Dolly (trailer)

A dolly is an unpowered vehicle design for connection to a tractor, truck or prime mover vehicle with strong traction power.

Dolly Classification by Axle Configuration

There are two types of dolly bogie:

Full trailer - 2 axle (4 wheels), with a draw bar which also controls the trailer's front axle steering. The draw bar does not take load of the full trailer. Heavy full trailer needs to have its own brakes remotely controlled by the prime mover vehicle.