The smalles mooring winch produced by THR has a nominal pull of 10kN. The maximum size still has to be found. The design principles of a mooring winch are based on the nominal pulling force of the winch. This force depends on the minimum breakload of the applied rope or wire. The rope diameter, length and material of the mooring line determine the diameter and length of the drum. To help increase the lifetime of mooring lines, the THR mooring winches have a large drum diameter than prescribed by Class societies. The mooring winches are delivered with a split drum when polypropylene is applied. On mooring winches with steel wire the drum will not be split.