1941: Top 3 Allied Bombers

tomo pauk said:

The second Mason's sentence is also true for the He-177:

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I agree, but without starting another He 177 thread I'll just say that the He 177 was plagued with far more fundamental problems than just a bad engine choice. The Manchester wasn't and the conversion to the Lancaster was relatively straight forward.

Cheers

Steve

Once the people at LW/RLM/Heinkel/you-name-it pulled their heads from their collective a$$es, the modification that yielded the He-177B was also straightforward. It was also too late to matter, though.

The He 177 B series would have had major modifications from the A series. Much more than a Manchester-Lancaster conversion. The first Lancasters were converted from Manchesters 'on the line'. This could never have happened for a four engine He 177. The He 274 was a better option, at least it ditched the troublesome wing of the He 177.
Cheers
Steve

nuuumannn said:

I think the problems with the short casing bolts was the most serious issue though, also the mating faces between the casing halves didn't line up and because of the short bolts fracturing under load, the casings ripped apart and the flailing interiors tore the entire engine to bits. Once these issues had been solved, the Vulture proved a good engine under test and the Vulture V in the Tornado didn't have the same issues, but Rolls ended production because there was little need for the engine, whereas concentrating on the Merlin and Griffon was more productive since more aircraft operated them. Still, fitting four Merlins was a better option than continuing with the Vulture, regardless of how much better it became after modification. It would be interesting to hypothesise what might have been had Chadwick opted to drop the Vulture engined Avro 679 and go stratight for a Merlin engined Manchester from the start as Handley Page did with the HP.56 powered by two Vultures that was not built, and went for the HP.57 Halifax. Volkert chose this route in 1937 because he had heard that there might be shortages of Vultures further down the line.

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The short bolts were on the connecting rods - not normal Rolls-Royce practice, but forced by the design of the master rod. It was this that needed the most work to fix.

Other problems included the crankcase halves moving relative to each other, causing main bearing failures. This was solved using locating dowels.

Another issue was overheating due to poor coolant flow. The reason for this was that two pumps were used, Rolls-Royce finding that one could get starved and thus cavitate. The solution to this was to fit a balance pipe between the two.

The weakness of the master connecting rod was the main outstanding issue for the Vulture. The time and resources required to do this would have distracted from the development of the Merlin and Griffon which was far mor important and affected many more aircraft in production or planned.

Thanks Wuzak, I read that the Vulture wasn't a Royce design in one of the RRHT books I have, so who was responsible for its conception since it was a departure from normal RR practise? Doesn't say in the book.

Handley Page fought harder against the air staffs requirements (or were a bit later in timing?). The Manchester struggled, in part, due to the air staff requirements.

The Catapult Idea. Dropped in 1938 (what month?) it was to save money because existing air fields would have to be expanded to operate big bombers. Once they decided to (with war looming larger) to spend the money on airfields and drop the catapult idea the planes under design could drop the structural weight (to some extent) and perhaps change wing size.

British were also calling for the ability to dive bomb from the big bombers, this requirement was also dropped before prototypes flew but when in the design process? Manchester got to drop most of the structural weight but was stuck with the two engine layout.

Air staff wanted to carry TWO 18in dia. 18ft long torpedoes. This resulted in the space for the looong bomb bays on the British big bombers even though the requirement was dropped. (4 engine bombers or even the Manchester zooming along at 100 ft over the water on a torpedo run???). Depending on plane or designer the space was either wide open or sub-divided lengthwise.

The ever popular ability to carry 24 troops meant bigger fuselages than needed for a bomber.

In what order these requirements were dropped or if they were dropped at different times for different aircraft I don't know but they obviously had an impact on ALL the British big bombers to some extent.

AS did the infamous wing span restriction (not hanger door width but treasury officials trying to limit size/price) and the tire pressure limit (wacking big wheels/tires).

British (and pretty much everyone else at this point in time) had small design staffs and could NOT throw out large amounts of work after the Air ministry dropped a requirement or two. They could only re-do the fewest number of parts/components that the change in requirement freed them from.

Another point here is, are we comparing aircraft as used in 1941 or what they would later become?

While the Halifax of would never equal the Lancaster the 1941 Halifax I was a far cry from the later Halifax bombers.

stona said:

The He 177 B series would have had major modifications from the A series. ...
The He 274 was a better option...
Cheers
Steve

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The He 274 was not a cure to anything, from the get-go for that project (give the, for the Germany of ww2, the cutting edge bomber, to the Farman company to develop??), no mass produced engines for it, but the DB 603 (another self-inflicted wound), the location of the French company too close to the UK (hence too easily bombed, like it happened to the Supermarine factory when they were building the 4-engined bomber prototype).
The He-177B shared with the He 274 the wrong engine choice - four DB 603s. Meaning that old wing need to be enlarged, ie. another delay.

