Stirling not ordered

[merlin]

It wasn't until early 1941, about the time that the Stirling became operational, that Churchill issued an instruction that Bomber Command's main operational effort should be against the two main threats to British shipping, the U-Boats and Focke-Wulf who built the 'Kondor'. A remarkable crystal ball would have been needed several years earlier to cancel the Stirling in favour of another type to meet this threat.

Cheers

Steve

Why should the Stirling be cancelled 'in favour of another type to meet this threat'!? My question posed if it wasn't ordered in the first place - there were other airframe companies bidding for an order. The Vickers's design was highly thought of - but they were busy, with the Wellington, Bolton-Paul came second initially, but after lobbying by Supermarine, it all changed with the latter first and Shorts the back-up.
So if The Bolton-Paul design stays at number two, or number one, Sunderland production continues, there is scope for Shorts to work on a military version of the 'G' Class, and B-P can point to Shorts production of the Bombay to deflect enquiries about a bomber/transport. Seems plausible to me - just wondered how many more Sunderlands etc.

 

[stona]

Why should the Stirling be cancelled 'in favour of another type to meet this threat'!? My question posed if it wasn't ordered in the first place - there were other airframe companies bidding for an order. The Vickers's design was highly thought of - but they were busy, with the Wellington, Bolton-Paul came second initially, but after lobbying by Supermarine, it all changed with the latter first and Shorts the back-up.
So if The Bolton-Paul design stays at number two, or number one, Sunderland production continues, there is scope for Shorts to work on a military version of the 'G' Class, and B-P can point to Shorts production of the Bombay to deflect enquiries about a bomber/transport. Seems plausible to me - just wondered how many more Sunderlands etc.

Yes, but why do we need Sunderlands rather than heavy bombers.

There are only ever limited resources and the correct decision was made to prioritise a heavy bomber. That bomber was not all it might have been but with well over 2,000 eventually built it served a useful purpose. Nowhere near that number of Sunderlands were built, why should they be? There is an on going debate about the resources devoted to Bomber Command and Coastal Command respectively, mainly focused on the U-Boat threat. The U-Boats did not lead to Britain's defeat and I am not alone in believing that they never came as close as some, both at the time and since, have postulated. What did for the U-Boats was not aircraft, though they certainly had a role, but the Royal Navy with new technology and cheap and plentiful escorts.

During the entire war Sunderland aircraft either sank or had a hand in the sinking of just 26 U-Boats. Many times that number never got built due to Bomber Command's efforts and more operations were curtailed by the bombing of the facilities that serviced them. All this forced a huge investment by the Germans in protective measures. All that man power and tons of steel and concrete might have been better used elsewhere. There is still a huge facility in Hannover, most recently used as a music venue, in which U-Boats were assembled before making their way by river and canal to the sea. Hannover is nearly 100 miles inland.

Cheers

Steve

 

[Shortround6]

It is very hard to quantify but the effect of air cover for convoys was much more than just sinking u-boats. It was about reducing the ship losses caused by u-boats which is not the same thing. Every time a u-boat returned to port with unfired torpedos aboard because it was forced under water by patrol planes (even if u-boat crew just thought they were spotted) was a "victory" for the aircraft. They kept the u-boat from doing it's job even if they didn't sink it. Even in WW I u-boats stopped operating in certain areas do to patrol plane activity.
However we also should remember that just like strategic bombing, the weapons, weapons loads, and tactics needed for ASW were woefully under estimated in the pre-war era. I mean 100lb antisubmarine bombs, really?

 

[stona]

It is very hard to quantify but the effect of air cover for convoys was much more than just sinking u-boats. It was about reducing the ship losses caused by u-boats which is not the same thing. Every time a u-boat returned to port with unfired torpedos aboard because it was forced under water by patrol planes (even if u-boat crew just thought they were spotted) was a "victory" for the aircraft. They kept the u-boat from doing it's job even if they didn't sink it. Even in WW I u-boats stopped operating in certain areas do to patrol plane activity.
However we also should remember that just like strategic bombing, the weapons, weapons loads, and tactics needed for ASW were woefully under estimated in the pre-war era. I mean 100lb antisubmarine bombs, really?

