A Dracone Barge is a large flexible watertight tube intended to carry a liquid cargo while towed mostly-submerged behind a ship. One large current example of the type has a capacity of 935 cubic metres (4.23m diameter, 91m long) while weighing only 6.5 tonnes empty. The Dracone Barge was invented in 1956 by Professor

William Hawthorne Sir William Rede Hawthorne CBE, FRS, FREng, FIMECHE, FRAES, (22 May 1913 – 16 September 2011) was a British professor of engineering who worked on the development of the jet engine. Bragg-Hawthorne equation is named after him. Life ...

as a new type of oil tanker. The intent was to create an improved transport technology: the long tube can be pulled by a lower powered vessel than the equivalent tanker, the cargo can be handed off at the destination very quickly, and incurs no drag cost when empty (because it can easily be taken aboard), as compared to the similar unladen to laden drag of the rigid-hulled tanker of equivalent capacity. The daytime signal (known as a day shape) for dracone is a diamond shape at or near the aftermost extremity of the last vessel or object being towed and if the length of the tow exceeds 200 meters an additional diamond shape where it can best be seen and located as far forward as is practicable. According to the

USCG The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, mu ...

's 72Colregs, For light signals, dracones less than 25 meters breadth (82.02') should display one all-round white light at each end. However, the "forward" light may be omitted. Provided, however, dracones with a breadth of 25 meters or longer MUST display one all-round white at each end and two additional all-round white lights on each side of its maximum breadth. Dracones exceeding 100 meters shall display additional all-round white lights between the fore and aft lights not to exceed 100 meters between these additional lights. While being towed by a vessel it displays only one all round light so that it can be seen by other vessels and risk of collision can be reduced. The common modern use (described in a patent application filed by BP in 1972 in combination with capture booms) is in the clean-up of

petroleum Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crud ...

spills or pollution slicks, where any small and manoeuvrable vessel (e.g. a harbour tug) with pumping gear mounted on it can gather up a much larger volume of liquid than it can carry by pumping it promptly back over the side into a tanker or Dracone Barge. A secondary, but related use, is the offloading of

bilge water The bilge of a ship or boat is the part of the hull that would rest on the ground if the vessel were unsupported by water. The "turn of the bilge" is the transition from the bottom of a hull to the sides of a hull. Internally, the bilges (usu ...

from large ships that must be treated (at a shore-side facility) and not dumped directly into the sea. The vessels were given the name "dracone" as it was "the nearest word in Greek for a mythical monster such as a sea serpent." However, one year earlier Frank Herbert wrote his first novel ''

The Dragon in the Sea ''The Dragon in the Sea'' (1956), also known as ''Under Pressure'' from its serialization, is a novel by Frank Herbert. It was first serialized in ''Astounding Science Fiction, Astounding'' magazine from 1955 to 1956, then reworked and published ...

'' about submarines towing large bags to carry oil, and other sources say the naming was an "overt acknowledgment of the source of his idea".

References

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External links

The Dracone Project
papers at the Churchill Archives Centre Ship types

See also

References

External links