 lb 2, STRUT “_D§i%§§éL .H-P?2{E§§ION LENGTH cogpsgggégu ab 1253 7.22 9.88 916 cd 1633 8.23 10.64 1263 of 2270 9.40 13.01 1640 gh 2901 10.85 15.10 2084 13 3685 12.58 17.91 2588 km 4268 14.53 19.83 3127 no 5896 17.04 26.47 3796 pr 6526 20.06 28.50 4593 STRUT SIZE OF STRUT AREA UNIT STRESS ab 3 x 3 x 1/4 1.44 636 lb/sq in cd 22 x 22 x 3/16 0.90 1403 " of 2 x 2 x 1/8 0.48 3417 " 5h 2% x 22 x 1/8 0.61 3416 " 13 3 x 3 x 1/4 1.44 1797 " km 3 x 3 x 1/4 1.44 2172 " no 32 x 32 x 1/4 1.69 2246 " pr 4 x 4 x 1/4 1.94 2368 " STRESSES IN HORIZONTKL GIRTS WHICH SUPPORT STQIREAYS- Although these members are not considered to take any of the live load stresses, they do support the dead weight of the stairways. Because of the fact that they are quite long and have the concentrated load of the stairways near the center of the girt, they are analyzed for both shear and bending moment. The method used for the analysis is as follows: The girt is treated as a simple beam. supported at both ends, and acted.up0n by tee loadings. The first is a uniformly distributed load equal to the weight per unit length of the member. The second loading consists of two concentrated loads. each one of which is equal to one half the weight of the stairway which it represents. The total shear and bending moment for each member are found by drawing their shear and bending moment diagrams. These are shown in Figures 12 to 19 inclusive. The unit shearing and bending stresses are then computed and the results are tabulated in Table 10. T _ _. — _ ,r. is M _ .WI. .. n rd, . . _ ---.—_ h“; ,.,‘.l‘luo ‘iltl!'“ll‘. nu I out; - ~_.‘ / g" .——.—_-‘_.-.—. ..._,. l‘...» . *"1--- r—0 -- . 7 a a a k _ m a . . _ / _ // . I... fl .I _ 1/ . / - _ , ...I'JIII.'II"I. I If .5 . . r r.’ .( _. ...—_ .—. _.... --—_¢~.-7—- r V. 2 . I “L, .1. .5 _ _ Y. n l / I . . I. .. 4..“ I.lll.!m..v' I! II I a .8. (b L l l a I y l .. u‘ b. - -4 4!! J .1 Y‘ ’ 7,. Z .# .Kfl a) i. a... r I. J u _ M . _ 3 \‘I‘ll‘ ' 1.1.1 iii": 10! I“ i _ . _, -~———. “fi-_.- \ w m ,4“- _ .f. W _.._ H—..— -_. _.- __—._.—.A_—.‘.H.~ r -A , .-v -.4 -'—— . -‘o _- l_~~__.-._._ *‘- A..— lJ‘I“llII!l ill! .‘I |\‘Vfi l . _- -. -.-.._- yr-u—..el.f _._, -~ m k .-....- —_ _.-__ -___..———_m_--, ‘~ \V‘I'l. LI“ .JvlllA..O‘ .—-d-o--..._ g--. {47‘ '7 I. ,_ .s w .7. _ m .l w _. _ .~ . . n _ a N _ . . j _ a. — c. _ a . c i ._ . . f M .. , k . ‘ ‘l ‘FA.II|J"1"I" 1' I 6 ./ 7| [I‘ll‘lli‘l‘ ‘llfxfl 7#__._‘.__..fi._-_._ ,1“~-. A! ‘.ll. ‘m .- Q ‘. ‘5‘“ ~'.——v“"~__’N--. 4,. ‘ .__K-__ ,, l K. g . e. .5. C l . _, dye] — .1...” f . _ p _ _ ‘ ‘lIt I; ‘ ll: . 