sete tere hpeverisndererneeriy [Jidtoapetheenenenerre fares ayo fa a gt Peon pies Ae ag be erage wee pers fished? lees tanet rors ee hee are leabpenesbennie weectameneet ts eres mine oT iG taketh rah terse tarts mest SEU etatebeee 3 Tee ne oO tibiasaseraret een meter easens caer ns et — ” ae ox © a oP ANS ) P| oo {- §¥600 eA ele, ~%2/90a ne £ a ww 4 "=> tal Ts » o ra: NJ ‘ =P) %a) | Ody . COMPUTATIONS FOR LIVE LOAD STRESSES Chord Members Chord LoLl ; Criterion for greatest chord stress is satisfied when the load on the left segment of the span is to the total load on the bridge as the length of the left segment is to the total length of the span. Wheel 4 at panel point Ll = 68.5 - 87.5 Length of train on bridge = 9.1 ft. Load on bridge = 355+( 9.1 x 2.5 ) = 3577.75 Kips According to above criterion the load causing the greatest stress is one-sixth of 377.75 Kips or 62.96 Kips, as this is between 62.5 and 87.5 the criterion is Satisfied. Moment at rt. support = 20455 + (355 x 9.1)+1.25 x oct =23789.0 Kip feet Moment ar section 600 Kip feet Bending moment =1/6 x 23789 - 600 = 3365 Kip feet Stress in LoLl = 3365 = 153000 # Bo The above method was used in computing the stresses in the other chords and the results are tabulated in Table III. The live load chord stresses all check with those used in the design except L2L3 which has a difference of 6000 #. Moments and loadings were taken from Cooper's Moment Diagram for E-50 loading. A drawing of this diagram may be found on page 122 of Merriman and Jacoby Vol. I. ANALYSIS OF COMPRESSION MEMBERS Compression members shall be proportioned by the following allowed unit strains; For Medium Steel Chord segments P=10000 - 45 1/r for live load. P =20000 - 90 1/r for dead load. All posts of P= 8500 - 45 1/z for live load. through bridges P=17000 - 90 1/r for dead load. All posts of P=9000 - 40 1/r for live load. deck bridges P= 18000 - 80 l/r for dead load. Lateral Struts and . rigid bracing P=13000 - 60 l/r. P=the allowed strain in compression per square inch of cross-section, in pounds, l1=the length of compression member, in inches, c. to c,, of connections r=the least radius of gyration of the section, in inches, SECTION OF ITHCLINED END Post - Lo Ul 1 Cover (ba) 19 x 4 ~T r i 2 Webs (ba) 18 x 4 La (be) 33 x 34 x 7/16 / 10 3/4" clear between Webs 1=2£9' - 8 7/8" =356 7/8" > oe - — — od Total Area of gross section = 38.98 l. Axis 1-1 I of cover plate =-19 x (.5)°/l12 = .198 Ad” of cover plate=9.5 x (9.375)2=835.050 I of 4 Ls =4x 3,3 = 13.200 Ad® of 4 Is =4 x 2.87 x 8.085* = 750.413 I of 2 Webs-£2£ x2 x18°/12 <= 486.000 Moment of Inertia of gross sec. = 2084.861 in.4 Axis 2-2 I of dover plate =4 x 199/12 = 285.791 I of 2 Webs=2 x18 x .5°9/12 = 0375 Ad® of 2 Webs=2 x9 x 5.625% = 569.520 Il of 4 Is =4 x 3.3 = 13.200 it Aa” of 4 Ls= 4 x 2.87 x 6.915% 549.168 Moment of Inertia of gross sec.= 1418.054 in.4 Least Radius of Gyration =//1418 .054 = 6.02 in. 38.98 P= 9000 - 40 1 = 9000 - 40 x 356.875 = 6621.00 #/in.*® r 6.02 , . Stress in Lo Ul = 267500.00 # 2 £67500 = 40.4 in.” reqd. 39.0 in.” used in gross section. 2 The formula used is from Cooper's 1906 Specifications while the structure was designed to Cooper's 1901. 10. SECTION OF UPPER CHORD Ul U2 1 Cover (bo) 19 x 7/16 = 8.31 2 Webs (bn) 18 x# = 18.00 4 Ls (bk) 34 x 34 x 3/8=9.92 1 = 20" = 240" 10 5/8" clear bet. webs Total area gross section = 36.23 in.2& From the design of Lo Ui we know that the least radius of gyration is about axis 2-2. Axia 2-2 I of cover plate 7/16 x 199/12 = 250.060 Iof2webs 2x18 x .59/12 = B75 Aad® of 2 webs 2x9 x 5.5622 = 556,830 Ilof4is 4x 28.9 = 11.600 Ad® of 41s 4x 2.48 x 6.8222 = 461.676 Moment of Inertia of gross sec, = 1280.541 Radius of gyration=//1280.5 = 5.94 in. 26 ebo P = 10000 - 45 1 = 10000 - 45 x 240 = 8162 #/in.* ro 5.04 ne reqd,. Gross section =36.3 in. ® 282700 = 34.6 I ll. SECTION OF UPPER CHORD U2 US 41s 33 x 34x 7/16 2 webs 18 x + Cover 19 x 7/16 10 3/4" clear between webs Least moment will be about axis 2-2 same as in predeeding work. Axis 2-2 I of cover plate (bu) 7/16 x 19°/12 = 250.060 I of 2 webs (bt) 2x18 x .59/le = 2375 Ad® of 2 webs (bt) 2x9 x 5.5622 = 556.830 I of 4 Ls (bp) 4x 3.3 = 13,200 Aad® of 4 Ls (bp) . 