The Manchester also needed the bigger wing to became Lancaster.

The first Lancasters were converted from Manchesters 'on the line'. This could never have happened for a four engine He 177.

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Depending on how good one's crystal ball was?

The He 274 was a better option, at least it ditched the troublesome wing of the He 177.

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The wing was the least of the He-177s troubles.

tomo pauk said:

The He 274 was not a cure to anything, from the get-go for that project (give the, for the Germany of ww2, the cutting edge bomber, to the Farman company to develop??), no mass produced engines for it, but the DB 603 (another self-inflicted wound), the location of the French company too close to the UK (hence too easily bombed, like it happened to the Supermarine factory when they were building the 4-engined bomber prototype).
The He-177B shared with the He 274 the wrong engine choice - four DB 603s. Meaning that old wing need to be enlarged, ie. another delay.

The Manchester also needed the bigger wing to became Lancaster.



Depending on how good one's crystal ball was?



The wing was the least of the He-177s troubles.

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A wing extension for the Manchester was already in the pipeline, initially an extension to 90' with a weight penalty of 600lbs to 'substantially improve take off performance'. It was no big deal to develop what was already on the drawing board for the Manchester to the Lancaster. The wing centre section was virtually unchanged.

There was no crystal ball. Avro were working up an improved Manchester in mid 1939. It was designated Type 683 and the Air Ministry expressed an interest in it following the issue of B.1/39. It would have had Merlin Xs and featured the extended wing (as above) and larger tail plane which would characterise the eventual Lancaster.
From this the design developed to a 100' wing span and Merlin XXs in early 1940. February 1940 is when Avro started to refer to the Type 683 as 'Lancaster', though not to the Air Ministry.

Huge impetus was given to the Lancaster project as a result of a proposal in August 1940 that once the initial run of 200 Manchesters was complete, production at Avro and Metrovick should switch to the Halifax. It is not difficult to imagine the reaction of Avro to this suggestion.
Avro's response was to remind the Air Ministry of the progress being made with the Lancaster (as it was now referred to) and the advantages of switching production to this four engine design which shared a more than 70% commonality of parts with the Manchester rather than switching to a completely different and anyway untried aircraft.
The Air Ministry authorised the Lancaster prototype with the proviso that it would have to confirm its potential superiority (over the Halifax) in plenty of time to pre-empt the plans for setting up of Halifax production lines in Manchester.
It did and the rest is history, but only because the four engine Lancaster had been conceived more than two years before this exchange of correspondence with the Air Ministry and because Avro was ready to manufacture the first Lancaster prototype before the Manchester had been delivered to its first squadron .

No crystal ball and a simple changeover for which the manufacturer was prepared.

The first Manchester III prototype, BT 308, (no longer Lancaster for security reasons) flew on 9th January 1941, just six weeks after work began to build it. It comprised a standard Manchester I fuselage and standard 22' tail plane complete with the then standard central fin. It was powered by Merlin Xs in Merlin XX cowlings. Details of the Whitley's Merlin engine mounts had been provided to Avro.
By 10th March the prototype was fitted with what would be the standard 39'tail plane and Merlin XXs.

An initial contract for 1,070 Lancasters was issued, production to start following the completion of 200 Manchesters, in fact 44 Manchesters became Lancasters.

The He 177s wing was a problem and was redesigned numerous times.

Cheers

Steve

Thanks for the overview.

There was no crystal ball.

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I was referring on how easy (or not) would've been to convert the He 177 to accept 4 individual engines, not the Manchester.

tomo pauk said:

Thanks for the overview.



I was referring on how easy (or not) would've been to convert the He 177 to accept 4 individual engines, not the Manchester.

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Well the Germans were really good at doing drawings of all the various versions of all their aircraft, they just weren't so good at realising them.

There was much more cooperation between British aircraft manufacturers (though details of the Whitley V's Merlin engine mountings were provided to Avro by a fellow member of the Hawker Siddely Group) and with the Air Ministry and Ministry of Aircraft Production.

Chadwick didn't want the Merlin Xs on the Lancaster prototype but conceded to the MAP which required all Merlin XXs for the Beaufighter II night fighter, this was the height of the Blitz after all. Nonetheless, as soon as four Merlin XXs became available Avro received them and fitted them to BT308.
Remember that Avro/Chadwick were keen to prove the Lancaster's superiority to the Halifax. Co-operation only goes so far, and they didn't want to produce Halifaxes for Handley Page at their plants. They would have been obliged to if the Lancaster hadn't been the outstanding success that it was.

