The Dracone barge may not be a household name, but for coast guards around the world, this gigantic rubber bladder is part of the first response kit in an oil spill.
The Dracone barge is a misnomer since it looks nothing like the barges populating canals such as those in Amsterdam. In fact, a Dracone barge looks more like a beached whale on land, and at sea, like a giant sea monster.
"It was called a barge for legislative and classification reasons," says Mike Saunders, Business Development Manager, Trelleborg Dunlop GRG which manufactures Dracone barges on demand for coast guard authorities. Dunlop GRG (General Rubber Goods), was once part of the Dunlop Group and is based in Manchester in the UK. Trelleborg acquired Dunlop GRG in 2005.
A Dracone barge is basically a vessel for transporting any kind of liquid - from jet fuel to crude oil - from point A to point B, without the need for the infrastructure of a tanker.
A tugboat usually drags a Dracone barge through the water. It floats because of large buoyancy panels on either end, but also because many of the liquids that it transports are lighter than water.
When an oil spill occurs, the first thing to do is to contain the oil with booms. Skimmers then set to work pushing the oil, water and other debris into a funnel where it all gets pumped into a Dracone barge for disposal on land.
Sir William Hawthorne, a Cambridge University engineering professor, invented the Dracone barge in the late 1950s following the Suez oil crisis. He was better known for his work developing the jet engine, but also had an interest in energy. Perfecting the design of the nose and tail mouldings accounted for the bulk of the empirical and theoretical analysis. Ocean towing trials and extensive stress analysis determined the precise profiles needed to transmit towing forces and snatch loads. The resulting composite technology used in the fabrication of the end mouldings is key to the overall strength of the Dracone and its unblemished operational record for over 50 years.
More than 500 of these barges have been produced since his invention.
According to Wikipedia, the name Dracone is a reference to science fiction author Frank Herbert's Dragon in the Sea novel.
"It needed a posh name," says Saunders. Dracone is close to the Greek world for a mythological monster, such as a sea serpent.
The largest Dracone barge can accommodate more than 935 cubic metres of liquid, is 91.5 metres long, 4.23 metres in diameter, and weighs 6.5tons empty. It can, however, fold up into the size of a medium van. Dracone barges are made from woven nylon coated with synthetic rubber polymers for high abrasion resistance.
Their lifespan is about 25 years and, unlike competitors' products, they are reusable.
Major growth market
According to Saunders, Dracone barges are a niche product, yet there is a major growth market for them in the cruise ship industry.
"Cruise ships are getting larger and larger and are having a harder time entering ports, but they still have to empty their bilge, waste and sewage water while anchored offshore," says Saunders. "That is where a Dracone barge can come in handy."
While Dracone barges are not the first items to capture world headlines during an oil spill, they are instrumental in mopping up the mess. Some famous disasters in which Dracone barges have been used include the Exxon Valdez spill and Hurricane Katrina in New Orleans in 2005.
After the hurricane, clean up crews used Dracone barges to empty the fuel tanks of capsized boats and ships.
Key customersinclude the US, Indian and Australian Coast Guards, and the Marine Spill Response Corporation.
When an oil spill occurs, the oil is first contained with so-called booms. Skimmers, containers floating on the water surface, then set to work collecting the oil, water and other debris into a funnel, with the help of a pump attached to a hose at the bottom of the skimmer.
The spill is pumped into the Dracone barge for discharge at land-based disposal facilities. The largest Dracone barge can accommodate more than 935m3 of liquid, is 91.5 metres long, 4.23 metres in diameter, and weighs 6.5tons empty.
For more information, visit www.trelleborg.com