4 x 2.87 x 6.852" = 638.974 Moment of Inertia of gress sec. = 1359 .439 Radius of gyration: y 1359.4 = 6,05 in. ¥ | @ ’ L P= 10000 - 45 1 = 10000 - 45 x 240 = 8125 #/in.® ~ 6.05 — r ° 310000 = 37.7 in.® read. Gross section= 37.8 in.@ |2 SECTION VERTICAL POST U2 L2 (V2) |! ml rl le 4 Ls (ce) 6 x 4 x 5/8 = 23.44 in.® l= 22'= 264 * Axis 1-1 I of 4 Ls (ce) 4x 21.1 Ad® of 4 Ls (ce) 4 x 5.86 x 2.21% Moment of Inertia of gross section Axis 2-2 I of 4 Ls (ce) 4x 7.5 aa” of 4 Ls (ce) 4 x 5.86 x 3.222 Moment of Inertia of gross section Least radius of gyration = 2.92 in. 84 .400 115.090 199 .490 50 .000 £42 .858 £72 .838 P= 9000 - 40 x 264 = 5384 #/ in.® Allowable unit stress. “B.98 | 126000 = 23.4 in.? reqd. Gross section = 23.44 in.® ee - Jf ys 4) ad 13. SECTION OP VERTICAL POST US L3 (V3) 2 Li a | 41s 6x 4x4 =19.0 in.® l= 22' = £64" From the previous post V2 we know that the least radius of gyration is about axis l-l. Axis 1-1 I of 4 ls (ca) 4 x 17.4 = 69.600 Aa® of 41s 4x 4.75 x 2.177% = 90.041 Moment of Inertia of gross section =~ 159,641 Radius of gyration = 2.90 in. P= 9000 - 40 x 264 = 5369 #/in.® 91000 = 17.0 in.® reqd. Gross section = 19.0 in. Bobo a y, 14, SECTION OF VERTICAL POST Uo Lo (V) 2 Lid. I 1 | 2 - —~ As before least radius of gyration is about axis l-l. 4 Ls (om) 6 x 4 x 3/68 =14.4 in.? 1 = 22" = 264" Axis 1-1 I of 4 Ls (cm) 4x 13.5 = 54.000 Ad2 of 4 Ls (cm) 4 x 3.61 x 2.1272 = 65.145 Moment of Inertia of gross section - 119.145 Radius of gyration =2.87 in, P = 9000 - 40 x 264 = 5321 #/in.® 68000 = 12.8 in.® reqd. Gross section=14.4 in.2 DSSL oe 15, ANALYSIS OF TENSION MEMBERS All parts of the structures shall be proportioned in tension by the following allowed unit strains, net sections: For medium steel -— Pounds per sq. in. Floor beams, hangers when permitted----------- 6000 Longitudinal, lateral and sway bracing, for lateral forces----------~----~-----~.----- 18000 Longitudinal, lateral and sway bracings, for live load------------------ eee 12000 Solid rolled beams, used as cross floor beams and stringers--------------------- 10000 Bottom flanges of plate girders chords and webs of lattice and pin- Dead load. Live load. connected trusseS------------------- 20000 10000 Verticals carrying floor beams----------- 16000 8000 The required sectional area of any member is obtained by dividing the sum af (Live #4 dead load strains) by the live load unit strains since the live load unit strains are equal to 4+ of the dead load unit strains, In members subjected to tensile strains full allow- ance shall be made for reduction of section by rivit-holes, screw threads, etc. 7/8" rivets are used throughout, therefore a 1" hole is to be deducted, SECTION OF DIAGONAL Ul L2 (D) Stress in Ul L2=174360 # Allowable unit stress 10000 #/in.® 174350 = 17.43 in.2 reqd. net sedtion. 41s 6x4x 9/1624 x 5.31= 21.24 in.® Gross section. 4 rivet holes @ .5625 = 2.25 21.24 - 2.25= 18.99 in.© Actual net section. SECTION OF DIAGONAL U2 L3 (D1) Stress in U2 L3= 138650 # 138650 =13.87 in.* reqd. net section. “10000 41s 6x4x 3/8 = 4x 4.75= 19.0 in.* 4 rivet holes @ ,.5 = £.0 19.0 = 2.0 = 17.0 Actual net section, SECTION OF LOWER CHORD Lo Ll AND Ll L2 Stress in Lo L1=180300 # 180300 = 18.03 in.® reqd. net section. “10000 418 6x4x9/16= 4x 5.31 = 21.24 in.2 4 rivet holes @ .562£5 = 2.25 21.24 - 2.25 = 18.99 in.* actual net section. SECTION OF LOWER CHORD L2 13 Stress in L2 L3= 282700 # 282700 = 28.27 in. © regqd. net section. 418 6x4x 5/8= 4 x 5.86= 23.44 in.® 2pl. 13 x 3/8 2x 4.875 = 9.75 " 33.19 " 8 rivet holes = 4.0 in.*® 33.19 - 4.0=29.19 in.*© iet sec. en , Y fot f" 44 hla —— & ' 17. SECTION OF HANGER Ul L1 (V1) Stress in Ul Ll = 90000 # 90000 = 9.0 in.* reqd. net section. “T0000 4148 6x4x3/8= 4x 3.61= 14.44 in.© Gross section. 