A New Take on Foam Trucks

Recently, KME Fire Apparatus constructed an unusual foam truck for the City of Long Beach, California. This truck, while relatively simple to operate and understand, has some unusual design features not always seen in industrial foam apparatus.

The City of Long Beach has a mandate to provide fire protection for some of the nation’s most critical infrastructure. The Port of Long Beach is one of the largest and busiest ports in the US, supporting trade throughout the world, especially Asia. In fact, the port is the nation’s second busiest container port, second only to the nearby Port of Los Angeles. In addition to shipping, with all the different types of cargo that entails, the city also boasts of a robust industrial and manufacturing base, including automotive, aviation, and high tech. The city also handles large quantities of petroleum, both from offshore and within its own boundaries. (The first Long Beach oil well was drilled in 1921.) In short, the city’s inventory of hazards is broad and wide, and the fire department must take all of it into account.

One of the challenges in designing industrial fire equipment is that it provides very high-risk protection in a very low-use environment. The high risk is self-evident. We’ve all seen videos of large-scale industrial fires spewing tons of black, sooty smoke into the air with maybe a fireball or two. With millions of gallons of flammable, caustic, and potentially explosive chemicals and hydrocarbons being handled every day, the risks to life, property, and the environment through a major industrial fire are difficult to understate. If an incident occurs, the apparatus that respond must respond quickly, carry a lot of suppression capability, and be ready to operate for extended periods of time. Fortunately, such large conflagrations do not happen often, and fire apparatus are just the last step in a long line of defense that includes both technology and procedure that makes these events exceedingly rare. But because that, many foam apparatus sit idle for long periods of time. This creates a different type of maintenance headache compared to apparatus that are used more frequently. Piping corrodes. Fluids gum up. Valves stick. And depending on the fire brigade, operational training may take a back seat to other more frequent hazards.

To that end, if there was such a thing as a perfect industrial foam fire truck, it would be a simple, easy-to-maintain, easy-to-understand design with a lot of capability. The specification writers at Long Beach tried to keep this in mind.

The Long Beach truck is mounted on a simple commercial chassis in the form of a Freightliner M2 with a crew cab and seating for up to five personnel. The engine is a Cummins 330 hp diesel, and the transmission is an Allison 3000 EVS automatic. While these components are relatively light duty, the unit does not have its own pump, so the chassis is appropriate for simple movement throughout the city. In addition, the body is a basic flatbed design made from marine-grade aluminum. Because the body is unpainted, there is no risk of any corrosion causing discoloration or bubbling of the paint, and structural inspection, repair, and maintenance is a breeze. And critical wear areas on the exterior of the unit are made from aluminum treadplate to provide a durable surface against minor impacts.

The heart of the unit is a stainless steel water manifold supplied with a stainless steel and non-metallic foam manifold. The truck does not have its own pump, but is designed to be supplied from industrial water mains or other fire apparatus. The intake manifold consists of dual 4” inlets gated down to six 2-1/2” connections, three on each side of the vehicle. This allows the potential for several thousand gpm of water movement. The nominal capacity of the manifold is about 3000 gpm.

The truck uses the water to supply two 1500 gpm monitors, two medium capacity handlines, and two dual agent reel lines. Each line features an independently controlled foam eductor.  The monitors are Williams Alpha series manually controlled monitors with Ranger automatic constant metering nozzles that self-educt foam from the concentrate manifold at 1 or 3%. The handlines and reel lines are each supplied by Elkhart 125 gpm eductors capable of supplying foam at up to 6%.

Controls for the eductors and valves are located on the left side of the unit behind the cab in the same location as traditional apparatus. What’s not traditional is the “top mount” operator’s platform that provides a wide, elevated working area for operation of the monitors from a safe location on top of the unit behind the cab. The monitors may be operated completely from the top of the unit without having to step down to the street.

In addition to foam, the truck is equipped with a Fire Combat 500 lbs dry chemical system that is loaded with Purple K Powder. The powder is deployed through the two reel lines to stop vertical spread. The dry powder system, perhaps using a different chemical, could also be effective for use in energized electrical gear without the risk of electric shock.

One of the most unique features of the truck is the palletized foam supply. Recent years have seen the development of high capacity totes for the transport of medium to low volumes of liquid chemicals. Where previously, such volumes had to be transported in barrels, the tote consists of a plastic tank with a capacity of 300 gallons or so surrounded by an aluminum framework. The framework makes handling easier as it incorporates pads for lifting with a fork truck or crane.  The totes may be stacked for transport, and they may be loaded directly into trucks, trains, and ships without any additional packaging.

The Long Beach unit takes advantage of the modular design of the totes. Instead of having to transfer many smaller barrels of concentrate into a larger tank on the apparatus, the totes are simply loaded onto the bed of the truck and connected to the foam manifold through an individual isolation valve. No air is introduced into the foam, and the possibility of contamination of the concentrate is virtually eliminated. Inventory control of the foam is easier, because foam may be replaced tote-by-tote rather than with the whole tank at a time. And if different types of foam are desired, either due to different hazards or to try the latest-and-greatest in foam technology, isolating the foam is very simple. In effect, the truck has four 330 gallon individual foam cells rather than a single 1320 gallon tank, and it costs less, too. Assuming an injection rate of 3%, the truck will be able to produce 44,000 gallons of finished foam at an incident without resupply.
 
Certainly, there is no magic fire truck, and this truck is not meant to be a one-sized-fits-all solution for all municipal or industrial brigades. Some trucks will require higher capacity foam systems (either balanced pressure or multi-port direct injection), large capacity water pumps, on-board water tanks, and larger chassis. However, this clean, simple design has some unique features that may be worth considering for application on other apparatus.

Stay safe,
Doug Kelley













Posted: 12/31/2013 8:35:09 AM
comments powered by Disqus