438 



ESTIMATES OF STRUCTURAL STEEL. 



CHAP. XIII. 



TABLE VII. 



NUMBER OF FIELD RIVETS IN RAILWAY BRIDGES, SINGLE TRACK, E 55 LOADING. 



(HARRIMAN LINES.) 



The field rivets on the 2Oth St. Viaduct, Denver, Colorado, cost 7 cts. each. The rivets 

 were driven by air riveters. 



Actual Costs of Erecting Railway Bridges. The cost of erecting railway bridges on the A. T. 

 & S. F. Ry. in 1907 are given in the report of the Assoc. of Ry. Supt. of B. & B. as follows: 



Trusses, 984 tons erected, cost $4.63 per ton. 



Plate Girders, 2,784 tons erected, cost $5.49 per ton. 



I-Beams, 2,837 tons erected, cost $2.88 per ton. 



All girders and I-beams were erected with a steam wrecker and the through spans with a derrick 

 car. The reason for the plate girders costing more to erect than the through trusses was that 

 many of the plate girders were on second track where the old girders had to be cut apart and moved 

 to the outside and heavier girders put in their place. All rivets were driven by hand. For addi- 

 tional examples of actual costs, see Gillette's "Cost Data." 



Transportation. Fabricated structural steel commonly takes a "fifth-class rate" when 

 shipped in car load lots, and a "fourth-class rate" when shipped "local" (in less than car load 

 lots). The minimum car load depends upon the railroad and varies from 20,000 to 30,000 Ib. 

 Tariff sheets giving railroad rates may be obtained from any railroad company. The shipping 

 clerk should be provided with the clearances of all tunnels and bridges on different lines so that 

 the car may be properly loaded. 



Freight Rates. The freight rates (1913) on finished steel products in car load shipments from 

 the Pittsburgh District, including plates, structural shapes, merchant steel and iron bars, pipe 

 fittings, plain and galvanized wire, nails, rivets, spikes and bolts (in kegs), black sheets (except 

 planished), chain, etc., are as follows, in cts. per 100 Ib. in carload shipments; Albany, 16; Buffalo, 

 ii ; Boston, 18; Baltimore, 14!; Cleveland, 10; Columbus, 12; Cincinnati, 15; Chicago, 18; Denver, 

 Colo., 85!; Harrisburg, 14^; Louisville, 18; New York, 16; Norfolk, 20; Philadelphia, 15; Rochester, 

 nf ; Richmond, 20; Scranton, 15; St. Louis, 23; Washington, 14!. 



COST OF PAINTING. The amount of materials required to make a gallon of paint 

 and the surface of steel work covered by one gallon are given in Table VIII. Structural steel 

 should be painted with one coat of linseed oil, linseed oil with lamp-black filler, or red lead paint 

 at the shop; and two coats of first-class paint after erection. The two field coats should be of 

 different colors; care being used to see that first coat is thoroughly dry before applying the second 

 coat. Steel bridges and exposed steel frame buildings ordinarily require repainting every three 

 or four years. 



The steel work in the extension to the i6th St. Viaduct, Denver, Colo., was painted with red 

 lead paint mixed in the following proportions, 100 Ib. red lead, 2 Ib. lamp-black and 4.125 gallons 



