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CAPSTAN (also spelt in other forms, o...

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Originally appearing in Volume V05, Page 293 of the 1911 Encyclopedia Britannica.
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CAPSTAN (also spelt in other forms, or as " capstock " and " See also:cable stock," connected with the O. Fr. capestan or cabestan, from See also:Lat. capistrum, a halter, capere, to take hold of; the conjecture that it came from the Span. See also:cobra, See also:goat, and estanto, standin  g, is untenable), an appliance used on See also:board See also:ship and on See also:dock walls, for heaving-in or veering cables and hawsers, whether of See also:iron, See also:steel or See also:hemp . It differs from a windlass, which is used for the same purposes, in having the See also:axis on which the rope is See also:wound See also:vertical instead of See also:horizontal . The word seems to have come into See also:English (14th See also:century) from See also:French or See also:Spanish ship-men at the See also:time of the See also:Crusades . The earlier forms were of a comparatively See also:simple See also:character, made of See also:wood with an iron spindle and worked by See also:manual labour with wooden See also:capstan bars . As heavier cables were supplied to See also:ships, difficulty was found, when See also:riding at See also:anchor, in holding, checking and veering See also:cable . A cable-holder (W . H . Harfield's) was tested in H.M.S . " New-See also:castle " (wooden See also:frigate) in 1870 and proved effective; its first development in 1876 was the application in the See also:form of a windYass secured to the See also:deck, driven by a messenger See also:chain from the capstan, fitted in H.M.S . " Inflexible " (fig . 1) . The capstans and See also:engine are shown at A,A,A, and the windlass B is driven by messenger chains C, C .

The four cables (dotted See also:

line D, D) See also:lead to their respective cable-holders, fitted with a See also:brake, and by these means each cable-holder can be connected to the See also:main See also:driving See also:shaft, and any cable See also:hove-in or veered independently of the other; by using See also:steam See also:power instead of manual, the previous slow See also:motion was obviated . In H.M.S . " See also:Col- lingwood " steam power was ' f used to See also:work the windlass ~ directly by means of See also:worm gearing; the windlass was divided into two parts, so that the one on the See also:port See also:side could be worked independently of that on the starboard, and See also:vice versa . An See also:independent capstan in both ships, arranged to take either of the cables, could be worked by See also:hand or steam . In the " See also:Collingwood's " windlass the cables remained on their holders, and could be hove-in or veered without being touched . See also:Napier's patent windlass for See also:merchant ships (1906) resembles an appliance fitted in the earlier second-class cruisers of the See also:British See also:navy (1890 to 1900) . Two cable wheels or cable-holders are moutited loose on a horizontal See also:axle, one on each side of a worm See also:wheel which is tightly keyed on the See also:middle See also:part of the axle . A vertical steam engine with two cylinders, placed one on each side of the framing, drives a second horizontal axle which is connected by a set of See also:bevel gears to an upright worm shaft, which See also:works the worm wheel . This worm wheel can be connected by means of sliding bolts to one or both of the cable wheels, enabling one or both cables to be hove-in or veered as necessary . A brake, of Napier's self-holding See also:differential type, is fitted to each cable wheel, and is controlled by hand wheels on the aft side of the windlass . For warping purposes, warping drums are fitted (made portable if required) . A third central capstan, fitted forward of the windlass, is connected to the upright worm shaft by a horizontal shaft and bevel wheels .

It can also be worked by manual labour with capstan bars . Fig . 2 represents the arrangement of the capstans on the forecastle of a battleship, fitted by Napier See also:

Brothers . Deep-A A bodied capstans have been superseded by See also:low See also:drum-headed ones, over which the guns may be fired . The three capstans or cable-holders of See also:cast steel, capable of taking z 6 in. cables, are fitted on vertical spindles, which pass down through the main and armoured decks to the See also:platform one, where the steam engine and gearing are placed . The gearing consists of worm and wheel gears, so arranged that the three capstans can be worked singly or in See also:conjunction, when heaving-in or veering, and the brakes (of the type previously mentioned) are controlled by a portable hand wheel fitted on the aft side of each . The cable-holders can be used for riding at anchor (see CABLE) . The middle line capstan E is keyed to vertical spindles and can be coupled up to the capstan engine, by clutch and drop bolts in the capstan engine See also:room; it is fitted with a cable-holder, to take either the port or starboard cables, and in addition is provided with portable whelps, enabling it to be used for warping . It can also be worked by manual labour with capstan bars, a drum-See also:head E', fitted on the spindle on the main deck, enabling additional capstan bars to be used if required . To avoid carrying steam pipes aft, the after capstan is worked by an electric motor which is kept below the See also:water-line . Napier Brothers' capstan (fig . 3) is for warping purposes, for working the stern anchor with See also:wire See also:hawser and for coaling .

It is placed on the upper deck, and is fitted with a drum-head for capstan bars, with pawls and pawl rim on the deck See also:

plate, the pawls A being lifted and placed on their rests B when working with the motor . The upper portion of the capstan, together with its drum-head, is portable, being fixed to the centre See also:boss with keys and See also:gun-See also:metal screws . The centre boss is keyed to the spindle, which passes through the deck and carries at its See also:lower end a coupling for connecting to the worm wheel See also:gear . For working by motor, the additional See also:security of two drop bolts is provided . The gearing consists of a single worm and worm wheel, working in an oil-See also:bath, the worm shaft being coupled See also:direct to the motor spindle . The motor is of the semi-enclosed type, the working and live parts being protected by a perforated metallic covering; it is worked off a roo-volt See also:circuit, at a See also:speed under full load conditions of 300 revolutions per See also:minute . The motor is of a 4-See also:pole type and See also:compound wound, the shunt winding limiting the speed on See also:light load to not more than r000 revolutions per minute . A frictional break is provided, pulled off by means of a shunt-excited magnet . The controller is of the See also:reversing drum type, with not less than four steps in either direction, and is fitted with a magnetic See also:blow-out . The See also:control is effected by a removable hand wheel on a portable See also:pedestal, fitted on See also:top with a circular See also:dial plate and indicating pointer; the hand wheel reverses the current as well as graduates the speed in either direction . All capstans of the British navy, after being fitted on board ship, are tested for lifting power and speed; with foremost (steam) capstans, the steam being at 150 lb pressure, the anchor is usually let go in 16 to 25 fathoms water, and the speed ascertained by observing the time taken to heave-in not less than a length of cable, 75 ft.; the length must be hove-in in three minutes, or at the See also:rate of 25 ft. per minute . With the after capstan (motor) of first-class battleships and cruisers, p. See also:weight is used instead of an anchor, the test being to lift g tons at the rate of 25 ft. per minute .

Capstans on dock walls in British See also:

government See also:dockyards are usually driven by See also:hydraulic or See also:air pressure, conveyed through pipes to small engines underneath the capstans . (J . W .

End of Article: CAPSTAN (also spelt in other forms, or as " capstock " and " cable stock," connected with the O. Fr. capestan or cabestan, from Lat. capistrum, a halter, capere, to take hold of; the conjecture that it came from the Span. cobra, goat, and estanto, standin
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