Rapid response vehicles: The answer to downsizing fire apparatus

Here's how volunteer departments and smaller career departments can right-size their apparatus without giving up operational capabilities


Remember what the first portable cellphones looked like? They came in a bag (hence the early nickname bag phone) that was about the size of a loaf of bread. They had a handset that looked just like a home telephone, and their only capability was making a telephone call.

Many things in life have shrunk in stature while growing in capabilities, and today’s wireless phones are a great example. When you think about it, even calling them a phone anymore is rather archaic, no? They’re more like handheld computers.

More firefighting capability in a small package

The same can be said about the mini-pumper. While the mini-pumper was a response concept that never really took root in the fire service, things have changed. Advances in vehicle technology and fire suppression technology – now, more than ever before – make smaller fire apparatus a viable option for many departments.

As there’s a lot to be inferred with a name, let’s not call this new generation of fire apparatus a mini-pumper, but rather – to use a term common around the world – a rapid response vehicle. Let’s look at how such technological advances can enable any department – particularly smaller career and volunteer departments – to get more for their apparatus dollar.

Newer truck chassis such as those found on the Ford F-550 extended cab and crew cab (both with 6.4-liter turbocharged diesel engines), GMC Yukon and Toyota Hilux are examples of beefier trucks that can serve as a rapid response vehicle, that is, first-arriving pumping apparatus. The Hilux is very popular in European fire departments. Typically, these new truck chassis feature:

  • Gross Vehicle Weight: 7,720 pounds (3,500 kg)
  • Payload: 2,755 pounds (1,250 kg)
  • Water Capacity: 50 to 150 gallons (200 to 600 liters)

This sized truck is serving as the platform for basic emergency response apparatus in fire departments around the world, especially in the congested cities of developing Asia and Old World cities of Europe.

Fire suppression technology

Advances in foam and pump technologies should really have us asking the question, “Why is the fire service still so firmly wedded to 18th century fire suppression technology?” The application of only water to burning materials (put the wet stuff on the red stuff) is woefully inefficient given that only about 10 percent of the applied water penetrates the fuel. The higher BTUs produced by today’s fuel loads – which are high in synthetic materials – require that fire suppression crews apply more water for longer periods of time.

The technology behind compressed air foam systems continues to improve and the price of CAFS for fire apparatus continues to drop. A rapid response vehicle can be outfitted with a CAFS to provide big apparatus fire power in a small apparatus package.

For example, a CAFS fire stream has a 20-1 expansion ratio when used according to manufacturer's recommendations. That means that for every gallon of water being used, 20 gallons of finished CAFS solution is delivered to the fire. So, a 150-gallon water tank on a rapid response vehicle could yield 3,000 gallons of CAFS fire suppression solution (for those readers keeping track, that’s equal to three type I engines with 1000-gallon water tanks).

Ultra-high-pressure pumps are the newest generation of high-pressure fire pumps designed to obtain greater fire suppression capability while using less water. The principle behind UHP straightforward: small, energetic droplets provide more surface area to combat fire.

A UHP pump boosts the pressure of water to the range of 1200 to 1400 psi (Compared to 100 to 200 psi used in low-pressure systems). The pressurized water is propelled through the hand-line nozzle creating a mass of micro droplets. These micro droplets create a much greater surface area as compared to the larger low-pressure drops, with the following benefits:

  • More water has more contact with flames;
  • Less water covers a greater surface area, which quickly reduces the fire’s thermal energy;
  • Micro droplets convert to steam more quickly and that steam displaces oxygen that’s fueling the fire
  • Converting water to steam draws energy from a fire (extinguishing the fire more quickly);
  • A UHP pump can support both positive ventilation and hydraulic ventilation to remove heat, gases and smoke more quickly increasing visibility and safety; and
  • Micro droplets reach confined spaces that large drops can’t reach.

WATERAX’s MARK-1 detachable four-stage centrifugal pumping apparatus was first patented in 1958 and quickly became the standard portable fire pump used by forest fire agencies around the world. Today, according to WATERAX, the WATERAX MARK-3 series of high-pressure wildland firefighting pump is the most widely used high-pressure portable pump world-wide for wildland firefighting.

In the mid-1960’s, WATERAX introduced its BB-4 series high-pressure centrifugal pumps that combine the more powerful four-stroke engine with WATERAX’s patented detachable high-pressure multi-stage pump end. The BB-4 quickly enjoyed the same success with wildland firefighters as the Mark-3 series pump.

Using these fire suppression capabilities, a fire department can have a smaller and less expensive piece of fire apparatus without sacrificing fire suppression capabilities.

Battery-powered fire tools and equipment

Advances in lithium-ion battery technology have led many firefighting equipment manufacturers to re-engineer their products to operate on battery power. From extrication tools to scene lighting to smoke blowers, the equipment that a fire department needs to meet its mission occupies less compartment space and weighs less than its predecessors. This new generation of tools and equipment can enable a fire department to outfit a rapid response vehicle without compromising its tactical capabilities when compared to a typical type I or II engine.

Why should a fire department look to downsize its fleet?

Smaller career fire departments and their volunteer department brethren should consider replacing their existing type I or type II engines with rapid response vehicles for some of the following reasons:

  • Those engines are a poor return-on-investment for the communities they serve. With new pumping apparatus costing $500K or more, is it really a sound ROI to purchase a piece of pumping apparatus with a 1,000-GPM pump and a 1,000-gallon water tank when most of the fires the department responds to could be extinguished with 100 gallons of water or less?
  • With the personnel turnover rates of smaller departments (e.g., when employees leave for a position with a larger department for more pay) and the retention problems faced by volunteer departments), is it worth the risk of having inexperienced or poorly trained operators driving today’s massive fire pumpers?
  • Our infrastructure of roads and bridges in the U.S. is in a terrible state of disrepair and it’s not likely to get better anytime soon. How many roads and bridges in smaller communities and rural areas can withstand fire apparatus weighing 24 tons or more?

Beyond those thoughts, isn’t it past time for many fire departments to systematically reengineer themselves to reflect the services they provide, and the communities they serve? Improvements in building and fire codes, and fire sprinkler system requirements for commercial structures have significantly reduced the potential for large fires in smaller communities in the U.S.

Does that mean that a fire department in such a community will never have a large fire? No, but why are most departments still structured with fire apparatus that’s designed for the possibility of the big one when the probability for such a fire is so small?

The continued existence of many small career departments and volunteer departments may very well depend upon their ability to right-size their fire apparatus fleet and operations to reflect today’s realities. And for many of those departments, the use of well-designed and fully capable rapid response vehicles may be just the answer.

References
1. HMA Fire. What is UHP? Available at: http://hmafire.com/what-is-uhp/

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