A fishing trawler is a commercial fishing vessel

Fishing vessel

A fishing vessel is a boat or ship used to catch fish in the sea, or on a lake or river. Many different kinds of vessels are used in commercial, artisanal and recreational fishing....

 designed to operate fishing trawls

Trawling

Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net that is used for trawling is called a trawl....

. Trawling is a method of fishing that involves actively dragging or pulling a trawl through the water behind one or more trawlers. Trawls are fishing nets that are pulled along the bottom of the sea or in midwater at a specified depth. A trawler may also operate two 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 ship

Factory ship

A factory ship, also known as a fish processing vessel, is a large ocean-going vessel with extensive on-board facilities for processing and freezing caught fish...

 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.

History

During the 17th century, the British developed the Dogger

Dogger (boat)

The dogger was a form of fishing boat, developed during the seventeenth century, that commonly operated in the North Sea. The dogger takes its name from the Dutch word dogger, meaning a fishing vessel operating a trawl...

, an early type of sailing trawler commonly operated in the North Sea

North Sea

In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

. The Dogger takes its name from the Dutch word

Dutch language

Dutch is a West Germanic language and the native language of the majority of the population of the Netherlands, Belgium, and Suriname, the three member states of the Dutch Language Union. Most speakers live in the European Union, where it is a first language for about 23 million and a second...

 dogger, meaning a fishing vessel which tows a trawl. Dutch trawling boats were common in the North Sea, and the word dogger was given to the area where they often fished, which became known as the Dogger Bank

Dogger Bank

Dogger Bank is a large sandbank in a shallow area of the North Sea about off the east coast of England. It extends over approximately , with its dimensions being about long and up to broad. The water depth ranges from 15 to 36 metres , about shallower than the surrounding sea. It is a...

. Doggers were slow but sturdy, capable of fishing in the rough conditions of the North Sea.

In the Middle Ages, Brixham

Brixham

Brixham is a small fishing town and civil parish in the county of Devon, in the south-west of England. Brixham is at the southern end of Torbay, across the bay from Torquay, and is a fishing port. Fishing and tourism are its major industries. At the time of the 2001 census it had a population of...

 was a fishing port, and at one time it was the greatest in England. Brixham is famous for being the town where the fishing trawler was improved in the 19th century. Known as the "Mother of Deep-Sea Fisheries", the design of her elegant wooden boats spread across the world, influencing fishing fleets everywhere. Their distinctive sails inspired the song Red Sails in the Sunset

Red Sails in the Sunset (song)

"Red Sails in the Sunset" is a popular song.Published in 1935, its music was written by Hugh Williams with lyrics by prolific songwriter Jimmy Kennedy...

 which was written aboard a Brixham sailing trawler called the Torbay

Torbay

Torbay is an east-facing bay and natural harbour, at the western most end of Lyme Bay in the south-west of England, situated roughly midway between the cities of Exeter and Plymouth. Part of the ceremonial county of Devon, Torbay was made a unitary authority on 1 April 1998...

 Lass. In the 1890s there were about 300 trawling vessels there, each usually owned by the skipper of the boat. Several of these old sailing trawlers have been preserved.
Trawler designs adapted as the way they were powered changed from sail to coal-fired steam by World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 to diesel

Diesel engine

A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

 and turbines by the end of World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. During World War I and World War II, many fishing trawlers were commissioned as naval trawler

Naval trawler

A naval trawler is a vessel built along the lines of a fishing trawler but fitted out for naval purposes. Naval trawlers were widely used during the First and Second world wars. Fishing trawlers were particularly suited for many naval requirements because they were robust boats designed to work...

s to be used as minesweepers, the activities being similar, with the crew and layout already suited to the task. Since World War II, commercial fishing vessels have been increasingly equipped with electronic aids, such as radio navigation aids and fish finders

Fishfinder

A fishfinder is an instrument used to locate fish underwater by detecting reflected pulses of sound energy, as in SONAR. A modern fishfinder displays measurements of reflected sound on a graphical display, allowing an operator to interpret information to locate schools of fish, underwater debris,...

. During the Cold War

Cold War

The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

, some countries fitted fishing trawlers with additional electronic gear so they could be used as spy ship

Spy ship

A spy ship or reconnaissance vessel is a dedicated ship intended to gather intelligence, usually by means of sophisticated electronic eavesdropping. In a wider sense, any ship intended to gather information could be considered a spy ship....

s to monitor the activities of other countries.

