SPECIFICATION'S FOR STEEL HIGHWAY BRIDGES. 45 
Column splices generally shall be located close to and 
above the panel points of the bracing. 
Horizontal diagonal bracing shall be provided at the 
tops and bases of towers and at least at all intennediate 
panel points of the lateral bracing where the tower 
columns are spliced. 
Provision shall be made in column bearings for expan- 
sion of the tower bracing. The struts at the base of 
towers shall be strong enough to slide the movable 
shoes with the structure unloaded. The coefficient of 
friction shall be taken at 0.3. 
Sole and masonry plates shall each be not less than ^ 95. soie and 
inch thick. masonry plates. 
Viaduct bents preferably shall have a sufficient spread 96. Anchorage. 
at the base to prevent tension in any windward leg. 
When this is impracticable, the column anchorages shall 
be designed to resist safely not less than one and one-half 
times the calculated uplift. 
The construction plans shall consist of shop detail, 97. Approval of 
erection and other working plans showing details, ^ ^^^' 
dimensions, sizes of material and other information and 
data necessary for the complete fabrication and erection 
of the metal work. Approval of the construction plans 
shall be secured before fabrication of steelwork is com- 
menced. 
The contractor shall furnish the engineer with such 
blue-print copies of the plans as may be required for 
approval and construction purposes and upon completion 
of the work the original plans if required shall be supplied 
to the engineer. No deviation from the approved plans 
will be permitted without the written order of the engineer. 
