Car float

A railroad car float or rail barge is an unpowered barge with rail tracks mounted on its deck. It is used to move railroad cars across water obstacles, or to locations they could not otherwise go, and is towed by a tugboat or pushed by a towboat. As such, the car float is a specialised form of the lighter, as opposed to a train ferry, which is self-powered.

During the Civil War Herman Haupt used huge barges fitted with tracks to enable miiltary trains to cross the Rappahannock River in support of the Army of the Potomac.

Beginning in the 1870s, the Baltimore and Ohio Railroad (B&O) operated a carfloat across the Potomac River, just south of Washington, D.C., between Shepherds Landing on the east shore, and Alexandria, Virginia on the west. The ferry operation ended in 1906. (See Capital Subdivision.)

The B&O operated a carfloat across the Baltimore Inner Harbor until the mid-1890s. It connected trains from Philadelphia to Washington, D.C. and points to the west. The operation was discontinued after the opening of the Baltimore Belt Line in 1895.

The Port of New York and New Jersey was especially rife with carfloat operations, which lost ground to the post-World War II expansion of trucking, but held out until and the rise of containerization in the 1970s.

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