1941: Top 3 Allied Bombers

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The Merlin may have been the last "Royce design" as he was a very sick man at the time work started. legend has it that some of 'sketches' were actually drawn in the sand at the sea shore so any/all detail drawings and actual engineering calculations were done by other people although the finished drawings and calculations would be brought to Royce for approval. Royce died the year before the Merlin first ran as the PV.12 so any engine that started design after 1933 had no real connection with Royce.
 
Arthur Rubbra was involved, but it doesn't sound like he was chiefly responsible.

"In October 1927, Rubbra (who had become known as 'Rbr' in company shorthand) was promoted to 'Designer' where he was further involved with the Buzzard, Kestrel and the new Rolls-Royce R. He also became deeply involved in the Goshawk, Merlin and Vulture projects. In 1934 he was appointed 'Assistant Chief Designer' and in July 1940 he was promoted further to 'Chief Designer Aero Engines'." From Arthur Rubbra - Wikipedia, the free encyclopedia
 
Having just had a hunt through some books away on dusty shelves, I found in The Magic of a Name, the first 40 years by Peter Pugh, the following:

"In the mid 1930s Rowledge [Arthur John, instrumental in the Napier Lion and RR Exe and Penine - that explains a lot] developed an engine, which was essentially one Kestrel above another, one upside down and both using the same crankshaft. The first prototype ran in September 1937, the second in January 1938 and the third in May 1938. Following lessons learnt, a prototype Vulture II, with a two-speed supercharger ran in September 1938."

Interestingly, following a description of some of the issues relating to cooling and misaligned crank cases, there is the following:

"The Vulture was prone to two sorts of failure. First it tended to throw con-rods, either through lack of oil or because of the mechanical loads on the big ends at maximum rpm. Second, it over heated ad the glycol coolant caught fire. This was not the fault of the Vulture engine itself, but rather of the installation, designed by Avro. The cowling was too close to the engine, and did not allow sufficient ventilation."

The book also mentioned Rubbra being closely involved and there is a quote from him regarding the misaligned joint faces, mentioning stepping of the bolts (stepping? The same as joggling?) and then the fitting of dowels in the casings.

It also goes into some of the issues and crashes suffered by Manchesters during testing, not all of them down to the engine nor the airframe. However, the Air Ministry was not happy with it and Freeman and Tedder went to see Dobson, who talked them into the four engined Manchester. There's that anecdote of Dobson holding a model Manchester, then in front of Freeman and Tedder, removing the wings and fitting a new set with four Merlins. According to Buttler in British Secret Projects, the first incarnation of a four engined Manchester appeared in April 1937, before even HP had had the HP.56 design and mock-up conference, where Volkert changed the configuration from two Vultures to four Merlins, although Chadwick at Avro was initially keen on four Hercules. Further investigation led to possibly Napier Sabres or Bristol Centaurus replacing the Vultures in a twin layout.
 
"Even today I find the issue very frustrating and it becomes exasperating when I read in Jagerblatt, June -July 1985, Adolph Galland's comments in an article entitled '45 Years Ago-At the Channel'. He writes, "Looking back at the Battle of Britain, there was no direct radio communication possible with the bombers, due to the differing frequencies. A situation almost unbelievable, which amongst other things had serious consequences when rendezvous points were missed or escorts/bombers were a little late." When I read this now it turns my stomach when I think of all the frustrations I had with this man when trying to sell good communications to the squadron leaders. He and our other 'Spaniards' were so entrenched in their views that they, collectively, put the Luftwaffe well behind and may even have cost us the Battle of Britain by their inflexibility. Adolph Galland was against progress in all forms of communications within I/JG 433 and later I/JG 52. He could apparently see no reason at all to have Funkgerate (FuG) in a fighter aircraft. Wing signals in the air and a telephone briefing would be sufficient..... What motivated this apparent obstinacy? I don't know but maybe it was a desire to be free in the air, unfettered by a ground based commander or directions from a bomber group. Equally, it could have been a complete lack of foresight; one can still only speculate after such a long time. It still angers me to read comments by a man who, along with his colleagues, was at the root of our poor communications."

Ulrich Steinhilper, Nachrichtenoffizier, I/JG 433 and I/JG 52.

Being a superb pilot and aerial tactician does not necessarily make a man a good technician, or even allow him to grasp the potential of relatively new technologies. Galland had a long term penchant for re-writing history to cast himself in a more favourable light and Steinhilper was not the only old comrade irritated by this.
At the root of this problem was the disproportionate influence the 'Spaniards', mostly relatively junior officers still, exerted over the immediate pre-war and early war Luftwaffe.

Cheers

Steve
 
Where does 1937 come from?

The four engine Avro bomber has its roots in the Type 680, the draft proposal for this was drawn up in February 1939, just before the issue of Specification B.1/39 on 6th March. The Type 680 was discussed informally with William Farren (Deputy Director, Scientific Research at the Air Ministry) before the issue of the specification to which the Type 680 largely conformed.

It was Rolls Royce who suggested that Chadwick might like to fit the new Merlin X to his design, promising 1,150 hp. The Type 683 proposal had Merlin Xs and the extended 90' wing. This 1939 design is really the direct ancestor of what became the Lancaster.

It wasn't until the summer of 1940 that the Air Ministry became seriously interested in Avro's work on the Type 683. Farren had moved to become Deputy Director of Research and Develoment at the newly created MAP in May 1940 and had written to Roy Dobson at Avro encouraging development of the 'four engine Manchester' whilst cautioning that with fighter production being given priority (the Battle of France was about to be lost ) no contract cover was likely in the foreseeable future.

By July 19th Norbert Rowe, Director of Technical Development at the MAP, was writing to Dobson, expressing a keen interest in the four engine Manchester. It is evident from his comments that production of the type is, at the very least, 'on the cards'.
"I think we will have to watch the weight of the Manchester with four Merlins very carefully during development. In particular I think it is essential to make the very closest estimates we can in the increase in weight over the Manchester as we know it now, since this increase would clearly govern the amount of redesign which is necessary from the stand point of strength and stiffness."
This was all informal, back channel communication. The Type 683 wasn't formally notified to the Air Ministry until August. It's a very British way of doing things.

It was in November 1940 that Avro was ordered to stop referring to the four engine Manchester as Lancaster and instead use Manchester III. Manchester II was reserved for a Napier Sabre powered version which remained a 'paper plane'.

Before the first prototype BT308 had flown, at Avro's expense, a contract was issued for four more prototypes, though only long term lead items for the second to fourth prototypes were authorised, pending an initial Service evaluation.
Following the Boscombe Down report on BT308 of 10th March 1941 a new contract was raised. It superseded the old Manchester contract. It allowed for the completion of 156 Manchesters by Avro and 44 by Metrovick, whereupon production would switch to the Lancaster with the least possible 'interruption and delay' and 'where possible using components previously prepared for the Manchester'.

Avro Contract No. B69274/40 covered a total of 1,070 aircraft. The Lancaster had arrived.

Cheers

Steve
 

Thanks for the excerpt.
We can recall that 'Spaniards' have established quite a war record, neutralizing the Polish AF, successfully engaged against Norway (despite the most numerous aircraft not having the sufficient range), crushing the Low Countries AFs, winning against the French AF and the RAF's part at the Continent (while helping to neutralize the Polish and Western armies), making the RAF BC to undertake the, inefficient for a good part of the war, night bombing.
The 'Spaniards' were not ideal people, but stating only what they did bad, while neglecting their successes, means a vastly skewed picture.
 

Nobody is suggesting that they did badly. Steinhilper's point is that they resisted the sort of technological changes that would have been helpful when they came up against a well organised, determined and radio controlled adversary, as they did in the BoB.

The connections in the fuselage of the early versions of the Bf 109 were not standard. Even fitting a radio could prove a difficult task.

Read any Luftwaffe pilot accounts of the battle. The Bombers morse communications seem to have worked reasonably well, but the wireless telephone system used by the fighters was thoroughly unreliable, not tuneable in the air and almost invariably overwhelmed at first contact with the RAF. Several Luftwaffe pilot accounts report that as the system was overwhelmed they had nothing more than a high pitched whistle in their earphones.

For whatever reason the older Luftwaffe officers, including of course the 'Spaniards' did not seem, at the time, to grasp the importance of communications to mounting a successful offensive against a well organised defence. Success often breeds complacency. As that well known intellectual Donald Trump once said, "Sometimes by losing a battle you find a new way to win the war." The Luftwaffe had become accustomed to victories and needed to lose a battle to learn. The lessons were eventually learnt and ground control was later essential for defence of the Reich operations.

Cheers

Steve
 
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Avro's initial ideas for the four engined Manchester were around earlier than the 680 and B.1/39. This from Buttler in British Secret Projects Fighters and Bombers 1935 - 1950;

"As early as April 1937, before the HP.56 was modified with four engines, Roy Chadwick, chief designer at Avro, was giving thought to fitting four Hercules onto the Manchester. Sir Wilfred Freeman (AMDP) also mentioned such a scheme and the first drawings were produced in 1939."

In the section about B.1/39 there is mention of the Type 680, but no mention of earlier gestation. There is also mention of the fact that initially, the first prototype Manchester was to be powered by Hercules engines as a stop-gap and the second with Vultures, but obviously this never happened.

Also, this from the Lancaster Archive online, but no source is quoted;

"Even prior to any formal orders being received for the twin-engine Avro Manchester [1 July 1937 off the drawing board], Roy Chadwick, Avro's Chief Designer, had unofficially proposed a four-engine variant of the Manchester to the Air Ministry. Although, the initial four-engine proposal was not given the total support of either Avro or the Air Ministry. With the Manchester design not fully finalized, a group of six draftsmen were assigned to the project. The Type 683 four-engine variant named Manchester Mk.III was already well under way long before the first Manchester rolled off of Avro's production lines."

Lancaster History

I also remember reading something about it in Leo McInstry's book on the Lancaster, but it was awhile ago when I read it, so can't remember exactly what was said.
 

that had always been my understanding...that there was a spartanistic view when it came to radio communication. the old guard ( who were in the position to make policy ) had the mind set, if it was good enough before there was no need to change it. but the complexion of the war was different. britian was not poland..or spain...by a long shot.
 

The Manchester originally arose from Specification P13/36 and was called the Type 679. It was never designed to carry four engines. Both Chadwick at Avro and Handley Page had doubts about the Vulture engine. Handley Page expressed these doubts openly to the Air Ministry and was allowed to fit four Merlins to what would become the Halifax, thus making it conform more closely to B12/36. In an interview that Chadwick gave to Air Ministry officials in January 1944 Chadwick, referring to the changeover at Handley Page in 1937, expressed the view that "he wished that he had similar engines." He didn't and he would never have got them at that time anyway.

Chadwick always preferred four engines, but at no time in 1937 was the Type 679/Manchester designed to carry them. Chadwick did ask his design staff to examine the possibility of powering the Type 679 with either four Merlins or four Hercules engines, but that's as far as it got. The four engine version, though Chadwick always wanted it, was not seriously considered until March 1939 and the issue of a new specification, B1/39, not least because the Vulture powered version was showing some promise. Neither the Avro board nor the Ministry men were interested and it would be a stretch of the facts to say that Chadwick designed a four engine version of the Type 679 in 1937.

Chadwick always had Merlins in mind for the Type 683/Lancaster and I've not seen any evidence that any radial engine was considered in the vital 1940/41 period.

Cheers

Steve
 
it would be a stretch of the facts to say that Chadwick designed a four engine version of the Type 679 in 1937.
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Yet there are two sources claiming that it originated in 1937, the first of which was carefully researched. None of those sources state that it was a paper design as such, but that Chadwick had discussed it and put the idea out there. Do you have concrete evidence that a four engined Manchester was not considered in 1937?

I'm well aware of the background of P.13/36 and the Avro 679, but the four engined Manchester did not begin with B.1/39. Perhaps and quite likely, the first concrete effort that it might come to fruition was done at that time in the form of drawings to B.1/39, but the idea had been discussed and maybe even put on paper unofficially by then - a back-of-the-envelope sketch, perhaps? Why would that be so hard to believe? If Volkert had had reservations about the availability of Vultures at the time of the HP.56 Mock up conference, why would we automatically assume that the idea could not have crossed Chadwick's mind because the twin engined Manchester was progressed with instead, unlike the HP.56?
 
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In 1944 Chadwick is on the record as wishing he could have got the same four engines as Handley Page wangled for the putative Halifax, but he didn't and Avro were made aware that they wouldn't have been available. That certainly only left the two engine option open to the Avro board who were financing the project.

McKinstry is the source for the suggestion that Chadwick asked the design team, who were busy drawing up the two engine Type 679, to 'examine the possibility' of attaching four Merlins or Hercules to it, despite being aware that these engines would not be available. Whether or not one of that team did a "back of a beer mat" type of sketch I don't know. That doesn't qualify as designing a four engine version for me, but I don't really want to start a debate on the semantics of what does or doesn't constitute a design

In February 1939 after Avro and Chadwick heard about the forthcoming Merlin XX and it's potential power and before the issue of B1/39 (though they would have been aware of the outline of the specification unofficially as indeed were other manufacturers) there was genuine interest in reviving the four engine Manchester. Chadwick had always seen this as a better option and it was at this point that serious design work began. This was entirely financed by Avro, but the company, with engines now potentially available, was now prepared to take the risk and foot the bill.

McKInstry doesn't provide much evidence to support even the contention that the design team 'examined the possibility' of a four engine version in 1937. Mason provides a lot of evidence (all sorts of documents and minutes from Avro, MAP, AM) to show that in 1939/40 there was both design work going on at Avro and considerable interest from the Ministries at that time. Avro did receive some conflicting sigmals from the AM and later MAP, but was prepared to push ahead with the project.

It is important not to underestimate the impetus given to the project by the appalling prospect (to Avro) of having to turn over its Manchester production lines to production of a rival aeroplane, one which Avro considered inferior, the H P Halifax.
This prospect did not rear its ugly head in 1937 but in 1940.

Cheers

Steve
 
Thanks Steve, but none of the suggestions you offered actually refutes the idea of Chadwick coming up with the idea back in 1937. I trust that Buttler might have found something that not only suggests the year 1937, but also a specific month, April, which leads to a specific source of information. A pity there is no clue as to what this might be. Yes, there was no doubt that anyone in Avro wanted the Halifax to be produced in their factories, but that doesn't mean the idea wasn't there beforehand; that just offers increased impetus to keep the lines producing an Avro product. I should add that at no time have I stated that Chadwick or the drawing office designed the aircraft in 1937, nor do the quotes I offered, but the fact that a four engined Manchester was discussed as early as 1937 should not be ruled out just because Mason does not include it in his take on the aircraft (This is beginning to sound like one of those fruitless arguments where "my historic information is more accurate than yours..." ).

I live in the middle of nowhere in a country on the other side of the world from any archives that might be able to confirm such a claim, so I take what information I have available to hand; granted, it's not always accurate and at times, the validity of some of it is worthy of question, but I suspect that Buttler is a little more informed than I am on the subject.
 
There is no doubt that Chadwick was interested in a four engine bomber in 1937. I agree with this 100%. The problem was that the engines were not available and that is why Avro proceeded with the two engine version. Chadwick had been at Avro for a long time and was very much respected, but without the backing of the board he could hardly divert any significant resources from the official company programme into his own pet project.

It must be eminently possible that some thought was given to a four engine Avro in 1937, but that is not the same as undertaking a design programme for the type. I don't believe that there is any evidence that a four engine bomber was designed by Avro in 1937. As I said before, whether some sort of conceptual sketches, beer mat outlines, were made I don't know. Blue Sky thinking has already been mentioned somewhere . For me that does not amount to a design in any case. The bomber that was designed in 1937 certainly couldn't mount four engines on its smaller wing. The wing was initially lengthened not to mount more engines but to increase take off performance.

Even later when the Lancaster prototype had been approved by the MAP there were still problems with supply of the engines. Avro were told that no Merlin engines would be spared from fighter production. Chadwick specifically remembered that when Patrick Hennessy at the MAP was told by Sir Wilfrid Freeman that he (Chadwick) required material to finish the prototype, Hennessy replied "He can dig for it."
Chadwick knew where to dig and it was Roy Dobson, who was a personal friend of Ernest Hives, who went digging at Rolls Royce. The initial four Merlins were provided through back channels to Avro with Hives' connivance (which also answers an earlier question). This was in Rolls-Royce's interests too. Hives and R-R was just as disappointed with the Vulture as Avro was, and herein lay a potential solution to the problems of both companies.

EDIT:

The first evidence at Avro for a serious attempt at a four engine bomber, a four engine version of the Manchester, is some calculations done by the design office in late 1938, not 1937. These estimated the weight of a four engine Manchester with four Merlin II/IIIs at 27,000lbs and with four Hercules at just over 28,000lbs. The wing extension to the final Lancaster length was not included in the calculations. There was no priority for such a project. No requirement existed for a replacement Manchester and anyway the Vulture installation was returning good figures in wind tunnel testing and provided the cabin heating and hydraulic power requirements of the Manchester with its installation.

In December 1938 a little more work was done on possible engines, the Merlin III being deemed unsuitable. Rolls-Royce suggested the Merlin IV, and this was to be given serious consideration over the winter of 1938/9. All this came to nothing when a few months later, in early 1939, the Merlin XX was muted as a contender. The story resumes where we started with the Type 680, in February 1939.

Cheers

Steve
 
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If you read my last post again, you'll see that no one has suggested they did.

The first evidence at Avro for a serious attempt at a four engine bomber, a four engine version of the Manchester, is some calculations done by the design office in late 1938, not 1937.
Click to expand...

I don't doubt it, but I still accept Buttler's version over yours. Again, I ask you, can you provide source information, Steve that proves that Chadwick did not consider a four engined Manchester in 1937?
 
I agree that he considered it. He always felt that it was the way to go. Constraints from the Air Ministry and later MAP placed on Avro prevented him from designing it. Why design a bomber with four engines that either didn't exist or were not going to be made available. The Avro board, who were footing the bill, wouldn't have backed it either.
There is a difference between a designer doodling on a beermat, designing concept aeroplanes, which is free of charge, and a company's design office starting serious design work, employing different engineers, draughtsmen etc which is most definitely not.
Also at this stage the Manchester/Vulture combination was showing some serious promise, the problems were well in the future. Chadwick calculated a theoretical top speed of 341 mph for the type, you can understand the disappointment when it only ever achieved 265mph! This was not entirely down to the Vultures. Not to bang a drum, but this is always a problem with figures for 'paper planes'.

The serious calculations for Merlin or Hercules versions (cited my Mason and McKinstry, I'll check for their source later) were done in late 1938, after Handley Page had got the green light for four engines on their bomber.

Cheers

Steve
 

Finally. I was beginning to think you were refusing to accept it simply because you'd never heard of it before. As posted in the last post and the one before; no one is claiming this, but that it had been contemplated and certainly discussed as early as April 1937. Unless we are able to get hold of the piece of evidence that Buttler had on which to base his claim, we can't be absolutely certain of how far this idea went at that time, but it shouldn't be dismissed just because we didn't know about it before now.
 
nuuumannn said:
Finally. I was beginning to think you were refusing to accept it simply because you'd never heard of it before.
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Well I did write this a way up this thread:

"Chadwick always preferred four engines, but at no time in 1937 was the Type 679/Manchester designed to carry them. Chadwick did ask his design staff to examine the possibility of powering the Type 679 with either four Merlins or four Hercules engines, but that's as far as it got. The four engine version, though Chadwick always wanted it, was not seriously considered until March 1939"

I think that March 1939 should be changed for "late 1938", as some sort of feasibility study was obviously carried out at that time, but I stand by the rest

The real design work, with assignation of resources and personnel, didn't start until 1939.

It seems much of the Avro material has been lost over the years, company mergers etc. Much of the information and papers referred to by both authors above is actually the other half of the conversation, so to speak, records and minutes from the various Ministries, preserved in the Public Records.

There is an Avro Heritage Centre based at the old Woodford aerodrome near Stockport, but I've no idea if they retain any archives.

Cheers

Steve
 
The four engine version, though Chadwick always wanted it, was not seriously considered until March 1939
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And I also wrote, three times no less, that we know this and are not disputing this. You did state earlier that the four engined Manchester bagan with the 680, which I refute. See:

Where does 1937 come from? The four engine Avro bomber has its roots in the Type 680
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I think we've gone as far was we are going to go with this, don't you?

There is an Avro Heritage Centre based at the old Woodford aerodrome near Stockport, but I've no idea if they retain any archives.
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They do. There's quite a bit of stuff around about the place in places where people might not think to look. Buttler has made the most of his travels and scoured less obvious places and turned up some real gems. When I wrote about Bill Reid's Avro Anson I restoration here in New Zealand, he told me that he approached the Avro Heritage Centre for info on the Anson, particularly photos of the interior, but most of the Chadderton Works - where MH120 was built, records, as well as complete Anson drawings were destroyed in a fire. Oddly enough, there is a largely complete set of Anson I drawings at the RNZAF Museum in Christchurch.
 
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