In this paper, the lateral instability of towed structures (trailers, caravans and
articulated buses) is investigated with special attention to the small amplitude lateral
vibration that leads to a higher energy consumption in certain parameter domains.
A low degree-of-freedom mechanical model of a shimmying towed tyre is used that describes
the dynamics of the tyre-ground contact patch by the time delayed differential equation.
Stability charts are calculated and the theoretically predicted linear unstable islands
of small amplitude shimmy motions are validated by laboratory experiments. A tyre
is towed by a relatively long caster, and its temperature and the input current of
the conveyor belt are measured in order to show the increased value of the rolling
resistance.
