When a malfunctioning pump could let a fire rage on, reliability becomes more than a cost-benefit analysis.From the time William Penn laid out his “green Country Towne,” Philadelphia, Pennsylvania, has been a city mindful of fire safety. Penn, a survivor of London’s great fire of 1666, designed Philadelphia in a grid pattern using open space as a natural firebreak.
Today the 2,500 employees of the Philadelphia Fire Department maintain Penn’s tradition of fire safety. The department’s 61 engine and 29 ladder companies protect 350 square kilometres of homes and businesses, including some of the nation’s most important historic buildings.
Fire departments handle much more than fires these days. In Philadelphia, the department also has 39 medical units managed by two supervisor units, one heavy rescue unit, one hazardous material and two mass casualty units. Two marine units patrol the Delaware and Schuylkill Rivers, and an aviation crew is stationed at Philadelphia International Airport.
Philadelphia’s fire – fighters responded to about 300,000 calls last year, including 10,783 structural and non – structural fires. The city’s department is considered among the nation’s finest, and its fire – fighters doused those blazes using the latest, most advanced technology available.

Track record required
Whether it’s the newest breathing apparatus or the most powerful deluge gun, the department demands that its equipment be tested, dependable and durable.
“We want equipment with a track record,” says Battalion Chief John Grillone, head of the technical support unit. “Reliability in a truck or equipment is probably one of the prime things we are looking for. We’ve rarely had problems with pumps.”
When you’re fighting fires in the second largest city (after New York) on the East Coast, having reliable pumpers is crucial. Pumpers are, after all, the backbone of any fire – fighting effort.
“If a pumper fails and it has a critical water supply, it has a major effect on the fire,” Grillone says. “If a pumper goes down, there are so many bad things that can happen.”
The department is awaiting delivery of three new dual pumper trucks that carry both water and foam – state – of – the – art vehicles that will make the department more efficient and flexible.
It’s not the first time that the fire – conscious city has been on the cutting edge of pumper technology. The first time was in 1730, when the city accepted delivery of the latest in pumper technology from England.
“They were essentially a bathtub on wheels with a water receptacle, a chamber and a hand pump,” says Jack Wright, a historian at Fireman’s Hall Museum in Philadelphia.

Pump history
Fire pumps – really nothing more than a water reservoir – first debuted in Europe in the late 17th century. A hand pump was added later to force water through a nozzle into buckets. The pumps Philadelphia purchased in the early 18th century were advanced versions that could spray water 9 to 15 metres (30 to 50 feet). But aim, pressure and volume were only as good as the men doing the pumping.
A few years later the Philadelphia Pump was introduced. It was narrow, so it could go down small streets, and it featured a more efficient gearing system that sprayed water up to 27 metres (90 feet). Its 12 – man pumping crews worked in 90 – second shifts.
“It was still pretty much a defensive operation,” Wright says.
That changed with the introduction of the fire hose in 1804. It wasn’t exactly a novelty – the first hoses were used in the Netherlands in 1672. They were hand – stitched leather and not very efficient. The newer hoses were also made of leather, with copper rivets securing the seams. Adding a hose to a pumper allowed firemen to attack a blaze. Fire fighting changed from a defensive to an offensive operation.
A half – century would go by before fire fighting evolved significantly again. But when the steam – powered pump was introduced in Cincinnati in1854, it changed fire fighting for good. The steam pumps were too heavy for men to carry, so horses were added. Because there was no pumping, fewer men were needed. This didn’t sit well with volunteer companies, and it took a while for the steam pump to catch on.
“You didn’t need as much manpower with steam, but the volunteer companies wielded a tremendous amount of political clout,” Wright says.

Volunteers first
Most American fire companies started out as volunteer operations. In colonial days, firemen were traditionally merchants and businessmen. In Philadelphia, merchants dropped out as the city grew and became a hub for trade. The companies were taken over by what Wright calls a “lesser element.”
“The companies degenerated,” says Wright. “There were fierce rivalries between the companies, and fights would often break out. Sometimes two companies would fight it out while a third was putting out the fire.”
That competition led Philadelphia in 1870 to create a professional fire department. The city put its first steam – powered pumpers into service in 1885. The city bought 40 rotary steam – powered pumps. But the rotary pump, which whipped water around and relied on centrifugal force to push it out, proved inefficient. Five years later the piston pump, which used pistons to discharge water – filled cylinders, was the choice of most fire departments. Things changed again in 1912 with the advent of the fire truck. Horses were phased out, and in 1923 Philadelphia took its last steam pumper out of service.
“Since then pumpers really haven’t changed that much,” Wright says. “People are amazed that things haven’t changed that much. Diesel engines help them to run cooler. But I think the biggest revolution has been air conditioning on the apparatus, and that came in 1995.”

Two impellers
Today the Philadelphia Fire Department uses a two – stage centrifugal pump with two impellers. The impellers are round, three – quarter inch (20mm) thick disks with deep vanes. The vanes catch the water and feed it to the impellers.
In the pressure stage, one impeller feeds water to the other, which then discharges it using centrifugal force. Depending on the fire operation, the pump can produce a hose line pressure between 75 and 125 psi (520 and 860 kPa) and a nozzle pressure of 30 psi (210 kPa), according to Captain Jack Maguire, the department’s apparatus officer. That translates to 175 to 260 US gallons (660 to 980 litres) of water a minute.
In stage two, both impellers discharge water to produce volume and a water stream of 90 feet (28 metres). Of course, those numbers would drop significantly if it weren’t for today’s computer – milled, ceramic seals.
“What makes today’s pumps better are the ceramic seals that are milled so finely,” says Capt. Jack Maguire, the department’s apparatus officer. “That keeps down the water loss and makes the pump better. The difference is amazing. The advances in technology – with everything being computerised from the trucks to the chassis and engine…. We’ve gone from the Wright Brothers to the space shuttle.”
New materials have also made equipment lighter.
“The biggest change in equipment today is that it is lightweight,” says Capt. Charles P. Bushka, the department’s equipment officer. “For example, deluge guns are made from an alloy. All of those improvements are dramatic because the materials are stronger and lighter and more reliable.”
Still, the pumper remains the most critical piece of fire – fighting equipment. It often can mean the difference of saving a life or not.
“We know it’s critical,” Grillone says. “People’s lives actually count on it working. If it doesn’t work we might as well go home.”

Robert Calandra
a freelance writer based in Glenside,
Pennsylvania, USA
photo Jack Wright