31.51; I {—53 5,. ._._ it-“ , -<~-- . .._ I... ‘h—fi—i‘f -._..._, , .u.‘ II. I' ‘iftl v: [I \I,’ e I. , [1. t -_..., -~ v'- . I“! w . . /: . w... . u. a f .. AI'JIAIIQI‘II..TI .l. , 1 _ ._..-._. -.—.——.- _. _..._._..._— _.‘ , ..~.__ M_- .5 l' *7 I ._.___-r—.. *7»._.,__. “‘~ ‘ ”9 ’4‘ y-x d—b’ I (70’? » m w _ g m i _ _ N _ a. 721.1. _.J 01/. .5 ,. _..“ _,,. ‘ r .. , , Iv. Ill)»; ll yvtl . ‘9‘ —~—"""N ‘g‘. i I _A__*. m“ ‘.-._ .- - I“..- IJVV! -.‘_-_...._.._...1 H? o‘-. l ,- V . _._,,._.__—_. -v_.. Pi... _- ii I. (U 45 {4(1): ‘ I'lltlvr'l ll" Tn! ‘lit‘I-IAI. (11",50...“ \ . \ lluL / 2., J / L 9'. ’ f I J 2‘ III- \_I 1"" /' ’ I . .—.4. --.—.- -A- .-——-..—o- a- . Ir\l " flr'r .. I” \ é V ...__-.H-J. ._....-. an -774. 11“”. £25!" .. - _ . _ ., _ _ / . . _ . _ 2.. 5 m 417 m? _ 4.1/ .15 ._—-v ._A - ~—-..-. .—.—--.—.—.—._‘-._.... .- -h _ -. - -___.____..._.....*_ _._. _-_._ --- -____._ i..- - ,_ -- - A7,, 5 a.-._ir_i-,-,. m... .._.....__.l ................t......_ -. .HV 5.. “—v-v. _‘7 .-. ~.~-~—_... i .i- J ul’nwnnniitl!i.lllo.r9.. I...) ti 1. _. COMPUTATIONS FOR SHEAR AND sesame nos-ENT- Maximum bending stress: f=: (MS: , where f ==maximum bending stress, M = bending moment (in-lbs), S = section modulus about axis parallel to short leg. Maximum shearing stress: v=§ ,,where v = maximum shearing stress, V = total shear, A = cross-sectional area or member. TABLE 10 memes BEN DING sums _ , = 2 6 x 12. = . =__ 4 = . u 921, f —5———-—-.79 3890. v €3.53 67 5 - . ___ 255 x 12 __, . z 1 ___ . U 92a, 1' .79 3870, v 73%; 82 3 - ’ .7. M = , ' == 6 -- U 923. r 1.1 3470. V l]? .. 90.8 - ... . = 1* x 12 = . __ 22 _ u 904, r 5127.... 2560. .v _. 3%; 64.4 U-925; r = §%’_%_L2. = 2820; v =. :4; 5 = 71.7 U-927; r = gig—gig = 5610; v = 33.51%. = 81.0 - . =_ 14 X 1 _ 2 . ___ 2 = . U 931. f “3.3 .. 5 25. v 3% 82 3 - . =_ 21 x 12 _ . ___: 2 __ U 940, r "‘2???- _ 6940, v .. 81.9 .1 The final step in the analysis or the fire tower is the determination of the allowable unit stresses in each member. and a comparison between the allowable stresses and the actual stresses as computed in the preceding pages, to make sure that none of the computed stresses exceed the allowable value. COLUEN STRESSES The column members are in compression. The allowable unit compressive stress is found by the formula, sc= 17,ooo-o.485 x «:12. where = allowable compressive stress, a 1 = greatest unsupported length, r least radius of gyration. N The computations for the allowable stresses in the column members, along with the computed actual stresses, are