My Compass Thread

[Let's Play]

Oh - I've found a degree-based prismatic. Currently negotiating with the seller, so I presume my collection will grow shortly...

Enjoy. I just want to be able to tell where is North in about terms

[iandvl]

Get a Patrol...

[Spliffcat]

The dying art of celestial navigation. Using a sextant to "shoot the sun." Another form of navigation a very old salty sea dog taught me 30+ years ago. Wish I had never lost my brass one overboard near Nosy Be Island.
One can get plastic ones. The original brass ones are hens teeth.
Oh and one needs a good chronometer.
Its all gps now.
Those compas' bring back some memories.

[iandvl]

There was another compass thread recently. I did not want to splurge money on compasses at the time and I sort of regret it.

However, I came across this compass recently and picked it up today for a few hundred ZAR.

This looks very modern. But it is actually a cheaper compass than the Francis Baker prismatic compass. They were manufactured between 1939 and 1944. From the serial number (there is more interistengness regarding that in a minute) this specific model would probably have been produced earlier in that time frame. The case is Bakelite, and the compass rose itself is not wet-filled. Meaning it is a little less accurate than the FB MK73 I have...

What is interesting in this case.

1: These were manufactured in large numbers for the war period.
2: This model was chosen as they were considerably cheaper than the F Baker compasses.
3: The manufacturer is listed as TG Co Ltd - basically, "The Gramophone Company" - who owned "His Master's Voice" etc. But were used as a war time front in WWII to prevent people from necessarily knowing who actually produced what.
4: The "B" serial number would indicate that this was actually produced by Francis Baker in any case.
5: I picked it up for a song - it is worth considerably more than that.





So... My collection is growing nicely. From left to right:

1: Lensmatic compass (My old go to)
2: F Baker M-73 (My new goto)
3: A compass my kids gave me
4: A sine compass
5: TGCo (FBaker) "Marching compass Mark 1"



I will hopefully be the owner of a FBaker MIII compass in the next couple of days. Waiting to see how that pans out.

[iandvl]

Right. The deal is done. My new compass is on the way. It is a Barker MkIII compass - but with a bit of an interesting story behind it...

Most war-time compasses similar to the Francis Barker compass types were built under license to Barker by other manufacturers in various commonwealth countries. Examples of these would be Kodak, etc. Most of these would include the actual manufacturer such as TG Co (the gramophone corporation - actually Barker as previously discussed on this thread) / CKC (Canadian Kodak Corporation) etc. Serial numbers would also often indicate the manufacturer (starting with "B", actual Barker etc).

This specific compass is called a Mk3A compass because it was built during the war under license to J.W. Handley in Australia. Earlier war-time models were designated "MkIII (Aust)". Later war-time models were designated "Mk3A". This is a later war-time model Mk3A.

Another interesting fact about the Mk3A compass was that they were only built by J.W. Handley around the war-time years and again from 1966. In 1966, Barker's patents expired and then Handley started manufacturing the Mk3A compasses for the Oz army without licensing obligations. These, although still designated as Mk3A were stamped Mk3 AUST/2 on the base.

The specific model I will receive in the next day or two (waiting for the courier) is a later-time WWII compass. I will post photos when it arrives.

[iandvl]

I collected my new compass from PostNet on Saturday...


But there are a few things...


1: It is in very bad shape.
2: Some prior moron decided to attempt get rid of the date stamp on the base and sort of destroyed a chunk of the serial number as well. More on that later.
3: It's not WWII. I was under the impression that Handley only manufactured these under license in the war years. But perhaps they produced for a year or two after the war ? Resources online indicate that this is probably a 1950's model.
4: It is war issue as it has the Oz war stamp on. In other words, it was probably Korean war issue as Oz was also involved in that. It perhaps also explains how it found its way here, as we were involved there too...


Regarding the missing date. I presume that some previous owner wanted to flog it as a WWII MkIII (they are pretty much identical) which are much more sought after and ground the date off.


What is wrong with the compass.


1: The dampening fluid is empty. I presume there was a leak at some point because the fluid has also destroyed the white backing on top of the compass oil well. ie: It is difficult to read the markings on the dial.
2: Some idiot also tried varnishing the case at some point. Considering these are built from solid brass, this is considered a big no no...
3: The grub thing that tightens to keep the dial in place for marching is missing. I was in touch with Peter Connan and he may be able to machine one for me...
4: The guard rails over the top cover are a little bent...


