There are many types of fire-fighting apparatus’ that are in use today and my research is not going to be limited on one particular type of engine but will include a vast majority of engines and their uses. To begin to understand fire apparatus, one must define the term engines or apparatus, which are what most fire departments, call the basic vehicle in this region of the country. But just about anywhere you can find a department where these kinds of apparatus are sometimes referred to as pumpers. Most of the time they can generically be referred to as “triple capacity” apparatus.
This is because they can do three jobs. They can pump, transport personnel, and carry hose. It is possible to have a single function vehicle. For example, New York has had vehicles with giant pumps mounted on them. It can pump tens of thousands of gallons a minute. But that is all it can do. A separate vehicle, called a “Hose tender”, must be dispatched with the pump vehicle. It is also possible to have apparatus that can perform four or five major functions. These are called “Quads” or “Quints”. Engines can also be classified as “Type I”, Type II” or “Type III”.
This classification refers to the size of pumps and uses. Quints, as the name implies are vehicles that carry out five functions. The two most notabe are that of pump and aerial device on one vehicle. Many city managers think that if you buy a quint you can do away with the need for having both an engine and a truck. Fire chiefs tend to point out that if you have only three or four people on the quint that you have the function of either a truck crew or an engine crew at a fire and not both. It should also be noted that there are pump/engine apparatus that have small ladders or booms mounted on them.
These are not “quints”. These are often referred to as “Squirts” or the like. It takes a large aerial device, mounted on apparatus with a full size pump, with a full load of hose, and a water tank to be called a quint. Brush truck; grass wagon, patrol truck, booster, are all vehicles that can be named for the specific purpose of fighting wildland or grass fires. Some of these are four wheel drive. In fact, there are some vehicles constructed from Hum-V’s. (But this is too expensive for most fire departments. ) Most often they are a water tank, and a pump mounted on a four heel drive pick-up. Some of these vehicles can be a simple as a pickup with a small tank, pump, and line while other can be equipped with all kinds of equipment. Some have plumbed in nozzles located on the bumper that can be operated from the cab. These vehicles are used to fight wild land fires where conventional trucks can not reach due to their size or lacking capability of four wheel drive. Compared to Type 1 engines these apparatus usually hold smaller tanks but longer hose lines to pump water. Wagon, is another all purpose regional, term.
Often this is applied to vehicles designed to fight grass or brush fires. Although some departments use this term to describe hazardous materials apparatus. In these cases they can pump foam or other specialized agents for the control of particular types of fires. The name comes from the fact that these vehicles, in the past, had an entirely separate “Auxiliary” motor that ran the pump. This allowed these vehicles to pump and roll at the same time. Modern fire apparatus pumps get their power from the vehicle’s engine.
The transfer case forces you to choose between rolling down the road or supplying the pump with power. From what one can read here, there are many different types of fire apparatus and each apparatus has their own specific capabilities and resources which help it carry out the task it was designed to do. Although this is just a glimpse of what Fire Fighters use their prestigious fire fighting vehicles for, I believe it provides a good analysis of what engines can do for someone who may be interested in learning such.