Commercial trawler

A commercial trawler is a commercial fishing vessel designed to operate fishing trawls.

Trawling

Trawling is a method of fishing that involves actively pulling a trawl through the water behind one or more trawlers. Trawls are fishing nets that are dragged along the bottom of the sea or in midwater at a specified depth. A trawler may also operate one or more trawl nets simultaneously (double-rig and multi-rig).

There are many variants of trawling gear. They vary according to local traditions, bottom conditions, and how large and powerful the trawling boats are. A trawling boat can be a small open boat with only 30 hp or a large factory trawler with 10,000 hp. Trawl variants include beam trawls, large-opening midwater trawls, and large bottom trawls, such as "rock hoppers" that are rigged with heavy rubber wheels that let the net crawl over rocky bottom.

Trawler types

* Side trawlers: Until the 1950s trawlers in the Atlantic Ocean were designed to shoot and haul trawl gear from the side.
* Stern trawlers: From the 1950s, trawlers have been designed to operate gear from the stern. Technically, stern trawling is more feasible than side trawling and uses space more efficiently. It can be fully mechanized, enabling faster and safer operation of the gear, and better performance in heavy weather.
* Factory trawlers: A factory trawler is a large stern trawler which has additional facilities for processing and freezing fish installed on board. This allows the factory trawler to stay for long periods at sea. Factory trawlers can displace up to 3,000 tons.
* Wet trawlers: Wet trawlers are designed to make short fishing trips and land fresh fish kept in ice.
* Sailing trawlers: Traditional sailing trawlers were limited to trawling at depths of 55-75 metres, but modern trawlers often trawl to 900 metres, with experiments having gone even deeper.

Design features

Design features for commercial trawlers vary substantially, as many national maritime jurisdictions do not impose compulsory vessel inspection standards for smaller commercial fishing vessels. [cite web| title =Navigation and Vessel Inspection Circular 5-86: Voluntary Standards for U.S. Uninspected Commercial Fishing Vessels | publisher =United States Coast Guard | month =August | year =1986 | url =http://www.uscg.mil/hq/cg5/nvic/pdf/1986/n5-86.pdf | accessdate =2008-08-25 ] [cite web| title =Survey and Vessel Registration | publisher =Maritime Authority of New South Wales | month = | year =2008 | url =http://www.maritime.nsw.gov.au/survey.html | accessdate =2008-08-25 ]

Modern commercial trawlers are generally diesel- or turbine-powered, with the trawl launched and recovered over the stern via a powered winch.cite web| title =Stern trawler | publisher =Britannica Online | month = | year =2008 | url =http://www.britannica.com/EBchecked/topic/565769/stern-trawler#tab=active~checked%2Citems~checked&title=stern%20trawler%20--%20Britannica%20Online%20Encyclopedia | accessdate =2008-08-25 ] Many older trawlers had coal-fired steam-powered engines. In older trawlers the crew had to place and retrieve the nets by man power; this is still so with some small trawlers. Smaller trawlers may supplement their net-fishing capacity with longline fishing gear.

The wheelhouse and superstructure are generally well forward to increase deck space for loading and unloading of nets. A large central hatch allows the swift unloading of netted fish directly into the hold. Larger trawlers may also have a stern ramp to allow easier recovery of nets.

Crew quarters are usually below the wheelhouse and may include bunks, with cot sides to stop the occupant from rolling out in heavy weather, and storage and drying facilities for seaboots and oilskins. The need for drying sea clothes is shown by a notice in at least one steam trawler's boiler room saying "Do not dry oil frocks [= a type of oilskins] over the boiler".

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Images on board 1960's-type trawler "Ross Tiger", now in National Fishing Heritage Centre museum, Grimsby. It is about 126 feet long.

History

:"See also: History of fishing"In the Middle Ages, Brixham was the largest fishing port in the South-West, and at one time it was the greatest in England. Brixham is also famous for being the town where the fishing trawler was invented in the 19th century. These elegant wooden boats were and all over the world, influencing fishing fleets everywhere. Their distinctive sails inspired the song Red Sails in the Sunset which was written aboard a Brixham sailing trawler called the "Torbay Lass". Known as the "Mother of Deep-Sea Fisheries", its boats sailed all round the coasts and helped to establish the fishing industries of Hull, Grimsby and Lowestoft. In the 1890s there were about 300 trawling vessels there, each owned by one man who was often the skipper of his own boat.

One of the biggest ports in England for trawlers was Hull in Yorkshire on England's north-east coast.

Trawler designs adapted as the way they were powered changed from sails to coal-fired steam (by World War I) to diesels and turbiness (by the end of World War II)

During World War I and World War II, many commercial trawlers were used as minesweepers and naval trawlers, the activities being similar, and both the crew and the equipment aboard already suited to the task.

The largest fishing port in Europe from the 1970s onwards has been Peterhead in the North-East corner of Scotland. In its prime in the 1980s Peterhead had over 500 trawlers staying at sea for a week each trip. Peterhead has seen a significant decline in the number of vessels and the value of fish landed has been reduced due to several decades of overfishing which in turn has reduced quotas.

py boats

During the Cold War, some countries used commercial trawlers fitted with additional electronic gear to monitor the activities of their enemies: see spy ship.

References

ee also

*For trawlers used for naval purposes (often during World War I and World War II), see naval trawler
*For pleasure boats that resemble commercial trawlers, see recreational trawler.
*Fishing industry
*Bottom trawling
*Midwater trawling
*Pair trawling
*Drifter
*Factory ship
*Net cutters

External links

* [http://www.vigilanceofbrixham.co.uk/history.htm Vigilance - A Brixham Trawler]
* [http://www.buddingrose.co.uk Budding Rose - A Scottish Trawler]
* [http://europa.eu.int/comm/dgs/fisheries/index_en.htm European Union Fishing Directorate]
* [http://news.bbc.co.uk/1/shared/spl/hi/pop_ups/05/sci_nat_bottom_trawled0_bottom_cleared/html/1.stm Pictures showing damage done by bottom trawlers]
* [http://www.hullheritageprints.co.uk/trawlerhistory/index.htm Trawler History]