Andy's Sun Compass

[Richard]

I was sitting on the bog this evening reading through one of my old Bushcraft magazines and found a cut out and use 'Moon Compass'.  Similar effort but made out of two pieces of sliding card with different phases of the moon around it.

We were of course admiring, and taking the p**s out of the sun compass in wet .n. windy Wales but the additional thought occurred about your navigating at night.  In the desert that could be preferable sometimes - being a bit cooler.  Thinking of you Andy.

Richard

[mini-thumper]

I was sitting on the bog this evening reading through one of my old Bushcraft magazines and found a cut out and use 'Moon Compass'. 

I would have thought filling in your log book would have been more appropriate. Unless Bushcraft magazine is some sort of feminine topiary inspired jazz mag!

I'll get my PVC romper suit...........

Boyd

[Andy M]

Interesting. The stuff I've read for night navigation always takes you back to basic (or not so basic in my case) celestial stuff. The pole star is obvious, but you can in addition use other stars or even Venus if you've got the tables and a means of measuring the altitude of an object. You need to be stationary to do this (or at least in something that stays at the same height and roughly level), so I'm guessing the Lunar compass allows you to hold a bearing? The problem at night in the desert is that you can't see into the shadows. At walking pace it makes sense to travel at night, but at 30 mph the risk of going into some wadi (a la Simon Pavey, who was going rather faster but couldn't find the bike when he came round hours later due to the distance he travelled after he came off!) would seem to outweigh the benefits. Dawn and dusk are good times for physical work. Riding never seemed that physical although I am yet to try three wheels 

The sun compass as I've been playing with it works two ways. Stationary and 10m away from the bike you align it via magnetic compass and it tells you the local time. Compare to a watch or radio time signal and the difference is Longitude via the Harrison method. The risk here is if you are close to the Grenwich Meridian you don't know if you are east of west, an error that can take you outside visual search distance. Measure the length of the shadow and calculate the angle of the sun via the known height of the gnomon and you have latitude (less accurate but less bulky than a theodolite). You can then set your local watch, put the compass back on a vehicle and travel on a bearing by keeping the shadow on the right time. All done by clockwork and the odd valve if you want to be flash 

The skill is in the estimating and confidence. With any analogue system the operator can choose to put the needle a fraction under or over the line. Knowing that at 11.10 the shadow should be just off the 11.00 line is the fraction of a degree that brings the target up right on the nose and makes you look like you know what you are doing. If you aren't that good, aiming off in a known direction (an idea from Sir Francis Chichester) means you half the search area when you think you have arrived. You need to practice and decide which system you go for. To me the big thing with GPS is that there is no skill required, they can train monkeys to follow the pointer until it says you are 5m from the target.

I think more research is required. If the lunar compass is what I think it is it shouldn't take a genius (not currently available) to make the sun compass work at night. Who was it who suggested using a torch 

Andy

[squirrelciv]

Andy mate, you're a great guy an' all, but I hope to God I never get trapped in a lift with you

The secret to successful navigation if you ask me, is the ability to comunicate with whoevever your asking directions from. Travelling within the UK, on the whole, I never get too lost for too long

Why travel in a desert? there is nothing to see and no one to talk too

[Steve Lake]

Not a lot of people know this........All 3 'V' bombers ( Victor, valiant, Vulcan) had equipment on board  for astral navigation......a little periscope above the navigators seat.....
And the crews had to practice navigating at night using it.
This was all installed and used because the EMP generated by a nuclear explosion could (would) knock out all the electronics within a considerable range of the explosion, including the aircraft.
A friend who was a navigator on Victors said he could'nt be arsed to use it, it was too complicated....so, during exercises where they had to practice astral navigation he'd bring them over the pole (north) (which is where a lot of exercises were held).....ask the skipper to look for iceland...then left a bit for the northern isles......pick up the A1 and follow it back to Wittering, job done
Our life in their hands 

[robG]

We won wars like this. Long live common sense, which seems to be getting eroded as time goes on.
Having done a few night yomps around Dartmoor and the Beacons and other bumpy places,once the stars are lost{cloud etc} , you have to resort to all sorts .Counting paces,bits of string and knots.All sorts . When your intended target is your grub for the next 24hrs ,you suddenly have a renewed focus on the task in hand .