The town of Grimsby on Lincolnshire's east coast once laid claim to the title of the 'largest fishing port in the world', Its fleet of over 700 trawlers and the rail links from the town to London's Billingsgate Fish Market

Billingsgate Fish Market

Situated in East London, Billingsgate Fish Market is the United Kingdom's largest inland fish market. It takes its name from Billingsgate, a ward in the south-east of the City of London, where the riverside market was originally established...

 allowed Grimsby fish to be renowned nationwide. Today Grimsby's fish docks are virtually deserted, though the towns port is still a hive of activity for cargo vessels. The glory days of fishing in the town are remembered at the town's Fishing Heritage Centre (previously the National Fishing Heritage Centre

National Fishing Heritage Centre

The Fishing Heritage Centre is a museum at Alexandra Dock, Grimsby, Lincolnshire, England, opened in 1991. It depicts the 1950s heyday of the distant waters fishing fleet. The centre also hosts a programme of temporary exhibitions throughout the year. Tours of the fishing trawler Ross Tiger are...

) where the preserved trawler Ross Tiger

Ross Tiger

The Ross Tiger is a traditional side-winder fishing trawler that was converted into a museum ship in 1992. She is currently berthed in Alexandra Dock at her home port of Grimsby, close to the site of the former PS Lincoln Castle. She forms the star attraction of North East Lincolnshire County...

 provides a unique glimpse into the lost lives of the 1950s trawlerman.

The largest fishing port in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 from the 1970s onwards has been Peterhead

Peterhead

Peterhead is a town in Aberdeenshire, Scotland. It is Aberdeenshire's biggest settlement , with a population of 17,947 at the 2001 Census and estimated to have fallen to 17,330 by 2006....

 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

Overfishing

Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....

 which in turn has reduced fishing quotas

Individual fishing quota

Individual fishing quotas also known as "individual transferable quotas" are one kind of catch share, a means by which many governments regulate fishing. The regulator sets a species-specific total allowable catch , typically by weight and for a given time period. A dedicated portion of the TAC,...

.

Modern trawlers

Modern trawlers are usually deck

Deck (ship)

A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary deck is the horizontal structure which forms the 'roof' for the hull, which both strengthens the hull and serves as the primary working surface...

ed vessels. Their superstructure (wheelhouse and accommodation) can be forward, midship or aft. Motorised winch

Winch

A winch is a mechanical device that is used to pull in or let out or otherwise adjust the "tension" of a rope or wire rope . In its simplest form it consists of a spool and attached hand crank. In larger forms, winches stand at the heart of machines as diverse as tow trucks, steam shovels and...

es, electronic navigation and sonar

Sonar

Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

 systems are usually installed. Fishing equipment varies in sophistication depending on the size of the vessel and the technology used. Design features for modern fishing trawlers vary substantially, as many national maritime jurisdictions do not impose compulsory vessel inspection standards for smaller commercial fishing vessels.

Mechanised hauling

Mechanised hauling devices are used on modern trawlers. Trawl winches, such as Gilson winches, net drums and other auxiliary winches are installed on deck to control the towing warps (trawling wires) and store them when not in use.

Electronics

Modern trawlers make extensive use of contemporary electronics, including navigation and communication equipment, fish detection devices, and equipment to control and monitor gear. Just which equipment will be installed depends on the size and type of the trawler.

Much of this equipment can be controlled from the wheelhouse or bridge. Smaller trawlers have wheelhouses, where electronic equipment for navigation, communications, fish detection and trawl sensors are typically arranged about the skipper's chair. Larger vessels have a bridge, with a command console at the centre and a further co-pilot chair. Modern consoles display all the key information on an integrated display. Less frequently used sensors and monitors may be mounted on the deckhead

Deckhead

A deckhead is the underside of a deck in a ship. It bears the same relationship to a compartment on the deck below as does the ceiling to the room of a house....

.

Navigational instruments, such as an autopilot

Autopilot

An autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. An autopilot can refer specifically to aircraft, self-steering gear for boats, or auto guidance of space craft and missiles...

 and GPS, are used for manoeuvering the vessel in harbour and at sea. Radar can be used, for example, when pair trawling to keep the correct distance between the two vessels. Communication instruments range from basic radio devices to maritime distress

Global Maritime Distress Safety System

The Global Maritime Distress and Safety System is an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft....

 systems and EPIRBs, as well as devices for communicating with the crew. Fish detection

Fishfinder

A fishfinder is an instrument used to locate fish underwater by detecting reflected pulses of sound energy, as in SONAR. A modern fishfinder displays measurements of reflected sound on a graphical display, allowing an operator to interpret information to locate schools of fish, underwater debris,...

 devices, such as echosounders and sonar

Sonar

Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...

