Another "How do they do it" Question.

[MikeH]

Hi,

When we modellers rig our biplanes we test to see that the tension is just right on out flying and landing wires. But, how was this done by the riggers on the actual planes? I know the tension was adjusted by using the turnbuckles, but how did they know when the right tension was obtained?

Hope one of you more experienced enthusiasts can explain it for me.

Cheers,
Mike

[Davos522]

Hi Mike, as bizarre as it sounds, in the old days part of the skillset of an aviation mechanic was the ability to take an aircraft out of a bunch of crates and literally assemble it like a 1:1 scale model... as I understand it, the manufacturer or air arm provided a set of diagrams giving the measurements of the airframe when it was rigged properly, and you bolted everything together and tightened/loosened the wires until the dimensions matched the given parameters, using plumblines, straightedges, and something called a "clock", or gonieometer, which read angles:






 
So ideally, once it was set up properly, all you had to do was keep an eye on the specs and adjust things when they got out of alignment or shot up or otherwise tweaked.

I think they do it somewhat differently nowadays, but Brad and Zac and Mike N, being real 1:1 tech guys, can probably speak to that better than I can :-)

All best,

Dutch

[macsporran]

In the RFC and RNAS at least, each aircraft came with an 'idiot's guide' in the form of detailed technical notes that showed the riggers exactly which specific lengths of RAF streamline wire or control cable was to be used where and what tensions to be applied. Once these were applied the truing up was within fairly small tolerances.
I've posted the notes for the Sopwith 2F1 Camel elsewhere, but I'll post them here again as an illustration.
Sandy

[macsporran]

Ship's Camel rigging notes part II
S

[macsporran]

Ship's Camel Rigging Notes Part III

These are from an RAF Museum compilation book of RFC and RNAS aircraft tech guides.
If there is any other type anybody would like posted , let me know.
Sandy

[MikeH]

Dutch and Sandy,

Thanks for the information. It seems that the tension of the wires was not the critical thing as long as everything else lined up correctly.

Cheers,
Mike

[Davos522]

Sandy, do you know if rigging was a specialty by the middle of the war? It seems to me that I've read mention of "riggers" (as a specific occupation) before, and given the increasing complexity of the machines one would think the Jack-of-all-trades mechanic would be a rare beast by the Armistice.

Dutch

[macsporran]

Dear Both

Remember, on the ground, the wings hang from the plane by the landing wires, but in the air, the plane hangs from the wings by the flying wires. So a bit difficult to adjust flying wire tensions while the plane is flying!

I have no idea if a rigger was a different trade from, say an engine mechanic but there would be specialists - like carpenters, so maybe they did. I'd think though that following the detail of these tech notes most groundcrew with a few spanners could set up the rigging.
My tuppence FWIW
S

[WD]

Excellent post and follow up replies gentlemen.

Warren

[Edo]

yes, very instructive and interesting.
thank you all

ciao
edo

[KiwiZac]

I'd love to see a high resolution version of that first diagram - it'd look terrific framed on my wall!

I think they do it somewhat differently nowadays, but Brad and Zac and Mike N, being real 1:1 tech guys, can probably speak to that better than I can :-)

I'm flattered for the shout-out but the moment I've had very little to do with Great War types - I cut out some Pup wing ribs a few years ago - and regrettably my aircraft engineering training course touches on neither wood nor fabric, so the only rigging I expect I'll be learning is the control runs in the school's Cessnas and Pipers! But I have some irons in the fire that should lead to getting to work on some relevant machines. In the meantime I just stand close by with my camera!!

[Davos522]

Zac, I'll see what I can do about getting a good scan of the Nieuport diagram and cleaning it up in Photoshop. It's from Maj Victor Pagé's book Modern Aircraft, a textbook on the state of the art in aviation in 1927—but it still has a lot of Great War-era material in it. I picked up on my town library's discard table many years ago, and it's been a goldmine, I refer to it constantly.

Dutch

[KiwiZac]

I picked up on my town library's discard table many years ago

That is fantastic!! That makes me very happy.

[Scaleber]

I have a great book "The First of the Few" by Denis Winter where he dedicates a chapter "Routine Work - the mechanic's view" on how British WWI aircraft were maintained from the moment they landed after a flight.  Too long to repeat here but fascinating reading if you can get hold of it.  I highly recommend the whole book / Ian

[KiwiZac]

Thanks for the tip Ian, I'll add it to The List of books I need to read.