tabulated in Table 11. TABLE 11 COLUMN i/r ALLOWABLE ACTUAL NO. §._+ V . s; u-9oo 72 14.5Ao Ib/sq in 3.620 lb/sq in 0-901 93 12.830 ” 6.335 " 3-902 96 12.150 " 8.633 " U'903 104 119775 fl 93238 " U-904 105 11.640 " 9.258 " U-905 83 13,670 " 11.190 " QJAGCNAL assesses The diagonal struts are in tension. Table 12 gives the comparison between the actual and allowable stresses. TABLE 12 STRUT UNIT STRESS UNIT STRESS n A Ag TUA L g ALLQ'saB LE ad 4.320 20,000 of 5,6h0 " eh 7,830 n 63 10,000 " im 12,700 “ ko 14,700 " nr 15,100 " pt 159730 " It is also necessary to check the bolts against failure by single shear or bearing. The computations for this are tabulated in Table 13. The allowable loads in single shear and bearing are based on the following allowable unit stresses: Shear: s = 10.000 lb/sq in Bearing: s = 20,000 lb/sq in TAB LE 1: STRUT NO. & DIAM. .ALLosABLs TENSION ACTUAL os_sopgs s15. BEARING TENSION ad 1 - 5/8" 3070* 3130 1253 cf 1 - 3/8" 3070* 3130 1633 eh 2 - 5/8" 6140* 6260 2270 g3 2 - 5/8" 6140* 6260 2901 im 2 - 5/8" 6140* 6260 3685 kc 2 - 5/8" 6140* 6260 4268 nr 2 - 3/4" 8840 7500* 5896 pt 2 - 3/4“ 8840 7500* 6526 * Governing values SI‘RES 3‘28 IN HORIZONT L STRUTS The horizontal struts are in compression. The allowable unit compressive stress is found by the formula, L2 s = l7,000-O.485 x r2 But, maximum l/r ratio ='87 s = 17,000-0.485 x 872 s== 17.000-3,670 s = 13,330 lb/sq in Table 14 gives the comparison between the actual and allowable unit stresses in the horizontal struts. TABLE 14 STRUT UNIT SPRESQ UNIT STRES‘ ACTUAL ALLOWABLE ab 636 13.330 cd 1,403 “ of 3.417 " gh 3,416 ” 13 1.797 " km 2,172 " no 2,246 “ DP 2,368 " As before. it is necessary to check the bolts against failure by single shear or bearing. The same allowable unit stresses are used that were used for the diagonals, and the computations are tabulated in Table 15. STRUT NO. & DIAM. .ALLOWABLE LOAD ACTUAL CF _QQLié. _s.s._¢_ BEARING LOAD . ab 916 cd 1 - 5/8" 3070* 3130 1263 of 1 - 5/8“ 3070* 3130 1640 gh 2 - 3/ " 8840 7500* 2084 13 2 - 3/4" 8840 7500* 2588 km 2 - 3/ " 8840 7500* 3127 no 2 - 3/4" 8840 7500* 3796 pr 2 - 3/4" 8840 7500* 4593 * Governing values gjssssss IN HORIZONTAL GIRTS The unit stresses in the horizontal girts which support the stairways are given in Table 10. They are well below the allowable unit stresses, which are: Bending; 3 20,000 lb/sq in Shear; 8 13,000 lb/sq in CONCLUSION From the standpoint of safety, this type of fire tower seems to be well designed. In most of the members which.were checked. the unit stresses