, are used to locate fish.

During trawling operations, a range of trawl sensors may be used to assist with controlling and monitoring gear. These are often referred to as "trawl monitoring systems" or "net mensuration systems".

• net sounders (trawl eyes
  Fisheye lens
  In photography, a fisheye lens is a wide-angle lens that takes in a broad, panoramic and hemispherical image. Originally developed for use in meteorology to study cloud formation and called "whole-sky lenses", fisheye lenses quickly became popular in general photography for their unique, distorted...
  
  ) give information about the concentration of fish around the opening to the trawl, as well as the clearances around the opening and the bottom of the trawl
• catch sensors give information about the rate at which the cod end is filling.
• symmetry sensors give information about the optimal geometry of the trawls.
• tension sensors give information about how much tension is in the warps and sweeps.

Fish storage and processing

Modern trawlers store the fish they catch in some form of chilled condition. At the least, the fish will be stored in boxes covered with ice or stored with ice in the fish hold. In general, the fish are kept fresh by chilling them with ice or refrigerated sea water, or freezing them in blocks. Also, many trawlers carry out some measure of onboard fish processing, and the larger the vessel, the more likely it is to include fish processing facilities. For example, the catch can undergo some preliminary processing by being passed through sorting and washing devices. At a further stage, the fish might be mechanically gutted and filleted

Fillet (cut)

A fillet is a cut or slice of boneless meat or fish.- Meat :In the case of beef, in the USA, the term most often refers to beef tenderloin, especially filet mignon.- Chicken :...

. Factory trawlers may process fish oil

Fish oil

Fish oil is oil derived from the tissues of oily fish. Fish oils contain the omega-3 fatty acids eicosapentaenoic acid , and docosahexaenoic acid , precursors of certain eicosanoids that are known to reduce inflammation throughout the body, and are thought to have many health benefits.Fish do not...

 and fish meal

Fish meal

Fish meal, or fishmeal, is a commercial product made from both whole fish and the bones and offal from processed fish. It is a brown powder or cake obtained by rendering pressing the cooked whole fish or fish trimmings to remove most of the fish oil and water, and then ground...

 and may include canning plants.

Other design features

Crew quarters are usually below the wheelhouse and may include bunks

Bunk bed

A bunk bed is a type of bed in which one bed frame is stacked on top of another. The nature of bunk beds allows two people to sleep in the same room while maximizing available floor space...

, with cot side

Cot side

Cot sides are raised sides fitted to a bed to stop the occupant from falling out of bed. They occur:*In toddler beds; however in infant beds the sides are to prevent intentional, rather than accidental, exit....

s to stop the occupant from rolling out in heavy weather. 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 over the boiler".

Trawler types

Trawlers can be classified by their architecture, the type of fish they catch, the fishing method used, or geographical origin. The classification used below follows the FAO

Food and Agriculture Organization

The Food and Agriculture Organization of the United Nations is a specialised agency of the United Nations that leads international efforts to defeat hunger. Serving both developed and developing countries, FAO acts as a neutral forum where all nations meet as equals to negotiate agreements and...

, who classify trawlers by the gear they use.

Outrigger trawlers

Outrigger trawlers use outrigger

Outrigger

An outrigger is a part of a boat's rigging which is rigid and extends beyond the side or gunwale of a boat.In an outrigger canoe and in sailboats such as the proa, an outrigger is a thin, long, solid, hull used to stabilise an inherently unstable main hull. The outrigger is positioned rigidly and...

s, or booms, to tow the trawl. These outriggers are usually fastened to, or at the foot of the mast and extend out over the sides of the vessel during fishing operations. Each side can deploy a twin trawl or a single otter trawl. Outrigger trawlers may have the superstructure forward or aft. Warp winches with capstans

Capstan (nautical)

A capstan is a vertical-axled rotating machine developed for use on sailing ships to apply force to ropes, cables, and hawsers. The principle is similar to that of the windlass, which has a horizontal axle.- History :...

 are installed on the deck to haul the catch.

