1912 PRR map showing the Greenville Terminal and its
operations, also the current crossing
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.
U.S. East Coast
Civil War Herman Haupt used huge barges fitted with tracks to enable military 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 car float 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 car float 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 ended after the opening of the Baltimore Belt Line in 1895. 
Port of New York and New Jersey had many car float 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. 
These car floats operated between the Class 1 railroads termini on the west bank of
Hudson River in Hudson County, New Jersey and the numerous online and offline terminals located in Brooklyn, Queens, Staten Island, Bronx & Manhattan.
 Class 1 railroads in the New York Harbor area providing car float services were:
as well as the offline
Car float service was also provided to many pier stations and waterfront warehouse facilities (that did not engage in car floating service personally) by the above-mentioned railroads.
At their peak, the railroads had 3,400 employees operating small fleets totalling 323 car floats, plus 1,094 other barges, towed by 150
tugboats between New Jersey and New York City.
Abandoned float bridges are preserved as part of this history at:
Several other abandoned but unrestored float bridges exist in other locations around New York Harbor. A complete list is available at
Surviving Float Bridges of New York Harbor
Freight cars do not run in the East River Tunnels nor the North River Tunnels (under the Hudson River), in part due to inadequate tunnel clearances of the New York Tunnel Extension.
Bay Coast Railroad formerly operated a 2-barge car float connecting Virginia's Eastern Shore with the city of Norfolk, Virginia across the Chesapeake Bay.
An Erie tugboat and barge on the Chicago River in 1917
Between 1912-1936, the
Erie Railroad operated a car float service on the Chicago River in Chicago, Illinois. 
U.S. West Coast
Santa Fe Railroad: San Francisco
Southern Pacific Railroad (?)
Union Pacific Railroad (?)
Western Pacific Railroad: San Francisco
Chicago, Milwaukee, St. Paul and Pacific Railroad: Seattle, Washington, Tacoma, Washington, Bellingham, Washington, Port Townsend, Washington Seattle and North Coast Railroad: Seattle, Washington, Port Townsend, Washington
Canada Various inland lakes of
British Columbia ( Okanagan, Arrow, Kootenay) (CN and CPR)
Port Maitland, Ontario - Erie, Pennsylvania (TH&B Railway)
Port Burwell, Ontario - Ashtabula, Ohio (CN)
Cobourg, Ontario - Rochester, New York (Ontario Car Company)
Sarnia, Ontario - Port Huron, Michigan - rail-barge - (CN, until the opening of the Paul Tellier Tunnel). The rail ferries Pere Marquette 10 Pere Marquette 12 and were converted to barges (PM 10 in 1974, PM 12 in the 1980s) and used until 1995 to carry dangerous cargoes and oversize cars. 
Windsor, Ontario - Detroit, Michigan (Grand Trunk, CN, CPR, Michigan Central, Wabash, until the 1980s)
BC Rail. until 1955 railcars were barged from North Vancouver to Squamish. A large number of isolated BC pulp mills had chemicals and freight moved by car floats.
Alaska Railroad provides the Alaska Rail Marine rail barge service from downtown Seattle, Washington to Whittier on the central Alaskan mainland. Additionally,  CN Rail provides the Aqua Train rail barge service from Prince Rupert, British Columbia to Whittier. 
New York / New Jersey
The only remaining car float service in operation in the
Port of New York and New Jersey is operated by New York New Jersey Rail. This company, operated by the bi-state government agency Port Authority of New York & New Jersey is the successor to the New York Cross Harbor Railroad. Car float service operates between 65th Street / Bay Ridge Yard in Brooklyn, New York and Greenville Yard in Jersey City, New Jersey. 
Lederer, Eugene H. (1945). Port Terminal Operation: Port Terminal Management, Stevedoring, Stowage, Lighterage and Harbor Boats. New York, NY: Cornell Maritime Press. pp. 291-292.
Wolmar, Christian (2012). Engines of War. London: Atlantic Books. p. 49. ISBN 9781848871731.
^ a b
Harwood, Jr., Herbert H. (1979). Impossible Challenge: The Baltimore & Ohio Railroad in Maryland. Baltimore, MD: Barnard, Roberts. ISBN 0-934118-17-5.
Cudahy, Brian J. (2006). Box Boats: How Container Ships Changed the World. New York, NY: Fordham University Press. pp. 45-47. ISBN 0-8232-2568-2.
Flagg, Thomas R. (2000). New York Harbor Railroads in Color, Volume 1. Scotch Plains, NJ: Morning Sun Books. ISBN 1-58248-082-6.
Flagg, Thomas R. (2002). New York Harbor Railroads in Color, Volume 2. Scotch Plains, NJ: Morning Sun Books. ISBN 1-58248-048-6.
^ Flagg, 2000, pp. 16-23.
^ Flagg, 2002, pp. 26-29.
^ Flagg, 2000, pp. 24-33.
^ Flagg, 2002, pp. 38-39.
^ Flagg, 2000, pp. 34-45.
^ Flagg, 2002, pp. 40-51.
^ Flagg, 2000, pp. 46-55.
^ Flagg, 2002, pp. 52-57.
^ Flagg, 2000, pp. 56-61.
^ Flagg, 2002, pp. 58-63.
^ Flagg, 2000, pp. 62-65.
^ Flagg, 2002, pp. 64-67.
^ Flagg, 2000, pp. 66-83.
^ Flagg, 2002, pp. 68-93.
^ Flagg, 2000, pp. 84-91.
^ Flagg, 2002, pp. 94-97.
^ Flagg, 2000, pp. 92-101.
^ Flagg, 2002, pp. 98-109.
^ Flagg, 2002, pp. 30-37.
^ Flagg, 2002, pp. 110-116.
^ Flagg, 2000, pp. 118-125.
^ Flagg, 2002, pp. 120-127.
^ Flagg, 2000, pp. 126-127.
^ Flagg, 2002, p. 118.
^ Flagg, 2000, pp. 110-117.
^ Flagg, 2002, p. 119.
^ a b Flagg, 2002, p. 117.
Sennstrom, Bernard H. (1992). "Erie Railroad's Chicago River Service". The Diamond. 7 (1): 4-10.
The Pere Marquette Marine Fleet, Pere Marquette Historical Society, 10-MAY-2011, accessed July 16, 2012
Alaska Rail Marine Archived December 21, 2013, at the Wayback Machine.
"Route Map". New York New Jersey Rail, LLC . Retrieved .
^ Trains (Magazine) February 2009 p9
, Railroad ferry, Hudson River, New York Andreas Feininger, 1940. Still Photograph Archive, George Eastman House, Rochester, NY.
NYNJ Rail - official site Industrial & Offline Terminal Railroads of Brooklyn, Queens, Staten Island, Bronx & Manhattan