01200cam a22002172 4500 hsl000704655 DGPO 20170826152503.0 100713s1937 dcu f000 0 eng d GPO GPO MvI Y 4.IN 8/4:SI 2/3 Y 4.IN 8/4:SI 2/3 Railway signal systems : hearing, 75th Congress, 1st session, on H.R. 185, to promote safety of employees and travelers on railroads by requiring common carriers engaged in interstate commerce to install, inspect, test, repair, and maintain block-signal systems, interlocking, highway grade crossing protective devices, automate train-stop, train-control, cab-signal devices, and other appliances, methods, and systems intended to promote safety of railroad operations, Mar. 19, 1937. [Washington, D.C.], 1937. iii, 64 p. Document for sale by the Superintendent of Documents, paper. CRDP Program Historic Shelflist record. Railroads Safety appliances United States. Railroads United States Safety measures. United States. Congress. House. Committee on Interstate and Foreign Commerce. BEV Fed Docs 262550 262550