A warping fairlead for ships is a fitting or device used to maintain or change the direction of a line, chain or cable so that it will be delivered "fairly" or on a straight lead to a sheave or drum without excessive friction. Often it has rolling cylinders in order to reduce friction. Fairleads for ships are usually located in the forecastle and on the poop maneuvering deck for use during docking or shifting the vessel over a short distance.
During berthing and undocking maneuvers the ship's lines pass through the fairleads, allowing them to run smoothly. Fairleads are used to handle mooring lines or from ship to ship. Some kinds of fairleads are located forward of the capstan to help direct lines straight to the capstan drum.
In its simplest form, the fairlead is a single piece of steel fixed on deck. Its inner, working surface is smoothly rounded to reduce wear on cables and lines. Other types consist of an opening with rolling cylinders along each side reduce friction.
The dimensions of the ship, the location of the fairlead, the dimensions of lines and cables to be handled and the specific use of the fairlead are factors to consider when choosing among the many different models.
