A covering system

A covering system for an open-top container or truck body 11 has upright walls 13 and a hollow top rail 19 at the uppermost edge of at least one of the walls. The covering system comprises a driving mechanism 43 the majority of which is housed within the void of one of the top rails 19, the driving mechanism being connected to an arm 33 which is pivotally connected to a wall of the container or truck body. The arm 33 extends upwardly from its pivotal connection to a position above the uppermost edges of the walls and is connected to a web of material 31, the driving mechanism being arranged in use to impart a rotational driving force on the arm such that the web of material can be drawn over the container or truck body.