Our object here is to indicate or suggest general design or arrangement
only, from which a selection can be made to suit requirements.
=325. Is the common type of wharf crane= with fixed post, the base plate
being well bolted down to a solid mass of masonry.
=326. Is also a common type of wharf crane,= but with the post revolving
in a footstep and base plate; this gives a better base than No. 325.
=327. Has no post,= but a revolving frame and base plate with front and
back friction rollers, and a centre pin.
=328. Post and jib in one piece,= usually of wrought iron. A balance
weight is fixed at ~A~ to balance the overhanging jib.
=329. Swing derrick crane,= generally of wood. The jib turns
three-fourths of a circle, and the two guys are fixed at an angle of 90°
apart, and well secured by anchoring or loading, often made with very
long jib for builder’s work.
=330. Wharf crane,= with centre tension bolt instead of crane post. In
this arrangement there is a vertical tension on the centre bolt and
thrust on the foot of jib.
[Illustration: 317.-330.]
=331. Warehouse wall crane.=
=332. Warehouse wall crane, with high jib-head.=
=333. Whip crane,= chiefly used in goods sheds. The barrel is sometimes
worked by an endless handrope as shown, and sometimes by a second rope
and drum with a hand crank as No. 1209.
=334. Portable hand crane,= with balance weight. The balance weight can
be shifted in or out to balance the load.
=335. Foundry crane,= sometimes with travelling carriage on the jib, as
No. 336.
=336. Swing bracket crane= and traveller, usually formed of flat bars on
edge; used only for light loads, for smiths’ shops, &c.
=337. Wharf derrick,= to turn an entire circle, similar to No. 329, but
employed for heavy loads.
=338. Floating derrick.=
=339. Light balance crane.=
=340. Trussed jib crane,= with centre tension bolt.
=341. Simple derrick and winch,= with two guy ropes; for temporary
purposes only, and may be easily shifted about.
=342. Sheers and winch.=
=343. Tripod and winch.=
=344. Sheers with screw adjustment= to back leg. This design is adopted
for very heavy lifts, such as loading heavy machinery, shipping masts,
boilers, &c.
[Illustration: 331.-344.]
=345. Four-guy derrick and winch,= used for fixing columns, bases,
masonry, &c.
=346. Fixed post steam crane,= for wharfs, piers, jetties, harbour
works, &c.
=347. Portable steam crane,= very largely used on wharfs, piers, &c.,
and sometimes fitted with travelling gear in addition to hoisting and
slewing motions.
=348. Wharf crane,= with fixed engine, centre bolt, and trussed arched
jib. This is a very good type, as the ground is kept clear for goods,
&c., and of course all motions, hoisting, lowering, and slewing are
controlled from the crane above ground by hand levers.
=349. Hydraulic wharf crane,= with fixed post. The common type
universally used in docks, &c., with the ordinary form of multiplying
hydraulic cylinder and chain gear; the valve for controlling its
movements is operated by hand levers extending up through slots in the
floor; the slewing is performed by a separate cylinder and chain gear,
with a distinct controlling lever. See Sections 42 and 83.
=350. Hydraulic short lift ram, centre crane, and traveller,= employed
chiefly to raise the ingots out of the casting pits of Bessemer steel
works. The ram is of course subject to severe cross strains, and many
designs provide an overhead guide or support for the ramhead.
=351. Automatic balance crane,= portable or fixed; the position of the
fulcrum varies with the load.
=352. Steam multiplying cylinder crane,= in which the ram is forced out
by steam pressure, acting either directly or by an intervening body of
water.
=353. Breakwater swing crane.=
[Illustration: 345.-353.]
=354. Overhanging travelling crane,= for use on breakwaters, &c.
=355. Overhead hydraulic travelling goliath,= to span a railway; has
slewing motion and a balanced jib.
=356. Single rail crane= with top guide rail.
=357. Overhead traveller= on gantry.
=358. Goliath.=
=359. Steam overhead crane,= with carriage to span a railway. Largely
used on dock wharves, &c., as they give a high lift and do not encumber
or encroach on valuable quay space.
=360. Hydraulic cylinder post crane;= sometimes adopted instead of the
type No. 349.
=361. Heavy hydraulic crane,= with suspended cylinder; employed for work
of the very heaviest class.
=362. Ship’s Davit.=
=363. Balanced jib post crane,= no tie rod. The weight must be
sufficiently heavy to balance the jib and load.
=364. Hydraulic strut jib crane.= The load is raised by raising the jib.
=365. Overside dock crane,= for discharging from ships into barges. The
overhang being very great in this design, it must be provided with a
heavy frame or balance weight.
=366. Wagon tip crane,= for loading vessels.
=367. Double sheave= 4 to 1 purchase for crane jib. See also Section 69.