4 rivet holes @ ,375 = 1,50 14.44 - 1.50 = 12.94 in.” Actual net section. ANALYSIS OF LATERAL BRACING To provide for wind and vibrations from hish-snreed trains: The top lateral bracing in deck bridges, and the bottom lateral bracing in through bridges shall be propor- tioned to resist a lateral force of 600 pounds for each foot of the span; 450 pounds of this to be treated as a moving load, and as acting on a train of cars, at a line 6 feet above base of rail. The bottom lateral bracing in deck bridges, and the top lateral bracing in through bridges, shall be propor- tioned to resist a lateral force of 200 pounds for each linear foot for spans up to 200 feet, All lateral, swey and portal bracing must be made of shapes capable of resisting compression as well as tension, and must have riveted connections, a5° = LED aa 18. ULrPER LATERAL BRACING Since the lateral diagonals are stiff members de- Signed to take both tension and compression it will be assumed that the shear in each nanel is equally divided between the two diagonals - P 163 M and J Vol. Il. Shear in first panel= 36000 - 6000 = 30000 # Stress in Bl0-11-12 = 30000 x 1.834 = 55000 Stress in B10 etc. = 55000 +2 = 27500 3/4 of 27500 = 20625¢ =live load stress in B10. 1/4 of 27500 = 6875 = dead " " fF , The other diagonals in the upper lateral bracing are all designed for the stresses in the first panel. Stress in H10 = 6000 # Stress in H11-12=12000 # Section of diagonal B10 1L5 x 34 x 3/8 = 3.05 in.” Gross section. 2 rivet holes @ .375 = .75 in.® 2.30 in.© Actual net section. 20625 = 1.72 in.® 6875 = .38 in.2 12000 T8006 Required net section = 2.1 in. section of Strut H10 1 L 34 x 34 x 3/8 = 2.48 in.® Gross section. 2 rivet holes = £75 1 =13' = 256" 1.73 in.® Actual net section, | For lateral struts and rigid bracing » =13000 - 601 r for 1 L 34 x 34 x 3/8 = 1.07 * 6000 = 1.41 in.® reqd. net section, 4253 P =13000 - 60 x 256 = 4253 #/in.® “I.07 19. | Section of Strut Hll 2s 34 x 3A x 3/8=2 x 2.48=4.96 in.*© Gross section, 2 rivet holes @ .75 _. = 1.50 4.96 - 1.50=3.46 in.* Actual net section. r =1.06 in, P = 13000 - 60 x 156 = 4170 #/in.* 1,06 12000 = 2.87 in.* reqd. net section. section of strut H1l2 is same as Hill. LOWER LATERAL BRACING The lower lateral bracing in deck bridges shall be propor- tioned to resist a lateral force of 200 pounds per lineal foot for spans up to £00 feet. L=200 x 20=4000 # per panel. sec @ =1.834 Shear in first panel= 12000 - 2000=10000 # Stress in L8-9-10 = 10000 x 1.834=18340 Section of Diagonal L8& 1 L 33 x 34 x 3/8 =2.48 ‘in.® 2 rivet holes = ,75 2.48 - .75=1.73 in.® Actual net section. 18340 = 1.02 in.® reqd. net section. 18000 Sections of other diagonals same as L8&. Section of Strut H8 2iLs 5 x 3i x 3/8=6.10 in.2@ r=1,44 in, 2 rivet holes = 75 P=13000 - 60 x 156 =6500 1.44 6.10 - .75=5.35 in.® Actual net section, H8 will take stress of 5.35 x 6500 =34775 # Extra sectinnal area is needed to stiffen lower section, 20. ANALYSIS OF SWAY BRACING All deck bridges shall have transverse bracing at the ends, and at each panel.point of sufficient strength to carry half the maximum stress increment due to latersl and cen- trifugal forces. All members of the web, lateral, longitudinal or sway systems must be securely riveted at their intersections to prevent sagging and rattling. All lateral, sway and portal bracing must be made of shapes capable of resisting compression as well as tension,: and must have riveted connections. P Uo Up Vo YU, Ug. Us vu) Ug _ U, A A 44 c+ Di 8 ws IC e We é 4, Lo Lo 4, Lo Ly OL, 4, ks t, Panel C L2 L2' C' Wl and W2 represent the wind loads at each panel, W2 being the smaller. The difference Wl - W2 would distort the panel, if the sway bracing did not prevent it, and hence one-half this difference may be considered to act as shear across the rectangle. Both diagonals are tension rods and C L2' receives the ten- Sile stress 4(W1l - W2) sec 0. Wl = Panel wind load at top =12000 # we= * " * pottom = 4000 # Shear across rectangle=4 (Wl - W2) = 4000# el. Stress in diagonal CL2'= 4000 x sec 8- Sec 9=1.23 4000 x 1.23 = 4920# Panel B Ll LI* BF Another function of the sway bracing is to prevent the distortion of the bridge under eccentric load. In rec- tangle B Ll L1' B' an eccentric load may come. The reactions of this load at the ends of the floor beam B B' are unequal, and since the trusses are made alike their deflections would be proportional to these re- actions unless they were equalized by the sway bracing. If R and R' be these reactions, one-half of R - R' acts as shear across the rectangle, and produces the tensile stress + ( R - R' ) sec O in the tie B Ll'. R= 36000 R' = 12000 sec 9 =-1.23 Stress in B L1l's 4 (36000 - 12000) 1.23 = 29880 # Allowable stress = 18000 #/in.