Frequently, we refer to the pump on fire apparatus, particularly engines, as the heart of the fire truck. Without a pump, the fire apparatus is nothing more than a very expensive personnel and equipment transportation vehicle.
Well, on one hand, yes. Historically, most departments have started the apparatus specification process with the specifications for the pump. Until NIMS and apparatus typing terminology came along, we described our pumping apparatus based upon its pump size, such as a 1,500-gpm engine.
On the other hand, for many departments their fire apparatus, particularly pumpers, has evolved into the expensive transportation vehicle that delivers personnel and equipment to the non-suppression emergencies like EMS, technical rescue, and hazmat, which represent the majority of call types for those departments.
This evolution is prompting departments to specify apparatus that have shorter wheelbases for increased maneuverability in tight spots and that have more compartment space for their non-suppression equipment.
When developing the specifications for the pump on your next piece of fire apparatus, start by determining the most common water flow requirements necessary for your department to provide fire suppression services for your community. Ask yourself questions such as these to get a good understanding of what the pump needs to be capable of doing.
- How good is the available water supply? Is it necessary to pump water through long supply lines because of hydrant spacing? Does the department depend upon drafting from static water sources?
- What kinds of fire flows are most commonly required for the occupancies in our community: single-family residential; multi-family residential; commercial occupancies like big-box retail, shopping malls, and office campuses; or industrial and manufacturing occupancies?
- What is the community's topography and geography: urban, rural, or wildland urban interface?
- How many lines, and what fire flow, does the department expect to operate from the fire apparatus?
- What is the available staffing for those hose lines?
Pump manufacturers have responded to fire departments' fire apparatus pump needs with an array of new products, from gallons per minute, PTO-driven pumps, to those with new casting designs and attachments, and from slimmed-down popular models that fit in smaller spaces to high-pressure models useful in pump-and-roll applications.
Apparatus manufacturers are using customized non-manifolded fire pumps. These have customized suction and discharge manifolds instead of large and bulky full cast mid-ship pumps that take up to 50 to 70 inches of space behind an apparatus cab.
These new technologies are enabling manufactures to be more responsive to fire departments' desire to have apparatus with shorter wheelbases, easier to reach hose compartments for cross-lay and speed-lay hose loads, and pump-and-roll capabilities for all engine types. While many of these pumps are PTO-driven they can be split-shaft pumps as well.
PTO pumps come of age
PTO-driven pumps are not just for wildland firefighting apparatus anymore. Several manufacturers, including Pierce and Rosenbauer, are selling apparatus with PTO-driven pumps rated up to 1,500 gpm. PTO-driven pumps have a couple of significant advantages for the buyer.
- The cost of the pump is about 50 percent less than a mid-ship pump.
- The manifolding on these large PTO-driven pumps is quite simple and custom designed enabling manufacturers to prefabricate custom suction and discharge manifolds that meet the customer's needs.
- The pump can be literally tucked underneath the cab or located immediately behind the cab, using often-wasted space.
- PTO-driven pumps make for compact pump modules, and there may not be a need for a pump module at all, freeing up compartment space in the vehicle.
- They have easier operations because the apparatus operator engages the pump by simply pushing a button in the cab, regardless of whether the truck is in drive, neutral or park.
These savings in weight and space dedicated solely to the pump and manifold can be a huge advantage for fire departments when considering the needs for a pumper and a rescue truck — one vehicle for all emergency needs. The pump-and-roll capability of a PTO-driven pump increases the firefighting capability of the apparatus, particularly during wildland interface operations to protect structures.
A favorite saying of Alan Brunacini, retired fire chief of the Phoenix Fire Department, is that if you are building a pumper today without a compressed air foam system, it's already obsolete.
Most of the PTO-driven pumps on the market can incorporate a CAFS, where the compressor is integrated into the pump transmission or powered by a second PTO drive. CAFS usually use much lower flow rates, but with PTO-driven pumps, departments still have the ability to provide the big-water fire protection when it is needed.
Because PTO-driven pumps have fewer parts they present less headaches when it comes to repair and regular preventative maintenance. Increasingly, many departments see this as a significant issue, especially those that do not have a full-time service department to maintain their vehicles.
Market research conducted by apparatus manufacturers also reveals entry-level members of both career and volunteer fire departments are not as mechanically orientated as their predecessors.
The newer firefighters entering the fire service today don't have that mechanical knowledge because practically everything in our society is electrical. The more simple design and operation of a PTO-driven pump are making them a more popular choice with apparatus design committees, especially when it comes to the training of new driver operators.
Today's fire chief is looking for fire apparatus that can support the department's multi-hazard mission, a mission where the fire suppression component has become a lower-frequency and lower-magnitude (fewer big fires) requirement. However, he or she still knows they still need a pump capable of providing high water volume for those large fires that still do happen occasionally. This newer generation of PTO-driven pumps provides them with a practical and economical solution.