Vertical-lift Railroad Bridge

From the U.S. Army Corps of Engineers, Headquarters:

#OTD: In 1933, construction began on the railroad bridge over New England District's Cape Cod Canal. Constructed close to the western end of the canal, the vertical-lift bridge has a 544-foot horizontal span, at the time of its construction the longest lift span in the world, supported by towers 210 feet high.

The span is normally kept in the raised position, 135 feet above mean high water. Almost exactly two years later, the first train rolled across it on December 29, 1935.