® £9880 = 1.65 in.® required. 1 L 3h x 34 x 3/8 ¢ 2.48 in.® 2 rivet holes | 075 2.48 - .75 = 1.73 in.© Actual net section. she stress in this last piece being greater than the one first computed, this was used throughout the bridge except in the end panels. LE. End Panel A Lo Lo! A® The bracing in the end rectangle A' Lo' Lo A must be heavier than the sway bracing between intermediate posts, because its function is to carry wind pressure and in some cases cintrifugal load from the upper latteral system to the abutment. If the sway bracing equalizes the wind loads between the two chords, as suggested above, the horizontal force W os one-fourth of the total wind pressure on the bridge; if the upper lateral bracing carries all the wind pressure specified for the upper chord, the W is one-half of this wind pressure. The stress in A' Lo = W sec @ W = # of total wind pressure for upper chord = 34000 # Sec 9 = 215.375 4 172.5 = 1.245 34000 x 1.245 = 42330 # Allowable stress = 18000 #/in.® 42330 = 2.3 in.& Required net section. T8600 1L5 x 33 x 3/8 = 3.05 in.® £2 rivet holes = .75 3.05 - .75 =2.30 in. Actual net section. The extra sectional area in members of the sway bracing adds additional stiffness to the cross section of the bridge, ZO. FLOOK BEAL (FB) web rlate The span of the floor beam (effective length) shall be considered as the perpendicular distance between the center lines of the trusses = 15.0'. ‘The floor beam carries in addition to its weight, two concentrated loads 3'-6" from its center, each load consisting of the maximum sum of the adjacent reactions of the stringers on both sides and of the track it supports, and the corresponding live load. From the analysis of the stringers the total dead load of one of the stringers was found to be 12600 =. The equivalent uniform live loaa must be taxen for a Span of two panel lengths or 40 feet, and by means of Table I, Coopers Specifications 1906, it is found to be 9048 # per lineal foot of track, for E-50 loadings. ‘Whis would give a uniform live load on each strinzer of 4524 # per lineal foot, or the total live load at each stringer con- nection would be 4524 x 20 = 90480 #7. The weight of the floor beam will be assumed as being 2500#. The totel max- imum vertical shear would be 90480+ 1250 t 12600 = 104330 #. The allowable shearing stress is 10000 #/in.® The net area required to resist this vertical shear is 104330 + 10000 = 10.43 in.* kequired net section, l web plate 34 x 4= 17.0 in.® 6 révet holes = 3.0 17.0 =~ 3.0 = 14.0 in,” Actual net section, The web plate used is plenty safe and the excess srea will CO away with the necessity of stiffeners, as the span is short. flanges the bending moment due to the two concentrated louds equals 103080 x 3=309240 ft. #, and that due to the weight of the floor beam is 4026 ft. #, making a total of 313302 ft. #. Assuming an effective depth of 30.58 inches and allowing a unit stress of 15000 #/ in.” the required net area of the lower flange is as follows:- 413302 x 12 = 8.2 in.” Required net section. 30.08 x 15000 2Ls 6 x 6 x 9/16=6.43 x 2=12.86 in.” gross section. £ rivet holes ¢ ,&625 = 1.13 12.86 - 1.18=11.72 in.” Actual net section, In the analysis of the web plate an allowance was made for 6 rivets , which is the maximum number used, a uniform pitch of 2-3/16" being used throuzhout. All floor beams used in the structure are identical in section and vary only a few inches in length. The other ficor beans are F Bl and F B8, Four Ls 5 x 31 x 3/8 are used as stiffeners under each stringer connection, which acts as a column with an excess of steel in cross~section,. The floor beams are connected to the posts by means of 2Ls 65x 5 x3/8, a rivet pitch of 2" is used. See estimate of total weight for actual weight of floor beam. omen 2 a PF 4 - ei iad een eile ol F eRe £56 TRACK STRINGENS The. span of the stringer equals the panel length of the truss or 20 feet. The loading is a load of 120000 # equally distri- buted on two pairs of driving wheels spaced 6 feet center to center, The maximum bending moment for one stringer equals 247500ft.