Folding wings on British bombers

[Shortround6]

The Supermarine was running late and was almost out of the picture when the Germans finished it off.
First flight of the Stirling was 14 May 1939.
First flight of the Manchester was 25 July 1939
First flight of the Halifax 25 October 1939.
Supermarine factory bombed 26 September 1940.
First flight of the Lancaster 9 January 1941.

With service use at least a year after first flight for most aircraft and the Supermarine being weeks if not months away from first flight when destroyed the actual performance of the 316 is pretty much academic and the estimates may be as reliable as the 370mph Beaufighter, 360mph Defiant and 460mph Typhoon.

The Huge Fuselage on the Stirling still needs explaining and the weight growth should not have been quite the surprise claimed.
Now maybe Shorts used some fuselage drawings from a previous unbuilt project to speed things up. Maybe they thought the Air Ministry would bring back the requirement for the 24 troops and they would be ready? I don't know but there has to be some reason for that fuselage.
As for the weight gain?
A Lancaster II (Hercules engines) needed 2150 imp gallons of gas to fly 2050 miles with a 6000lb bomb load. The specification called for 12,000lbs to be carried 2000 miles. a 12,000lb bomb load and 2000imp gallons of gas ( 14,400lbs) equal 26,400lbs of payload not including crew, weapons, radios or "operational equipment" and indeed the Lancaster II has a "payload" of 27,400lbs but after you take-out the crew, weapons, ammo, armor, etc the payload shrinks to 22900lbs.
In other words and bomb and fuel load of 26,400lbs (or anything near it) was totally unrealistic for any 4 engine bomber being designed in the mid to late 30s.

 

[pbehn]

Did Shorts have an eye on the civilian market should a war not happen.?

 

[Shortround6]

Did Shorts have an eye on the civilian market should a war not happen.?

I would tend to doubt it.
Shorts had experience with the C class (first flight 3 July 1936)and G class (first flight 21 July 1939) flying boats and for long distance spacious accommodations were the order of the day. While the Stirling was roomy for a bomber it was NOT roomy for a commercial aircraft.

Stirling in 1945.

From Stirling interior | 75nzsquadronremembered

 

[Robert Porter]

Very cool! Was the center structure for the bomb bay or was it somehow related to structure for the wings?

 

[Shortround6]

I believe the center structure is for the wing but could be wrong. The bomb bay was entirely underneath the "floor".

Better picture of 'commercial' cabin

interior of a "trooper" with wing bracing in the center background.

 

[Airframes]

Center pic in Post #43 looks more like a Manchester or Lancaster. Note the flaps screw jack under its fairing in the foreground, and crew member straddling rear spar.

 

[stona]

The Huge Fuselage on the Stirling still needs explaining and the weight growth should not have been quite the surprise claimed.
Now maybe Shorts used some fuselage drawings from a previous unbuilt project to speed things up. Maybe they thought the Air Ministry would bring back the requirement for the 24 troops and they would be ready? I don't know but there has to be some reason for that fuselage.
.

The fuselage is not particularly wide, it's just very long. Each of the three longitudinal bomb cells is only 19" wide. As it was possible, in theory and before the fuselage became crammed with equipment, to fit 24 troops in a Lancaster I think the troop carrying is a bit of a red herring. Shorts did make 'provision' for the aircraft to serve as a troop carrier, but then this was still in the specification, as explained earlier. It was not a dual role aircraft, and in any case and demonstrated by other designs, such a long fuselage was not needed to meet this requirement.
Shorts did have a design on the drawing board which met many of the requirements of the specification and on which the Stirling was based. The long fuselage may be a hang over from that, but I don't know.

The point about the Supermarine project is that if the prototype had ever flown then we would have a direct comparison between two aircraft built to the same specification, with its loss the Stirling is alone in being built to that specification.
I agree that to take the projected performance as that which a service version of the aircraft might actually have achieved would be extremely foolish.
I also think that the Supermarine bomber might have struggled to carry, internally in wing cells, the larger bombs carried as the war progressed.