I agree 100%, this was a role that aircraft could and did play and it did force the U-Boats to adopt different and more difficult tactics.
In the end, with the resources anyway deployed against them, the U-Boats were defeated. I'm not sure that more resources to Coastal Command would have made much difference to the Battle of the Atlantic. Not every campaign can be made easier or shortened by throwing resources at it. Starving Bomber Command to feed Coastal Command would have made a difference to the strategic bombing campaign, for which, at this time as it was beginning to be rapidly developed and expanded, there were great hopes. These hopes proved impossible to fulfil, but nobody knew that in 1941/2 as Harris was always keen to point out.
Cheers
Steve

 

[merlin]

What gives you the idea that it would be 'starving Bomber Command' I think you are jumping to conclusions that aren't there. Incidentally before I go into that - the RAF had 19 Singapore III 15 Stranraer biplane flying boats an 12 squadrons of the inadequate Ansons - at the outbreak of war.

To rephrase by opening post - whilst in OTL Shorts still made Sunderlands, while they much more involved with building the Stirling, if somebody else won the Bomber contract (so Bomber command don't lose out), then how many more Flying-boats can they build before they are brought in to build the other company's bomber!? Maybe only one of the plants does the bomber rather than both.

 

[stona]

Is the premise now that the Stirling (or some other bomber) gets built elsewhere and that Shorts concentrate on the Sunderland until the new bomber (Halifax, Lancaster?) comes into production?

Someone would need to check just how many Stirlings were manufactured by the relevant Short plants. I don't think I have that data.

Cheers

Steve

 

[Koopernic]

It might also be a cautionary tale for those who advocate the Germans (or substitute other countries) should have built some sort of 4 engine bombers in 1938-39-40 so has to have an airframe in production in several factories when higher powered engines became available. Even switching from 1375hp to 1635hp engines was not enough to save the Stirling.

The Ju 89 Bomber developed directly into the Ju 90 transport (same wings) that became the very impressive Ju 290: powerful, well armed, long ranged, phenomenal lifting capacity and ready in 1942 but alas a transport being used as a maritime reconnaissance aircraft, without a bomb bay. Had the route been direct from Ju 89 to a putative Ju 289 the narrow body would have added speed and Bombay would have given the Luftwaffe one of the most impressive bombers of the war.

The limitations of the Stirling were entirely the Air Ministries Fault.

Wiki:
"The S.29 used the Sunderland's 114 ft (35 m) wing and it had to be reduced to less than 100 ft (30 m), the same limit as that imposed on the P.13/36 designs (Handley Page Halifax and Avro Manchester). In order to get the needed lift from a shorter span and excess weight, the redesigned wing was thickened and reshaped. It is often said that the wingspan was limited to 100 ft so the aircraft would fit into existing hangars but the maximum hangar opening was 112 ft (34 m) and the specification required outdoor servicing.[4] "The wing span was limited by the Air Ministry to 100 ft"[7][8] The limitation was actually to force the designer to keep overall weight down.[9]"

Note: Stirling had to be used as a 24 man transport unlike Lancaster and Halifax.

I asked myself why not use the Stirling as a ASW aircraft? I would say because the Wellington actually had more range with 3500lbs of bombs than the Stirling had with 3500lbs. The low aspect ratio Stirling wing generated plenty of lift (it could out turn a Ju 88 and Me 110) but without the efficiency of a high aspect ratio wing long range with load and high altitude are restricted.

 

[Shortround6]

The Ju 89 Bomber developed directly into the Ju 90 transport (same wings) that became the very impressive Ju 290: powerful, well armed, long ranged, phenomenal lifting capacity and ready in 1942 but alas a transport being used as a maritime reconnaissance aircraft, without a bomb bay. Had the route been direct from Ju 89 to a putative Ju 289 the narrow body would have added speed and Bombay would have given the Luftwaffe one of the most impressive bombers of the war.

