Railroad drawbridge
The Charles River Bridge is a pair of railroad
single-leaf, through-truss, rolling bascule bridges across
the Charles River that connects North Station in Boston,
Massachusetts to MBTA Commuter Rail lines in northern
Massachusetts.
These bridges were designed by Keller & Harrington of
Chicago, Illinois and built by the Phoenix Bridge Company of
Phoenixville, Pennsylvania. Each bridge uses a 629-short-ton
over-head concrete counterweight. Originally, there
were four bridges, but only two of them remain.
Photo 33, May 2012