Sailboat winches are used to help sailors manipulate the control lines that control the position and shape of the sails. Unlike most winches sailboat winches usually only have the ability to winch in the rope, but not to reverse. To reverse the line a sailor needs to manually manipulate it, this is both inconvenient and can also be a safety hazard.

This master’s thesis will focus on the development of a self-locking braking system that will be used to allow a sailboat winch to reverse. The goal of the thesis is to design a braking system that works with a modified version of the E40i winch produced by Seldén.

The braking system that was developed during this thesis is made up of two main parts, a one-way mechanism and a brake. The type of one-way mechanism that was chosen was an overrunning roller clutch. For the brake a wet disk brake was chosen with an outer diameter of 50mm and an inner diameter of 28.8mm.

A 3D model of the braking system has been generated and materials have been selected so that the system is ready for prototyping and physical testing.