are far below the allowable. In only a few cases do they even approach the allowable. In addition, there are a great many small bracing members which were not taken into account in the checking. These members increase the strength and rigidity of the tower..Apparently a generous factor of safety was used in the original design. From the standpoint of economy, it seems possible that the design could be better. However, it may be that the tower was purposely over-designed to take care of stresses which might possibly be introduced either in the erection of the tower'or’by forces or loads which were not taken into account in the design. 1. 2. 3. 4. 5. BIBLIOGRAPEX Howe, G. E., "Wind Pressure on Structures", Civil Qgineerigg, Vol. 10, No. 3. Grinter, L. E., Theog of Modern Steel “Structures. Vol. 2, let Edition, 1937. Ketchum, M. S. , Strugtura; Engineers: Handbook, 2nd Edition, 1918. \ Sutherland, 2%. and Bowman, H. 1... Structural The-or , 2116. Edition. 1935. American Institute of Steel Construction, Steel Construction, 3rd Edition, 1%0. ’4/ 7?” Jam; p= 2230 # __::____:__::__:smug____:____:_ ::_:__:_ buxumw.‘ mywflfi, , ...Y,.. A fit}. . .fiirwfl . d H. ., ‘- a £1... . II] [J] Ill 11 99’ /\ V F/é. ll .mwwx x .vouQ .mu ox R» ..Q . sums .o.\ NW ..mN WU. WIND LOAD F0? MAX/MUM C‘ 01 (/MN 57.9555 I ,,,,, :: ll 375 ' o J? I t: 4%: n q 675%75 ‘é it ‘H T ‘é‘ 1%: (q m i go. T S it m5 K /275’ 4 If a i: S I: 99 75 X /3.5' J (0 8} fl: Q [—-/47o# ‘Q \ t: 20: 25’ _ 2a 25’ W/ND LOAD ON ONE BEA/7' ONLY TENS/0N D/A G'O/VAL 5 5HOW/V F/é . III II] VQQKV F76. / F/ \\ DEAD LOAD 0N C01. UM/VS K a ‘I T7 In ZJXZELXéZ __j[_ .535fo 627/007!) r 1 57A lg WA 7 W/ND D/BECT/O/V _l .1 _J HOE/ZONTAL SECT/O/V N524]? 5x455 F/é TOTAL AEEH , NORM/4’4 7'0 W/ND, FEE F007 0F HEIGHT .' 5x545 .- 4//2x5) = 240 59. 127. zz’ngés: 4K/Zx Z5): /20 57/) wpm r: /2x /7 , 204 707344 654 57 /}z = 47.531 :9. W/ND [.0/20, FEE F007“ 0F HE/G/r’ff pg/OXA 30x 475' /425 957/,- 1“); , ,.- .\,- um ... - ._ . w- 1.332“? v 9/ .o {37(1), AXE-”5,77 , _ M, 2 M/ Jon/55 ’4/ D/STE/BUTED LOAD OF /45 £6! PEP F72" /5 (DA/5705350 A5 CONCENTIGATED A7 7H5 JO/A/f'fi' , A5 SHOW/V. /4.6‘ /é. /r2 WIND LOAD FOE MAX/MUM D/AGONAL 5759555 F/é R W 224ngle 5x5x§§1 Co/amn flOE/ZO/VTAL 5EC770/V NEAR BASE F/é Z d=5 5ec45": 207” b = 2.5 sec 45": 5.54" c = 25 5f” 45°=/.77 -3541! 0’: 5 .57}; 4’5"- AEEA , NORM/4L 7 O W/A/O, P45? FOOT OF HE/GHT: 5x543“ Zf/Zxa54’) 85' 5g x27. 2 {/2X 707): /70 ~ .. 224ng 5 4 {/2 x / 77): 4//2x 3.54) = /70 57A/EWAYf /Z X 24’ = 266’ 707'AL = O 7.95 5¢ /}z = .555 sy: {E W/NO LOAD, FEE FOOT OF flE/é'f/Tf ,0 -‘-' pr = 50x 556' = /66.5 9%. 