This kind of co-operative effort, in pursuit of a common objective, seems to have been almost impossible for the various German organisations.

Cheers

Steve

We've seen that Fairey was strictly against navalizing the Spitfire, so the situation between British firms was not always a honeymoon.
The wast majority of Lancaster used 'power-eggs' developed by RR. The German engine firms were also offering power egg variants of their engines, more times than not.

Well the Germans were really good at doing drawings of all the various versions of all their aircraft, they just weren't so good at realising them.

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They realized what they could, it is far easier to draw something than to produce it. Contrary to the UK, Germany have had no another major power or two as allies.
We can see in the book 'British secret projects' that people in the UK were not shy to draw stuff either.

We can see in the book 'British secret projects' that people in the UK were not shy to draw stuff either

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Or the US or Japan or Italy or................

They just don't seem to get as much "press".

Initial sketches for the Lockheed P-38.

The difference is that German manufacturers were forever drawing unrealisable plans and submitting them to the RLM in order to gain or keep lucrative contracts.
Many British drawings, you should see some of the stuff Mitchell drew at Supermarine, never left the company premises and eventually archives. I can't comment on the Americans or Japanese.

All designers indulge in 'blue sky thinking', the drawings above illustrate this perfectly. Usually there is some kind of filter between their wilder flights of fancy and the organisations which might actually finance their dream machines.

The Lancaster is a case in point. For much of its development it was a private venture by Avro. A very informal interest, no suggestion of contracts, was expressed by the Air Ministry in an improved, four engine Manchester following the issue of B.1/39, but work was continued at Avro's expense.

It was only in August 1940, five months before the first prototype flew, that the Air Ministry became officially involved, and only in November or December (a bit unclear, needs a bit of investigation) that any financial commitment was made.

There is a fundamental difference in the way the various independent aircraft manufacturers were financed in a democracy like Britain, even during the war, and the centralised system of both finance and control that characterised the Nazi dictatorship.

The British system produced the Lancaster from the Manchester. The Nazi system produced the dog that was the He 177, inefficiently, never in significant numbers, at vast expense and with minimal impact on the air war. It is typical of the He 177 saga that the units trying to operate it never received the tools to service it!

Cheers

Steve

stona said:

The difference is that German manufacturers were forever drawing unrealisable plans and submitting them to the RLM in order to gain or keep lucrative contracts.
Many British drawings, you should see some of the stuff Mitchell drew at Supermarine, never left the company premises and eventually archives. I can't comment on the Americans or Japanese.

Steve

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you think they played on hitlers facination with "wonder weapons"?

stona said:

The difference is that German manufacturers were forever drawing unrealisable plans and submitting them to the RLM in order to gain or keep lucrative contracts.

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Not sure that has to do with anything. Designers were trying to do their best, and that does not involve staying at the previous state-of-the-art. Had they opted to do otherwise, the Bf-109 would've emerged as a biplane, and Spitfire would've been the cranked wing, fixed UC aircraft.
It was up to RLM to decide what to fund or not, just like it was the case for the AM in the UK.

Many British drawings, you should see some of the stuff Mitchell drew at Supermarine, never left the company premises and eventually archives. I can't comment on the Americans or Japanese.
All designers indulge in 'blue sky thinking', the drawings above illustrate this perfectly. Usually there is some kind of filter between their wilder flights of fancy and the organisations which might actually finance their dream machines.

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Indeed.

The Lancaster is a case in point. For much of its development it was a private venture by Avro. A very informal interest, no suggestion of contracts, was expressed by the Air Ministry in an improved, four engine Manchester following the issue of B.1/39, but work was continued at Avro's expense.
It was only in August 1940, five months before the first prototype flew, that the Air Ministry became officially involved, and only in November or December (a bit unclear, needs a bit of investigation) that any financial commitment was made.

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Vast majority of the aircraft funded produced was a response to the official AM tenders.

There is a fundamental difference in the way the various independent aircraft manufacturers were financed in a democracy like Britain, even during the war, and the centralised system of both finance and control that characterised the Nazi dictatorship.

The British system produced the Lancaster from the Manchester. The Nazi system produced the dog that was the He 177, inefficiently, never in significant numbers, at vast expense and with minimal impact on the air war. It is typical of the He 177 saga that the units trying to operate it never received the tools to service it!

Cheers

Steve

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The British system also produced a number of designs that were dogs, too. The Manchester was one of those. It used plenty of resources, it was never fielded in significant numbers, and it had no impact on war. Luckily, I repeat, the people around it have had common sense to redesign it to accept 4 smaller workable engines instead of 2 bigger and troublesome ones. It dawned too late to the Germans to do the same for the He 177.

