Leschi: Pumped up and ready for anything: the dreadnought of Seattle's fireboat fleetJan 9, 2008 12:00 AM
|Top: Leschi demonstrating its 20,000 gallon-per-minute capacity. Above: Dick Chester (left), Leschi's chief engineer, and Chris Dahline, captain of Fire Station No. 5, in front of the boat's fire monitor. "We're looking for this to be the ultimate fire-fighting platform," says Dahline. (Photos by Brad Warren)|
Meet Leschi: Seattle Fire Department's newest floating disaster-fighter was delivered this spring by Dakota Creek Industries of Anacortes, Wash., and crew members have been training and outfitting the high-tech vessel for months as they prepare to bring it into service.
By any measure, this 108-foot craft is the dreadnought of Seattle's fire navy. "We're looking for this to be the ultimate marine firefighting platform," said Chris Dahline, captain of Fire Station No. 5, where Leschi will guard the city's saltwater shore. Beyond its own formidable response capabilities, the fireboat is also being outfitted as a mobile command center that provides an alternate base of operations for the department's leaders and incident-response managers.
Leschi's propulsion and pumping power come from two pairs of identical diesels. Two MTU 8v-4000 M71 diesels drive ZF W4610 gears turning 72-inch, four-blade propellers. Each of these engines is rated to deliver 1,550 hp at 2,000 rpm, giving the vessel a top speed of 14 knots.
The second pair, rated at 1,440 hp at 1,900 rpm, drives the four 5,000-gpm water pumps from Fire Fighting Systems (FFS) of Moss, Norway. Leschi's two Key Power thrusters, rated at 200 hp in the bow and 100 hp in the stern, are driven by a pair of power takeoffs mounted to the front end of the main propulsion engines.
Seattle's far-flung shorelines offer plenty of challenges for firefighters, and Leschi was conceived to help surmount them. The vessel enables the department to keep one heavy-duty fireboat downtown and another inland, along the city's freshwater shore. That will allow firefighters to pounce on waterfront blazes wherever they break out, and to bring in real marine pumping power when they do â a dream of Seattle fire crews for decades.
As many mariners know, Seattle occupies a narrow wrist of land between the saltwater of Puget Sound and 22-mile-long Lake Washington. The two bodies of water are linked by a busy canal on the north that passes through locks (a euphemism for "delays") to Lake Union and ultimately to Lake Washington. From the south, the narrow, crowded Duwamish River links Elliott Bay to a fertile bottomland that now grows mostly warehouses, cold stores, industrial plants and other businesses.
Top, Chief Engineer Chester with one of Leschi's fire pumps. Two pairs of identical
MTU 8v-4000 M71 diesels provide both propulsion and pumping power. Above, an array of fire equipment surrounds the fireboat's pilothouse. The vessel can also withstand chemical, biological, radiological, nuclear and explosive threats.
From a firefighter's perspective, the city's shorelines are nests of fuels and ignition sources. Around downtown, Elliott Bay bristles with shipping and cruise terminals, tour boats, ferries, tugs, barges, factory trawlers, shipyards and industrial facilities, plus the usual modern hubbub of eateries, condos, offices and yacht basins that muscle into the working waterfront. Tens of thousands of recreational vessels, plus more industrial facilities and boatyards, crowd the city's waterways and lakes. For a fireboat, threading these congested passages can consume fatal hours.
That lesson burned home on the night of July 4, when a four-alarm fire broke out at the NOAA dock on Lake Union, damaging four piers, a pair of decommissioned ships and two buildings. It took three hours to bring Chief Seattle â the flagship of the city's fireboat fleet since it entered service in 1985 â through the canal from downtown. The fireboat Alki, located at nearby Fishermen's Terminal since 2003, was able to respond within 30 minutes. Still, in the end it took 100 Seattle firefighters, plus dozens more from the Coast Guard and suburban fire departments, to quench the fire.
Leschi may solve that kind of problem. Once the crew finishes training and outfitting, the vessel will take over as the main responder on the marine waterfront, paired with the city's new small, fast fireboat, Engine No. 1. With Leschi handling the marine beat, 80-year-old Alki is set to retire, and Chief Seattle will then get a retrofit and move to the city's freshwater shore.
