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