Shorts Stirling, Wingspan, Hangar Doors?
 

It is often recounted that the Stirling had to have <100 Ft wingspan due to the RAF insisting it fitted through existing hangar doors.

I've found nothing with internet searches to prove this.

Mostly the reason for the wingspan being restricted was to save weight and other aspects of the design were so it could ferry troops, then provide bomber support around the Empire and operate from unprepared (short) runways & clear obstructions quickly after getting airborne.

Internet searches also show that RAF hangar doors varied and some were greater than 100ft, also it would seem strange for only one aircraft to be restricted in wingspan due to the width of doors...

Would anyone have any information to confirm whether the rumor of hangar doors being the reason for the Stirlings wing span is true or not?

- Can not get it to load. What is it about?

Some Halifax variants also had a 99ft wingspan.

Don't know why it won't load, I managed to get it up on my phone.

Anyway, I googled 'RAF bomber specification B12/36' and it comes up about halfway down on the 3rd page as a PDF. The thesis is entitled 'RAF operational requirements 1923-1939' by Colin Sydney Sinnott submitted in 1998 and is archived by KCL. As you would expect the author has used PRO documents as references. He points out that some contemporary RAF hangars had door openings well in excess of 100ft, and some were considerably shorter, and posits the theory that any limitation imposed in size was due to the forthcoming treaty limitations.

I searched the document using 'hangar' it turns out that earlier, in 1932 Salmond had expressed concern regarding allowing designers free reign that may result in 'these machines may become so large that we cannot get them into any of our sheds; e. g., the bomber transport machine will not fit into any shed we have at home or abroad. "

It is actually quite an interesting read and certainly gives a lot of context as to why the Air Ministry specified requirements as it did.

I've appended the link again here just in case I didn't do it right earlier. LINK

Colin Sinnott's thesis has in fact been published in expanded form by Routledge. The title is 'The Royal Air Force and Aircraft Design 1923-1939' subtitled 'Air Staff Operational Requirements' . Paperback ISBN 978-0-415-76130-7. A very interesting read. The 'wingspan restricted by hanger door width' myth is shown to be just that - mythical.

That doesn't tend to work very well, as a rule, and it clearly didn't in the case of the Stirling. :O

Most authoritative sources, including Barnes and Thetford, quote the 100 ft limit as being imposed on Shorts by the 1936 specification.

The limit was suggested by the head of the Operational Requirements section (Gp Capt Oxland). This was not directly related to hangarage of the aircraft, but to minimise weight whilst having a structure strong enough to be catapulted with an acceleration of 2.5g at the end of a launch. Previously specifications had limited span to 100ft citing hangar doors as the reason, but not apparently B12/36.

Interestingly in 1934 one AT Harris, then in charge of Plans wrote on 6 Mar 34 "Hangars are already proved an unessential luxury, except for repair purposes & in wartime hangars will be the last place in which to keep aircraft."

Always treated the Stirling wing span story with scepticism, so thanks to you who have provided background.

https://cimg0.ibsrv.net/gimg/pprune....14f57e0ccb.png

Megan
That's a nifty drawing. May I suggest one small improvement that will make it easier to follow?
Increase the width of the coloured bars and put the relevant text on the coloured background.
Rgds

Megan,

Really impressed with that graphic: I hadn't realised the similarity in wingspan between the heavies but how much longer the Stirling fuselage is. Many thanks for posting.

The sterling was a bigger aeroplane all-round - 10,000lbs (~25%) more structure weight for the same MTOW and rated payload (ie 14,000lbs, although as we all know the Lanc was later cleared to over 22,000lbs) and giving it a much shorter range with decent-sized payloads. The lower aspect ratio for the same span gave 150sqft extra wing area, making the aircraft manoeuverable but at the expense of higher induced drag and frontal area. The two aircraft had similar installed power giving similar sea-level speeds, but the Hercules had a less effective supercharger than the Merlin, so it became a bit asthmatic at altitude and I suspect that's what really limited the Stirling's effectiveness (well that and the silly split bomb-bay design).

PDR

The Stirling, while it was clearly never destined to be as light as the Lancaster, reportedly suffered from more-than-average weight creep during its development, with the above-mentionen impact on payload/range.

Not the first, nor last, time that Shorts built an aircraft like a brick outhouse. :O

I always suspected that the Stirling wing was a copy of the Empire Flying Boat wing, and that Shorts used that wing to either reduce development time and or costs.

Mind you i could be talking 'Bull***t'!!!

Staircase, seem to recall that the Short Belfast used Britannia wings...

Bullshort?

Sorry but one * extra needed for Short - smell the cows mate, smell the cows.

I was always curious about the undercarriage. I realise it was modified to provide a better angle of attack for take off and landing, but it must have been very delicate, with lots of extra articulations in the structure.

Looking t that diagram it certainly illustrates how much extra weight the Sterling had to carry a round to deliver fewer bombs -a large part of it in the wheels alone which look enormous and of course it does look extremely ungainly on the ground and must have been a nightmare to land with that extreme deck angle. The Lanc and Halifax look almost exactly the same so where does the Lancs advantage come in there-I think there we some Merlin Halifaxes so perhaps it was structural weight for same bomb load ?

With their Provincial city naming scheme its a shame they didnt find a way to give one an extremely Welsh name so that German fighter controllers couldnt say it perhaps a Vickers Llanelli

That door-width rumour has been around for a long time. I specifically recall it - and being highly amused by the ridiculousness of it, from the background info in an Airfix kit in - what? 1968-70 perhaps?

I agree, I remember reading something in the early 70s in a library book, along with a restriction on individual component size so they would fit inside a 'standard packing case' whatever one of those is. Maybe sized to fit a Queen Mary or its predecessor perhaps?