30 Jun 2023

Frontline Communications, a division of Pierce Manufacturing, Inc., and a subsidiary of Oshkosh Corporation announced the Seattle Fire Department has unveiled a new energy response unit (ERU) equipped with advanced carbon dioxide fire suppression technology to combat fires occurring in underground electrical vaults. 

Sold through Hughes Fire Equipment and funded by the public utility providing electricity to Seattle, Washington, Seattle City Light, the Frontline Communications’ CO2 Vault Fire Response Truck includes an 11,000 lb CO2 vessel, 600 feet of 1.25-inch hose, and flows 220 lbs of liquid CO2 per minute with a 34 PSIG pressure drop. 

Electrical vaults

Approximately 20 percent of the U.S. electric distribution system is underground. Electrical vaults are most common in large cities and densely populated communities, such as Seattle.

CO2 extinguishes fire by robbing it of oxygen and is an offensive approach

Underground electrical vault fires are difficult to combat because of accessibility challenges and damage caused to electrical infrastructure using traditional fire suppression agents, such as water. CO2 extinguishes fire by robbing it of oxygen and is an offensive approach to keeping the fire from spreading throughout an entire electrical vault system. 

educational sessions

Fire Captain Chris Greene of the Seattle Fire Department, a foremost thought pioneer in the U.S. on fighting energy fires, has facilitated many educational sessions on the topic and assisted with directing the development of the department’s new ERU.

The revolutionary design of our new emergency response unit is a remarkable evolution of the Pierce vehicle retrofitted for us back in 2018, which allowed Seattle firefighters to be armed with carbon dioxide canisters to address electrical vault fires,” said Fire Captain - Chris Greene.

CO2 canisters

Chris Greene adds, “We were proud to be the first to design a critical resource incorporating this advanced method of fighting electrical fires, and we now welcome into service the next generation of leading-edge technology in energy emergency responses.”

In 2018, the Seattle Fire Department worked with Seattle City Light to take a unique approach to fight electrical vault fires by retrofitting a decommissioned Pierce vehicle and equipping it with CO2 canisters and 120 feet of hose line. The department’s next-generation ERU from Frontline Communications incorporates an innovative design addressing the department’s previous limitation gaps.

Increased capacity

We increased our capacity by 11-fold compared to our old rig, now with three hose lines 200 feet each"

Captain Greene stated, “We increased our capacity by 11-fold compared to our old rig, now with three hose lines 200 feet each, which can be deployed simultaneously or connected for a total of 600 feet of hose line."

He adds, "We are now able to go deeper into spaces, and there is not an area in the city we can’t combat, which is a reassuring feeling for our team.”  

New ERU

The new ERU will be housed at Seattle Fire Department’s Station 25, where 48 members of an energy response team are trained to safely address the public safety needs resulting from energy hazard incidents.

In the event of an electrical vault fire, the team removes the utility hole cover, inserts the hose/metal wand, and injects the vault with CO2 while covering the opening with a fire-resistant tarp. Once the fire is out and cleared of smoke and CO2, Seattle City Light personnel de-energize electrical equipment, making the area safe for crews to begin repairs.  

Additional Features

Other features of the Seattle Fire Department’s new CO2 Vault Fire Response Truck include:

  • Freightliner M2-114SD crew cab.
  • Generator power: 35kW PTO (pressure build vaporizer system), 5kW (utility and refrigeration system power).
  • TOMCO2 Systems 5.5-ton DOT steel skid tank on a skid, 11,000 lb of CO2.
  • Two CO2 extinguisher storage compartments.
  • Aluminum rescue hook compartment and CO2 deployment pipe compartment on the rear of the vehicle.
  • Firecom wireless intercom system.