Hale DSD User Manual
Page 8
CENTRIFUGAL PUMP DRIVE
There are four common types of centrifugal pump drives used with fire fighting apparatus:
Operation from the truck chassis drive shaft (split-shaft PTO).
Operation from a separate engine.
Operation from the front of the truck chassis engine (front engine PTO) crankshaft
Operation from a PTO from the truck transmission. A PTO before the engine transmission or a
PTO from the (four wheel-drive) transfer case.
Midship pumps are so named because of their mounting location on the fire apparatus. They are
normally driven through an integral transmission that has a sliding gear shaft and sliding gear that
selectively directs the engine power to the pump or the rear axle. Figure 1-7 shows the midship
pump split-shaft arrangements.
The midship transmission is capable of handling full engine horsepower enabling the pump to meet
optimum performance levels as well as all torque requirements for over-the-road applications.
MIDSHIP PUMP
SPLIT SHAFT
DRIVE TRAIN