• Outrigger trawlers with a forward superstructure and aft working deck are widely used to target shrimp
  Shrimp
  Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
  
  . The towing winch is usually located to the rear of the superstructure so warps from the drums feed to bollard
  Bollard
  A bollard is a short vertical post. Originally it meant a post used on a ship or a quay, principally for mooring. The word now also describes a variety of structures to control or direct road traffic, such as posts arranged in a line to obstruct the passage of motor vehicles...
  
  s on the cap rail, and then to towing blocks on the outriggers.

• Outrigger trawlers with aft superstructure and midship working deck are usually beam trawlers (see below). These use large beams to rig the trawls.

Outrigger trawlers use vertical fish finders

Fishfinder

A fishfinder is an instrument used to locate fish underwater by detecting reflected pulses of sound energy, as in SONAR. A modern fishfinder displays measurements of reflected sound on a graphical display, allowing an operator to interpret information to locate schools of fish, underwater debris,...

 of different kinds, according to their size. Drawing (FAO)

Beam trawlers

Beam trawlers are a type of outrigger trawler (above), with the superstructure aft and the working deck amidships. They use a very strong outrigger boom on each side, each towing a beam trawl, with the warps going through blocks at the end of the boom. This arrangement makes it easier to stow and handle the large beams. The outriggers are controlled from a midship A-frame or mast. The towing winch is forward of the superstructure, with the towing warps passed through deck bollards and then out to the towing blocks on the booms.

Beam trawling is used in the flatfish

Flatfish

The flatfish are an order of ray-finned fish, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the head, one or the other migrating through and around the head during development...

 fisheries in the North Sea

Fishing in the North Sea

Fishing in the North Sea is concentrated in the southern part of the coastal waters. The main method of fishing is trawling.Annual catches grew each year until the 1980s, when a high point of more than 3 million metric tons was reached...

. They are equipped with equipment for hauling the net and stowing it aboard. Typically an echosounder and sonar is used for finding fish.

They are medium sized and high powered vessels, towing gear at speeds up to 8 knot

Knot

A knot is a method of fastening or securing linear material such as rope by tying or interweaving. It may consist of a length of one or several segments of rope, string, webbing, twine, strap, or even chain interwoven such that the line can bind to itself or to some other object—the "load"...

s. To avoid the boat capsizing if the trawl snags on the sea floor, winch brakes can be installed, along with safety release systems in the boom stays. The engine power of bottom trawlers is restricted to 2000 HP (1472 KW) for further safety. Drawing (FAO)

Otter trawlers

Otter trawlers deploy one or more parallel trawls kept apart horizontally using otter boards. These trawls can be towed in midwater or along the bottom. Otter trawlers range in size from sailing canoes to supertrawlers.

Otter trawlers usually have two gallows at the stern with towing blocks. The towing warps run through these, each regulated by its own winch. Medium and large trawlers usually have a stern ramp for hauling the trawl onto the deck. Some trawlers tow twin parallel trawls, using three warps, each warp with its own winch. Some otter trawlers are also outrigger trawlers (above), using outriggers to tow one or two otter trawls from each side.

Usually otter trawlers have the superstructure forward, though it can be aft or amidship. Gallows are on the stern quarters or there is a stern gantry for operating the otter boards. Pelagic trawlers can use fish pumps to empty the cod end.

Pair trawlers

Pair trawlers

Pair trawling

Pair trawling is a fishing activity carried out by two boats, with one towing each warp . As the mouth of the net is kept open by the lateral pull of the individual vessels, otter boards are not required...

 are trawlers which operate together towing a single trawl. They keep the trawl open horizontally by keeping their distance when towing. Otter boards are not used. Pair trawlers operate both midwater and bottom trawls.

The superstructure is forward or midships and the working deck aft. Pelagic trawlers can have fish pumps to empty the codend.

Side trawlers

Side trawlers have the trawl deployed over the side with the trawl warps passing through blocks suspended from a forward gallow and another aft gallow. Usually the superstructure is towards the stern, the fish hold amidships, and the transversal trawl winch forward of the superstructure. A derrick may be a boom rigged to the foremast to help shoot the codend from the side. Until the late sixties, side trawlers were the most common deep sea boat used in North Atlantic fisheries. The 1950s side trawler, Ross Tiger

Ross Tiger

The Ross Tiger is a traditional side-winder fishing trawler that was converted into a museum ship in 1992. She is currently berthed in Alexandra Dock at her home port of Grimsby, close to the site of the former PS Lincoln Castle. She forms the star attraction of North East Lincolnshire County...

is preserved in Grimsby. These trawlers were used for a longer period than other kinds of trawlers, but are now being replaced by stern trawlers. Some side trawlers still in use have been equipped with net drums. Drawing (FAO)

Stern trawlers

Stern trawlers have trawls which are deployed and retrieved from the stern. Larger stern trawlers often have a ramp, though pelagic and small stern trawlers are often designed without a ramp. Stern trawlers are designed to operate in most weather conditions. They can work alone when midwater or bottom trawling

Bottom trawling

Bottom trawling is trawling along the sea floor. It is also often referred to as "dragging".The scientific community divides bottom trawling into benthic trawling and demersal trawling...

