Abstract: A roller assembly including a frame member, a plurality of front roller members, and plurality of rear roller members corresponding in number to the plurality of front roller members is described. A plurality of walking beams are pivotably connected to the frame member. Each of the walking beams connects one of the front roller members with a respective one of the rear roller members. The front roller members and the rear roller members have respective radial axes. The front and rear roller members are mounted on the walking beams such that the radial axes of the front roller members are offset from the radial axes of the rear roller members. The frame member can include a generally rectangular outer frame, which can be fabricated from tubular steel. An attachment mechanism can be secured to the frame member to facilitate attachment of the roller assembly to an operating tow vehicle. A hitch mechanism can be secured to the frame member to facilitate attachment of the roller assembly to a second vehicle.