Leschi's systems offer both greater capability and more complexity for its crew to manage than earlier vessels in the fleet. "This is a complicated vessel," said Dahline. "And the engineers have by far the most complicated task of anybody."
A work skiff sits on the fireboat's stern ramp. Directly below Leschi's pumps, water is available in several screened sea chests to reduce intake friction and raise the total volume of water the vessel can hurl at a fire. Each of the four pumps can deliver 5,000 gallons per minute.
Several screened sea chests hold water directly below Leschi's pumps, reducing intake friction and raising the total volume of water the vessel can hurl at a fire. With a center bow monitor capable of pumping 7,000 gpm, and a battery of seven smaller monitors that range from 1,500 to 5,500 gpm capacity, the vessel's crew can drown most conventional fires.
Operator: Seattle Fire Department
Like all big guns, these water cannons deliver a kick. Leschi weighs almost 300 tons, but the natural recoil from the monitors can move it briskly. "We can push the boat astern at 8 knots by operating the two housetop monitors and the big center bow monitor facing forward," said Dick Chester, Leschi's chief engineer, a 35-year veteran in the department who played a key role as liaison to the shipyard during construction.
The monitors can also shoot heat-sapping foam to control chemical-fueled fires that resist water alone. Drawing from a 6,000-gallon reservoir, the firefighting foam system has its own network of piping and valving, which integrates with the water system. Pipes carry foam concentrate to each monitor, where a valve gives operators the choice of water or foam.
Dahline takes particular pride in using Baum's Novacool foam in this system, citing its efficiency, effectiveness and environmental benefits. "It's mixed at 0.4 percent with water, as opposed to normal foam that you mix at 3 percent to 6 percent," he said. "It works at a molecular level and basically takes the heat out of the fire triangle â I couldn't believe it until I saw it. It's also green â nontoxic to plankton and fish."
Water manifolds on the decks provide multiple ports to supply fire hoses in the event that shore-based crews require pump capacity if city water mains are damaged in a catastrophe such as an earthquake. Chester notes that such pumping capability has proven crucial in two recent disasters in other cities. After 9/11, New York pulled in retired fireboats to pump seawater to the hose crews working to extinguish the burning rubble of the World Trade Center. San Francisco firefighters used the same method to supply water to crews responding to blazes in the 1989 Marina District earthquake.
Possibly the most unusual feature of Leschi is its system for combating the worst nightmares that disaster planners can conjure: chemical, biological, radiological, nuclear and explosive (CBRNE) events. The central function of this system is to protect the atmosphere in key areas of the vessel.
At the touch of a button, the vessel goes into CBRNE mode. An alarm sounds, lights flash, and the bridge, mobile command center and several other parts of the boat become Toxic Free Areas (TFAs). The doors are sealed, fans and filters kick in, and pressure inside the TFAs increases to two atmospheres. That's enough to give contaminants little chance of entry â and to give unwary visitors to the TFA areas a powerful shove when they unlatch one of the heavy doors. "If you're outside and you open a door, you should be cautious," chuckled Dahline. A muscular man, over 6 feet tall, he said he was barely able to stay on his feet the first time he made that mistake.
The CBRNE system was custom-designed and built for Leschi by Dakota Creek Industries, the vessel's builder. This unique system brought greater complexity to the construction process. The TFA areas, and all the wiring and service connections to them, had to be sealed tightly, allowing just enough air to escape to maintain the flow and air quality within the protected zones. "They basically invented it for this vessel," said Dahline. Even so, Dakota Creek managed to complete construction in less than a year. For obvious reasons, representatives of both the shipyard and the fire department are reluctant to disclose much about its specifications and components. But CBRNE disaster-response capability was one reason the U.S. Department of Homeland Security helped pay for the boat.
A crew of four can run this $12 million vessel comfortably, but in the event of a major event it has room to host medics â with their own emergency treatment room â along with teams of firefighters and department brass. The mobile command center provides satellite and multiple radio connections, Internet and a navigation station with an AIS screen. If an earthquake were to cripple downtown Seattle, it's likely this vessel would play a significant role. With its stores of diesel and potable water, on-board kitchen, bathroom and other facilities, Dahline said Leschi could become "basically a self-sustaining floating station."Edit Module