# ( Table I Coopers Specifications ) The total dead load on one stringer equals 12600 #. The dead load moment equals 30500 ft. #. The total moment equals 30500+ 247500 = 278000 ft.# The diegram of end shears gives 60000 # for a span of 20 feet. The shear due to dead load is 6300 #, thus giving a total ver- tical shear of 66300 #. Allowable shearing stress.is 10000¢ / in,” 66300 = 6.63 in.” Required net section, 10000 1 Web plate 32 x +=216.0 in.® gross section. 7 rivets @ 1/2 2 3.5 16.0 - 3.5=12.5 in.” Actual net section, This section is large enough so that stiffeners are not nec- essary. As flange angles 6 inches wide are most suitable for stringers without coyer plates, the clear distance between flange angles is 26 inches. The extra material in the web plate increases the stiffness of the strixiger. Flanges 2 The specified allowable tensile stress is 10000 #/ in. Bending moment to be resisted by the lower flange 278000 ft .¥ £78000 x 18 = 11.7 in.” Required net section. e x 26. 2ls 6x 6x 9/16 2 x 6.43=12.86 in. gross section. £ rivet holes @ .562 = 1.12 12.86 - 1.12=11.74 in.” Actual net section, The effective depth is taken as 28.58 inghes. (The distance between the centers of gravity of the flange areas will be considered as the effective depth of all plate girders. ) Cooper specifies that plate girders shall be proportioned upon the supposition that the bending or chord stresses are resisted entirely by the upper and lower flanges, and that the shearing or web stresses are resisted entirely by the web plate ; no part of the web plate shall be estimated as flange area, Rivet Pitch in Flanges, The maximum vertical shear at the end is 66300 #, and the increment of flange stress per lineal inch is----- 11.74 x 66300 = 2830 ¢ . Il.” 88.56 : The vertical load on the flange is 24024 - 750 ~ SE The resultant of these horizontal and vertical components is 2450 pounds. The allowable bearing of a 7/8 inch rivet in a + inch web is 7880 #, and hence the theoretic rivet pitch at the end is 7880 / 2450=3.2 in. The pitch used runs from 2 inches at the ends to 5 inches at the center. The sections of all stringers ,3, $1 and S2 are the same except for a slight variation in length. ESTIMATE OF WEIGHT Material for one Span End Post LO Ul Four required. 2Le 34 x 3k x 7/16 x 28'~9" @ 9.8 # ----------- 563.50 # 2Ls * " nx «28'~42" © 9,8 -------------: 556.55 2Wbs 19" x 4"x 23's24" @ 32.3 ------------------ "1495.17 1Cov * y on 8 @ 38,3------------------ - 747,58 2P1 422" x 15/16 x 4'~8i" ---------------------- 103.73 1P1 19" x 3/8" x 1'-6" @ 24,23 ----------------- 36.35 1P1 19" x 3/8" x 21204" @ 24.23 ---------------- 49.43 1P1 * " x 1'-72" @ 24.23 ---------------- 39.88 50 Lat. bars 24" x 7/16" x 1'-5.11/16" @ .5 ---- — 25,00 Total weight of one post ----------~----- 3617.17 # Upper Chord UO Ul Four required. 4Ls 34 x 34 x: 5/16 x 18'-74" @ 7.2 # -------- wn- 6355.68 # 2Wbs 18" x 5/16" x 18'~74" @ 19,13 ------------ - 711.36 1P1 19” x 3/8" x 2'-2" @ 24,23 ----------------- 52.34 1Pl * "ox 21-24" @ 24.23 ------------- w=- 52.82 2P1 * nx 1%27" @ 24,23 ----------- ------ 77.34 2P1 Z0Z” x 4" x 1'-103" @ 52.28 --------- ~------ 193,75 44 Lat. bars 24" x 7/16" x1'-5 11/16" @ .5 ----- 22,00 Total weight of one section ------------ ~ 1645.29 ¥ Upper Chord Ul U2 Four required. 4 le 34 x 3k x 21'-44" @ 8.5 # -------- wen-- 727.77 F 2 webs 18 x $ x 21'-4%4 @ 30.60 # ----------- 1309 .68 1 cover 19" x 7/16" x 21'-44" @ 28.26 # ---- 604.76 2 pl. 47 3/4 x + x 6'-0" @ 81.18 # --------- 974,16 2 pl. 19 x 3/8 x 1'w6" @ 24.23 # -----~------ 72.69 36 lat. bars (:same as above) -------------- 18.00 2 pl. 47 3/4 x 4 x 4'-1 3/4" @ 81.18 # ----- 665.97 Total weight of one section ----------- 4372.03 # Upper Chord U2 L2 Two required, 4 Ls 34 x 34 x 7/16 x 41'-14" @ 9.8 # ------ 1612.10 # 2 webs 18 x + x 41'-14" @ 30.6 # ----------- 2516.85 1 cover 19 x 7/16 x 41'-14" @ 28.26 # ------ 1162.19 4 pl. 19 x 3/8 x 1'-6" @ 24.23 # ----------- 145.38 36 lat. bars (same as before) -------------- 18 .00 2 pl. 30 3/4 x + x 2'-8 1/4" @ 52.28 F ----- 280 .85 Total weight of section---------------- 5735.37 ¥ Lower Chord B Cl Four required. 