Fishing was a major industry in Scarborough with the trawlers going to areas such as the Dogger Bank to catch fish. At one time it was up to the skill of the skipper to decide where to fish, using his experience and watching the natural signs such as sea bird behaviour. As technology developed, electronic equipment could assist the skipper and make fishing more reliable. This included the development of echo sounders.
Echo sounding is a type of sonar used to determine the depth of water by transmitting sound pulses into water and detecting the return transducer. The time interval between emission and return of a pulse is recorded, which is used to determine the depth of water along with the speed of sound in water at the time. This information is then typically used for navigation purposes or in order to obtain depths for preparing charts.
German inventor Alexander Behm was granted German patent No. 282009 for the invention of an echo sounder on July 22, 1913. The technology was developed in World War One for trying to detect submarines and further developed in World War Two.
One of the first commercial echo sounding units was the Fessenden Fathometer installed in the liner SS Berkshire in 1924.
As echo sounders improved it was found that they could be used to detect shoals of fish so fishing vessels were able to work more efficiently. Echo sounders were then developed specifically as fish detectors which again enhanced the ability of fishing boats to detect fish. Technology continues to help the fisherman. The latest developments include placing a CCTV camera inside the trawl net so the crew can monitor exactly what is being caught.
The echo sounder on display in the Maritime Heritage Centre is a Furuno FE-4200 which is thought to be from a fishing coble. It records the depth of water beneath the vessel on a paper roll. More up to date sounders have LED displays and combine the display with GPS so the exact location of a wreck or shoal can be determined.
Echo sounders are now an essential piece of electronic equipment on all but the smallest boats.
In the Centre the echo sounder is displayed on our “bridge” which has a ships wheel, compass and wind gauge. This gives children some idea about fishing boats.
A recent study by Glasgow University claimed that fish are now evolving to swim faster enabling them to escape being caught in trawl nets. Perhaps technology will also have to keep evolving to keep pace with the fish.
l Scarborough Maritime Heritage Centre is run entirely by volunteers and public donations. we are open Wednesday to Sunday 11am to 4pm and entrance is free.