文档介绍：24 cargo handling equipment
Cargo handling
The duty of a deck winch(甲板绞车) is to lift and lower a load by means of a fixed rope on a barrel(卷筒),
or by means of whipping(缠绕) the load on the warp ends(带缆端);
to top or luff the derricks(吊杆), and to warp the ship.
Hydraulic winch(液压绞盘) systems are now mon but electric drives for cargo winches and cranes are most widely used.
For the conventional union purchase(绞盘,起重装置) cargo handling arrangement or for slewing (旋转式) derrick systems handling loads up to 20 tons,
standard cargo winches are normally used for hoist(起升), topping(顶索) and slewing(回转) motions ,the full load duties varying from 3~10 tons at to m/sec.
For the handling of heavy loads ,although this may be plished with conventional derrick systems using multipart tackle(多组滑轮), specially designed heavy lift equipment is available.
The winches used with these heavy lift systems may have to be specially designed to fit in with mast(桅杆) arrangements and the winch duty pull may be as high as 30 tons.
Cargo winches are used with the various derrick systems arranged for cargo handling .
The unit is rated according to the safe working load to be lifted and usually has a double speed provision when working half load.