After weeks of preparation, the Japan-based, Nimitz-class aircraft carrier USS George Washington’s (CVN 73) Engineering department successfully tested one of the most critical fire fighting systems May 12-13.
Crew members conducted a test of the ship’s countermeasure washdown system, which also helps guard against chemical, biological, and radiological (CBR) attacks, on the ship’s flight deck and in the hangar bay.
The countermeasure washdown system, overseen by George Washington’s Damage Control division of Engineering department, uses a mixture of sea water and aqueous film forming foam (AFFF) to combat aircraft and ordnance fires by cutting off the fire’s oxygen supply.
AFFF is also used to protect the crew from CBR contaminants by washing any contaminant from the ship’s skin before it has a chance to enter the ship and contaminate the crew.
“We always test the AFFF countermeasure washdown system at the start of every cruise,” said Damage Controlman 3rd Class Antonio Garcia from Los Angeles. “We do it to ensure that all of the systems are in proper working order before going underway so we can use it in case of fire or CBR attack.”
During this test, a concentration of 94% water and 6% AFFF is sprayed over every square foot of the ship’s three hangar bays and exterior skin. After the solution is sprayed, Sailors use sea water to hose the deck down for scrubbing.
While this test of the countermeasure washdown system sprays the concentrated solution on the flight deck and the hangar bay once a year, the system is tested quarterly, said Garcia.
“Each quarter we ensure that each system having to do with our countermeasure washdown systems are functional, from our bilge sprinklers, hangar bay sprinklers and our weapons elevators,” said Garcia. “Instead of flooding the spaces with AFFF, we recirculate the solution as we run the tests to ensure everything is in working order.”
The AFFF countermeasure washdown system, while tested quarterly, has more than 200 individual preventative maintenance checks; each individual maintenance check requiring anywhere from weekly to yearly inspection. Although the system is routinely maintained in preventative maintenance, this is the only time that every system is set off at once.
“There are a lot of components involved with the countermeasure washdown system that we oversee and maintain regularly,” said Garcia. “From each AFFF station aboard, to various individual pumps, systems and valves, we uphold each one of them.”
“The AFFF solution can’t be allowed to stick on the deck, otherwise the deck can corrode,” said Damage Controlman Fireman Jamie Parker from Memphis, Tenn. “That’s why we hose and scrub down the deck after each washdown.”
After the systems are tested and the decks scrubbed, all hands join in to rinse the AFFF from the ship in order to prevent corrosion to the metal components of the ship.
Not only is AFFF potentially damaging to the decks, it can also be hazardous when left on the skin too long. To prevent mishaps, Sailors participating in each washdown protect themselves with foul weather suits, as well as gloves and eye protection, to ensure as little skin as possible is exposed.
“AFFF is very harmful to skin,” said Chief Aviation Boatswain’s Mate (Handling) Tony Lawrence from Barnesville, Ga. and George Washington’s Safety department. “If left on the skin too long, it can cause serious skin damage as well as serious damage to the eyes if the proper protective equipment isn’t in use. We don’t ever want to see anyone getting hurt out there so personal protective equipment (PPE) is a must.”
The hangar bay washdown started late in the evening May 12 and the flight deck washdown started early the next morning, allowing little sleep for George Washington’s damage controlmen.
“We’re worn out and exhausted, but we understand the importance of these tests,” said Parker. “The AFFF countermeasure washdown system is our baby and we want to make sure it’s in perfect working order if the need for it ever arises.”
With brooms in hand, more than just the Sailors of Air and Engineering departments made an appearance on the flight deck in the early morning. Sailors from all rates and departments came to scrub down the ship as George Washington continued its return to sea.
“I had a blast!” said Master at Arms 1st Class Shaun Ruschhaupt from Fountain Town, Ind. “I know that this is vital to the ship’s safety and mission readiness, but it’s just nice to get out and get some fresh air and have a good time.”
With hundreds of Sailors on deck to give their ship a good, pre-deployment scrub down, the crew reinforced their teamwork and camaraderie and is now one step closer in preparations for the ship’s next patrol.
George Washington has completed a six-month, routine maintenance period and is now underway conducting sea trials.
Naval Today Staff , May 15, 2012; Image: US Navy