CRANE (AS. emu, cornoch, 011G. cranuh, ehranih, Ger. Kranieh, crane; connected with Welsh, Corn., Bret. garan, ()Church Slay. zhera ri, ru'rwr, (3-k. y‘paros, arranos, crane; so called from the resemblance of the arm of the machine to the neck of the bird). A term used in mechanics to designate a hoist which can also move the load in a horizontal or lateral rection. Cranes are divided into two classes, as to their motions—viz. rotary and and into four groups as to their motive viz. hand, when operated by manual power: power. when driven by power derived from line shafting.: steam, electric, hydraulic. or pneu.- =tic, when driven by an engine or motor tached to the crane, and operated by steam, tricity, water, or air transmitted to the crane from a fixed source of supply: locomotive, when the crane is provided with its own boiler or other generator of power, and is self-propelling, usually being capable of both rotary and recti linear motion. Rotary and rectilinear cranes are thus subdivided: (1) Swing cranes, having rotation but no trolley motion; (2) jib cranes, having rotation and a trolley traveling on the horizontal jib; (3) column era IleK, identical with the jib crane. lint rotating around a fixed col umn, which usually supports it flour or roof above; (1) derrick cranes, identical with jib cranes, except that the head of the mast is held in position by guy rods, of by atta•h ment to a roof or ceiling; (5) pillar cranes. hav rotation only, the pillar or coin ]]]]] being supported entirely from the foundations; (0) pillar jib cranes, identical with the last, except in having a jib and trolley motion; (7) walk ing cranes, consisting of at pillar or jib crane mounted on wheels and arranged to travel longi tudinally upon one or mote rails; (8) locemo tive cranes, consisting of a Cra 11P mounted on a truck, and pro% bled with a steam-engine capable of propelling and rotating the crane. and of hoisting and lowering the load: (9) bridge cranes, having a fixed bridge spanning an opening and a trolley moving across the bridge; (10) tram cranes, consisting of a trunk or short bridge, traveling longitudinally on overhead rails and without trolley motion; (11) traveling cranes. consisting of a bridge, traveling longi tudinally on overhead tracks, and a trolley mov ing transversely on the bridge; (12) gantries, consisting of an overhead bridge carried at each end by a trestle traveling on longitudinal tracks on the ground, and having a trolley moving on the bridge; (13) rotary bridge cranes, combin ing rotary and rectilinear movements and con sisting of a bridge pivoted at one end to a central pin or post and supported at the other end on a cirenlar truck, provided with a trolley moving on the bridge.
Cranes are built of wood and iron, but at the present time east iron and steel are employed nearly exclusively. Fland cranes are employed
for handling comparatively light loads, and the manual power is usually applied by means of a crank or cranks operating a windlass, around the drum of which the hoisting rope is wound and unwound. For heavy loads some form of mechanical power is always employed, which is applied through a suitable train of mechanism for performing the various movements of hoisting, rotation, and horizontal travel. A great variety of such mechanisms are in common use for each of the principal kinds of motive power, and for details the reader should consult speeial treatises on hoisting machinery. Cranes are built with capacities of from a few hundred pounds to as much as 150 tons. The traveling crane in the 12-ineh gun shop at the Washington Navy-yard has a capacity of 130 tons; the span of the bridge is feet : the maximum travel of the trolley lengthwise of the bridge is 44 feet 2 inches, and its traveling speed is from 25 to 50 feet per minute; the effective lift is 40 feet. with four speeds of hoist: the speed of travel of the bridge is from 30 to GO feet per minute.
The Finnisston Quay, at fllasgow, Scotland. is equipped with a pillar crane of 130 tolls ea pacity. The jib is formed of two steel tubes, each 39 inches in diameter and 90 feet long; the ra dius of sweep for heavy lifts is (15 feet; the jib and its load are counterbalanced by a weight of 100 tons; and in a test a 130-ton load was lifted at a rate of 4 feet per minute, and a complete revolution was made with this load in five min utes. The floating crane at Cramp's shipyard, in Philadelphia, Pa., has a steel mast 116 feet high and 3 feet in diameter, carrying a hori zontal jib 65 feet long with a counterbalance arm 50 feet long which is stayed to the bottom of the mast and to the hull of the barge. The barge is 69 feet long, 62 feet wide, and 13 feet deep. This crane has a lifting capacity of 125 tons. A floating crane owned by the Chapman Wrecking Company. of New York City, has a mast 92 feet high and a jib 98 feet long, and is capable of lifting a load of 265 tons.
On board ship cranes are fitted for handling cargo, coal, boats, anchor, etc. The boat-erane of a large modern man-of-war is built up, box girder fashion; it rises 20 or 25 feet above the skid-beams on which the boats are stowed, and the horizontal arm extends 10 or 15 feet beyond the ship's side when turned out for the purpose of lowering or hoisting a boat. The power is either electricity or steam, and serves to hoist and lower the boat, run it in or out on the horizontal arm of the crane, or train (i.e. turn horizontally) the latter. Consult: Glynn, Trea tise on the Construction of Cranes and Other hoisting Machinery (London. 1887) ; Marks, Notes on the Construction- of Cranes and Lifting Machinery (London, 1889) ; and Towne, A Trea tise on Cranes (New York, 1883). See DER ,