CAPSTAN (Fr. cabestan, Sp. cabestrante, probably from Lat. capistrarc, to tie with a hal ter, from rapistrum. halter, from copere, to hold). A machine nsed on shipboard for hand ling the anchor and other heavy weights. It was formerly made of wood, with iron fit tings, but is now generally of iron. It con sists of the barrel, drum-head, wildcat, pawl head, and spindle. The axis of the capstan is vertical, and is formed of an iron or steel spindle. The barrel is not cylindrical, hut is smaller at the centre, toward which the upper and lower ends curve. This curve causes a rope which is wound round the barrel to slip toward the centre as it is pulled in by the capstan in turning. To increase the friction around the barrel, ridges, called trhrips, extend up and dewn its surface. Around the circumference of the drum-head are square lades extending in toward the centre to a depth of several invites, forming sockets for inserting the capstan-bars, which stand out when in place like the spokes of a wheel. The bars have scores or grooves in the outer ends, through which is passed a small rope called the swifter, that serves to keep the bars in place. A capstan-bar of ordinary size is suffieiently long to permit three or four men to push against it in hearing. The wildcat is a deep groove between the lip on the lower end of the barrel and the pawl-head. and is designed to grip the chain which rests in it for about half the circuinterence. To prevent the chain from slipping, there are. on the upper and lower sides of the groove, ridges or whelps extending radi ally, and growing thicker and higher as they approach the axis. These whelps catch between
the links of the chain that stand vertically, and so prevent the latter from slipping. On the circumference of the pawl-head are pivoted the pair*, which are short bars of iron working in a itawl-rack in the capstan-bed, which is bolted to the deck. To walk back the capstan, or re verse the motion, it is necessary to lift these pawls and throw them over, SO that they will net only in the opposite direction. Wooden cap stans, of very similar form to those now used, hut without the wildcat, were devised by Sir Thomas Moreland in 1661. In the days of rope anchor-cables they were hauled in by means of a messenger, as the cable itself was to() large to be worked around the capstan-barrel. The messenger was a smaller rope, which was gripped to the cable by rope nippers. it led to the barrel of the capstan and back again to near the hawse-pipe. The nippers were taken oil' one by one as they approached the capstan, and others put on farther forward. After the introduction of chain cables, messengers emit limed to be used until the invention of the wildcat enabled the chain to be brought directly to the capstan. In steamers, capstans are now generally worked by steam power; lint they are rapidly being ills placed by steam triad/asses, which resemble two capstans placed base to base, with the axes hori zontal. See ANenou.