Title: Concrete Roadbed onn the Pere Marquette Railway
Author(s): Paul Chipman
Publication: Journal Proceedings
Appears on pages(s): 143-156
This paper describes in detail two experimental installations of concrete roadbed near Detroit, Mich. The first was built in 1926 and is 1326 ft long. It is made up of 34 sections, each 39 ft long, IO ft wide, and 21 in, thick. In addition to ordinary reinforcement, a light truss is used under each rail. Experience under operation of trains led to the second rnstallatton late in 1929. This is 390 ft Ion J and made u of 20 sections, each 19 ft 6 in. long. se of a cellu ar type of construction resulted in a 40 percent reduction in concrete, bringing it to about 3/8 cu yd per lin ft.. An improved type of rail fastening was used. The feelinig of rigidity experienced in riding over the first installation was eliminated by the use of a 7/8 in. board under the rail, set in a depression formed in the concrete.