Some photos of what it looked like on arrival...






So, I've decided to go for the restore route. The first thing was to strip down the compass case.


This relatively easy to accomplish - remove all the screws and take the thing apart. The rotating dial at the top of the compass simply clips off once the clamp on the side is removed... And two screws keep the oil reservoir / compass compartment in place inside the brass case. Once these are removed, the compass compartment can be removed.


The prismatic assembly is help in place with two screws covering a small plate on the front. Once these screws are removed, the plate can be removed by lifting the prismatic assembly to max height and sliding it out towards the top of the compass (the prismatic assembly has an angled side specifically for this) and after that everything just falls apart.


After stripping it down, I gave the case a good medium roast with my plumbing blowtorch for a minute or two to burn off the varnish.


Stripped down, it looks like this:




What you're looking at. Left hand side top to bottom.


1: Sight thingy / lid handle.
2: Graduated rotating dial.
3: Top cover.
4: Brass case.
5: Compass card / container / oil well.


Right hand side top to bottom.


1: Tupper holding a gazillion tiny screws.
2: Prism holder.
3: Prism.
4: Cover guard rails.
5: Clasp which locks the rotating dial.
6: The thumb attachment thingy...
Not present - not sure why it is not in the picture, but it is in a later one: The prism riser thingymabob. You can see it in later pictures..


Anyways, using a gazillion litres of brasso, elbow greese, a dremel tool with polishing attachment, I've successfully for the stuff cleaned up and reassembled partially.


What still needs to be done is.


1: Refill the dampening fluid.
2: Paint the inside of the top cover flat black (as per original spec).
3: Add a glow-in-the-dark stripe on the inside of the top cover on the sighting line (as per original spec).
4: Add a glow-in-the-dark blob on the compass oil well where it used to be.
5: Paint the silver looking bits of the compass oil well white. Final assembly.
6: Straighten the guard rail.
7: Have a grub screw thing machined.


Oh - I also need to remove one of the screws that broke during disassembly and find a new countersunk brass bolt for it.


Looking much better. Still a bit of work to do...





Regarding the dampening fluid... Originally, FB compasses were filled with whale oil (this is what the official literature I have on this for the MkIII compass says). This is difficult to obtain these days, and apparently purified kerosene can be used. However, before breaking something this dear, I've been given a contact of somebody whose work is fixing and servicing optical and surveying equipment for the artillery (I chatted with the old man) and I just need to give him a call to hear what he would recommend.

Bottom line: I was disappointed in my purchase, although I still paid a song for what this is actually worth. And I've enjoyed actually stripping one of these down. Will update post details when my restoration project is done.

[walkabout]

Sorry to hear Ianvdl. As I am looking for a basic compass myself to teach my daughter a bit I was excited for your part.

Hope the restorer can sort you out.

Kudos for having the guts to repair it this far!

[iandvl]

Sorry to hear Ianvdl. As I am looking for a basic compass myself to teach my daughter a bit I was excited for your part.

Hope the restorer can sort you out.

Kudos for having the guts to repair it this far!

Nah. I'm still happy. After going through this process, this will probably become my go-to compass. And the repair itself has been fascinating so far... Cannot wait to get it restored to former glory.

[Jonatan]

I have been curious about magnetic compasses over the years, probably because I built and installed sundials. The one issue that always concerned me was the "zone". I couldn't find a quality brand (before internet days) that was zoned for southern hemisphere - the card would not lay flat out here. This is all a distant memory now. But curious how a military issue compass dealt with zoning?


Edit to add: https://www.ritchienavigation.com/re...one-balancing/

[iandvl]

I have been curious about magnetic compasses over the years, probably because I built and installed sundials. The one issue that always concerned me was the "zone". I couldn't find a quality brand (before internet days) that was zoned for southern hemisphere - the card would not lay flat out here. This is all a distant memory now. But curious how a military issue compass dealt with zoning?


Edit to add: https://www.ritchienavigation.com/re...one-balancing/

My understanding is that this is a minor issue. You will only run into this effect pretty much at the poles.

Not an expert, but my compasses all run level.