41s 6x 4x 9/16 x 38'-8)" @ 18.1 # ------- 2800.87 # 15 pl. 6 x 3/8 x 0'-84" @ 7.65 # ----------- 78.72 2 pl. 40 x x 6'-3" @ 68.0 # -------------- 850.00 2 pl. 22 x 3/4 x 0'-7 7/8" @ 56.1 # -------- 73.61 21s 6x 4 x 3/4 x 2*-14" @ 23.6 # --------- 100.30 1 pl. 172 x 3/8 x 2'-34" @ 22.31 $ --------- 51.31 1 pl. 20% x 3/8 x 2'-82" © 26.14 # --------- 70.22 Total weight of one section ----------- 4025.03 # 28. Lower Chord B C2 Two required. 4 ls 6 x 4 x 5/8 x 40'-0" @ 20.0 # ------ 3200.00 # 2 pl. 13 x 3/8 x 46'-3" @ 16.58 # ------- 1533.65 14 pl. 9 x 3/8 x O'-83" @ 11.48 # ------- 110.25 6 pl. 10 x 3/8 x 2-10" @ 12.75 # ------ 229.00 2 pl. 354 x + x 4°-54" @ 60.35 # -------- 543.15 Total weight of one section ----- awe~- 5616.05 Post V Four required. 41s 6x 4x 3/8 x 21'-74" @ 12.3 ¢ -=--- 1057.80 2 pl. 12 x 3/8 x 2'-6 7/8" @ 15.3 # ----- 76.50 6 bat. 6 x 3/8 x 0'-84" @ 7.65 # -------- 230 .00 1 pl. 8} x 3/8 x 6'-11" @ 10.52 # ------- 73.64 1 pl. 8} x 3/68 x 2-24" @ 10.52 # ------- 22.72 Total weight of one gection -------- 1460 ,66 Hanger Vl Four required. 418 6x 4x 3/8 x 22'-04" @ 12.3 # ----- 1082 .40 1 pl. 9 x 3/8 x 6'-11" @ 11.48 # -------- 80.36 1 pl. 9 x 3/8 x 1'-44" @ 11.48 # +------- 17.22 1 pl. 124 x 4x 2'-1 3/4" @ 21.25 # ----- 45.90 1 pl. 124 x 9/16 x 1'-6 7/8" @ 23.91 # -- 47.82 1 pl. 12 x + x 1'-5 3/4" @ 20.40 $ ------ 40.80 4 bat. 6 x 3/8 x 0'-9" @ 7.65 $ -----~-=- 22,95 Total weight of one section -------- 1337.45 ¢ - 29. Post V2 Four required. 41s 6x 4x 5/8 x 22"-04" @ 20.0 # ------ 1760.00 # 1 pl. 12 x4 x 1'-5 3/4" ® 20.4 $# -------- 30.60 1 pl. 9 x 3/8 x 2-1" @ 11.48 # ---------- 23.88 1 pl. 9 x 3/8 x 6'-11" @ 11.48 # --------- 80.36 6 bat. 6 x 3/8.x 9" @ 7.65 # ------------- 34.43 Total weight of one section --------- 1929.27 # Post V3 Two required, 4 ls 6 x 3k x + x 22'-04" @ 15.3 # ------- 1346.40 # 1 pl. 9 x 3/8 x 2'-1" @ 11.48 # ---------- 23.87 1 pl. 9 x 3/8 x 6'-11" @ 11.48 $ --------- 80.36 6 bat. 6 x 3/8 x 9" @ 7.65 # ------------- 34.43 Total weight of one section --------- 1485.06 # Diagonal D Four required, 418 6x 4x 9/16 x 28'-1 3/4" @ 18.1 # -- 2038.78 # 1 pl. 9 x 3/8 x 3'-8" @ 11.48 # --------- ~ 42.02 1 pl. 9 x 3/8 x 3'-34" @ 11.48 # --------- 37.31 6 bat. 6 x 3/8 x 0'-9" @ 7.65 # ---------- 34.42 Total weight of one section --------- 2152.53 # Diagonal Dl Four required, 41s 6 x 3 x 4x 28'-1 3/4" @ 15.3 # ------ 1723.39 # 1 pl. 9 x 3/8 x 3'-24" @ 11.48 # ----------- 36.74 1 pl. 9 x 3/8 x 2-5 3/8" @ 11.48 # -------- 34.32 11 bat. 6 x 3/8 x 0'-9" @ 7.65 # --e3e------- 63,19 Total weight of one section ----------- 1857.64 # Lower Lateral Bracing fwo required, 1 L 34 x 34 x 3/8 x 21'-94" @ 8.5 # -------- 215.30 # 1 L 3b x 34 x 3/8 x 9'-6 3/4" @ 8.5 # ------ 80.75 1L 3b x 34 x 3/8 x 11'-8 3/8" © 8.5 # ----- 99.88 1 pl. 7 x 3/8 x B'-1 3/4" @ 8.93 # --------- = 19,31 2 Ls 34 x 34 x 3/8 x 0'-6 3/4" @ 8.5 # ----- 8.60 2 Ls 34 x 34 x 3/8 x 22'-5" @ 8.5 # -------- 382.50 2 ls 34 x 34 x 3/8 x 11'-02" @ 8.5 # ------- 18.75 2 Ls 34 x 34 x 3/8 x 10'-114" @ 8.5 # ------ 18.65 4 le 34 x 34 x 3/8 x 0'-6 3/4" @ 8.5 # ----- 20.40 2pl. 7 x 3/8 x 2'-1" @ 8.93 $ ------------- 35.72 1L5 x 34 x 3/8 x 2'-103" @ 10.4 # -------- 31.20 Total weight of one section wu--------- 930.96 # Lower Strut H B Two required. 2is 5 x 34 x 7/16 x 11'-4" @ 13.5 $ ------- 305.91 # 2 Ls & x 34 x 7/16 x 10'-0" @ 13.5 # -------- 270 .00 8 lat. bars 2 3/4 x 5/8 x 2'-1 5/8" @ .5 # -- 4,00 2 pl. 23 x $ x 3-2" @ 39.1 F -------------- £247.11 4is 6x4x 3/8 x 1'-84" @ 12.3 # --------- __ 86.10 Total weight of one section ----------- 913.12 # She Lower Strut H9 Five required. 21s 5 x 3 x 3/8 x 11'-5" @ 10.4 # -------- 239.20 # 2 pl. 144 x 3/8 x 1'-5" @ 18.49 # ---------- 55.47 4 Ls 34 x 34 x 3/8 x 1'~5" @ 8.5 # --------- 51.00 Total weight of one section ----------- 345,67 F Upper Latteral Strut H10 Two required, 1 L St x 34 x 3/8 x 14'-7" @ 8.5 # --------- 124.10 # Strut Hll Two required. 