Abstract: According to one aspect, a supporting truck for a crane comprises a load bearing member and a frame rigidly coupled to the load bearing member. A plurality of substantially equally spaced and substantially equally sized wheels is rigidly journaled in the frame at substantially equal heights such that the wheels have a single degree of freedom comprising rotational movement with respect to the frame and the load bearing member. The load bearing member and the frame have a moment of inertia of at least a particular value to cause the wheels to experience substantially equal loading by forces applied to the load bearing member.