, or two can work together as pair trawlers. The superstructure is forward with an aft working deck. At the stern are gallows or a gantry

Gantry crane

Gantry cranes, bridge cranes, and overhead cranes, are all types of cranes which lift objects by a hoist which is fitted in a hoist trolley and can move horizontally on a rail or pair of rails fitted under a beam...

 for operating otter boards. Drawing (FAO)

Any fish processing

Fish processing

The term fish processing refers to the processes associated with fish and fish products between the time fish are caught or harvested, and the time the final product is delivered to the customer...

 usually occurs in deck houses or below deck. A wet fish stern trawler stores the fish in ice or sea water which has been refrigerated. A freezer stern trawler stores the fish in frozen boxes or blocks, and a factory stern trawler processes the catch. A pelagic stern trawler may use fish pumps to empty the codend.

Freezer trawlers

The majority of trawlers operating on the high seas are freezer trawlers. They have facilities for preserving fish by freezing, allowing them to remain at sea for extended periods of time. They are medium to large size trawlers, with the same general arrangement as stern or side trawlers. Drawing (FAO)

Wet fish trawlers

Wet fish trawlers are trawlers where the fish is kept in the hold in a fresh/wet condition, in boxes covered with ice or with ice in the fish hold. They must operate in areas close to their landing place, and the time such a vessel can spend fishing is limited. Drawing (FAO)

Trawler/purse seiners

Trawler/purse seiners are designed so the deck equipment, including an appropriate combination winch, can be rearranged and used for both methods. Blocks, purse davits, trawl gallows and rollers need to be arranged so they control the pursing lines and warp leads and in such a way as to reduce the time required to convert from one arrangement to the other. These vessels are usually classified as trawlers, since the power requirement for trawling is higher.

Naval trawlers

During both World Wars some countries created small warships by converting and arming existing trawlers or building new vessels to standard trawler designs. They were typically armed with a small naval gun and sometimes depth charges, and were used for patrolling, escorting other vessels and minesweeping.

Images

Images on board 1950s trawler Ross Tiger

Ross Tiger

The Ross Tiger is a traditional side-winder fishing trawler that was converted into a museum ship in 1992. She is currently berthed in Alexandra Dock at her home port of Grimsby, close to the site of the former PS Lincoln Castle. She forms the star attraction of North East Lincolnshire County...

(before her 2010 renovations), now in National Fishing Heritage Centre

National Fishing Heritage Centre

The Fishing Heritage Centre is a museum at Alexandra Dock, Grimsby, Lincolnshire, England, opened in 1991. It depicts the 1950s heyday of the distant waters fishing fleet. The centre also hosts a programme of temporary exhibitions throughout the year. Tours of the fishing trawler Ross Tiger are...

 museum, Grimsby

Grimsby

Grimsby is a seaport on the Humber Estuary in Lincolnshire, England. It has been the administrative centre of the unitary authority area of North East Lincolnshire since 1996...

. It is about 126 feet long.

See also

• Drifter (fishing boat)
  Drifter (fishing boat)
  A drifter is a type of fishing boat. They were designed to catch herrings in a long drift net. Herring fishing using drifters has a long history in the Netherlands and in many British fishing ports, particularly in East Scottish ports....
  
  
• Net cutter (fisheries patrol)
• Pair trawling
  Pair trawling
  Pair trawling is a fishing activity carried out by two boats, with one towing each warp . As the mouth of the net is kept open by the lateral pull of the individual vessels, otter boards are not required...
  
  
• Recreational trawler
• Trolling (fishing)

External links

• WorldFishingToday - Fishing vessels photos and data
• Vigilance - A Brixham Trawler
• Budding Rose - A Scottish Trawler
• European Union Fishing Directorate
• Pictures showing damage done by bottom trawlers
• Trawler History
• Trawler Pictures - A Forum and Gallery Dedicated to Commercial Trawlers
• Trawlers from the east coast of the UK
• Rough seas, Iceland YouTube.