K.u.k Tarnstoff rib tapes

Rowan Broadbent · 31 August 2008, 02:11 AM

I have been unable to find any photographs to show the rib tape treatment of the Austro-Hungarian "whorl" printed fabric used on late-built Oeffag DIIIs.

I assume that rib tapes were used, if so were they from the same material or plain fabric?

Thanks in advance for any help you can offer.

Kirk R. Lowry · 1 September 2008, 07:03 AM

Bonjour Rowan!

Assuming that you are referring to the Albatros D.III (Oef) types to which the hand printed camouflage fabric was applied, I do not believe that tape was applied over the ribs of the wings. That stated, the only evidence I can offer are the photographs of the aircraft which do not appear to sport tape. We know that the print was applied to the fabric which was manufactured as large sheets and, presumably, based on the photographic evidence, added to the wing structure as a single piece for each.

Certainly a beautiful and interesting scheme!

Salut!
Kirk

Rowan Broadbent · 1 September 2008, 07:37 AM

Thanks for the reply Kirk!

I couldn't see any tapes on the low quality photos in my refference library, which I found a bit of a puzzle.

Looking at Koloman Myerhoffers wonderful albatros repro, there are no rib tapes, just beautiful stitching to each rib. Given Oeffag's reputation for the highest quality of work, perhaps tapes were not needed if the "sewing" and covering quality were of the highest. In the absence of any info to the contrary I will assume no tapes. I believe that the fabric was printed in 64 to 66 inch wide bolts of seven pattern-repeats, with a quarter pattern overlap at each edge, so this should just fit the top wing of an albatros (which I make around 58" chord) and easily cover the lower wing. As I believe the fabric was only produced for the Oeffag Albatros , this is probably no coincidence!

Kirk R. Lowry · 1 September 2008, 08:02 AM

Re-bonjour Rowan!

Well, how about that ... we are in agreement! Most every topic raised at The Aerodrome seems to result in controversy, so, it is quite an event when there is concurrence.

As you are aware, known photographs of the type with the scheme are rare. Images of the Albatros D.III (Oef) sporting the fabric in Polish service may offer the most clear evidence of the lack of tape on the wing ... I could post scans if so desired, but, you seem to have undertaken research to the maximum so are probably in possession of such ...

I agree that the patterned fabric was produced specifically for the Albatros D.III (Oef) ... that said, study of Austro-Hungarian aviation indicates that one should never say never ... Certainly the covering was in limited supply due to the complexity of manufacture and apparently there was never enough which is why the material was applied to so few aircraft and in some cases only to parts of a machine ... note, for an instance, that, apparently, the patterned fabric was only to be found on the upper surface of the wings.

Salut!
Kirk

Martin Irvine · 2 September 2008, 04:28 PM

Hmmmm....
I can't argue with the observation that there aren't rib tapes, so that begs the questions:

a) WHY would they be omitted? I can't see a benefit worth mentioning and

b) how can they omitted safely? Tapes have been used for a hundred years, presumably because they are needed!

Any thoughts?

Martin

Rowan Broadbent · 3 September 2008, 12:39 AM

Hello Martin,

I don't have the knowledge to answer your questions, but I surmise that there is a benefit in production costs and time in omitting the taping process.

Perhaps it would be better if we start from the other end - why attach rib tapes in the first place? The answer must, presumably, lie in protecting and reinforcing the vulnerable and - let's be honest - critical, stitching of the fabric to the wing from wear and damage. As I understand the conventional attachment process, wing ribs were wrapped in fabric, secured by dope and the covering stitched to that. The rib stitching then being covered with tapes doped on top. Maybe Oeffag used a different process or better (stronger) attachment thread which was less vulnerable to damage?

As Oeffag spent some effort in improving and strengthening the original Albatros design, with consequent improvements in robustness, it is surely doubtful that they would omit a process specifically designed to provide said quality?

The man with the answers must be Herr Mayrhofer : here's a few photos of the wings for his masterful "new-build" Albatrossen:

I don't recall this process being covered in his thread? (pun unintentional...sort of..)

EDIT:
I've just found the ref to rib tapes on Koloman's thread - it appears on p17. He simply confirms that he adhered to Oeffag practice and no rib tapes were used. No explanation, though. I'll ask...

tengew · 3 September 2008, 01:27 AM

he did touch on the fact it was not needed when he posted the pics of his wings

Koloman Mayrhofer · 3 September 2008, 07:34 AM

hallo,

i based my covering practise on several dokuments and facts.
first i have a original siderudder which give a very good clue to the system they used and i have fotos from the oeffag factory indicating that they did not use ribtapes usually.
i enclose two pictures from my archive to show this. one is from the testing center aspern showing two ailerons tested to destruction and the other one is the storage room of the oeffag factory . the picture is taken at the very end of the war or probably short after.
i am convinced that they did not use ribtapes on the printed camouflage fabric also . why should they change there practise?

technically ribtapes are more important for longivety than for strength.
the very accurate and thight stiching and the glueing effect of the dope are more than adequat to hold everything in place. i learned it the hard way when i have to redo a tailplane and have to cut every single thred otherwise i would have destroyed the ribs. ribtapes are certainly a good idea if you expect a longer service life out of your plane. oeffag took great care of making the wing airthight so that the airstream does not pump up the wing which is the biggest problem for that kind of design and obviously they did not have problems in service. at least i could not find anything in the documents.
it is interesting to note that austrian authorities obviously accept a lot of different ways to attach fabric. some producers used nails coverd with tape.

the biggest problem was the quality of the covering material . this seems to be very low later in the war and several manufactures reported big problems as also frontline reports indicate this. although oeffag seems to be in a better position and had probably secured supply before it was getting worth.

the original fabric sample i have is from a very early D III and is of incredible high quality linnen.

the finest picture i have showing printed fabric

hope this helps
cheers
koloman mayrhofer

womenfly2 · 3 September 2008, 08:00 AM

Great info and pictures. Now I am curious as to the covering on the wings leaning against the wall.
It looks like a swirl pattern printed fabric (?). Any info on this?

Thanks for sharing,
WF2

Awsome build!!!!

Rowan Broadbent · 3 September 2008, 09:43 AM

Quote:

Originally Posted by Koloman Mayrhofer

hallo,

i based my covering practise on several dokuments and facts.
first i have a original siderudder which give a very good clue to the system they used and i have fotos from the oeffag factory indicating that they did not use ribtapes usually........snip

Thanks, Koloman!

Great information and the photos are so useful - A very tidy factory!

R