7E? 14/ Java-1r 147/ .-.AAAA.RUNDLING AND LOADING CHECKLIST FOR ONE 99'-9" STAIRWAY TOWER, WITH ANCHOR FIXTURES- DRAWINGS MIC-39 & MD—7O ORDER No. CAR NO. DESTINATION TALLIED IN BY DATE LOADED TALLIED OUT BY DATE UNLOADED TALLY NO. NO.PCS. TALLI IN BDLS. MARK IN BDL. DESCRIPTION OUT A U~9OO 1 #1 Corner Post~ 3 x 3 x 1/A 19' 9 3/ " ._1____1 __1_.1_4 U~901 1 #2 n v - A x 3% x 1/A 16' O" ___*____ _______A U~902 1 #3 n n - A x A x 1/A 16' 2 3/16" A U—903 1 #A N H - A x A x 5/16 13* 6 1/8" _~__*m, .A U~9OA 1 ' #5 n u - A x A x 7/16 19' 9 9/16" __1..1_ 3 U~905 1 #6 " " - 5 x 5 x 3/8 22' 3" ___1_._ 1 U~905X 1 #6 " " — with U-A5 Pl.~ 5x5x3/8 " 1 U-914 A #1 Splice Angle~ 3 x 3 x I/A O' 10" 1 U—915 A #2 " " ~ 3% x 3% x 1/A 1' 0 1/2" 1 U-916 A #3 " n — A x A x I/A 1' 3" 1 U-917 A #A u " — A x A x 5/16 1' 5 1/2" 1 U—918 A #5 u n - A x A x 7/16 2' 1" 1 U~546 8 #1 Angle Brace- 2 x 2 x 1/8 9' 6 3/ H 1 U~547 8 #2 " n - " 9' ll 7/16W__1____ - 2 U-548 A #3 " " - " 12' 5 1/8" ... 2 U~549 A #4 " " - " 14' 6 1/4" ____ 2 U-sso A #5 " " - " 17v 3 5/8" 2 U—55l A #6 " " — " 19' 3 1/16" 1 U—552 A #7 " n - Upper Sec.~ 2%x2%xl/8 12' 9 I/A" 1 U-553 4 #7 " " - " " - " 11' 3 3/ " _____w_1 U—SSA A #7 " " 1 Lower " - " 1A! 9 l/A" 1 U-555 ! ‘4 #7 " " — " " - " 13' 3 3/A" 1 U-556 A #8 " n _ Upper " - " 12' 5 1/16" 1 U—557 A #8 " " ~ " " - " 13' 8 1/16" 1 U-558 A #8 " fl — Lower " — " 1A1 9 1/16" 1 U-559 A, #8 " " ~ " n — I n 16' 0 1/16" ' i- 99'-9" Stairway Tower~ ~2- Drwgs. MC—39 & MD47O 1 U—562 A #1 Tie~ . 2 x 2 x 1/8 x 3' 8 3/AH _fl___ 1 U~563 A #2 H — H x 3' 9 3/8H 1 U—seA A #3 H ~ H x 5' 0 5/16" 1 U-ses A #A H ~ H x 5' 9 7/8" 1. ~,_____; U~566 A #5 " — " x 7' 0 13/16" __<_,__1 U~567 A #6 H - H x 7' 5 1/8" -_ ___,~___ U~568 A #7 H ~ 2% x 2% x 1/8 x A' 6" .111..._ "_ 2 0-569 2 #8 H - 3 x 3 x l/A x 9' 7 1/16H_____M__ 2 U—575 A Gusset Plate~ #10 Girt- 8 x 1/A x 1223/16H Plate __1___ 2 U~576 A H H — #12 H n 8 x 1/A x 13~3/8H H _fl___~*. 2 U—579 A " " ~ #15 H 2 11 x I/A x l7~l5/16" Plate 2 U-58O A H H - Base~ 10 x l/A x 9-5/8H H ________ _ 2 U-919 2 Roof Oirts- 3 x 3 x 1/A x 6' 11 5/8H 1 U~587 A Window Sills- H x 6' 10 3/AH________ 1 U~588 2 Cab Girt- H x H U-589 1 H H - R.— H x H U-59O 1 H H - L.— H x H ___1___l U-591 1 H H - 1' x 6' 11H .1______ U-592 1 H H - H . x H 1 U-593 1 H H — HI x 2' 10 1/2H___“~___ 1 U—596 8 #1 Girt~ 2 x 2 x 1/8 x 3t 9 9/16" 1 U—756X 2 #2 H - 2% x 2% x 3/16 x 7' 5 I/AH 1 U-598 1 #2 H . H x H U-599 l #2 " ~ H x u 1 U~921 1 Girt- lst Landing— 3% x 3% x I/A x 7' 1 3/8H 1 U—éOl 1 H - lst H 1 ' 2% x % x 3/16 x 2' 10 3/8H i 1 U~602 2 H — lst H — 2 x 2 x 1/8 x 5' 1 1/16" 1 U—6OA 8 #3 Girt— " x 4' 3 5/8" 1 U-605 2 #A H 1 H x 8’ A 7/16H 1 U~606 1 #A H — R.