[BushNomad]

I also have a Brass Stanley Transit Compass
but it needs the little spirit level to be carefully re-soldered to the base … properly aligned.
So Ian, would be grateful for contact details
of that guy who can fix such ?

Post #22 below refers :

https://www.4x4community.co.za/forum...-Compass/page2

[iandvl]

I also have a Brass Stanley Transit Compass
but it needs the little spirit level to be carefully re-soldered to the base … properly aligned.
So Ian, would be grateful for contact details
of that guy who can fix such ?

Post #22 below refers :

https://www.4x4community.co.za/forum...-Compass/page2

If you are referring to the sine compass (big one with two spirit levels amd the extended aperture), if it states 'Stanley' on the card inside, it is a fake.

That was a gift to me. It works and is probabably worth a few K

But... Stanley were never in the game with Brunford (Spelling) compasses.

Edit 1: just checked. I stand to be corrected. But need to do my research. Brinfords are not totally my cup of tea

Edit 2: I will forward details.

[iandvl]

Second from right in this photo ?

[iandvl]

I also have a Brass Stanley Transit Compass
but it needs the little spirit level to be carefully re-soldered to the base … properly aligned.
So Ian, would be grateful for contact details
of that guy who can fix such ?

Post #22 below refers :

https://www.4x4community.co.za/forum...-Compass/page2

I've done my research. Stanley produced a few models of Brunton-type (transit) compasses but were better known for their marching compasses modelled on the FBarkers.

Issue is: the market is flooded with fakes of Brunton-type compasses. If your compass is marked "Stanley London" inside the dial, it is in all likelihood a fake as some company purchased the name of the original Stanley compass maker when they went belly up.

The note from people in the know is: They cannot be used as measuring instruments but only for decoration purposes.

https://www.compassmuseum.com/diverstext/fakes.htm - refer section about Brunton transit compasses.

Also:

https://www.compassmuseum.com/divers...es.htm#STANLEY

[iandvl]

I have been curious about magnetic compasses over the years, probably because I built and installed sundials. The one issue that always concerned me was the "zone". I couldn't find a quality brand (before internet days) that was zoned for southern hemisphere - the card would not lay flat out here. This is all a distant memory now. But curious how a military issue compass dealt with zoning?


Edit to add: https://www.ritchienavigation.com/re...one-balancing/

Jonatan,

I did a bit of reading about this because I was sort of intrigued. This all deals with magnetic inclination - which presents three issues:

1: Compass cards may get stuck because the card is not centred and this may provide dodgy readings.
2: Compass cards may "lag" or "lead" when turning.
3: Depending on the direction of the tilt, this may also result in skewed readings.

All three issues are exacerbated the closer you are to either pole.

In aviation, this point 2 is apparently a massive issue when turning as depending on the hemisphere and direction of turn, the compass may "lead" or "lag"... But they (Aviation compasses) apparently have a centre of gravity muuuuch lower than the pivot which prevents magnetic forces turning the compass out level (Earth's magnetic force is actually super weak).

I am not sure if this (the lower CG thing) is also the case with mil-spec compasses. I know the Barker compasses do have a counterweight underneath the compass card (ie: below the pivot), so perhaps. The cards sit super level at all times though - unless you physically turn the compass skew. Put it down level, and the card is level...

I am not sure how this affects sundials (unless it goes specifically about accurate readings).

Dip has never been an issue for any compass I've owned, apart from the "cheapy" that my kids gave to me on my birthday (post 14 right) where the needle gets stuck occasionally - I keep it for the sentimental value only - I'd never stake my life on that. Similarly, the "fake" Stanley Sine compass that is listed here somewhere. It works, but not fantastically. I get's basic North and the "sine type glass bubble and thingies work". But I would also not stake my life on it. I'd also not use it to do anything apart from rudimentary "surveying" type stuff....

My lensmatic, and M73 later, have all been my go-to compasses, but I only use them for bearings and mapwork. I've never had issues about magnetic dip affecting any reading.

Wikipedia mentions that inclination can cause a problem in terms of readings when compasses use cheaper pivots. Military style compasses - such as the FB compasses - actually pivot on a jewel / crystal as used by other high precision measuring equipment. In the case of the Francis Barker compasses, this is apparently a saphire gemstone. I've never opened the "compass compartment" proper thing, so I have no idea.

