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Being catering we had no need for compass, we all knew how to get from the galley to the dinning saloon.
But at the Vindi we had to do life boat and I did exceptionally well at the compass, still can remember quite a bit of it.
When on the road I use the sun as a guide as to where our compass point may be, in the out back you need to know where the main compass points are as you can go for up to a day without a sign post.
John in Oz ... Is that compass adjuster friend of yours still in business.? Don’t even know if it still a requirement to have a magnetic compass, or even in the lifeboats as it once was. The lifeboat compasses were always handy for testing the cables for reversing the polarity of the ship as an anti mine magnetic mine deterrent which all British. New buildings were fitted with up until about 1960. The de-gaussing cable being mostly copper wire was worth a fortune if taking a ship to the scrapyard. To test if working however the small compass was placed above the cable and when the engineers switched on the special generator the compass card would swivel right round. Wonder how many merchant ships are still left fitted with de-gaussing. Your friend might have an idea. Cheers JWS.
John I may be wrong but I seem to recall they tested the de-gaussing system at a point on the River Thames where you passed over something on the river bottom?Quote:
Originally Posted by j.sabourn
Bill
There was a deguassing test facility in Southampton water.
Vic
Yes that's right Bill we used to do it for the minehunters and they were mostly non ferrous material. this was more to test the ships gear and the generator using the boat compass. the actual degaussing was a different thing.... I think. Years ago when building a ship in the yard was when a ship acquired most of its magnetic properties all the banging and riveting disturbing all the molecules this together with the earths magnetic lines of force running from the earths magnetic poles north to south, to minimise this most yards tried to build on the north to south line I think there is one of the members on site who is RNVR and worked out of Rosyth and he spent time on the hunters, he no doubt will have received training on magnetic mines and the theory on which they work. A compass Error is derived of two errors variation and deviation, variation is like climate change you aren't going to change and remains the same with annual changes. deviation however can be altered by various magnets in and around the compass binnacle. if you can get the same variation as the deviation one error east and the other west then you can cancel out the error. that is only a rough description of compass error. the actual degaussing of a ship steaming over cables on the bottom is done by people with the electronical knowledge and techniques and was not a subject I took much notice of. So when I say testing the gear with the boat compass it was just that testing the defences of the ship against magnetic mines and not de-gaussing. Cheers JWS
John, when a British ship was nearing completion (in Greenock) an Admiralty vesel would come alongside.
Cables were wrapped round the widest part of the ship and electrically energised, this de-magnatised the ship, this operation took about 3 days from memory.
The Admiralty paid for the deguassing cable and equipment. Shipowner paid a nominal fee of £100.
This only applied to UK shipowners.
I knew the Admiralty paid for the fitting of the degaussing cable which was nearly all copper wire. Nearly every ship had it in the 50s and 60s probably most didn't notice it, but ran right round the ship at scupper level with a solid steel grating over it. Cheers JWS
HI Ivan.
You awakened my old brain, I was on a ship with rod and chain steering, but had forgotten about the compass with the little mirror, in bad weather sometimes I couldn't remember which way the compass heading I was to steer by had gone, not bad in the daytime as it was written on the board in the wheelhouse, but at night it was wait until the mate was in the chart room then dash across and have a shuftee.
Oh! bring back the days of old, but of course not rod and chain.
Cheers Des
Yes John he sure is.Quote:
Originally Posted by j.sabourn
He told me it is now a requirement for all ships compasses to be checked every year.
Yes Des, once your little quadrant had disappeared out of the mirror and ye olde vessel was yawing to and fro it was sometimes difficult to decide which way to turn the wheel, as the trawlers I was on you had to stand at one side of the wheel (5 foot in diameter) as the shaft ran through the bulkhead abaft the wheel. Imagine trying to steer one of today's bemoaths with rod and chain!Quote:
Originally Posted by Des Taff Jenkins