Coming back to the hangars, the 'C Type Aeroplane Shed' designed in 1934 at the beginning of expansion, before the 1936 specifications, had a clear opening of 150'.
The 'A Type Aeroplane Shed' dating back to the 1920s had a clear 120' opening.
There is no relation between hangar size and a 100' wingspan restriction. If there are any older erks lurking on this site they will remember Shackletons and Lincolns being trollied sideways into the T2 hangars.

Here's a T2 (the T stands for 'transportable!') hangar at North Weald. The doors can open to 113' 6". These hangars were built on UK airfields throughout the war.

I think it was Harris who said words to the effect that hangars were the last place you would put your aeroplanes in wartime

Cheers

Steve

 

[Shortround6]

The fuselages

Center pic in Post #43 looks more like a Manchester or Lancaster. Note the flaps screw jack under its fairing in the foreground, and crew member straddling rear spar.

Could very well be, I went by the caption which, as we all know, can be wrong.

 

[pbehn]

During the Battle of Britain I believe an airfield commander blew up his own hangers to prevent further raids.

 

[stona]

Very cool! Was the center structure for the bomb bay or was it somehow related to structure for the wings?

Wing spars.
The bomb bay, which you can see in that image is divided longitudinally, was 42' long, that's 9' longer than a Lancaster's. The problem was the narrow cells created by the divisions which limited the bombs carried to less than 19" in diametre.
For examples, the 4,000 lb HC bomb (cookie) had a diametre of 30" and the larger 8,000 lb and 12,000 lb versions (super cookies) had an even larger diametre of 38".
Luckily the ubiquitous 500 lb MC (13") and 1,000 lb MC (18") bombs would just fit.
Cheers
Steve

 

[ChrisMcD]

Did Shorts have an eye on the civilian market should a war not happen.?

I would suspect that Shorts had an eye on the "military transport/bomber" market. Between the wars it was quite a major market with aircraft like the Vickers Vernon clocking up useful production runs during the depression. The RAF in the Middle East seems to have had a love for these dual purpose types. If WWII had not turned up Shorts could have had a useful production run for Middle East trooping aircraft.

You could see the Stirling as a much superior aircraft continuing the line of the HP Harrow, Bristol Bombay and Armstrong Whitworth AW23.

Remember Shorts had impressed everyone with their Empire class flying boats when most large British aircraft looked like leftovers from WWI - AW Argosy Anyone?

 

[ChrisMcD]

Well, at 33 feet (10 meters) long, the Lancaster's bomb bay was certainly big enough.

I gather the consensus is that Roy Chadwick prioritised the dual torpedo aspect of specification P.131/36

"In May 1936, Group Captain R.D. Oxland, Director of the Air Ministry's Operational Requirements, issued specification P.131/36 for a twin engine bomber capable of carrying internally a 12,000 lb maximum bomb load, or a single 8,000 lb bomb, or a pair of torpedoes. "

As has already been pointed out. The earlier specifications tended towards the "lots of little bombs" approach with multicellular bomb bays - but an 8,000 pounder or dual torpedoes does demand one huge void.

I still remember being stunned by the bomb bay of a Vulcan - Roy Chadwick was consistent!

 

[Shortround6]

I would suspect that Shorts had an eye on the "military transport/bomber" market. Between the wars it was quite a major market with aircraft like the Vickers Vernon clocking up useful production runs during the depression. The RAF in the Middle East seems to have had a love for these dual purpose types. If WWII had not turned up Shorts could have had a useful production run for Middle East trooping aircraft.

The requirement for such a replacement had been issued in 1931, in true British fashion of the 1930s it took until 1935/36 to fly prototypes and 1937/9 to get planes into squadron service.

Three companies submitted proposals and built prototypes, Shorts wasn't one of them.
Armstrong Whitworth A.W.23
Bristol Bombay
Handley Page Harrow.

Much cheaper aircraft than trying to use something the size of a Stirling. The British had a real thing for cheap during the 30s.

 

[Robert Porter]

The requirement for such a replacement had been issued in 1931, in true British fashion of the 1930s it took until 1935/36 to fly prototypes and 1937/9 to get planes into squadron service.

