View Full Version : Compass Adjustment
11th May 2009, 18:15
It would be interesting to hear any tales re subject matter. Let's have no talk of 'Splitting B' etc. Just interesting tales, tips of what can go right or wrong.
12th May 2009, 07:29
Walking into to the corrected Deviascope and scattering the correctors after an hour or so of labour, and then being interrogated by the Examiner as to "What the hell is going on on there?!!"
12th May 2009, 08:37
Don't remind me of the horror stories
12th May 2009, 08:48
1973 Training Ship Worcester . Apprentice malarky , dead of night, Very large, very old Binnacle shifted bodily from its position atop the deck house to a position in the Staff room three decks down . That was it adjusted alright!
Problem was the next morning , massive hangover . Told to "put it back" Mummm
pretty heavy those things !!! How it ever got done ,even when alcohol powered I shall never know.
12th May 2009, 08:49
On a DF Calibration with the local compass adjuster, we had for the first time an electronic two way talkback. We explained to the capt that we wanted a swing about 3 miles off the Humber LV to calibrate. The compass adjuster was present to take bearings. We were told everything was ready, we started taking radio bearings, but the visual bearings were way out. Forgetting the new talk back I muttered "does this ********** know how to take visual bearings."
The reply quick as a flash came back "This ********* knows how to take visuals does ********** know how to take DF bearings.
After a discussion we found that we were making a turn around the Bull LV
whilst taking DF bearings of the Humber LV.
This incident was never forgot, and became part of the folklore!
12th May 2009, 08:58
Last trip an air bubble appeared in the bowl of our standard magnetic compass. An email was immediately dispatched to the UK manufacturer, who replied that the bowl should be topped up with a 50/50 mixture of pure alcohol and distilled water. As pure alcohol is almost impossible to obtain, the manufacturer did say we could use a colourless spirit such as vodka instead. I'm afraid the Chief was not pleased when I "liberated" a small measure from his gin bottle.
In this day and age of dry ships, what are we supposed to fill the compass bowl with?
12th May 2009, 09:48
In for Masters orals and anxiously waiting my turn. The previous candidate emerged not looking too happy, whilst trying to adjust the compass one of the casters had come adrift from underneath the binnacle and the whole thing had dropped a couple of inches on one side. The examiner obviously did not have a sense of humour and threw him out, fail. Fortunately he regained his sense of humour and passed me a couple of hours later.
12th May 2009, 10:36
Lying off the Bluff awaiting a berth, the OM decided to adjust the standard compass. I had been up relieving the third mate for his breakfast and taking sights, on his return I jokingly told him he was going to have a busy watch as "Old Paddy" was going to start after he had taken his breakfast. A couple of hours later, and wiser, I left the bridge. The OM had arrived back on the bridge before I scampered. I stood in the chartroom working out the compass deviation each time the OM hollered down the sun's bearing. The chartroom clock was set to 12 hours - the LHA. As we were going on time charter on the Aussie coast the compass was being adjusted for the southern hemisphere. I lost count of the number of times I heard him shout down "we'll give her one more swing". I was fortunate in sailing with him, he was a wise old shipmaster.
12th May 2009, 11:22
Has anybody noticed just how badly built many modern magnetic compasses are?
On my last ship which was 5 years old they had got through 3 new bowls and were still having problems with leaks.
At home I have an old Sestral lifeboat compass which (while pretty small) is still going strong after 60 years!
As for trying to ensure that the younger generation of watch-keepers take regular errors ! This is unfortunately an endless Matra from us oldies!!!!
All these things seem to come under the "Nostalgia " label nowadays!!!!
Many of us I am sure have experienced the "Broken gyro" syndrome , and have in the past been perfectly happy to do long ocean passages with this , the prince among navigational gear.
12th May 2009, 11:35
Was Henry with you ?
12th May 2009, 12:03
No Henry was not with us, it was Ken, John and Myself. After this incident everyone doing a calibration was told Remember the HumberLV and forget the Bull !!!
Whilst doing my deviascope in Dock Street I realised that Lord Kelvins B*lls were badly magnetised. Removed same and started to bang them together and roll them around the deck. The next thing I knew was Capt. Piggot, Chief Examiner Masters & Mmates slammed the door open and words to the effect of "Stop this Bl**dy racket, there's a Mates written exam going on next door". Oops!!!. Passed though.....................pete (==D) (==D)
12th May 2009, 20:45
Brocklebank ship I was on - shortly after ww2 - justr clearing Sokotra island in SW monsoon ( G of Aden). Ship started rolling heavily in beam sea.
Indian seaman came rushing on the bridge - "Sahib - after compass fall down"
The Gyppos had stolen the brass pins holding the emnergency compass on the poop down so whenshe rolled it fell over !!
17th May 2009, 13:29
Once, in a foreign port, the Master of an old Greek tramp freighter came aboard the ship I was on to inquire if we had any spare Varsol, which was the name of the alcohol-based liquid with which ship's compasses were filled. He claimed that all the liquid in his compass had either leaked out or been drunk by one of the crew, he was a bit vague on which. In any case we didn't have any, but suggested he might make do with whisky if he had any.
17th May 2009, 15:40
I need some expert advice here. Just took off the covers of the Magnetic compass to find a humongous bubble. I have Ethanol in my medical locker. Will it be OK if I dilute this with water and fill up the bowl, or should I order anything else?
17th May 2009, 16:23
I posted this previously in another thread a while ago.
If it's a matter of topping up then distilled water will do.
The liquid should not cause turbulence.
"This is achieved by using a liquid of S. G. (Specific Gravity) 0.93 consisting of
absolute ethyl alcohol and distilled water. The liquid has the further property of
being easily de-aereated, does not discolour the card and other fitments, has a
small coefficient of expansion, and will remain fluid at temperatures of minus 30°C.,
while it satisfies the obvious necessity of being transparent."
"The Ship's Compass" by Grant & Klinkert. Routledge & Kegan Paul, 1960
ISBN 0 7100 6522 1
17th May 2009, 16:48
Be careful ! While being no expert I have come across a few problems topping up compasses (All the modern ones seem to get bubbles at the slightest opportunity) It all depends on the compass! Some "compass fluid" is not compatible with what's already been used(from new). This only becomes evident after you have done the job !!!! Someone will hopefully tell me just why this is so ! I suspect that the underlying problem is that not all compass fluids are miscible with water. You know you have a problem when the two fluids fail to mix.
17th May 2009, 17:03
Some modern ones are filled with white kerosene or oil but you should be able to tell by the smell and feel when you remove the filler cap.
I've heard baby oil does quite well.
Using alcohol in an oil filled compass could be embarrassing as the numerals float off the card. (EEK)
18th May 2009, 22:48
Thanks for that. I pulled out some of the fluid using a syringe and it is alcohol. So will top it up today. Found the washer of the filling screw worn out. Probably the reason for the air bubble perhaps.
Once again thanks for the help.
vBulletin® v3.6.8, Copyright ©2000-2014, Jelsoft Enterprises Ltd.