- 2% x 2%~x 3/16 x H U-607 1 #A H — .— H x H 1 U~922 1 Girt~ 2nd Landing- 3% x 3% x 1/A x 6' 2 3/16H t .l— 99‘—9" Stairway Tower- Drwgs. MC—39 & MD-7O l U-609 U~610 U~6ll U-6l2 U-613 U—923 U-615 U-616 U-617 U~618 U~619 U~62O U-924 U~622 U-624 U—625 U—626 U~627 U~925 U—629 U-éBO U~631 U—632 U~633 U~63A U~635 U-927 U—928 U~638 U~639 U—673 U—674 3 8 -3- Girt~ 2nd Landing~ #5 Girt» #6 n _ #6 " - R.« #6 " ~ L.— Girt— 31d Landing~ n _ 3rd n _ n * 3rd n _ #7 Girt~ #8 n _ #8 n - R.- #8 I! - L." Girt at 4th Landing» n H 4th " .. #9 Girt» #10 Girt~ #10 H - R.- #10 H - 1.2 Girt at 5th Landing” n n 5th n i " " 5th " ~ n n 5th n - #11 Girt- #12 " ~ #12 " - R.~ #12 H — L.“ Girt~ 6th Landing" 2 X N K!“ N w'd 4 X 2 X 1/8 H s X 2% X 1/8 1 x 2% x 3/16 I! A X 1/4 2% x 2% x 1/8 H 2 X 3 X A) N 5 X 2% x 2% x 3/16 3 X 2 x 1/8 3 X 1/4 3 X 1/4 H I" 1. . ' ) 2% X 2% X 1/8 _1‘. 5 X n _ 6th, 7pm & 2th Landing~ " ~ 6th Lending» n _ 6th n _ n _ 6th n H ~ 6th H - L 32 X A 1 -- 5 X 35 k 1/4 H H 3% X 7/16 252(25):,2/ 16 :2: 5' 7" 32>:1AA H 2’7 X 3/16 X 3' X n H x 10' 3 3/." x 6' 1 15/16n“* x A' 10 5/8" X 91 g 3/16n X N X H x 6' A 3/ " x 7' 5 11/16H- X 71 l 5/16u x 5' 7 1/2H X 11' 3 9/15" 1....L._ X 7' 8 15/16"*~. x 8' 1 13/16H x 6' 5 11/16H x 13' 2 3/8H X 7' 9 7/8" X 3' 4 3/3" x 101 A 5/8H ”MWI__. x 9' e 1/AH X 7' 5 13/16"__mm___ x 15' 2 3/A" x 15' 2 3/A" X n x 12' 1 7/8" —-—v——-—n—-.—- x 10' 11 3/16H 5 7/18H.m._ .... .l- 99'~9" Stairway Tower- Drwgs. MC—39 & MD—7O l 2 U-640 U~6A2 U—643 U-6AA U—931 U-646R U~646L U~651 U—652 U-65A U-655 U-656 U~9AO U-658R U-658L U~623 U—661 U-662 U-666 U~669 U-67O U—947 U-676 U-677 U—678 U—679 U—680 U~681 U«682 U-683 A l 1414 N 1043b 84 1~c\ #13 Girt- #lA " — #14 " ~ #lA " - Ro" Lo” Girt at 7th Landing- #15 Girt— 7th H — 7th H - Girt- Section E—E~ #l6 Girt- #16 " ~ #16 " — Girt— 8th " ~ 8th " - 8th #17 Girt~ Roof Angles— R.n H H - L.- 2% X 2% X 1/8 X 3 x 3 x 1/4' x " x I! x 6 X A X 3/8 X 2% X 2% X 3/16 X H X A x A x 1/A x H X 3 x 3 x 1/A x H X H X 6 X A X 7/16 X 2% x 2% x 3/16 x 3x3xUA x 2 X 2 X 1/8 X H x 16' 9 1/2" N H 13' 7 5/8" A' 2 5/16" 1: 18' 1 3/8H 12' 11 5/8H 19' 10 1/8H " V! 17' 11 7/8" 6' A 7/16" 4: 10 3/8" 17' 9 11/16H 20' 10 5/16H Sash with Glass & Uu668 Clips— Mark: "GLASS HANDLE WITH CARE" Siding~ Roof Section- Flashing for Roof~ #1 Stairway #1 " #2 " — R. #2 " ~ L. #3 " 9 R. #3 H - L. #4 " - R. #4 " — L- #20 Ga. Galv. Sheet Steel a, 99'-9" Stairway Tower~ Drgs. MC-39 Revised -51 & MD-7O l l W ..