By the time they were done the Ju 290 used an entirely different wing than the Ju 90. It also used different horizontal stabilizers and elevators with a different dihedral and different vertical stabilizers and rudders. With only 18 Ju 90s built there wasn't a whole lot of production tooling that had to be scrapped. Adding fuselage length isn't as hard (transport planes often using a lot of parallel fuselage sections) and the added length helped with the CG problems and directional stability after one or two JU 90 were fitted with BMW 801 engines. Both planes may have been very good planes for their times but their times were 5 years apart and Junkers was not using a 5 year old wing on the Ju 290.

 

[stona]

The only production break down I have found is in Michael Bowyer's 'The Stirling Story'. It's a book that concentrates on the long and illustrious service of the type rather than how and where it was made. Nonetheless he gives us this:

Mk 1 Production. 264 Short, 265 Short and Harland, 191 Austin for a total of 720. There were also 2 prototypes.
Only 3 Mk IIs were built
Mk III production. 264 Short, 342 Short and Harland, 429 Austin for a total of 1,036. 143 of these were later converted to Mk IVs.
Mk IV production. 11 Short, 450 Short and Harland for a total of 461.
Mk V production. 1 Short, 160 Short and Harland for a total of 161.

For such a 'dog' we should remember that the last Mk III was delivered to the RAF in January 1945 and the last Mk V well post war in December 1945. The last Stirling unit, 1588 Flight, received orders that no more maintenance was to be carried out on its aircraft and that they were immediately to be struck of charge on 17th July 1946. This was the end of the Stirling as an operational RAF aircraft.

The Stirling flew 290 day time bombing sorties carrying an average of 9,482 lbs of bombs per aircraft, more than the Halifax on this type of raid. It also flew 10,784 night time bombing sorties carrying an average of 6,557 lbs of bombs per aircraft, about 1,000 lbs less than the equivalent Halifax. It also flew 513 sorties for 8 Group (Pathfinders).

Add to this its extensive use as a radio counter measures aircraft and operations with all sorts of disparate units from at least 11 conversion units to the Central Navigation School, the Bomber Development Unit and various Freight Units to more esoteric roles at the Telecommunications Flying Unit and the Airborne Forces Experimental Establishment and I think that it is safe to say that the RAF got their money's worth out of what was an aircraft that failed to live up to impossible expectations. It was just a few years too early.

Cheers

Steve

 

[stona]

I forgot to mention the Stirlings crucial role in developing the TR3098 navigation beam radio equipment, code named 'Trinity' which evolved into the 'Oboe' radio aid. The TR1154/1155 'Gee' was also first fitted to a Stirling (N3639) as Modification 436.

The original proposal was that the Stirling was not ordered. Without it the RAF would have been without a versatile and important aircraft that served from early 1941 until the end of the war. Bomber Command would have been left without its principle heavy bomber for the first years of its campaign. The decision to remove the Stirling from Bomber Command came on 31st December 1943. At the time there were still 13 operational Stirling squadrons within the Command.

Later one wonders what would have towed the gliders and dropped the paratroopers and supplies in British airborne operations.

In 1943, according to the MAP figures, 881 Stirlings were produced. This compares to 1,848 Lancasters, 1,824 Halifaxes, and 2,536 of the often overlooked Wellington. A further 11 Stirling transports were also produced, a figure which would increase to 407 in 1944.

Cheers

Steve

 

[Greyman]

... the Wellington actually had more range with 3500lbs of bombs than the Stirling had with 3500lbs.

Looking at the data sheets of these aircraft I don't think this is the case. Especially when you factor in things like leading edge/auxiliary tanks the Stirling had.

eg:

Wellington X -- 1,500 lb bombs -- 1,885 miles
Stirling I -- 1,500 lb bombs -- 2,330 miles (with wing aux. tanks)

 

[stona]

Yes. On real operations Stirlings consistently dropped far greater loads than Wellingtons.

On a typical attack on Brest, where Gneisenau, Scharnhorst and Prinz Eugen were the current threat, just 4 Stirlings dropped 30,000 lbs of bombs (15 x 2,000 lb AP) whereas it took 19 Wellingtons to drop just over double that, 66,500 lbs (6 x 4000 lb, 4 x 2000 lb AP, 45 x 500 lb SAP and 24 x 500 lb).