Any thoughts ,Jules ?

[Richard]

If Andy is planning some desert travel in North Africa then I can see the point of a sun compass, though I myself prefer the magnetic variety.  The Moon Compass simply adds a few hours and strikes me as a sort of portable Stonehenge.  No doubt somebody will be along in a moment explaining how they would carry a minituarised stone version of the same thing in a sidecar.

I am not a fan of GPS as it rots the ability to read maps - and I see this regularly amongst colleagues at work.  Most important of all is having two indpendent systems to check off against each other and have a system you can operate and understand.  Then I would use a GPS.

I wonder how good the Bonnie and sidecar would be 'off piste' anyway.

[robG]

I am not a fan of GPS as it rots the ability to read maps - and I see this regularly amongst colleagues at work.  

I'm with you on that one ,Richard . Had to go to London recently , to pick up a customer . Had a massive falling out with the job sat-nav , which simply wouldn't work in central London .

Resorted to dead reckoning and sorted it out .Went to Llanthony on a map on unclassified roads and only missed the one turning but was able to retrace using the mileometer and arrived as per..... .

How about a treasure hunt for the annual rally ,instead of a ride out ?

Rob .

[Richard]

They give you a Sat Nav !!  I even had to buy my own maps.

Country cousins I suppose.

Richard

[guest40]

Navigating at night is easy.. 1st step, find a lampost
2nd step look up just under the lamp
3rd step read sign and note where its pointing... follow your desired route in the dirction of the signs orientation.
Bingo.... home and hosed.

[Andy M]

Magnetic compasses only work off a vehicle unless you start swinging them , adding magnets and so on. They are fine in Europe as you stop, work out you need to be to the right of that hill on the horizon. You can then head off and stop again a few hours later. If the place is like a billiards table you need to check a magnetic compass every few miles which doesn't sound fun. The sun compass seems to be simply convienient for deserts where you have sun and lots of shifting geography.

GPS is the best bit of navigation kit ever, I'm only playing with the sun compass to see what it'll do. It's the map software thats behind the times. The trick with GPS is to turn the sound off (the tart in the box screeching about "turn right onto the Great North Road" when you are at the junction of the A-1 and North Circular is neither use nor ornamaent) and look at the bit of map it's showing you.

The performance of the oufit on sand it to be seen. The last piste I was on was no worse than any gravel road.

Andy

[guest40]

In the antipodes, we have the Southern Cross to guide us at night. Unless its totaly overcast a true heading of south can be calculated easily. If you do purchase a compass spend the little bit extra and get a 1 degree graduation, as minor errors with 5 degree can really mess with your navigation over longer distances. Personally I use a hand held GPS. It can be setup off Google with waypoints installed prior to heading off.
Cheap compasses can be used to trade with the natives for food and sometimes even water.

[Steve Lake]

hang about Kurt.......I thought YOU were the native?

[guest40]

No mate, I'm an adopted furrinner in this country.
this lets me poke fun here,  as well as dish it out to other furrinners.

By the way Andy, that's amazing that you can find your way being piste, man, I keep going around and around in ever diminishing circles until I dissap.......

PS if you see the same nite sky as us here, you will see a big smiley face up there tonite in the western sky. have a look and have a giggle!

[xbruby]

I was sitting on the bog this evening reading through one of my old Bushcraft magazines and found a cut out and use 'Moon Compass'. 

I would have thought filling in your log book would have been more appropriate. Unless Bushcraft magazine is some sort of feminine topiary inspired jazz mag! Sounds bloddy good to me, if it exists where do I get my copy?

I'll get my PVC romper suit...........

Boyd