Hobbles are usually short pieces of line fixed to a point on the boat with a shackle that attach to a loop spliced into the jib sheet, to facilitate transferring one sheet to the winch from another. Its quite common on large race boats. Saves the weight/complexity of another winch. Didn't you ever wonder how a TP52 can have only 5 winches? Even on the 65'er I sail we use hobbles to get the kite sheet on the primary winch during a set, and we have 11 winches.