The use of tankers or other water supply apparatus was relatively rare 50 years ago. A few innovative departments saw the value of such vehicles, but most relied on whatever water sources were available. When a hydrant, pond or stream wasn't readily available, firefighters often had to watch helplessly as fires consumed structures, fields and forests.

The few departments that ran tankers in the 1950s often used converted military vehicles or second-hand gasoline trucks that weren't entirely suited for firefighting. Some tankers were built in fire department shops without regard to the center of gravity, internal baffling or weight distribution. The results were usually underpowered, overloaded, top-heavy rigs that sometimes failed disastrously.

Instead of tankers, many rural departments ran engines equipped with large tanks to allow a sustained attack until additional apparatus and personnel could arrive. Although these early pumper/tankers were useful in situations where there were no other water sources, the need to make the water last as long as possible often meant that firefighters found themselves chasing the fire but never catching it.

Tank capacities on first-generation water supply apparatus were limited by the frame and axle ratings of the vehicle. For most commercial chassis with steel cabs and bodies, that meant no more than 1,000 gallons on a two-axle vehicle or 1,800 gallons on three axles.

Need for a change

Several trends in the 1960s and 1970s led to a major change in the design and use of water supply apparatus. Commercial chassis were being built with stronger components, which allowed the use of larger tanks. Two-axle tankers with 1,200- to 1,500-gallon tanks and three-axle tankers with 2,200- to 2,500-gallon tanks became common.

At the same time, some volunteer departments started using a variety of innovative pumper/tanker configurations that could attack a fire directly with a minimum number of personnel. Remote-controlled monitors and easy-to-operate aerial devices allowed a single firefighter to make a high-volume attack within minutes of arrival.

Finally, there was a growing pressure from property owners for better fire protection in areas without hydrants. Specifically, they wanted to pay lower fire insurance premiums if the local department could provide water with tankers or other methods instead of taking it from hydrants. The International Association of Fire Chiefs and several other groups took up the challenge, and in 1980 the fire department rating system was revised and placed under the Insurance Services Office. One of the most significant changes was the recognition of alternate water supply sources, including tanker shuttles.

First bigger, then smaller

At first, the quest to maximize water supplies with tanker shuttles led to the use of larger and larger tankers. Tank capacities climbed into the 3,000- to 4,000-gallon range, and some departments even tried tractor-trailer tankers that carried up to 10,000 gallons of water. While these large units did maximize the amount of water available for the initial attack, they had several limitations. They were more expensive, heavier and more difficult to maneuver than smaller rigs. When used in tanker shuttles, they tended to tie up the fill site and disrupt the flow of other units when the supply source had a limited fill rate. In many cases, they also required special driving skills and licenses to operate.

Tankers weren't the only thing that got larger during the 1980s and 1990s. The development of large-diameter hose suddenly gave departments an attractive alternative to tanker shuttles. Some departments designed special hose layers equipped with up to 5,000 feet of 4- or 5-inch supply hose. Others combined large-volume pumps, tanks and full loads of large-diameter hose to make dedicated water supply apparatus. Although these units could move a lot water, they also had limitations, including the fact that very few people wanted to pick up, clean and reload a mile of heavy hose.

The current generation of water supply apparatus combine function and capacity in a compact package. Most tankers now have 2,000- to 2,200-gallon tanks on short two-axle chassis that are easier to drive and maneuver on narrow roads. Many also have pumps and several preconnected attack lines to let them attack fires directly. Large side and rear dump valves give them the flexibility to discharge water quickly.

The use of large-diameter hose has generally been shifted to relatively shorter lays along city streets from distant hydrants or up narrow access roads from rural drop tank sites. The first-due engine usually carries the hose, instead of a special hose carrier. In these situations, 5-inch hose is usually favored because it offers significantly lower pressure drops than 4-inch hose with only a slight increase in cost and weight.

Tankers and other water supply apparatus will continue to be an important part of the fire service. That won't change. What will change will be an increased emphasis on apparatus safety to reflect the special dangers associated with operating tankers and other large vehicles. Tanker configurations and dynamics are different, and they need different specifications and operation skills. Letting poorly trained drivers operate poorly designed tankers will become a thing of the past — and that needs to happen right now, not 50 years from now.