Ever see a ship lose an anchor? Or see the wildcat fail while hauling an anchor chain up? Ft Or those of you that haven't imagine this .. the anchor on the end of the chain is not what holds a ship in place how ever it's the weight of the total amount of chain let out. Each one of those links weighs 100 + pounds and lengths of 100s of ft move into the tons this change gets let over the side in a controlled manner using winches with drum breaks like your car except much much larger scale.. these friction breaks are ment to slow the speed that the chain is let out to a controllable speed in that the friction breaks can stop the release with out being over  competed with by the weight of the chain. On occasion the speed at which the chain is released is more then the created friction can resist an thus the breaks lose control, when this happens the crew manning the forecastle attempt to apply more and more friction to hopefully over come the speed of the release and stop the chain. If that fails the chain is painted white yellow and red called shots, these shots help identify how much chain is left because the very end of the chain is not attached to anything.. the saying goes see red your dead because by the time you see red the end of the chain will come whipping out of the locker at a high rate of speed thrashing thousands of pounds is steal about.