What's this plastic plotting tool?

[MadamBreakneck]

On a recent (first) visit to the Channel Islands, hubby & I visited an occupation memorial museum in an old gun bunker. Amongst a display of ex-Lufwaffe memorabilia was a display of nav plotting tools, most of which I could recognise from my old PPL training (plus a bit of imagination), but this one has me stumped. Apologies for quality, I've over-enhanced it from a dull photo photo.




Thanks
MB

[dook]

I've copied it to an ex-colleague who was head of nav. training RAF, the CO of AIDU (charts etc.) and B Sqn at ETPS.

He knows a little about navigation and plotting. One of the few left who taught astro navigation too.

If he can identify it I shall get back to you.

[Timelord]

I don’t recognise it from my time at a plotting table. Given it’s location could it be something to do with artillery?

[ex82watcher]

This question re-activated a memory in my failing mind. Back in 1974,while in the VIth form,I took an ' O level 'in Air Navigation,which was taught by our art teacher,Terry Jones,who was CO of the local ATC squadron,and had trained as a Pilot with the RAF in Canada,and then flew F86 Sabres.However,after a career in ATC,and knowing a lot of people involved in flying and aviation,I never met another person who admitted to having an 'O level' in this subject.Are there any others out there in PPruneland with this qualification ?

[PDR1]

Originally Posted by ex82watcher

Are there any others out there in PPruneland with this qualification ?

Yes - and by the same route, probably around 1976. One of the civilian instructors at my ATC squadron (1075, Camberley) was an ATPL who offered to tutor any flying scholarship cadets for it. I think at that time the O-level gave me a waiver in some of the PPL ground subjects (nav & met IIRC) and the idea was to get these out of the way before going to Biggen to do the scholarship so that we could make better use of the (RAF-funded) classroom time.

I remember it as being pretty easy - the met stuff was mainly applying what I'd already done in physics and the nav stuff was three-dimensional geometry that I'd already done in additional maths. Three months of an hour every wednesday night and swatting the textbook for the nomenclature the night before the exam got me an A without much actual work.And as I remember it did give me more time to focus on stuff like air law and RT during the actual PPL course.

PDR

[FantomZorbin]

MB It looks very similar to a Trajectory Table, I was on a course (FORTRAN) where a member was programming such a thing. Not being a Gunner it was all a bit 'over my head'.

[dook]

My colleague thinks it is similar to a device used to calculate the forward throw of a bomb, but since it was found in an old gun bunker it's probably an early form of analogue shell ballistics/ trajectory calculator.

Seems logical.

[MadamBreakneck]

Originally Posted by dook

My colleague thinks it is similar to a device used to calculate the forward throw of a bomb, but since it was found in an old gun bunker it's probably an early form of analogue shell ballistics/ trajectory calculator.

Seems logical.

That's what I wondered, but I can't for the life of me work out what the scales mean (doesn't help that one scale is illegible) and how it'd be used.

Originally Posted by FantomZorbin

MB It looks very similar to a Trajectory Table, I was on a course (FORTRAN) where a member was programming such a thing. Not being a Gunner it was all a bit 'over my head'.

Ditto... but don't get me on a nostalgia-fest about FORTRAN

MB

[dook]

Would you like to post the original photograph please, before you tried to enhance it.

I'll take it into Photoshop and try to reveal more detail.

[golfbananajam]

looks very similar to this

https://www.google.com/search?rlz=1C...b6GX3hY6BGKqM:

or many other similar examples (all paper based) I can find on Google

Would it be the same calculations for air-launched ordnance?

[MadamBreakneck]

Originally Posted by dook

Would you like to post the original photograph please, before you tried to enhance it.

I'll take it into Photoshop and try to reveal more detail.

Here you are; you can see it at the left.



have fun
MB

[DaveReidUK]

Looks like a flight time calculator to me.

[J1N]

"Are there any others out there in PPruneland with this qualification ?"

Yes - circa 1975 and again through my ATC squadron. Largely self-taught although we had one session with an ex-RAF Liberator navigator.

[dook]

Photoshop reveals nothing new.

[MadamBreakneck]

Originally Posted by golfbananajam

looks very similar to this

https://www.google.com/search?rlz=1C1GCEA_enGB807GB807&q=artillery+trajectory+chart &tbm=isch&source=univ&sa=X&ved=2ahUKEwjnvvSE3YviAhWRo3EKHf4E Do4QsAR6BAgGEAE&biw=1920&bih=1095#imgrc=nb6GX3hY6BGKqM:

or many other similar examples (all paper based) I can find on Google

Would it be the same calculations for air-launched ordnance?

That link shows similar curves so I'd guess that's what it is, and no wonder I didn't cover it in my PPL studies ;-)
It would be of passing interest to know what the scales meant and how it was used, if anybody knows. Otherwise I'll take it that it's some sort of ballistics calculator that's got mixed up in a display of air navigation bits.

Dook, many thanks for trying photoshop.

thanks all
MB

[dook]

I am almost certain it was mixed up with navigation pieces because the people who set it didn't have a clue.

I conclude that Pruners have probably solved it.