Stern trawlers
| Characteristics |
| Deck TypeDecked vesselsOverviewOn stern trawlers the trawl is set and hauled over the stern. Stern trawlers are designed with or without a ramp, depending on the size of the vessel. Some pelagic stern trawlers are built without a ramp. Stern trawlers are built for nearly all weather conditions. Trawlers can work as single vessel in bottom or midwater trawling or as pair trawlers where two vessels tow one large trawl or a double trawl.Vessel ClassLengthnormally > 15 meters (LOA)Powernormally > 90 HpTonnagenormally > 25 GT (GRT in register tons)Deck ArrangementThe superstructure is placed forward with the working deck aft. Gallows are placed on the stern quarters or there is a stern gantry for the operation of the otter boards. Net drums and gilson-winches are installed to assist in the handling of gear and catch. Fish pumps are often installed on pelagic trawlers. In most cases the handling of the catch and any processing of fish will take place below deck or in deck houses.Catch Handling and Processing EquipmentFresh fish in ice (Wet-fish stern trawler) or refrigerated sea water and/or frozen fish in blocks or boxes (Freezer stern trawler) and processed catch (Factory stern trawler).EquipmentDeck EquipmentThere will be various arrangements of the deck equipment depending on the type of trawler concerned. All trawlers will carry trawl winches for handling and storage of the towing warps. Gilson winches, net drums and other auxiliary winches are commonly installed to handle the gear and the catch. Pelagic trawlers may be equipped with fish pumps for emptying the codend.Fish Detection EquipmentAccording to its size, the stern trawlers may be fitted with a combination of detection equipment such as sonar, net sounder, various echo sounders and some gear control and monitoring equipment; like catch sensors, that gives information about the filling rate of the codend; symmetry sensors, that provide information about the trawls optimal geometry; tension sensors, that gives information about the tension in warps or sweeps; "trawl eye", that gives additional information about fish concentrations over, under and in the trawl opening, plus clearance from the bottom and opening of the trawl.Fishing Gear Bottom trawls Source: http://www.fao.org/ |
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