Page:1902 Encyclopædia Britannica - Volume 26 - AUS-CHI.pdf/631

 CAPSTAN 581 even to write memoirs for later publication. The last years The electrical capstan (Harfield), introduced in H.M. ships of his life were spent in absolute retirement, for he could not or stern moorings and warping, is illustrated in Fig. 5. The return even to the military duties which he had left with capstan is on the upper deck, the cable-holder A works the stern outside of which are the portable whelps B, B, for steelgreat reluctance at the orders of the Emperor. He died moorings, wire lawsers ; the capstan is driven through the worm-wheel C by unmarried on 6th February 1899, at the age of sixty-eight. le motor 1), and can be disconnected by the clutch E for working See Die Reden des Grafen v. Caprivi (Berlin, 1893). (j. W. Be.) Capstan (Windlass), an appliance used on board ship and on dock walls in connexion with weighing anchor and transporting ship. Its earlier forms were of a comparatively simple char—H.M 5 'Inflexible acter, but, as heavier cables were supplied to ships, the difficulty when riding was in holding and veering. A new cable-holder made by Mr W. H. Harfield was tried in H.M.S. Neivcastle and proved effective ; its first development was the application in the form of a windlass secured to the deck driven by means of a messenger chain from the capstan, fitted in H.M.S. Inflexible (Fig. 1). The capstans and engine are shown at A, A, A, and the windlass B is driven by messenger chains C, C. The four cables (dotted line D, JJ) lead to their respective cable-holders, fitted with a brake similar to that in Fig. 2, and by these means each cable-holder can be connected to the main driving shaft, and any cable hove-in or veered independently of the other; by using steam-power by hand. The electric motor is controlled from the upper deck by instead of hand- the slow motion is obviated. In H.M.S. Colling- the lever F, working through the main switch G and the resistwood steam-power is used to work the windlass directly by means ances H. This design is somewhat extravagant in electrical conof worm gearing ; the windlass is divided into two parts, so that sumption, but a stern capstan is seldom used, even then only for a the one on the port side can be worked independently of that on short period, and in its favour are perfect control and noiseless the starboard, and vice yersd. An independent capstan in both working, and no automatic brake is required. ships, arranged to take either of the cables, can be worked by hand In the electrical capstan (Clarke, Chapman, and Co.), the motor or steam. In the Colling wood’s windlass, the cables remain on drives the vertical shaft of the capstan by means of a worm and their holders and can be hove-in or veered without touching the worm-wheel. The gear is fitted with an electric brake actuated by a chain. Fig. 2 is Harfield’s frictional brake, which also acts as a solenoid connector. A is the cable-holder loose on the shaft B, C and C are held out of action against the force exerted by a spring, but, when the a series of plates connected to the spindle by a suitable carrier, D circuit is broken, the spring causes the brake to act. The contacts and D another series connected to the cable-holder, and E a plate are in the upper portion of the resistance coil, and its controlling into which the bars are inserted, revolving the screw F. By means spindle is worked from the deck; from the off-contact point one of the latter the two series^ of discs are pressed together, obtaining direction of the rotation of the switch causes the motor to run in the necessary amount of friction for veering slowly or rigidly connecting; when the top plate is screwed back the cable - holder revolves freely. Fig. 3 is the gear fitted in the Formidable class(15,000 tons). The two cableholders on the upper deck, A, are each fitted with a frictional brake for veering and connecting, the former — • being worked from below the armoured deck by steam - engine B and worm-wheel C, and the compound clutch at D enables the cables to be worked together, or separately, one direction and the opposite direction reverses it. The motor will or simultaneously with up to about 60-belt horse-power. To meet the difficulty in one “ heaving in ” and the other veering. The middle-line capstan give warping when the ship remains stationary instead of moving, and B, on the upper deck, is not fitted with brake gear, but will take the when armature of the motor would run the risk of burning main cables, and, by portable whelps, wire and hempen hawsers ; it owing the the rush of current, an automatic circuit-breaker is inserted can be worked by steam from engine B, through worm-wheel F, or in the tocircuit, to break at the maximum current which by capstan bars GG (Capstan, ninth edition). The capstans are of the machine is adjusted intended to carry. When the automatic circuitcast-steel, capable of taking 2x-inch cables, and can be controlled breaker acts, it inserts a resistance in the circuit capable of taking rom the upper deck or engine-room. The capstan engines have up the whole back E.M.F. of the armature ; therefore, the current cylinders of 14 inches in diameter, with a 13-inch stroke, and are through the armature remains as it would be at full load, but designed for a steam pressure of 300 tb to the square inch. Fig. 4 cannot be exceeded. By these means the torque due to this shows the upper deck of the Irresistible {Formidable class) fitted by current in the armature is maintained, but the latter cannot turn Messrs Clarke, Chapman, and Co. until the ship moves, when it would commence to rotate and
 * when the current is passing in the solenoid the brake is