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WW1 Aircraft Modeling => WW1 Aircraft Information/Questions => Topic started by: richard.kiss on April 25, 2024, 04:53:35 AM

Title: Nieuport's engine cowling
Post by: richard.kiss on April 25, 2024, 04:53:35 AM
I've found an interesting photo about Nieuport on website of US Library of Congress Prints and Photographs Division.
I cropped the photo to show only the engine cover, the subject of my question:
(https://i.postimg.cc/RhMMSG43/Nieuport-cowling-zoomed.jpg)

The caption says "LANGLEY FIELD, VA. FRENCH NIEUPORT PLANE, TYPE 17, WITH GNOME ROTARY ENGINE AND CHAUVIERE PROPELLER".

I would be very interested to know why the engine cover is so dotted?
Reference books say that the Nieuport 17 had a spun aluminium engine cover. As far as I know the metal spinning technique produces a quite perfect, continuous, smooth and shiny cone/dome shaped surface -- at least in modern days. See picture below:
(https://i.postimg.cc/QtjPHdnt/Metal-Spinning-800-Cowl-wmv-10-55-screenshot.png)

In most Nieuport photos I don't see this mottled surface.
Is this an exceptional engine cover made with a different technology?
Or it's a regular outlook of Nieuport's cowling and we can't see the details on other photos due to the poor photo quality?

(The original photo can be viewed in full size here: https://loc.gov/pictures/resource/hec.09326/ (https://loc.gov/pictures/resource/hec.09326/))
Title: Re: Nieuport's engine cowling
Post by: Dutch522 on April 25, 2024, 05:12:37 AM
Neat picture! I'm no expert, and someone with more knowledge may well have a definitive answer. That said, I've done some research on Nieuport cowlings and this particular example appears to have been treated with what's referred to as "engine turning" or "jewelling" (https://en.m.wikipedia.org/wiki/Engine_turning) after being imported into the US. It was used on various other period metal panels, some Sopwiths had it and it was closely related to the Fokker "sworling" process. Both, I believe, were employed in corrosion prevention, although the actual degree of protection it provided is somewhat unclear (at least to me).

Dutch
Title: Re: Nieuport's engine cowling
Post by: WD on May 02, 2024, 01:54:09 AM
Dutch pretty much nailed it there IMHO Richard.

Warren