Cranes 101: Types of Crane Hoists and Their Different Applications
Today’s overworked warehouse floors use a diverse range of machines to lift and shift unwieldy loads. The different crane hoists go about their business, perhaps on a rail or supported by a cage of steel beams. They’re manually operated or electrically powered. More often than not, a light-duty model uses compressed air. Whatever the power source, the overhead lifters perform at their best when operating in confined quarters.
Light-Duty Manual Hoists
It’s the confined quarter’s environs that call the shots in here. There’s no room for a large, powered hoist, so a block and tackle type system uses multiple loops of chains to raise heavy loads. By using multiple sheaves in the block, plus additional chain loops, minimal input effort can create magnified output lifting force. Used in garages, packaging warehouses, and construction sites, light-duty hand chain hoists can lift engines, medium-sized boxes and pallets filled with building materials.
Powered Bridge Crane Hoists
Sometimes rails are mounted and installed on the existing walls of a factory. If that’s not a viable option, a steel cage is erected on the floor. This is a bridge crane, a device that carries a cradle along two different axes. One method of carrying out this action is to mount a rolling bridge section on parallel runways. Then, when the bridge section is situated above its drop point, a second drive system rolls the travelling crane at ninety-degrees to the runways. When the crane hook is finally positioned above its load, an electric motor lowers a hook. Machine shops and fabrication services favour this heavy lifter, which can travel in any direction above crowded shop floors.
Mobile Gantry Hoists
Why use a busy bridge crane when a mobile gantry is available? A key part of a production line, the rail-mounted equipment rarely takes a break. Opting instead for a movable steel frame, the man-high apparatus rolls across open floor areas. A hydraulic piston or pneumatic actuator lifts the hook. The gantry shifts easily to fit itself over a high-value component load, then the chain or wire-rope mounted hook attaches. Popular inside industrial workplaces that aren’t packed with fabrication gear, mobile gantry units feature added extras, like foldable lifting frames and telescopic booms.
Crane hoists are powerful pieces of equipment. There are even heavy-duty variants that stack shipping containers down at the loading docks. Back to the factory floor, bridge crane units trail long loops of cable. They move effortlessly on rails above crowded fabrication areas, but those runways can become obstructed. Even air-powered hoists can run into trouble, perhaps because of a loose hose. Preventative planned maintenance routines are important in here, for overhead crane hoists are powerful but mechanically vulnerable beasts of labour.