__._14 1 1 fi 1 2°- 1 1 1 1 1 1 1 1 1 1 1 1 _‘.__“_2 ”_~‘__~_2 2‘ U—684 U—685 U~686 U—687 U-69O U~69l U—692 U-693 U~694 U—695 U~696 U-698 U—949 U~950 U~951 U~952 U—703 U—704 U~955 w 3w U—959 U~96O U~96l U~956 U~715 U-’7lé U—976 l l M I‘.) N (\3 #5 Stairway; R. H #5 .IH» — L. #6, 7, 8 & 9 Stairway~ R. #6, 7, 8 & 9 H — L. Railing for #1 Stairway“ 1% X 1% X 1/8 X 2' 2 7/8" H n #1 n _ n X 4' 6 3/8" H n #2 n _ n X 8' 5 9/16n n u #3 u v n X 11' 3 3/3u u xx #4. 11 _ n X 13: :3 5/8“ H u #5 u * n x 161 O 1/4” -m*_*“~_ n n #6,7,8&9 Stairuayw 1%Xlfixl/8 x 16H 11 13/16H Post for Railing~ 2 x z x 1/3 x AI 5 3/8" , n n n , R.~ n K 4: on n n n _ L.~ n X n n u n _ R.fl h A 41 2 1/3" H u u _ L.— n A n H H H — 212X1/S x 3' 11 5/8‘ 1 . . I s: I! n 1 n Xf n 4:, ‘ H H H - 6th,?th,&th~ H x 3' 7 3/8H hailing for 6th,?tn,6th Land.~H.—1%X11X1/5 X 2' 9 7/8"__~W____ n n n u n n ~L.— n 3 n u n n n u u _ n X 51 1 L/2"_> Ventilator with Base per Drawing MD—97 Anchor Plate~ R.~ 5 x 1/2” Flat X 1’ J 1/16” Ancher Rods {Plain)» 1 l/“" Ed. (2 Nuts) X 7' 2 7/8” Bearing Pletee 1 1/4” Holes— 1?” X l/H” Pl. X 1' 0" Reinfoycing nods (unform10)~ 3/3” Rd. x 11! 2" u n n 1 l/I" n x 6| 5 5/8" Reinforcing Hoops (Plain)~ 1/4” Rd. X 4' 4 1/8" Boxes 0? Bolts flexes 01 Small Parts 9 b CHECKLIST OF BOLTS WITH LOCK NUTS FOR ONE 99'—9" STAIRWAY TOKLR, WITH ANCHOR FIXTURES— DRGS. MC—39 REVISED 3/20/36, MD—97 & MD-7O (Box 5) “fi—M—“**n—~—_~—~_~———-—-~-—.——*—~~—w—~*u——”m~‘“~~ Unthrd. Length Location 205 — 3/4 X 1 3/4" Galv. BOlts with Hex. Nut 1/2" E & J Note: 3/ " Bolts shall have Square Heads and shall be Galvanized after Threading. 3/4" Nuts shall be Tapped after Galvanizing. If you find “ny errors or shortages, return this checklist with your complaint. AERMOTOF CO. 3-23~36 Chicago CHECKLIST OF BOLTS KITH LOCK ‘ 101 ONE 991-9" STAlfiwnY Zowgn, CITE ANCHOR FIXT’RFS ones. MC~“9 REVISED 3/20/36, fiD—QV & mo~7o (Box 6) M—flfl—m*“fl-m’UM—‘fifi—flaw—‘fiflMy ,' bnthrd. Length 92222122 204 — 3/4 x 2H Galv. Bolts with Hex. Nut 3/4” F & K Note: 3/4” Bolts Shnll have Square H¢1d5 ““d Shall be Galvaniaod after Threading- 3/4” Nuts sh1ll on Topped gftor Gui finizing. Hacked by Dato _~ I“ You find any errors or shortigess return thib chncklist with your complaint. AERMOTOR CO. x“23”36 Chicago ’ fl CHECKLIST OF 809 405 919 39 23A Note: CHLCKLI *——-—-——‘———-— If you find 3~73—36 afiY V‘ LAIJI BOLTS AND LOCK NUTS FOR ONE 99'*9” STAIRWAY TOW l, VHITE ANN HOR FIXTURES— E DRGS. MC-39 REVISED 3/20/36, 7 (Box 7) MD—97 & MD~ O .... n.