Figure 7-20.--Brake on a roller conveyor.
Figure 7-22.--Warehouse crane, gasoline-powered.
operations. They have 270 degree sluing booms and have
a capacity of 6,000 or 10,000 pounds.
A wa r e h o u s e c r a n e i s a p ow e r- d r ive n ,
self-propelled unit consisting of a boom mounted on a
The mobile crane consists of a boom mounted on a
mobile wheeled chassis. The boom can be operated
truck chassis and has characteristics similar to that of a
independently so that sluing and topping can be
warehouse crane. However, the mobile crane has a
accomplished without movement of the chassis. Power
greater topping distance and is, therefore, used in a wide
is supplied by a gasoline engine or by electric motors.
range of operations.
Gasoline-powered cranes (fig. 7-22) are equipped with
The gantry crane is a hoisting unit mounted on a
pneumatic tires for outdoor operation. They have 180
gantry (any frame or structure spanning or bridging an
or 360 degree sling booms, and have capacities of
intervening space). Gantries may be arched, bridged, full,
6,000, 10,000, or 20,000 pounds. Electric-powered
cranes are equipped with solid rubber tires for indoor
LATCH TO HOLD
CHUTE IN UP
NOT IN USE
Figure 7-21.--Stores strike-down chute.