G-CPTN
30th June 2011, 18:53
http://www.youtube.com/watch?v=VVwTnJFRj5Q
Roadrailers first appeared on American railroads in the 1950s. The trailers were built with integrated railroad wheelsets that could be lowered into position when the trailer was pulled behind a train. More modern roadrailers do not include integrated railroad wheels, but ride on specially-manufactured bogies that do double-duty, serving as articulation points between multiple trailers in a train. Each truck is equipped with two fifth wheels and at one end (or both ends) of a convoy there is an adaptor truck equipped with one fifth wheel and one regular AAR Type "E" or Type "F" automatic coupler. Each semi-trailer has one king pin at each end. Because the bogie is significantly lighter than a rail flatcar or well-car, roadrailer freight trains are much lighter and therefore are more energy efficient than traditional intermodal trains.
Roadrailers first appeared on American railroads in the 1950s. The trailers were built with integrated railroad wheelsets that could be lowered into position when the trailer was pulled behind a train. More modern roadrailers do not include integrated railroad wheels, but ride on specially-manufactured bogies that do double-duty, serving as articulation points between multiple trailers in a train. Each truck is equipped with two fifth wheels and at one end (or both ends) of a convoy there is an adaptor truck equipped with one fifth wheel and one regular AAR Type "E" or Type "F" automatic coupler. Each semi-trailer has one king pin at each end. Because the bogie is significantly lighter than a rail flatcar or well-car, roadrailer freight trains are much lighter and therefore are more energy efficient than traditional intermodal trains.