2 Ls 3k x 3h x 3/8 x 14'-7" @ 8.5 # ------ ~- 248.20 # 4 fills 3 x 3/8 x 1'-03" @ 3.83 # --~------- 15.62 Total weight of one section ----------- 263.82 # Strut H12 Three required, 2iLe 34 x 34 x 3/8 x 145-7" @ 8.5 # -------- 124.10 # Sway Bracing in Intermediate Posts Five required, 2s 34 x 3A x 3/8 x 19'-7 5/8" @ 8.5 F ---- 334,22 # 4 Ls 33 x 34 x 3/8 x 0'-64" @ 8.5 # -------- 17.00 1 pl. 7 x 3/8 x O'-8 3/4" @ 8.93 # --=------ 6.25 2 pl. 134 x 3/8 x 1'-33" @ 17.21 # --------- 43.03 4 Ls 4 x 34 x 3/8 x 1'-0" @ 9.1 $ ---------- 36.00 4 is 4x 34 x 3/8 x 1'1t" @ 9.1 # ---------- 40.04 Total weight of one section -----~------ 476.54 ¥# Upper Latteral Bracing Four required. 1L5 x 3 x 3/8 x 21'-9 3/4" @ 8.5 # ------ 184.96 # 1L6 x 34 x 3/8 x 10' -7" @ 8.5 # --------- 124.10 1L5 x 3t x 3/8 x 10'-73" @ 8.5 $ ---~----- 125.00 1 pl. 8% x & x 2-104" @ 14.03 § ----------- 42.00 2 Ls 34 x 34 x 3/8 x 0'=-94" @ 8.5 $ -------- 12.65, 2Ls 34 x 34 x 3/8 x O'-11 3/4" @ 8.5 # ---- 17.00 2 ls 34 x 34 x 3/8 x 0'-934" @ 8.5 # -------- 12.65 1 pl. 14 x 3/8 x 3'-94" @ 17.85 # ---------- 66.94 1L 4 x 3i x 3/8 x 1'-3" @ 9.1 # ------------ 11.38 114 x 33 x 3/8 x 2'oBi" @ 9.1 # ---------- 20.48 1 pl. 14 x 3/8 x 3'=64" @ 17.85 $ --en-=---- = 62,47 2 L4'x 34 x 3/8 x 3'-1 1/8" @ 9.1 # ------- 13.75 + pl. 124 x 3/8 x 3'-7" @ 15.94 # ---------- 65.79 Total weight of one section ----------~- 749.17 # Bracing of Inclined End Post Four required, 2 Les 3h x 34 x 3/8 x 15'-9" @ 8.5 $ --n----- 267.75 # 6 pl. 9 x 3/8 x 1'-64" @ 11.48 # --~-------- 103.32 2 Ls 34 x 34 x 3/8 x 7'-83" @ 8.5 # -------- 130.22 3 pl. 9 x 3/8 x 1'-64" @ 11.48 # ----------- 51.66 2 Ls 34 x 34 x 3/8 x 7'-84" @ 8.5 # -------- 130.22 3 pl. 9 x 3/8 x 1'-64" @ 11.48 # ----------- 51.66 4 pl. 144 x 3/8 x 2'-0 3/8" @ 18.49 # ~----- 148 .00 2 pl. 12 x 3/8 x 1'-9 5/8" @ 15.3 # -------- 55.08 1 fill, 3 x% x 1'-6 7/8" @ 5.1 # ---------- 7.65 2 pl. 12 x 3/8 x 1'-9 5/8" @ 15.3 # ------- ~ 565.08 Total weight of one section ----------- 1000.64 # Strut HS Two required. 4 Ls 34 x 34 x 3/8 x 11'-44" @ 8.5 # ------- 8 lat. bars 24 x 3/8 x 11'-41" @ 3.19 # ---- 2 pl. 18 x 3/8 x 1*-3" @ 22.95 # ----------- Total weight of one section ----------- Strut H6 Two required. 4 Ls 34 x 34 x 3/8 x 11'-434" € 8.5 7 ------- 8 lat. bars (same as above) @ 3.19 # ------- 2 pl. 18 x 3/8 x 3/8 x 11'- 44" @ 22.95 ¢ -- Total weight of one section ----------- 391.00 # 292.68 57.58 741.06 # 391.00 # 292.68 57 .58 741.06 # Sway Bracing in Vertical End Post Two required, 2ls 5 x 34 x 3/8 x 18'-2 3/8" @ 10.4 # ---- 4 Ls 3k x 3 x 3/8 x O'-114" @ 7.9 # -------- 1 pl. 10% x 3/8 x O'-84" @ 13.39 # --------- 2 pl. 154 x 3/8 x 1'-5" @ 19.45 # ---------- 41s 4x 34 x 3/8 x 1'-34" @ 9.1 # --------- 4 Ls 4 x 34 x 3/8 x 1'-14" @ 0.1 # -------- ~ Total weight of one section -«----<----- Stringer 3 Four required. 37.79 £ . 51.60 8.97 58 .35 45.50 42.96 225.17 4 Ls 6 x 6 x 9/16 x 19'-11 3/4" @ 21.9 # --- 1732.00 # 418 6x6x%x 2'=7 1/8" @ 19.6 --------- 203 .84 4 fill. 6.x 9/16 x 1'-81" @ 11.48 # -------- 76.23 l web 32 x 4 x 19'=11 3/4" @ 54.4 # -------- 1088 .00 Total weight of one section ----------- 3100.07 # 34. 3D. Stringer 51 Four required. 41s 6 x 6 x 9/16 x 19'-11 3/4" ) 41s 6x 6x 9/16 x 2'-7 1/8" ?) Same aS 5, 4 fill. 6 x 9/16 x 1'-84" ) 1 web 32 x 4 x 19'-11 3/4" 3100.07 # Stringer 82 Two required, 41s 6x 6x 9/16 x 21'-1" © 21.9 # -------- 1846.61 # 41s 6x6x4x 8'-7 1/8" @ 19.6 # -------- 203.84 1 web 32 x & x 21'-1" @ 54.4 fF ------------- 1088 .00 4 fill. 6 x 9/16 x 1'-82" @ 11.48 # ---=---- 76.23 Total weight of one section ----------- 3214.68 # Stringer S3 Two required. Same as stringer 82 3214.68 # Floor Beam F B Four required. 41s 6 x 6 x 9/16 x 12'-1 3/8" @ 21.9 # ---- 1059.96 # 1 web 34 x & x 12'-1 3/8" @ 57.8 # --------- 699.38 418 5x 5 x 5/8 x 2'-9 1/8" @ 20.0 # ------ 220.00 4 fills 8 x 9/16 x 1'-104" @ 15.3 # -------- 122.40 8 Ls 5 x 31 x 3/8 x 2'-9 1/8" @ 10.4 # ----- 228.80 4 fills 7 x 9/16 xl'-104" @ 13.39 # -------- 107.00 Total weicht of one section ----------- 2437.54 + OO. End Frame for Stringers seven required. 2 Ls 34 x 3h x 3/8 x 5'-114" @ 8.5 $ ------- 102.00 # 1 L 34 x 34 x 3/6 x 5'-92" @ 8.5 ff --------- 48.88 2 pl. 10 x 7/16 x 1'-14" Q 14.88 # --------- 32.74 Total weight of one section ----------- 183.62 # Floor Beam F Bl Two required. 