Author Topic: Compass Reversed Polarity  (Read 459 times)

BuzyG

  • Veteran Member
  • *****
  • Posts: 2147
Compass Reversed Polarity
« on: 21:13:06, 02/01/21 »
An interesting thing happened today. I had been navigating on my Compass since the weather closed in, an hour or so. Then I sat down at Yes tor set the next bearing. Got up to start walking and instantly noted it was pointing the opposite way. I rechecked and realized in must have swapped polarity.  I have never had that happen before.  Happily I was at a spot I know well when it happened, so there was only a momentary sense of confusion, before I worked out what was going on.

It's in the bin now after many years of faithful service.  It had a tiny but growing bubble so it's days were numbered any way.  Happily I have a spare now in my sack for tomorrow. :)

I'd put my phone, with a magnetic clasp on the jacket, in my chest pocket and had the compass around my neck.  I'll try not to do that again.

Has that ever happened to any one else on here?

sussamb

  • Veteran Member
  • *****
  • Posts: 7502
Re: Compass Reversed Polarity
« Reply #1 on: 22:44:58, 02/01/21 »
No but I was handed one on my NNAS Silver course as a test to see how soon I realised, thankfully I did  O0
Where there's a will ...

windyrigg

  • Full Member
  • ***
  • Posts: 175
Re: Compass Reversed Polarity
« Reply #2 on: 09:46:03, 03/01/21 »
Never had that. Once at the rear of Blencathra, maybe Bannerdale Crags way, I walked past a large rock in fog guided by my Silva compass. As I walked past the rock the needle slowly described a complete 360 degree turn. I retraced a few steps and the needle again deflected. I presume that rock had a big lump of iron in it  :P   

archaeoroutes

  • Veteran Member
  • *****
  • Posts: 1510
Re: Compass Reversed Polarity
« Reply #3 on: 18:27:24, 03/01/21 »
It happens a surprising amount. I was scoffed at by another member of staff when I opened up a box of compasses (an official Silva storage one) and laid them all out on a wooden table to check them before handing out. He was concerned I was wasting a lot of time. Out of about 30, 3 had reversed. Glad I didn't send children out onto Dartmoor in the mist with them!
About a month ago we had an orienteering event and one very good competitor kept heading off the wrong way, then realising and turning round. I watched his GPS track with interest. After about five times, he stopped moving for a minute or two then got everything right after that. Talking afterwards, it turned out he had forgotten his arm holster and was holding his phone (used to transmit the live GPS location) in the same hand as his thumb compass. The pause had been him trying to work out why he kept going wrong and eventually twigging it. At least that wasn't a permanent reversal.
Walking routes visiting ancient sites in Britain's uplands: http://www.archaeoroutes.co.uk

archaeoroutes

  • Veteran Member
  • *****
  • Posts: 1510
Re: Compass Reversed Polarity
« Reply #4 on: 18:29:43, 03/01/21 »
There's a spot I use sometimes on nav courses as an example of weird stuff happening. I think there must be a large lump of iron buried, possibly a vehicle, but it puts needles off by a good few degrees - enough to be an issue.
Walking routes visiting ancient sites in Britain's uplands: http://www.archaeoroutes.co.uk

BuzyG

  • Veteran Member
  • *****
  • Posts: 2147
Re: Compass Reversed Polarity
« Reply #5 on: 00:51:39, 04/01/21 »
In was chatting with our Ramblers group during today's walk and a number had experience it happening whilst out on the hill. So as mentioned it appears not uncommon.

richardh1905

  • Veteran Member
  • *****
  • Posts: 5978
Re: Compass Reversed Polarity
« Reply #6 on: 07:51:02, 04/01/21 »
Has that ever happened to any one else on here?


Yes. Happened to me on the top of a cloud covered Ben Hope a couple of years ago; the needle was all over the place - magnetic phone case clasp the suspect. Caused some considerable confusion, and some anxiety too - I didn't know the hill, and there were some mighty big cliffs to the north and west.
WildAboutWalking - Join me on my walks through the wilder parts of Britain

richardh1905

  • Veteran Member
  • *****
  • Posts: 5978
Re: Compass Reversed Polarity
« Reply #7 on: 07:53:09, 04/01/21 »
It happens a surprising amount. I was scoffed at by another member of staff when I opened up a box of compasses (an official Silva storage one) and laid them all out on a wooden table to check them before handing out. He was concerned I was wasting a lot of time. Out of about 30, 3 had reversed. Glad I didn't send children out onto Dartmoor in the mist with them!


I once had to take a Mountain Warehouse compass back as it was reversed.
WildAboutWalking - Join me on my walks through the wilder parts of Britain