In the bad old days a man had to be sent up the mast to remove the topmast fid so that the topmast could be lowered when the wind piped up, not the best of times to climb a mast. There are many solutions to this problem and this is one I designed for Alberta. The fid is made from 40 x 20 steel bar, hinged on the port side and operated by control lines on the starboard side which run down to deck level. The fid engages in a slot cut in the after face of the topmast which is reinforced at that point with steel straps. Built into the bottom of the straps are two sheaves to take the topmast heel rope for hoisting and lowering. A 3mm nipple is welded onto the top of the fid so that it can't work out in use; the topmast has to be raised 3+mm before the fid can be slewed clear aft. A photo of the starboard side is next.