LOCOMOTIVE ERECTING SHOP, PHILADELPHIA & READING R. R. 373 



tween each pair of columns, 35 pits on each side spaced 20 feet apart 

 c. to c. Over each side bay there are two traveling crane tracks, 

 one above the other. The top track will be for a crane of 120 tons 

 capacity, capable of lifting a locomotive and carrying it the entire 

 length of the building at a height great enough to clear the locomotives 

 standing on the repair pits beneath. On the lower track there will be 

 placed a number of 35-ton cranes for handling parts of locomotives 

 and material. The middle bay composes the machine shop, and it is 

 also covered by a track for a number of traveling bridge cranes of 10 

 tons capacity each. A material track runs lengthwise of the middle bay 

 at the center, and for bringing the locomotives into the shop there is a 

 track extending transversely through the shop at each end. These 

 transverse tracks connect by means of turntables with a yard track- 

 running parallel with the east side of the shop. 



Taking up the construction in detail, the steelwork is the first part 

 perhaps to demand attention. As already stated, the nature and gen- 

 eral arrangement of the steel frame is shown by Figs. 176 and 177. It 

 may be divided into two parts for description. The first part comprises 



FIG. 177. TRANSVERSE SECTION OF FRAMEWORK. 



the main columns and the traveling crane track system which they sup- 

 port directly, and the second part comprises the roof framing. Con- 

 sidering the construction of the main columns first, it will be seen that 

 it had to be devised to withstand an unusually severe combination of 

 loads, including not only the dead and wind loads usual to all building 

 frames, but also a very heavy concentrated moving load from the trav- 

 eling cranes. Careful attention was also required to provide means 

 for longitudinal expansion of the columns and crane track girder sys- 

 tem and still preserve the utmost stiffness possible in the heavily loaded 

 crane tracks. 



