Patricia Bridgen Farley was a Wren (Womens Royal Naval Service) stationed at Portkil, Near Kilcreggan, Scotland during World War II, living in a house affectionately known to the group of Wrens that were based there as 'The Barn'. The Wrens came to be known as the 'Barnites'.

After France and the other countries capitulated to the Nazis in early 1940, the struggle became even more strenuous. Although the common folk did not realise it, the British Empire was nearly brought to its knees by one thing - the loss of shipping - both British and Allied.

Convoys going across the Atlantic lost most of their ships and precious cargoes, because the Germans had a powerful fleet of unchallenged U-boat hunting packs. They also used giant magnetic mines in the oceans that would explode with great force as soon as a vessel sailed over them.

The news was so grave that Winston Churchill told his cabinet and team of scientists that getting rid of the magnetic mine menace was of the utmost importance and priority for national security.

Steel ships have many components of different ferromagnetic characterisation. The magnetic field generated by these ships caused deviation of the magnetic compass and would trigger magnetic mines or other explosive devices.

They proposed 'degaussing' the neutralisation of the magnetic field of a ship, using properly located and oriented current-carrying coils. These coils would produce a second magnetic field of desired strength and in the opposite direction of the field generated by the ship.
   
The government set up several degaussing inspection stations around the country but some were too close to the enemy. The safest place was north, in Scotland, and it was decided to use an old concrete fort from World War I, located on the Clyde opposite Greenock and Gourock - very busy ports that handled many vessels, merchant and military. It was here that I received my indoctrination into degaussing operations.
   
The Fort, as it was always called, was a stone's throw from the Barn, and we passed a full workday there six days a week. If we had an early call for a ship, we would be there and, in the summer months when it stayed light until almost 11.30 pm, due to British double summer-time hours, we could be working after 9 or 10 pm.
   
There was deep water close offshore to our offices deep enough for the biggest aircraft carriers and warships to make several runs through a selected passage, marked by buoys, while taking the degaussing tests.
   
Special underground cables ran from that area up into one of the buildings, where the information was processed in a temperature-controlled room furnished with camera equipment. The data would emerge onto heavy photographic paper, encased in rolls located in a row of machines.

Our job was to wait for the data to appear in its entirety, rip it off the machines, and take it into the dark room. There we would develop the photographs in a hydrochloric solution. When they reached the correct intensity, we washed them thoroughly in clear water and dried them on a huge revolving frame.

I can still smell the chemicals and feel the heat in that room, but it took me quite a time to realise what we were actually doing - learning how to process photographs!
   
The finished product was brought into the adjoining office where we traced the graphs onto special paper for the civilian engineers. All corrections and suggestions from the technical people were passed on to the ship's officers by means of semaphore with flags or Aldis lamp using the Morse code. There was no need for anyone to leave a ship to talk to us.

As the vessels we tested were mammoth, with plenty of tonnage, it took time to swing them around to return through the degaussing range. The weather did not favour us every day. Storms could quickly develop, and it was awesome to see a mighty cruiser so close to shore, battling the currents and the gales.

One November, it rained all day with such fierce, strong winds that, by nightfall, a merchant ship anchored in midstream broke its moorings. As it drifted towards shore, the keep ripped through the underwater cables on the range. Next morning, when we viewed the damage, we knew immediately it was enormous. It took two weeks to repair the range and we all received an unexpected but enjoyed two weeks leave!