LXIV. 



J. I. HAYCROFT. 



in order to give stiffness ; but, even so, it is only as deep as the 

 Vierendeel bridge, and the flange area is greater than might be 

 necessary, owing to the expediency (in construction) of putting 

 three plates in the centre half, then two for the ^-length outside 

 that, and one plate at the ends of flanges. 



Weight op Plate Girder, 103-35' Span. 





D' 



Lbs. 



Tons. 



Web, f" x 9-75' x 1 05-32' 



102687 



15-3 



7-00 



Flange plates, 10" x \" x ( l / 52) l / 80j 7 105 . 32 









= /237-32 



237 32 



17-0 x 2 



= 3-60 



Flange angles, 2/3 J" x 3£" x \" x 









105-32' 



210-64 



110 x 2 



= 2-00 



Stiff eners (outside), 21/9' x (5" x 3£" x 









r Tee) 



205-80 



13-6 



1-25 



Stiff eners (inside), 21/85 x (5" x 3£" x 









V Tee) 



178-50 



13-6 



1-08 



End Posts, 2 plates, 10" x \ x 9 75' 



19-50 



17-0 



014 



4 angles, 2>\" x 3*" x |" x 









9-75' 



39-00 



11-0 



0-19 



Cross girders, 23/15'', I beams 9*8' long- 



225-40 



50-0 x I 



= 2-50 



Kail bearers, 2/105 32' 15" I beams 



210-64 



25-0 x £ 



= 1-18 



Add 5% for rivet heads 



Total tons 



18-94 

 0-96 



19-90 



Say 20 tons. 



/. Whole bridge = 20 x 2 = 40 tons. 



Deflection under full load of 202 x 20 = 222 tons. 



I = 160,600. E = 13,000 tons. 



-f" = 5 x 222 x (03-35' x 12) 3 _ fi „ 

 J 384 x 13,000 x 160,600 



Sectional area of flange at centre — 



Plates, 3 x 10" x \" = 15 sq. in. 



Angles, 2 x (3J" x 3|" x £") = 6-5 sq. in. 



Add | web area J (117" x §") = 7*3 sq. in. 



28 8 sq. in. 



Stress in flanges = -5-^ 



W L 222 x 103 35' 



x 9-75' 



29415 tons 