Those figures are the actual loads delivered, according to Bomber Command, not some book estimate or manufacturer's claim for the aircraft concerned. They show that the average load dropped by the Stirling was more than double that of the Wellingtons (7,500 lbs to 3,500 lbs). These figures are not atypical, but a reflection of the general trend in the data.

Cheers

Steve

 

[Shortround6]

This actually goes along with "book" figures fairly well.
On short range Missions the Sterling could carry well over double what the Wellington could. And Brest is a short range Mission. Trouble comes in with the long range missions and more especially the often suggested use by forum members to use Stirlings for anti-sub patrols. The bomb load may still be double although the fuel burn certainly double, contact is rare so bombs are often brought home. The measure of effectiveness changes from tons of bombs dropped per mission (or per 100 missions) to missions flown per 100,000 gallons of fuel used and/or missions per 1000 hours of maintenance when bombs are dropped on fewer than one mission in 20. Only a certain number of bombs are dropped per "attack" and repeat attacks are rare.

Actual 'range' is not quite as important for ASW either, endurance is. A Wellington X stooging around at 155mph can stay in the air for around 12 hours with a 1500lb bomb load after using 125 gallons for warm up and take-off.

 

[nuuumannn]

Merlin, I see where you're going with this, but as I mentioned earlier, I think a more pertinent question might be, what would the impact be on the various commands if the Stirling was not built in favour of more flying boats, which Steve answered regarding its roles within BC. If we wanted to presume either the Supermarine or the BP design had won B.12/36, then we'd have to look at their capabilities to ascertain how effective they were or what impact they might have had on the war.

Examining the state of play if the RAF had more Sunderlands and their theoretical impact on the war in 1939/1940 raises a few questions, of course, but with the U-boats being small in number and firing defective torpedoes, one has to consider that the Kriegsmarine had bigger issues to sort through than a larger number of British flying boats. Would there be a greater number of sinkings of U-boats? Who knows. What impact might that have had on the early war years, well, until the Germans sort their torpedo woes out, then, not a lot. The German production lines would still be building more effective submarines.

It's also worth remembering that the first orders for Sunderlands and Stirlings were built in peacetime, not during the war, so how many more Sunderlands could we expect to see? Is it going to be a substantially larger number of aircraft? I'm not overly certain of that, to be honest.

 

[Koopernic]

The Wellington had an aspect ratio of nearly 10:1 the Stirling, due to bureaucratic insistence, was 6.5:1. Over long ranges the margin of advantage the Stirling has in fuel and payload and reduced 'wetted area' would tend to be significantly eroded by the superior lift to drag ratio of the high aspect ratio wing at cruising.

To me it looks like the Wellington, at the limits of both aircrafts ranges, is almost though not quite as good as the Stirling. The difference may have been starker with early Pegasus/Merlin powered variants of the Wellington. At long ranges the Sunderland, with its high aspect ratio wing that had been originally wanted by Shorts would likely be more effective than both. In that sense the Wellington is most cost effective and can cover 80% of the area while Sunderland can do a better job for the remainder.

It was of course the B-24 Liberator that 'filled' the Atlantic gap but while the gap was there Sunderland looks better at filling in as much of its as possible.
The Stirling might have been stunning in this role with the high aspect ratio wing that Shorts wanted originally and that the RAF or Air Ministry prevented Shorts from producing retrospectively.

The Stirling was optimal for short to medium range missions in terms of load. It could carry out long range missions but at a proportionately reduced load compared to say Lancaster. Id still regard it as better than the Wellington. It's capacity for carrying "Window" must have been most useful. The inability of Luftwaffe aircraft to carry enough "Dupel" undermined their attempts to disrupt RAF defences.

To summarise, the Stirling lost efficiency in terms of bomb load at long ranges though it could still carry out those missions.

Aircraft seems to have been most effective at forcing u-boots to submerge: under water they lacked the ability to keep up with a convoy.

More Sunderland means less merchant ships sunk. However if at the expense of Stirling the equation is more problematic as we must analyse Stirlings advantages or disadvantages of alternate aircraft (Wellington mainly) in suppressing U-boat operations at their coastal bases and construction slipways.

If the Stirling's advantage was at bombing U-boat bases then it could carry a heavy load, if at distant U-boat slipways less so.
Really needs some basic spreadsheet works