. The Americana : a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc. of the world. and swing to position weights offrom 5 to 50 tons are now made in this coun-try. In the contemplated work on the PanamaCanal, derricks capable of moving 100-ton loadsof stone and rock are to be built, with a radiusof over 100 feet for the jib. Crane.— Thus named because the arm orboom resembles the neck of the crane, whichraises and lowers its neck to lift objects from theground. It differs from the derrick in nothaving any mast or upright,
. The Americana : a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc. of the world. and swing to position weights offrom 5 to 50 tons are now made in this coun-try. In the contemplated work on the PanamaCanal, derricks capable of moving 100-ton loadsof stone and rock are to be built, with a radiusof over 100 feet for the jib. Crane.— Thus named because the arm orboom resembles the neck of the crane, whichraises and lowers its neck to lift objects from theground. It differs from the derrick in nothaving any mast or upright, usually. In thecommon form of crane the whole apparatus iscentered upon a heavy platform which is itselfon wheels. The engine which operates thewinch also slews the boom in a circle, and, insome cases, moves the whole outfit along therails upon which the wheeled platform the base of the boom, on the platform, is aninverted V horse, to which are attached thepulley blocks through which run the ropes forraising and lowering objects to be lifted. Inlarge foundries, ship-yards and like places, theloc»motive crane runs upon a track whiah usu-. HOKUSAI —HOLBEIN ally extends the length of the yard or shop, orperhaps clear around it. Under its own steam,the ponderous machine runs along this track tothe object it is desired to move. Steam powerthen slews tho machine laterally so that the endof the jib or boom is over the object, when thelatter is attached to the rope running over theend of the jib, the winch turned by the engineand the object lifted into the air. A secondrope over another winch then raises the jib tothe desired height and the machine runs backover the track to the point desired, where theobject is deposited. The utmost expertness anddelicacy of handling is acquired by the operatorof this steam locomotive crane, which will thusgrasp and carry where desired objects weighingoften so tons or more. The common size is theone capable of lifting five tons only, tho
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Keywords: ., bookcentury1900, bookdecade1900, bookidamericanauni, bookyear1903