Whilst one probably does not want to take a bearing reading when the compass is not level, the Mk73 compass will happily still turn northwards when it is super skew. Pretty sure once I've refilled the Mk3A's dampening fluid thingy, this will be the case with that compass too... Pointless point though, as who takes readings when the compass is not level... The benefit with the prismatic though, is that you can see when the compass card is not level as it magnifies the compass card markings etc.

Some compasses also feature little counter-balance sliders to counteract this thing. Not sure how they work. Definitely not present on any one of the compasses I have.

Anyways, long-winded answer... Perhaps it clarifies something...

Edit 1: Bold bit - let us not forget the WWII prison escapes and stuff like "The Great Escape" from Stalag Lufte III where various people got home with home made compasses consisting of magnetised needles and other arbitrary home-brewed mechanisms built out of minimal resources as befits POW's.
Edit 2: Italic bit - added some more stuff re levelling and bearings with prismatics.

[iandvl]

Right.... I had some time over the weekend to continue on the restoration of my Mk3A compass.


I've flat blacked the interior of the cover as per original spec and added luminiscent paint to the reticules on the inside cover and latch. I need to neaten up the edging of the luminiscent paint on the reticules, but I will do so when the painted has hardened approrpiately.




The cover guard has been straightened nicely, and everything nicely polished etc.




I've also added luminiscent paint inside the oil bowl and sealed it. This makes the compass card super easy to read in the dark. It's not the neatest job, but considering it will all be covered by the compass card when I reassembled the oil bowl bits, I am happy. Not the best photograph of the glow emited by the reticules and bowl, but I had the light off for effect.





There was one major setback. I was originally not considering painting the entire oil bowl with luminiscent paint - but rather to stick with the glow in the dark stuff underneat the prism, on the north bit of the compass card and on the spce underneath the reticule. But.... I unfortunately asked the teenager (the LF's daughter) to mask the compass card with masking tape for me as her hands are smaller, and doing a lot of graphic work, she is very good with this sort of thing. In her eagerness, she did not realise how brittle the card was, and managed to crack it...


Luckily it was a fairly clean break and I've managed to repair it with clear card and glue. The cracks are visibile from the top, which is sad, but considering the fact that I probably will not get parts for this, it is the best I can do. I am somewhat disappointed.




I've also roughened up the bit of the brass on top of the oil well where the luminiscant paint must go under the reticule. But I will only be able to paint that once I've refilled with oil etc.


I've also got to get gasket paper to make a new gasket for where the crystal get's screwed down inside the oil well, as the old gasket broke when I stripped it down. This is not surprising considering the compass' age, and will be relatively easy and cheap to get sorted.


All in all, I am happy. Coming along nicely, and I guess I may finish this project next weekend. And I'm happy with how it has turned out so far.

[iandvl]

Oh - before I fill the compass with paraffin, I do need to test the reactivity of the plastic card I used to repair the compass card. I'll chuck a piece of the plastic into a bit of it and see how it holds up over the next few days. Otherwise I will need to seal the compass card too. That might be tricky. We'll see.

[iandvl]

As I mentioned earlier - the broken compass card is a massive setback for me. I've got it fixed and the "fix" does not seem to react with the dampening fluid - which is good news. But it irks met...

And then, trolling one of my regular sites, I found a Mk3 compass in very poor shape.... It's in absolutely shoddy state - it's missing the entire prism assembly, the guard on the front cover and the crystal on the front cover. All of the crystals are very badly scratched...

But... It has a complete compass card... It also has the grub screw on the side, which my MK3A is missing...

It has cost me virtually nothing to acquire - which is not surprising considering the shape the unit is in - and it is currently on it's way to me via PostNet...

So I'll be delaying my refilling of the Mk3A compass as I will wait for the spare compass card. But this should all be done shortly.

The sad part is that I've got no idea what I'll be doing with my weekends once I'm finished with this...

[Peter Connan]

Nice.

If this one still has the plate that is bolted to the lid and covers the prism, can I buy that and it's screws from you?

[iandvl]

Nice.

If this one still has the plate that is bolted to the lid and covers the prism, can I buy that and it's screws from you?

It does. And no, you may not buy them - you may have them.