SCIENCE AND THE SEA 



ers. Each class has definite characteristics which make accurate 

 identification a simple matter regardless of size. 



The key feature to side trawler identification is the pair of heavy 

 A-frames they all carry. These A-frames, each fitted with a block, are 

 mounted on one or both sides, with one located well forward and the 

 other aft. A large winch is mounted on deck forward of the wheelhouse 

 to handle the trawl warps. Once the trawl is streamed these warps 

 are secured to a special towing block on the vessel's quarter. Trawling 

 speeds vary from 2 to 5 knots. 



A typical North Atlantic side trawler is shown in figure 1. This 

 195-foot trawler, built by Brooke Marine Limited of Lowestoft, 

 England, is arranged to trawl from the starboard side only, providing 

 for spacious Officer's quarters on the port side. The vessel has an 

 iced fish hold capacity of 18,200 cu. ft., a loaded speed of 14 knots, 

 and a complement of 26 men. 



Accompanying the trend toward stern trawler construction has 

 been the increased interest in, and use of, mid-water trawling gear. 

 Mid-water trawls permit vessels to fish either on the sea bed for 

 demersal species or at any desired height above it for pelagic varieties. 

 To accommodate this dual capability with one trawl requires some 

 modification of the conventional otter board trawl. Many design 

 concepts have been developed and tried with varying degrees of 

 success. One promising design, however, is the versatile Grouselle 

 trawl from France, shown in figure 3. 



The Grouselle trawl has a trapezoidal-shaped opening with two 

 triangular fillets between the wings and start of the cod end, a head 

 line, and ground line. The float equipped head line trails behind the 

 ground line which takes most of the strain during trawling. The head 

 line is trailed as fish tend to dive in their attempt to escape the 

 approaching net, an important consideration in mid-water work. 



Phofo — Brooke Marine Limited 



In recent years the trend in new trawler construction has been 

 toward building stern trawlers rather than the conventional side types. 

 Most stern trawlers over 150 feet in length are equipped with fish 

 processing machinery, and excellent refrigeration or freezing facilities. 

 Located near the stern, which often has a trawl slipway, is either a 

 swinging gantry or a fixed gantry for handling the trawl warps. 



On those vessels having the trawl slipway, the catch is hauled 

 directly aboard via the slipway to the working deck where the fish are 

 eviscerated and washed before being sent to the processing rooms. 

 Stern trawlers without the slipway bring the catch over the stern by 

 means of the hydraulically-operated gantry. 



The 130-foot stern trawler Seahorse, built by Brooke Marine 

 Ltd., is shown in figure 2. The design incorporates a soft nose stem, 

 well flared bow, and a transom type stern with hydraulically powered 

 gantry. This vessel has a 9,500 cu. ft. fish hold capacity, a loaded 

 speed of 10.5 knots, and carries a crew of 18. 



The Grouselle trawl 



Figure 3 



34 



