chamber at the bottom hatch or at a side door. Bells are usually designed to carry two or three divers, one of whom, the , stays inside the bell at the bottom and is to the working divers. Each diver is supplied by an umbilical from inside the bell. The bell has a set of high pressure gas storage cylinders mounted on the outside containing on-board reserve breathing gas. The on-board gas and main gas supply are distributed from the bell gas panel, which is controlled by the bellman. The bell may have viewports and external lights. The divers' umbilicals are stored on racks inside the bell during transfer, and are tended by the bellman during the dive. The bell is deployed from a gantry or A-frame, also known as a bell launch and recovery system (LARS), on the vessel or platform, using a winch. Deployment may be over the side or through a moon pool. The handling system must be able to support the dynamic loads imposed by operating in a range of weather conditions. It must be able to move the bell through the air/water interface (splash zone) in a controlled way, fast enough to avoid excessive movement caused by wave action. A bell cursor may be used to limit lateral motion through and above the splash zone. It must keep the bell clear of the vessel or platform to prevent impact damage or injury. It must have sufficient power for fast retrieval of the bell in an emergency, and fine control to facilitate mating of the bell and transfer flange, and to accurately place the bell at the bottom. It must include a system to move the bell between the mating flange of the transfer chamber and the launch/retrieval position. Diving bells are deployed over the side of the vessel or platform using a gantry or A-frame from which the clump weight and the bell are suspended. On dive support vessels with in-built saturation systems the bell may be deployed through a moon pool. The bell handling system is also known as the launch and recovery system (LARS). This is also used to move the bell from the position where it is locked on to the chamber system into the water, lower it to the working depth and hold it at that depth without excessive movement, for which heave compensation equipment may be fitted to the winch,