184 



STEEL RAILWAY BRIDGES. 



CHAP. IV. 



b. A film of the asphalt having a thickness not less than & inch shall be so pliable at zero 

 degrees F. that it can be bent in a radius of 2 inches. The total time consumed in the bending 

 of this film shall not exceed 3 seconds. 



10. The asphalt shall not be affected by any of the following solutions, after being immersed 

 in them for a period of 3 days: (a) a 25 per cent solution of sulphuric acid; (b) a 25 per cent 

 solution of hydrochloric acid; (c) a 20 per cent solution of ammonia. 



FLOORBEAM CONNECTIONS. The details of floorbeam connections depend upon the 

 clearance, depth of truss, length of panels and type of floor. A standard type of floorbeam con- 

 nection for a pin-connected truss of 150 ft. span is shown in Fig. 28, and details of the lower lateral 

 connection are shown in Fig. 27. Details of a floorbeam connection for a pin-connected truss with 



" 



f^^^&6m*fa! 



IHTERMEDIATE FLOOR BEAM 

 FIG. 29. INTERMEDIATE FLOORBEAM CONNECTION. A. T. & S. F. RY. 



four stringers is shown in Fig. 29. Details of a floorbeam for a riveted truss bridge are shown in 

 Fig. 40. Details of an end floorbeam are shown in Fig. 40. Details of the standard end floorbeam 

 of the A. T. & S. F. Ry. are shown in Fig. 30. The end floorbeam in Fig. 30 is supported directly 

 on the end pin, and gives a very satisfactory solution of a difficult problem and requires the driving 

 of a minimum number of field rivets. 



PEDESTALS AND SHOES. Details of standard cast steel pedestals and shoes as designed 

 by the Chicago, Milwaukee & St. Paul Ry. are shown in Fig. 31, Fig. 33, and Fig. 34. Details 

 of segmental rollers are shown in Fig. 32, and Fig. 35. Details of expansion bearings for plate 

 girders are shown in Fig. 36, and Fig. 37. Details of a built-up end shoe with circular rollers 

 are shown in Fig. 40. Details of a built-up end shoe and segmental rollers are shown in Fig. 41. 



EXAMPLES OF PLATE GIRDERS. Details of an 8s-ft. span single track deck railway 

 plate girder bridge as designed for the Kansas City, Mexico & Orient R. R., by Mr. Ira G. 

 Hedrick, Consulting Engineer, are shown in Fig. 36. The upper flanges are made of four angles 



