A capstan is a rotating machine used to apply force to another element, notably used on board ship and on dock walls, for heaving-in or veering ropes, cables, and hawsers. Forecastle, also spelled fo'c's'le (ˈfoʊksəl originally meant the upper deck of a Sailing ship, forward of the Foremast. An anchor windlass is a machine that restrains and manipulates the anchor Chain and/or Rope on a boat allowing the Anchor to be raised and lowered In Physics, a force is whatever can cause an object with Mass to Accelerate.
Contents |
Early form
In its earliest form, the capstan consisted of a timber mounted vertically through a vessel's structure which was free to rotate. Levers, known as handspikes, were inserted through holes at the top of the timber and used to turn the capstan. A rope wrapped several turns around the drum was thus hauled upon. A rudimentary ratchet was provided to hold the tension. The ropes were always wound in a clockwise direction (seen from above).
Later form
Capstans evolved to consist of a wooden drum or barrel mounted on an iron axle. Two barrels on a common axle were used frequently to allow men on two decks to apply force to the handspikes. Later capstans were made entirely of iron, with gearing in the head providing a mechanical advantage when the handspikes were pushed counterclockwise. One form of capstan was connected by a shaft and gears to an anchor windlass on the deck below.
Modern form
Modern capstans are powered electrically, hydraulically, pneumatically, or via an internal combustion engine. For the mechanical technology see Hydraulic machinery and Hydraulic cylinder Hydraulics is a topic of science and Engineering Pneumatics, Pressurized gas to affect mechanical motion Pneumatic power is used in Industry, where it is common to have factory units plumbed for Compressed The internal combustion engine is an engine in which the Combustion of Fuel and an Oxidizer (typically air occurs in a confined space called a Typically, a gearbox is used which trades reduced speed, relative to the prime mover, for increased torque. A torque (τ in Physics, also called a moment (of force is a pseudo- vector that measures the tendency of a force to rotate an object about
Similar machines
A capstan differs from a windlass, which is used for similar purposes, in having the axis on which the rope is wound vertical instead of horizontal. A windlass is an apparatus for moving heavy weights Typically a windlass consists of a horizontal cylinder (barrel which is rotated by the turn of a crank or belt In yachting terminology, winches function on the same principle as capstans, though in industrial applications, the term winch generally implies a machine which stores the rope on a drum. Yachting is an activity involving boats It may be racing Sailing boats cruising to distant shores or day-sailing along a coast A winch is a mechanical device that is used to pull in (wind up or let out (wind out or otherwise adjust the " Tension " of a Rope or Wire rope
Derivation
The word, connected with the Old French capestan or cabestan(t), from Old Provençal cabestan, from capestre "pulley cord,", from Latin capistrum, -a halter, from capere, to take hold of, seems to have come into English (14th century) from French or Spanish shipmen at the time of the Crusades. Old French was the Romance Dialect continuum spoken in territories which span roughly the northern half of modern France and parts of modern Belgium The conjecture that it came from the Spanish cabra, goat, and estanto, standing, is untenable.
Use on land
Hydraulically-powered capstans were sometimes used in railway goods yards for shunting. A Hydraulic motor is a mechanical actuator that converts hydraulic pressure and flow into torque and angular displacement (rotation A ( US and Canada) classification yard or ( UK and Canada) marshalling yard (including hump yards) is a Railroad One example was Broad Street goods station in London. This article is about the closed railway station in London For other stations of the same name see Broad Street Station. London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. The yard was on a deck above some warehouses, and the deck was not strong enough to carry a locomotive, so ropes and capstans were used instead.
See also
Sources
(incomplete)
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic