One Night In December

In Podcast No 5 we discussed some of the more unusual methods crews used to access the bomb bay in flight, and touched on the history and development of the Lancaster.

Pete has written up some notes that you might find of interest. I will post the complete essay at a later date, however here is a taster, and some photographs which may help you visualise more clearly what we are talking about. The podcast lasts for about an hour and can be found here.

The Development of the Avro Lancaster.

The Avro Lancaster can be traced to an Air Ministry Operational Requirement written in the early 1930s. This was long overdue. As I explained in my Anthropology of Strategic Bombing post, the idea of aerial bombing as a war winning strategy had become widely accepted during the inter war years; but even the most loyal adherent of General Douhet’s maxim that the ‘bomber would always get through’ must have struggled to believe that a force of RAF Vickers Virginias, Boulton-Paul Overstrands, Handley Page Heyfords and Fairy Hendons could bring about the collapse of a modern industrial society.

(The Handley Page Heyford was the RAF’s ‘express’ night bomber between 1934 and 1937).

A quick literature review brings up plenty of articles in the British press which talked up the RAF’s capability. One notable puff-piece in Flight magazine for example went so far as to describe the Handley Page Heyford (see picture above) as ‘the finest bomber aircraft of its type in existence’. However by the mid 1930s the disparity between aspiration and ability must have been obvious to even the non specialist audience (1). A complete overhaul was required.

In July 1935 the Air Ministry issued Specification P12/36, and this it was hoped, would encourage tenders for a new and more capable four engined heavy bomber. P12/36 called for an aircraft capable of carrying a bomb load of 14,000 lbs for 2,000 miles at 230 mph. This aircraft was to have three powered gun turrets for self defence and also be able to carry 24 fully equipped soldiers on temporary seating in the fuselage. Since it was likely to be operated from unpaved airfields it must also be rugged enough to use a grass runway, and be able to clear a 50 ft obstruction within 500 feet of starting the take off roll. Lastly, as if all this wasn’t enough, each of the major components had to be transportable by standard British troop train !

Clearly this is a very ambitious wish list, but if it could be done, then it would constitute a remarkable leap forward. By comparison the Heyford could just about carry a bomb load of 1500 lbs at 115 mph.

By 1935 the prospect of another European war was becoming obvious. Hitler and Mussolini were firmly in power, a progressive coup in Greece had been crushed and Franco looked likely to win in Spain. However it is interesting to see that the assumptions behind this specification were predicated upon the need to fly the British Army to distant points of the Empire, and once there support them with tactical bombing. The UK was nothing if not a colonial power.

Two tenders were received. The first from Shorts Brothers, which after initial plans to convert an S29 flying boat had been put aside went on to become the four engined Stirling; and the second from Supermarine, the Type 316, which after some modifications to the wing planform became the Type 317.

The Supermarine aircraft never flew. The prototype fuselages were destroyed in a German attack on the factory in 1940, and soon afterwards the company was instructed to abandon the project in favour of Spitfire production. Given the threat of invasion at the time this was probably the correct decision, however it is intriguing to run a counter-factual ‘what-if ?’.

The Germans probably never knew how successful that raid on Southampton had been, after all they were targeting British fighter production, but in destroying the 317 they may have killed off the outstanding bomber of the war.

In what drawings remain the 317 looks unusually futuristic; with trapezoidal wings and gracefully streamlined curves there is definitely something of Flash Gordon about it – but its projected performance was futuristic too, a maximum speed of 360 mph, an operating ceiling of 30,000 ft, a bomb load of 21,000 lbs and a combat range in excess of 3,000 miles (2). This makes it comparable to a Boeing B29 Superfortress, the war’s most expensive project, but built in suburban Hampshire and operational with the RAF in 1941.

It’s not beyond the realm of possibility that a large force of these aircraft, operating from bases beyond the range of German retaliatory bombing may have profoundly altered the landscape of the war. However it is also just as possible that like the TSR-2 twenty five years later, the 317’s reputation benefits from having never been put to the test.

In retrospect the Supermarine performance figures appear rather unlikely, but we will never know.

(The Supermarine 317).

On 6 September 1935 the Air Ministry released a second specification, this time numbered P13/36 which called for a for a twin-engine medium bomber capable of carrying bombs or torpedoes and operating from airfields or an aircraft carrier anywhere in the world. Given the range of roles assigned to it, this specification was perhaps even more ambitious than the first.

Handley Page won the right to produce a prototype, the HP 56, but soon withdrew from the project, added two engines and made the HP 57, which in time evolved into the Halifax. Avro pursued the twin engined contract alone, and by 1937 had produced the Manchester.

(The early Mk I Avro Manchester).

The Manchester entered service in November 1940 with 207 Sqn, and carried out its first operational mission by attacking the naval dockyards at Brest during the night of 24/25 February 1941. But as we detail in the podcast, the problems encountered in developing the aircraft were enormous, and on several occasions it looked as if the project would be abandoned. Several times during its development the Air Ministry recommended that that the factory space should be given over to Halifax production. Speaking after the war, Jonathan Lake, an Avro Manchester pilot said:

“… the engine made the Manchester mainly notable for its unreliability, poor performance, and general inadequacy to the task at hand …

I was one of the six original pilots to have flown with the first Manchester squadron. That was a disaster. The aircraft itself, the airframe, had many shortcomings in equipment in the beginning, but as we found out, Avro were excellent in doing modifications and re-equipping the aeroplane. The engines never were and never did become reliable. They did not give enough power for the aeroplane, so we ended up with two extremely unreliable 1,750 hp engines having to haul a 50,000-pound aircraft. We should really have had 2,500 hp engines. You felt that if you’d lost one, that was it, you weren’t coming home. It didn’t matter if you feathered the propeller or not. There was only one way you went and that was down.

I have seen an aircraft doing a run up on the ground and have two pistons come right out through the side of the engine. The original bearings were made without any silver as an economy measure, so they weren’t hard enough. The bearings would collapse the connecting rod and the piston would fling out through the side of the engine and bang! Your engine just destroyed itself.” (3).

A Royal Aeronautical Society symposium recently concluded that, “In response to the question why the RAF persisted with such an unsuitable aircraft, the answer is that it was all they had. On the vexed issue of whether aircrews were ever told the depth of the Vulture’s problems, the categoric answer is – mercifully not!” (4).

The 193 operational Manchesters flew 1,269 sorties with Bomber Command, dropping 1,826 tons of bombs and losing 78 aircraft in doing so. A further 45 aircraft were lost due to non-operational reasons, of which more than 30 involved engine failure. This is an astonishing 64% loss rate.

However some creative thinking by Roy Chadwick, the chief design engineer at Avro, had led the company to explore options away from the original specification from the outset. So when an exasperated Air Ministry official told Avro that priority would now only be given to four engined aircraft he found that a team of the company’s designers had been quietly working on a proposal for just that for some time. Six weeks later the four engined prototype of the Manchester Mk III was test flown and immediately renamed the Lancaster. One could uncharitably conclude that this rapid rebranding may have been as much a political move as an administrative one, after all the reputation of the Manchester among the engineers who worked on it and the aircrew who had to go to war in it was pretty awful, but there is little denying that it worked.

As Pete details in the podcast, the progress of the Lancaster thereafter was remarkably quick. The principle reason for this was that although the Manchester as was fatally flawed,  Chadwick had in fact got something approaching 70% of the design right (5). The modular airframe construction, the logical positioning of the crew stations in the fuselage (in contrast to the shambolic crew arrangement in the nose of the Halifax), the good visibility afforded to the pilot, the extremely strong main spar and a single large uncomplicated bomb bay were all Manchester characteristics which proved central to the Lancaster’s success.

It is true that some significant technical challenges remained, such as dealing with the alarming swing to port on take off, but on the whole the RAF were impressed with the new aircraft and it passed service acceptance trials at Boscombe Down without much modification.

The first operational Lancaster was delivered to 44 Squadron at Waddington over Christmas 1941, and by 1944 Avro were producing more than 130 aircraft a month. In total 7377 aircraft were built at a cost of 50,000 GBP each, approximately 4,500,000 GBP in 2015 prices (6).

57 Squadron converted to Lancasters whilst at Scampton in September 1942.

Four main Lancaster variants were produced during the war, namely the Mk I, the Mk II with Bristol Hercules radial engines, the Mk III and the Canadian built Mk X. Other variants were manufactured for special projects such as the Mk III Special for the Dams Raid in 1943, and the Mk I Special for the Tallboy and Grand Slam bombs in 1944 and 1945.

(DX-B, a typical example of a main force Avro Lancaster Mk I).

Unfortunately this DX-B is not our aircraft, but rather W5008 the DX-B loaned to 617 for an attack on a power station in Italy. Completed by Metropolitan Vickers at Trafford Park in May 1943 (6) this airframe was lost on the night of the 27/28th August 1943 whilst carrying out an attack on Nuremberg. Six of the crew were killed including the pilot F/O Levy. One crew member, Sgt May the wireless operator, survived and was made a POW (7).

Our DX-B, LM582, was a Mk III and had a H2S blister fitted. On a visit to the RAF Museum at Hendon (thank you Bryan Legate) we traced the history of this aircraft and its eventual demise: but, as they used to say in second rate Victorian novels, forgive me dear reader, for I anticipate …

Notes:

1. https://www.flightglobal.com/pdfarchive/view/1934/1934%20-%200160.html
2. http://www.rjmitchell-spitfire.co.uk/otheraircraft/1932to1937.asp?sectionID=4
3. http://www.rafbombercommand.com/personals_1_earlydays.html#ml_2_beforethelancs.
4. https://www.aerosociety.com/Assets/Docs/Events/Lectures/2016/L186_Avro.pdf
5. http://www.lancaster-archive.com/lanc_hist.htm
6. http://www.concertina.com/calculator/
7. Chorley W R. (2003) RAF Bomber Command Losses Vol.4. Midland Publishing, UK.