Swivel (swivel) ==> Device / chain device that enables jangkarberputar, without causing the chain to be installed before or behind the device is twisted.
Crab Link (chain of crab) ==> One type of chain that is installed at the end of the fastener chain blocks and others. Not berbentuklingkaran but resembles a crab.
While the former became the latter 15 fathoms, at which time the ship docks next up is also done likewise. So at the time of the second seal (15 fathoms) the third before the first dock had now become the first seal and second seal prior to the first dock is now a final seal. Thus if the ship has 10 seals (150 fathoms), then after 9 times the dock, the first seal seals moved into the last or come back again into the first seal. Do not let happen that every time the chain just behind the dock, that is the last seal to seal the first and as are next on the next dock. So that wear is part of the edges.