# Compass Adjusting



## Trevorw (Jun 5, 2006)

Just been looking at the thread about Colliers. Apropos of that, does anyone remember leaving the shipyards on the Tyne and going out to Souter Point to adjust compasses and calibrate D/F? I might be sad, but I always found this fascinating!


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## John Rogers (May 11, 2004)

I do it now to calibrate my GPS on my car,also done it on aircraft on what we called a compass rose.
John


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## raybnz (Sep 10, 2005)

Last time I was involved in doing this the chappy with a beard on the bridge gave us in the engine room a lot of movements while he pushed thingy bits in and out of the compass.

This would have been a few years back in Auckland on the Daldy. He used different houses, trees and marine markers to get his compass right. 

To technical for a Scotch Boiler Triple Expansion Engineer to comprehend.

The was a compass dolphin in the harbour but after many years it dissappeared during a storm.


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## K urgess (Aug 14, 2006)

Calibrating the D/F had to be done every year at least (I think).
Favourite place was Robben Island beacon at Capetown. I can't remember doing it in a supertanker but cargo boats did it all the time. I always seemed to join a ship when it was due. Never knew then what Robben Island was.
Quadrantal (?) error correction chart for Bellini-Tosi D/F loops! Damn that hurt (Ouch)

PS the big thingy bits on magnetic compasses are Lord kelvin's Balls! (*))


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## lakercapt (Jul 19, 2005)

When up doing my Masters certificate one of the courses was magnetism.
Had an immitation ship that was fitted with a compass. 
Differant pieces of steel there placed on it and the idea was that you had to swing (turn it in a 360 circle) this and adjust the compass.
I am sure it had a name but a senior moment has kicked in and I am at a loss to what the proper name was (was it a deviascope?)(where did I put my car keys???)
As to adjusting the D.F. if you had records of taking bearings and included this with visual or correct postitions to show the errors in differant quardrants it usually was sufficient for in radio inspector.
New ships of course would have to do it for their orginal.
By the way do modern vessels have D.F.??


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## John Rogers (May 11, 2004)

Never swung a compass on a ship, how we done it on aircraft was for one person to sit in the cockpit while the aircraft was parked on the compass rose(Points of the compass painted on the ground) then another person would stand in front of the plane holding a master compass with the readings opposite to the compass in the aircraft,then we would move the aircraft around all of the points and adjust accordingly. The master compass was always painted red for obvious reasons.
John


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## K urgess (Aug 14, 2006)

Lakercapt

Probably no D/Fs left except for sale on eBay. We hardly used them in the '70s unless the radar she was broke. Which is why we took the opportunity to do the D/F chart while the compass was being swung. I think I only ever used it in anger once and that was approaching Kiwi from Panama having not had a single sight of the sky for about a week.

John

Just up the road in York there was still an aircraft swinging circle until they built a shopping precinct on it. Always fascinated me as to how it was used. It was at YARD (York Aircraft Repair Depot) which was Handley Page's spot for repairing all the damaged bombers (Halifaxes) that couldn't be repaired by the squadrons. Also the place they took torches to them in 1945 when nobody wanted them any more. A bit like the Alang of Yorkshire.
Bits of aeroplane all over the place still in the '80s and '90s.

Cheers


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## Trevorw (Jun 5, 2006)

Marconi Sahib said:


> Lakercapt
> 
> Probably no D/Fs left except for sale on eBay. We hardly used them in the '70s unless the radar she was broke. Which is why we took the opportunity to do the D/F chart while the compass was being swung. I think I only ever used it in anger once and that was approaching Kiwi from Panama having not had a single sight of the sky for about a week.
> 
> ...


We always used D/F to find Jeddah. The land was too low lying to get a decent radar image, so we used to tune into the radio beacon, go hard aport when it was at 90 degrees and then straight down the zero until we sighted land or got a decent radar fix!


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## slick (Mar 31, 2006)

*Compass Work and DF's*

All,
Yes, it was Beales Deviascope (somehow I don't think it would be named that today), some Examiners (Burtons Building, Hull) made a meal of its use, anything up to one and a half hours followed by an hour plus of Orals.
In Palm Line (MV Badagry Palm) in the mid 60's, I remember coming up the Channel to Rotterdam on DF alone, I seem to remember the Stations/Beacons were grouped together in sixes which made it easier, above all it was a confidence building execise for later use.
Yours aye,
Slick


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## J Boyde (Apr 7, 2005)

I know of a ship that put a magnetic torch alongside the compass. Found the rocks very quickly. These torches were banned through out the company, quickly.
Jim B


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## Derek Roger (Feb 19, 2005)

New vessels today in Canada at least still require a magnetic compass which requires a compass adjuster to come on board during sea trials and " swing the card " and adjust the compensation balls ( small steel things to make correctionsin each quadrant a s required ) This is despite having Radar GPS Gyros etc. The Philosophy eing if all fails one still can rely on the Mag Compass if properly adjusted .
I found it novel in that we would adjust the compass of say a ferry on trials and all was well . The first load of trucks carring different cargos from containers containing who knows what ? to truck loads of scrap etc would totaly change the magnetic profile of the vessel and of course the accuracy of the compass .


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## Pat McCardle (Jun 12, 2005)

I told you Jeff, we can adjust compass' off landmarks & not just leading lights!!


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## Tony Crompton (Jul 26, 2005)

The first load of trucks carring different cargos from containers containing who knows what ? to truck loads of scrap etc would totaly change the magnetic profile of the vessel and of course the accuracy of the compass .[/QUOTE said:


> If I remember correctly from years ago doing Magnetism for Masters Ticket,
> the compass was adjusted to compensate for magnetism that was induced
> in a ship when she was building and lying on the same heading for possibly many months. Cargo, even scrap, had little or no effect on the ships magnetic
> "Character". Anyone else agree?
> ...


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## Tony Crompton (Jul 26, 2005)

Totally off subject, but why was my last message so "Disjointed"?

When previewing the post it was all in nice paragrahs and lines yet when posted it looks as though I did not know about such things. Help please, what am I doing wrong?
--------------------------------------
Tony C


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## Pat McCardle (Jun 12, 2005)

Of course cargoes will have an effect on the compass due to the cargoes magetic properties. The use of ships cranes & derricks also have a magnetic effect as do the use of radio's, while some, usually wives, are having a bit bronzy time on the Monkey Island. Hence the need for regular compass corrections per watch.


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## Tony Crompton (Jul 26, 2005)

Possibly my wording or meaning was unclear. A ship gets a magnetic character, profile or whatever you call it from lying constantly at the same angle in the earth's magnetic field, usually on the building slips, a prolonged lay up or spell in drydock, These conditions induce a permanent magnetism in a ship. This is what is compensated for when compass adjusting.
Small deviations caused by cargo, derricks, etc are found by taking a compass error and applying it. In theory this should be done every time a course is changed. Certainly the compasses are not adjusted for every cargo or if the derricks are up or down etc.
Sorry if I was unclear.
------------------------------
Tony C


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## Pat McCardle (Jun 12, 2005)

I thought that was what you were meaning Tony but thought I'd add what I did just incase. No change of course so all OK upstairs!!(Thumb)


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