Take a large number of people, crowd them into semi-confined areas, and throw in temporary electrical connections and cooking equipment and you have a scene that plays itself out in fairs and festivals across the country all summer.

In Yarmouth, Maine, the big event is its annual clam festival. The southeast coastal town will swell to 150,000 visitors for three days in July. The main attraction is, of course, the clams and other seafood that vendors will cook up, many using deep fryers, in booths along Main Street. It's a mouth-watering prospect for many, but a frightening one for Yarmouth's fire chief.

“We have a whole section of town that is just cooking. Those booths have one, two, sometimes three deep-fat frying units in them,” says Yarmouth Chief Pat Fairbanks. All of the vendors are required to take a fire extinguisher class. Still, the potential for one of those to catch fire is tremendous and one that worries the chief. Getting a brush truck or full-size apparatus into this area is extremely difficult, he says.

Neighboring Cumberland, Maine, has a similar problem with its annual county fair. And this fall about 50,000 will descend on the fairgrounds to try to make it into the Guinness Book of World Records for the largest number of lit jack-o'-lanterns. Cumberland Chief Daniel Small has 22 years of service, the last nine of those as Cumberland's chief. He's also a full-time lieutenant with the Portland Fire Department, where he's now stationed at the airport.

For the past nine years, Cumberland has used utility vehicles equipped with extinguishers for these events. “The vulnerability has always been there for us,” Small says, “and we are very lucky that nothing significant has happened.”

It was while going through airport firefighting equipment when Small stumbled on a unit that might work for festivals. Crash Rescue makes a 60-gallon, self-contained CAFS unit with one 75-foot, I-inch booster line, and powered by four SCUBA tanks. The unit was made to go in the back of a pickup or utility vehicle. The unit can be switched from Class A to Class B for something like an auto race or monster truck event where fuel fires are a concern.

“It was kind of by accident that we came across it,” Small says. “But we realized that the capabilities went beyond what airport firefighting would do. It really answered the vulnerability question that we've had so long.”

Small sold Fairbanks on the idea. But neither Yarmouth nor Cumberland could afford the unit's $10,000 price tag — so they pooled their resources. Yarmouth and Cumberland are like communities. Yarmouth has a slightly larger population, 8,600 to Cumberland's 7,200. Cumberland has a slightly larger area, 26 square miles to Yarmouth's 14 square miles. Both respond to about 1,200 fire and EMS calls per year. To buy the unit, Small tapped some money left over from buying snow-rescue equipment. Fairbanks jokes that he contributed money that was hidden away from his council. The rest came from donations raised by the towns' Explorer and Junior Firefighter groups.

But Fairbanks and Small had no intention of using the unit for airport firefighting, and consequently modifications were needed. They swapped out the SCUBA tanks with four one-hour SCBA tanks. This allows them to recharge the system with spare tanks from their rigs. The unit came with an adaptor to thread the SCUBA tank to a compressor. But the SCUBA tanks couldn't be filled, as the SCBA tanks can, in a containment system designed to protect against exploding tanks. A second modification was to add a 100-foot, 1-inch forestry line.

Fairbanks and Small say they are happy not to be running a pump on the unit. The hot exhaust and fumes emitted near a crowd, to say nothing of the added maintenance, were enough to put them off an engine-powered pump. Reliability also was a deciding factor.

“We worried about pulling up and having 2,000 people watching us put out a French fry booth fire and have the pump not start,” Small says. “This unit is always going to start. There's no starting engines. You hit it and go.”

When the air tanks are on, a diverter valve directs the charge to either or both of the handlines. It takes two full air tanks to run out 60 gallons of foam, which Fairbanks says will take about 4 minutes of continues spraying through one line. That is not much time, so Fairbanks and Small had to train their firefighters to use this unit with a different mindset.

“You've got a small amount of product,” Fairbanks says, “and you've got to make every drop count.” He says this forces the firefighters to think more and be more aggressive by getting closer to the fire.

Small says he stressed to his firefighters that when they use this unit they “are not sitting on 1,000 gallons of water.” Instead, compared it to an oversized fire extinguisher. “When you've got a fire extinguisher, you don't want to waste half the product by being 50 feet away from the fire,” he says. “That resonated with them.”

Both chiefs say that more capacity would have increased the unit's size and reduced the portability. The downside is that small tank size could mean frequent refills. And that is one of the problems they still hope to fix. Currently, only a garden hose will fill the tank. But they plan to modify the intake to accept a 1H-inch line. Fairbanks says this will prove critical if they use it to battle a stubborn fire in a wooded area with low accessibility. With the larger feed, they can refill from a tender and get back to the fire.

Whereas modifying for faster refill should be a simple matter, moving the unit is a bit trickier. Neither department has a dedicated vehicle. The departments have been borrowing UTVs from golf courses and parks departments. But the 1,100-pound unit is difficult to move and a dedicated UTV, along the lines of a Gator, is the preferred way to go. Fairbanks and Small say it will likely take another $10,000 to buy a UTV, which they've asked their Explorer and Junior Firefighter chapters to begin work on.

Another hurdle facing these departments is how to share the unit. Small and Fairbanks have a long history of mutual aid and shared equipment. The two departments also are part of the 11 departments that make up a Coastal Mutual Aid Chiefs' Association.

“The boundary lines have long since dried up around here,” Fairbanks says of the group. “If someone needs some help, we're going and there's no questions asked. There's no billing or anything like that.”

The other departments know the unit is available and want to borrow it. Which is fine, Small says, except that it is different responding to a mutual aid call and handing over a piece of equipment. When the unit gets a dedicated UTV, it will be shipped by trailer to the borrowing departments. Sorting out the details of how repairs and wear and tear will be handled is something Small and Fairbanks are working on.

Modifications and lending practices aside, Fairbanks and Small are no strangers to CAFS. Yarmouth has CAFS on its brush truck and rescue pumper. Fairbanks also teaches CAFS courses to Maine fire departments. Fairbanks retired from the Portland Fire Department as lieutenant in 1987. In 1996, he took the chief's job in Yarmouth.

“We've fooled around with foam since the late 1970s,” Fairbanks says.

What they won't be fooling around with anymore is protecting crowded, outdoor events from fire.