22 
BULLEIIX 1259, U. S. DEPARTMENT OF AGEICULTUEE. 
Upon bridges constructed for the combined use of 
highway and electric railway traffic the concentrated 
electric railway loads, unless other\vise provided, shall 
be one of the following two classes, viz: 
inch per ton of gross 
y/|weight of truck and load 
■-i/f-^ ih 
Fig. 5.— Diagi-am showing distribution of typical truck load 
1. A train on each track composed of two double-truck cars 
coupled together. Each car shall be assumed to weigh, when 
loaded, 60 tons. The length of each car over bumpers shall be 
taken as 54 feet with axle loads and spacing as shown in Figure 6. 
2T-0' 
roi-i3'-o-i*-7-o 
i 
mn 
mm (trm 
Fig. 6.— Distribution of axle loads of two 60-ton cars 
2. A train on each track composed of two double-truck freight 
cars coupled together. Each car shall be assumed to M-eigh, when 
loaded, 100 tons. The length of each car over bumpers shall be 
taken as 45 feet with axle loads and spacing as shown in Figure 7. 
fS'-O^ 
^ V o 
I ^ 
19^0- 
6^< 
•!4'-0- 
•19-0- 
e^oi 
■^^y^ 
ffi (D <J) (D 
mM 
Fig. 
-Distribution of axle loads of two lOO-ton freight cars 
The wddth of car bodies over side plates shall be taken 
as 10 feet and their height from top of rail to top of roof 
as 14 feet. The gauge of the trucKS shall be taKen as 4 
feet 8y2 inches. 