4 Ls 6 x 6 x 9/16 x 12'-33" @ 21.9 # ------- 1073.10 # 1 web 34 x 4 x 12'-31" @ 57.8 # ------------ 708 .05 41s 5x5 x 5/8 x 2'-9 1/8" @ 20.0 # ------ 220.00 4 fills 8 x 9/16 x 1'-105" @ 15.3 # -------- 122.40 8 ls 5 x 3i x 3/8 x 2'-9 1/8" @ 10.4 # ----- 228 .80 4 fille 7 x 9/16 x 1'-104" @ 13.39 # ------- 107 .00 Total weight of one section ----------- 2459.35 # Floor Beam F¥ B2 One required, 4Lls 6x 6x 9/16 x 12'-24" @ 21.9 # ------- 1068.72 # 1 web 34 x 4 x 12'-23" @ 57.8 # ------------ 705.16 418 5x 5 x 5/8 x 2'-9 1/8" @ 20.0 # ------ 220.00 4 fills 8 x 9/16 x 1'-104" @ 15.3 # -------- 122.40 8 Ls 5 x 34 x 3/8 x 2'-9 1/8" @ 10.4 # ----- 228.80 4 fills 7 x 9/16 x 1'-102" @ 13.39 # ------- 107.00 Total weight of one section ----------- 2452.08 # -——_ Lateral Bracing for. Stringers 9 6 6 1 “ 2g 2 1 1 1 1 1 1 Ls 34 x 34 x 3/8 x 8'-9" @ 8.5 # ---n----- pl. 103 x 3/8 x 1'-10i" @ 13.39 # -------- pl. 103 x 3/8 x L8 -13" @ 13.39 # -------- L 5 x 33 x 3/8 x 21'-9" @ 10.4 # --------- pl. 123 x 3/8 x 2*-2" @ 15.94 # ---------- Ls 4 x 4 x 3/8 x 1'-03" @ 9.8 # ---------- Ls 34 x 34 x 3/8 x O'-113" @ 8.5 # ------- L 5 x 34 x 3/8 x 10'-10" @ 10.4 # -------- L 33 x 33 x 3/8 x O'-11" @ 8.5 # --------- pl. 84 x 4 x 2'-74" @ 14.45 # -.---------- L 5 x 34 x 3/8 x 10'-14" @ 10.4 § -------- L 33 x 34 x 3/8 x O'-114" @ 8.5 # --«----- L 34 x 33 x 3/8 x O'-9 3/16" @ 8.5 # ----- Two required. 669.38 # 160.68 88.37 226.20 68.63 19.60 17.00 20.80 8.50 37.57 10.50 8.50 6.46 Total weight of one section ----------- 1342.19 # 37. ee oP +3 E end posts LO Ul upper chord Uo Ul ve ve Ul U2 " " Ue UE B Cl B C2 Lower " " " Post V Hanger V1 Post Ve vy (V3 Diagonal D PrP PF wo PP fF FSF DW FP TH HP P HL " ~ DL Lower Lateral 2 " Strut H8 5 * " H9 5 Upper " H10-H12 2 " " H1l " Lateral Sway bracing Int. " " End Bracing Inclined Post 4 Strut H5-H6 8 Stringer S-S31l 4 ad S2-83 7 End Frame PrP © fF FF HN OF FF DW TD NO VN HO fF Ff DH FSF Fe fF HD FF HY FP FP PK ~J t3 td P4 p4 OF WEIGHT 3617.17 14468.68 # 2645.29 6582.16 4372.03 17488 .12 5735.37 11470 .74 4025.03 16100.12 5616.05 11232.10 1460.66 5842 .64 1337 .45 5349 .80 1929.27 7717 .08 1485.06 2970.12 2152.53 8610.12 1857.64 7430 .56 930 .96 1861.92 913.12 1826.24 345.67 1728 .35 124.10 620.50 263.82 527.64 749.17 2996.68 476.54 2383.70 225.17 450.34 1000 .64 4000.66 741.06 2964.24 3100.07 24800 .56 3214.68 12858.72 183.62 1285 .34 38. 39. Bracing for Stringer 2x 1342.19 2684.38 # 4 Floor Beam F B 4 x 2437.54 9750.16 2 " " Ff Bl 2x 2459.35 4918.70 1 +" " F Be 1 x 2452.08 2452.08 Weight of Tradk 20 x 220.00 4400.00 Total weight 197770 .45 # Rivet Heads @ 6% of total weight 12623 .65 Total weight 210394.10 # 210394 + 120 = 1754.6 #/ lin. ft. of Bridge. 496 BIBLIOGRALHY Books MERRIMAN and JACOBY, Roofs and EBridges-rart I-Stresses MORRILMAN and JaCOBY, Roofs and Bridges-rart III Bridge Design THZODOKE COOPER, General Specifications for Steel Railroad Bridges 1906 CARNEGIE StkuL CO. Hand Book CONCLUSION In concluding this analysis, it may he said that the structure, from the standvoint of design is an exceedingly safe one. Specifications were followed closely and all cross-sectional areas are safelv in excess of those requi- red. she design was made without ellowing for imoact, which may be exnilained by the fact that at the time the bridse wus designed this practise was not closely folloved. we can offer no exnlanation for the live load stress, which may be notec on hancver V1l.«a feneral idea of the structure mav be geuines by reference to the rhotorrarhs which are to he forvrnd in the fore surt of this book. as has teen before noted, the bricve althouzh being over twenty vears old, ernexnrs to ke in very -sood condition, It is the intention of the writers to construct a model of this bridze, to one-eishth scale, the muterial used heinc a snecial moldings of cross-section yerresenting the different Sizes of anzsles in the structure, the verious sizes of anvies beint reduced to three sizes with @ mintinun thicihness of one- ¢) 3 eishth inch, at tne time of writing the model snoxen of is not completed, Pr ee ee ei cai, all ‘can