SCIENCE AND THE SEA 



loss. Costs for repair of one break run from $2,000 to $20,000 for 

 cable alone depending upon the length and type of cable. To include 

 the repair ship costs would bring the expense to as much as $50,000 

 or more. Service losses on one transatlantic cable off Newfoundland 

 may run into thousands of dollars per hour. Costs to the individual 

 trawler that fouls a cable are difficult to compute. The fishing gear 

 will be replaced by the cable companies if the fisherman will make a 

 claim reporting the time, location and depth of the fouling. However, 

 a trawler working a long way from its home port would have a con- 

 siderable financial loss, above the price of gear alone, if he lost his 

 trawl and had to return to port without a catch of fish. 



Investigation of many breaks has revealed miles of trawler-dam- 

 aged cable with numerous crushed places, broken armor wires, and 

 electrical faults. The increasing number of cases of cable cut with 

 an axe, burned with a cutting torch, or parted under strain require 

 that the problem be given prompt attention. An examination of the 

 background of both the fishing and undersea communication indus- 

 tries may lead to a better understanding of the present situation. 



Historically, fishing has played an important role in the econo- 

 mies of many nations, and it is the leading industry of at least one 

 nation, Norway. Actually fishing is probably the oldest industry 

 pursued by man and may even have preceded his efforts at hunting. 

 Man's first venture from shore in a dugout canoe may have been to 

 "go fishing". In medieval times, fish was a most important winter 

 food and it still is the "Lenten Fare" of Europe. Fishing fleets were 

 also the backbone of many early navies. 



At present, commercial fishing is generally conducted within the 

 limits of the 200-fathom curve, although the trend is toward greater 

 depths. Fish in any great abundance are not easy to locate or catch 

 outside these depths. The fish populations are constantly on the 

 move and normally productive fishing grounds are often temporarily 



deserted. Commercial fishermen are alert to these migrations and 

 concentrate eagerly wherever fish are found. 



The Grand Banks of Newfoundland, one of the world's impor- 

 tant fishing grounds, is located on the North American continental 

 shelf. The fishermen of many nations appear on these banks regu- 

 larly. Their fleets of powerful ships are equipped with the latest 

 and most modern navigational instruments including loran, Decca, 

 gyro compass, fathometer, and specialized devices. Factory ships 

 and even hospital ships accompany the fleets. Their fishing gear 

 includes otter trawls and nets for taking ground fish such as cod, 

 haddock, pollock and redfish. 



The otter trawl is a device for taking bottom fish. It is so con- 

 structed that when fully assembled and rigged it will take the shape 

 of a huge funnel while traveling along the bottom. Correctly rigged, 

 the trawl doors or "otter boards" keep the mouth of the net open by 

 operating at an outward angle from the direction of the towed trawl. 

 The fish are swept into the belly of the net by the wings and are 

 trapped in the "cod end" until the catch is hoisted on deck. The net 

 is usually towed at 2 to 3 knots, using two flexible steel wire cables 

 about 11/16 of an inch in diameter. The rig weighs about 2 tons and 

 a good haul can average about 1 ton of fish. A spare set of gear 

 may be rigged for use on the port side of some trawlers but the star- 

 board gear is used almost exclusively. Parts from the port side gear 

 are used as replacements, when needed. Most trawlers would not 

 be able to continue fishing after fouling and losing the working net. 

 A replacement will cost $2,500 or more and would usually have to be 

 purchased in the home port. 



Since the trawl is operated at depths which preclude a visual ex- 

 amination of its workings, it is extremely vulnerable to snags, wrecks, 

 rocks, cables, or any other obstruction with which it may become en- 

 tangled during its sweep along the bottom. However, it is usually 

 profitable to fish in the vicinity of known wrecks. Trawlermen will 



A trawler head rope and floats being cleared from a communications cable during repair operations aboard a cable 

 vessel 



62 



