Lighters were barges used to convey cargo from ship to shore, or vice versa. They lacked their own means of propulsion and were either rowed by lightermen with sweeps or towed by steam tugs. At the height of the port's prosperity some 6000 lighters were engaged in carrying cargoes from the docks. As a result of the 'free water clause' the dockers were able to enter the docks and receive or deliver goods directly to or from vessels.