NAVSEA Removes Fuel from Sunken WW II Era Ship

Friday, April 16, 2010

Naval Sea Systems Command's (NAVSEA) Supervisor of Salvage and Diving (SUPSALV), in a U.S. Coast Guard directed initiative, provided a key operational and technical role in removing 60,546 gallons of petroleum products from the sunken ex-USS Chehalis (AOG-48) , concluding, April 6. 

Ex-USS Chehalis sank in Pago Pago Harbor, American Samoa, Oct. 7, 1949, as a result of a gasoline tank fire and multiple explosions on the ship.  The fire caused the ship to sink and subsequently capsize in more than 160 feet of water. 

The Coast Guard requested SUPSALV expertise to support American Samoa's request for assistance by conducting a ship diving survey, detailed planning for, and the safe removal of the petroleum products from ex-USS Chehalis that represented a potential threat to Pago Pago Harbor. 

"What's unique about this Patapsco-class gasoline tanker that sank off the coast of American Samoa more than 60 years ago is that highly volatile gasoline remained in several of the ship's cargo tanks," said Kemp Skudin, SUPSALV's ex-USS Chehalis project lead.  "We do not normally encounter gasoline in sunken wrecks. Gasoline is not usually a maritime fuel and normally would have been consumed by fire or lost since it has a much lower flash point compared to diesel fuel marine or black oil."

Typically, and in this case for ex-USS Chehalis' diesel bunkers, less volatile fuels are removed using the "hot tap" method, requiring the tank to be cut into in order to install a valve and attach a pumping system .  This method causes heat that can be explosive when combustible fluids like gasoline are involved.  Also, gasoline in motion can explode due to electrostatic discharge caused by pumping turbulence in hoses, or when falling into a storage tank. Since safe diving operations are the highest priority for Navy divers, SUPSALV had to develop an alternate means of removing the gasoline. 

"We used a buoyed suction head fed into the cargo tanks through their hatches by divers and controlled by an air hose on the surface. This meant we did not have to hot tap into the gasoline tanks. To pump the gasoline we used an intrinsically-safe pneumatic pump on a small floating platform through internally and externally bounded suction and discharge hoses," said Skudin.  "Our barge was rigged to load the tanks through the stripping lines. This limited the gasoline fall into the barge's tank to only a few inches, further reducing the potential for static electricity. As an added precaution, the Mobile Diving and Salvage Unit One Divers, working from USNS Sioux (T-ATF 171), were put in a separate moor from the pumping platform and ocean-going barge to which the gasoline was removed. "

The Navy's Salvage capability typically requires cooperation between uniformed fleet Navy Divers, Military Sealift Command, and SUPSALV civilian and contractor resources to accomplish complex or technically challenging salvage and pollution response evolutions. The Navy team involved in the ex-USS Chehalis offload was able to exercise the coordinated effort necessary to meet salvage mission challenges while demonstrating our commitment to preserving and protecting the environment.

Maritime Today

The Maritime Industry's original and most viewed E-News Service

Maritime Reporter July 2016 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds


Kooiman to Repair MTS Julius Rütgers

Eiltank Schiffart GmbH & Co KG has placed the order for the repair of the inland waterway tanker vessel Julius Rütgers Shipyard with the shipyard Gerb. Kooiman B.

AFMA Moves to Strengthen Seabird Safety

Being followed by an albatross is considered to bring good luck to mariners but the birds themselves aren’t always so lucky when trying to pick up a free feed from fishing boats.

Houston Ship Channel Closed after Benzene Spill

A section of the Houston Ship Channel has been closed following the release of approximately 500 gallons of benzene from the tanker Maritime Jingan while moored at Vopak Terminal Thursday afternoon.

Maritime Contracts Maritime Security Maritime Standards Naval Architecture Offshore Oil Pod Propulsion Ship Electronics Ship Repair Shipbuilding / Vessel Construction Sonar
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.0906 sec (11 req/sec)