Three companies submitted proposals and built prototypes, Shorts wasn't one of them.
Armstrong Whitworth A.W.23
Bristol Bombay
Handley Page Harrow.

Much cheaper aircraft than trying to use something the size of a Stirling. The British had a real thing for cheap during the 30s.

I agree about cheap, the US was in the same mode in the 30's. But that said, their specifications IMHO tended to be more forward looking than most. Maybe because of the lead time?

 

[Shortround6]

I agree about cheap, the US was in the same mode in the 30's. But that said, their specifications IMHO tended to be more forward looking than most. Maybe because of the lead time?

US lead times tended to be shorter than British lead times. The US, being not quite so frantic to build up numbers of aircraft and squadrons, ordered a lot few aircraft. While price entered into it, like the B-18 vs B-17 purchase, the US didn't resort to large numbers of single engine bombers or ordering hundreds of small twin engine trainers as coastal patrol planes.
Granted once the war started a number of less than optimum (understatement) aircraft were pressed into the coastal patrol role.
Unfortunately for the British they tended to order a lot of interim aircraft with the idea of replacing them later, as soon as possible. But with the small size of the British aircraft industry some of these interim aircraft took too long to develop while delaying the later replacements. I understand that given the conditions of the time waiting for the better planes to come along would have left them in a world of hurt had the war started earlier (like 1938), so the British had a real dilemma facing them.

 

[stona]

The replacement of any type, interim or not, always filled the Air Staff with a certain trepidation. The only thing to delay production and lower productivity more than the never ending upgrades and alterations to existing designs was the change over from one type to another. Harris was acutely aware of the likely delays in the changeover from the Stirling to the Lancaster. It is safe to say he had a low opinion of Short Bros. and its management, maybe not quite as low as his opinion of Handley Page and his antipathy to the man himself, but not far off.
It is reflected in his December 1942 letter to Sinclair on the subject of the Stirling-Lancaster transition.

"I understand that the Stirling is to go in favour of the Lancaster as fast as the changeover can be achieved. But it will not be fast, or achieved at all with goodwill and good intent, as long as His Majesty's Government balk at the issue of taking the Stirling management away from the incompetent drunk who at present holds our fate in his hands. The Stirling Group has now virtually collapsed. They make no worthwhile contribution to our war effort in return for their overheads."

One thing Harris always did, which is a bonus for us today, was to say exactly what he thought. He can rarely be accused of mincing his words.

Cheers

Steve

 

[Robert Porter]

Come on Harris don't hold back! Tell us what you really think of the man! Awesome!

 

[stona]

Harris was referring to Oswald Short who did resign as chairman in early 1943 when the government finally took control of the company under some wartime Act.
I don't know whether he was an alcoholic, as Harris certainly suggested, but he was known to drink. He lived until 1969 when he was well into his seventies, though one of the reasons given for his resignation(s) in 1943 was 'poor health', a well known euphemism for bad habits
A discreet veil often gets drawn over such things by later writers who are often, and justifiably, more interested in the aircraft than the personalities behind them
Cheers
Steve

 

[XBe02Drvr]

While we are on the subject of slander, I always liked the comment that Shorts, as a specialist flying boat manufacturer, were rubbish at making retractable undercarriages - hence the excessively complicated, double retraction of the Stirling.

And they never got over it! The SD-30s I worked on in the '80s had the trailing-link torsion bar landing gear from hell. If the aircraft touched down in a turbulent crosswind you could count on the torsion bars would be all screwed up and the gear would have scraped the sides of the sponson wells going up and down. Catch that? Sponsons, like a seaplane? Not nacelles, or wells in the fuselage. And the cockpit was laid out like the bridge of a tugboat, not the flight deck of an aircraft. One of our First Officers, (excuse me!) "Quartermaster's Mates", even had a suction-cup effigy of a ship's engine room telegraph that he stuck on the throttle quadrant and a stick-on plaque embossed "HMS Shortcoming".
Cheers
Wes

 

[stona]

Shorts had built retractable undercarriages before, not everything the company built floated.

They didn't have experience of building an undercarriage on this scale!

Cheers
Steve