— .1. ...-— ’uu .- ...- .- - act-D .- c-n- u-o. Q‘— —— ...-nu —- out. n.— .. —.— tun- -. u. an .— w-b _o —. _— .- u.- ~ 0— .— Location 3/8 X 21/2" Galv. Carriage Bolts ’Galvani.ed Lock Nuts— 5/8" with Hex. Nut Wood n u n _ 3/In n n n 1/2" H n n EC 3/8" ,'3 (.1 3//8” Carrizioe Bolts shall be GolvoniE d after Threading. 3/8” Nqu Shall oe Tapped after Galvanizing- All lock nuts of the Sime EiZL t1 bo S”?d" toly lAhmad ‘Vashor s not to bL uS<3d with 1/4" Br S‘S bOlCS or 3/8” Caeringo Bolt . Lock nuts not to be used on 3/8" Carriage Bolts. Paw}? Lu. by L? to— rnJ errom11 or short 30;, return thin ChSCkLiSL with your complaint. A‘ERADTLH SC. Chicago ST CE WASHLES PO» ONE 99‘*“‘ STLIRJAT TSXCR, KITS C.CTL 1 IUnLo~ DECS . 11121.- "7% Elm-JTIELELI‘H ,5/20/36. MD 9. / 1111140 (L02 8) Loonticn i" ' ’ f " ’ I "I ‘7 ’V .. .. ‘. . 40; — 11/1C x 1_1/Av ~/LCH GiLN. :SLQF 919 — 13/16 X J~’7/16 1: 3/16” ” “ r r I n q .59 ~ 9/1L>:< 1—1/16>: -MLCH H H l / . 3 ' :38 77/16 :3/"74 3’". .1-//(A;) 3' H H . . . ., / . . ~ 1' ~ . . ... .-‘ 50 ~ ll/lo L lwl/A X l/A" Sol . Iillor WaShCrs L iNotL: 'Il‘Iu Imyt t3 1n1 usrii WiTfi1.L/4" .11.C. {hilts arr 3 E" Carriage «o1... ILLl w:.sfngr:; “Ugo :Sank: 8111 t :ZDL 13$: ft‘tolgf Forflood. Pookod by Date "\ orzxxrs Ln? shcu"tzgax:, T‘ mirn 1111s Lib ox ixyt'LiiEI ycnn7 COHEIUllHTw :‘IIT AJ 7.1. KW )'.: hioigo J. ‘ 1' .1 R; \J . CHECKLIST OF SMALL PARTS FOR ONE 99'—9" STAIRWAY TOWER, WITH ANCHOR FIXTURES- DRGS. MC‘39, MD”97 8C MD'JZO .(Box 1) 8 — U—57l- Gusset Plate, No. 2 Girt- 10 x 1/4 x 6 1/2" Plate 8 , u_572- u n ’ n 4 n _ 8 X 1/4 X 11 3/ n n 8 ~ U-573- " " , " 6 " ~ 8 x l/z x 11 3/4" H 8 - U-574- " " , " 8 " - 8 x 1/L x 12 1/4" " Packed by Date If you find any errors or shortages, return this checklist with your complaint. AERMOTOR CC. 2-92-39 Chicago CHECKLIST OF SMALL PARTS FOR ONE 99'-9" STAIRWAY TOWER, WITH ANCHOR FIXTURES- DRGS. MC-39, MD-97 & MD-7O (Box 2) .ww-~‘-__-“*——_-_o-——~~—_~c_-~-.”~--—~--~—-—”-u 4 — U-920— Roof Girt Clip“ 3 x 3 x 1/4 x ov-5 5/8" Angle 4 — U—663— Gusset Plate for Roof Angles- 4 x 1/4" Flat x O'-5 3/4" 4 _ U-664* n n n n n _ n X n n X n l - U~665- Cap Plate- 12 x 3/16 x l2" Plate 8 - U-67T« Filler Washer- #20 Ga. Galv. Sheet Steel 2 ~ U-o75- Flange for Flag Pole, Cast Iron 8 U-721~ Washer for Anchor~ 5 x l x 5" Flat 8 U—667— Clips for Sash~ 7/16" hole- 1 x 3/16" Flat x o'-1 3/4" Packed by Date If you find any errors or shortages, return this checklist with your complaint. AERMOTOR CO. 2—22-39 Chicago __.2._;_____ :2 __ ww.mh_w¢m>.23 mh