A railroad trailer chassis comprising two or more road axles, two or more rail axles operable to be moved between first and second positions, and a work unit. The railroad trailer chassis is operable to be driven or towed in a road mode when the two or rail axles are in their respective first positions. The railroad trailer chassis is operable to be driven or towed in a rail mode when the two or more rail axles are in their respective second positions. The work unit is operable to perform one or more railroad maintenance or operation functions when driven in the rail mode.

A system for a well car includes a frame, a hitch coupled to the frame near the first end of the frame, and a first deck coupled to the frame. The frame includes a first pair of sockets located near a first end of the frame and a second pair of sockets located near a second end of the frame. Each socket of the first pair of sockets is configured to engage a support casting of a first pair of support castings located at a first position along a length of a well car. Each socket of the second pair of sockets is configured to engage a support casting of a second pair of support castings located at a second position along the length of the well car. The first deck is configured to hold wheels of a trailer when the trailer is coupled to the hitch.

A system for a well car includes a frame, a hitch coupled to the frame near the first end of the frame, and a first deck coupled to the frame. The frame includes a first pair of sockets located near a first end of the frame and a second pair of sockets located near a second end of the frame. Each socket of the first pair of sockets is configured to engage a support casting of a first pair of support castings located at a first position along a length of a well car. Each socket of the second pair of sockets is configured to engage a support casting of a second pair of support castings located at a second position along the length of the well car. The first deck is configured to hold wheels of a trailer when the trailer is coupled to the hitch.

A chain of semi-trailer vehicles is intended to be articulated to a main vehicle. Each semi-trailer vehicle includes a body and a single bogie supporting the body, known as a trailer bogie. The bodies of the semi-trailer vehicles are successively articulated to one another from a first semi-trailer vehicle of the chain by a separate inter-body joint. Each inter-body joint is carried by one end of each semi-trailer vehicle connected to a following vehicle. Each inter-body joint is articulated along a vertical pivot axis. Each trailer bogie of a body carries an inter-body joint arranged longitudinally with respect to the body so that the bogie axis and the interconnection axis are offset.