British designs were funded privately in response to Air Ministry specifications, though sometimes specifications were written to match an existing design. There was a degree of co-operation, give and take if you like.

The fundamental difference is the way in which German aircraft manufacturers were financed and capitalised. This gave the RLM, or at least the technical office, a much more prominent role in what would or would not be financed. British designers had to contend with their own boards of directors, not always easy.

200 Manchesters were ordered and 166 were completed on time. The remaining 44 became Lancasters. The changeover from Manchester to Lancaster on the two production lines running at the time was quite literally seamless. As Mason has written, the reason more Manchesters were not produced was not due to a failure of the Manchester, it was a very good aeroplane, it was because the development of two engine design was not the correct decision. Chadwick realised this and had been working on the four engine version, to become the Lancaster, since 1939 which in turn led to an easy transition to the best British bomber of WW2.

If the Manchester had been as bad as you seem to be suggesting the Lancaster project would have played out like the He 177 saga, except that the AM/MAP would have pulled the plug on it. The cronyism so endemic to the Nazi system was the only thing that kept the He 177 and any number of other projects, both at Heinkel and elsewhere alive. One of the most insidious effects of this cronyism was the over promotion of incompetent people.
It exerted a baleful influence on the Luftwaffe. You could easily argue that it was the out of date theories of the 'Spaniards' (Legion Condor veterans) that led to the woeful state of communications within the Luftwaffe and Jagdwaffe in particular at the beginning of the war. Why carry a wireless when you could use hand signals or waggle your wings? It worked fine in Spain

Cheers

Steve

Shortround6 said:

Another point here is, are we comparing aircraft as used in 1941 or what they would later become?

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Definitely as they were in 1941.

stona said:

...

200 Manchesters were ordered and 166 were completed on time. The remaining 44 became Lancasters. The changeover from Manchester to Lancaster on the two production lines running at the time was quite literally seamless. As Mason has written, the reason more Manchesters were not produced was not due to a failure of the Manchester, it was a very good aeroplane, it was because the development of two engine design was not the correct decision. Chadwick realised this and had been working on the four engine version, to become the Lancaster, since 1939 which in turn led to an easy transition to the best British bomber of WW2.

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The main shortcomings of the Manchester and He-177 were the same - troublesome engines. Successfully solved when Lancaster became 'alive'; almost successfully solved when DB 606s were substituted with Db 610s.

If the Manchester had been as bad as you seem to be suggesting the Lancaster project would have played out like the He 177 saga, except that the AM/MAP would have pulled the plug on it.

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Bad it was, the redesign solved the problem.

The cronyism so endemic to the Nazi system was the only thing that kept the He 177 and any number of other projects, both at Heinkel and elsewhere alive.

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The RLM was indeed guilty that it didn't exert a greater control over many programmes, the Me 210 being point in case. The RLM/LW (Udet? Goering?) were also guilty for insisting with the dive bombing requirement for all of the bombers, no matter how big those were; not Heinkel's fault. Don't know whom to blame for going with 2 x 2500 PS engines initially, instead of 4 x 1300, though.

One of the most insidious effects of this cronyism was the over promotion of incompetent people.
It exerted a baleful influence on the Luftwaffe. You could easily argue that it was the out of date theories of the 'Spaniards' (Legion Condor veterans) that led to the woeful state of communications within the Luftwaffe and Jagdwaffe in particular at the beginning of the war. Why carry a wireless when you could use hand signals or waggle your wings? It worked fine in Spain

Cheers

Steve

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It was due to the 'Spaniards' the LW introduced finger-four fighter section, much better than the pair or the vic used by other airforces? Not sure that woeful state of communications existed, even in early ww2.
The over-promotion of wrong people was not endemic to the LW, though.

The main shortcomings of the Manchester and He-177 were the same - troublesome engines.

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I think comparing the two is fruitless, although they did have a few things in common; engine issues and advanced construction, as well as a convoluted initial specification, but if we must, then the conversion to the Lancaster was relatively trouble free and happened at a time when the conversion was able to make a significant difference to the course of things. I disagree that the Manchester had no impact on the war simply because of the Lancaster. Without the Manchester and P.13/36 and its catapult and other extraordinary requirements, there would have been no Lancaster. Putting the two machines into perspective, the Manchester Prototype first flew on 25 July 1939 and entered service with 207 Sqn in November 1940. It handled well and pilots praised its qualities, its first ops carried out on the night of 24/25 February 1941. The Manchester III first flew on 9 January 1941 and entered service as the Lancaster I with 44 Sqn in December 1941.

By comparison, the He 177 V1 first flew on 19 November 1939 and the He 177 V6 and V7s went to IV.(Erg)/KG 40 (not sure if that unit designation is right - more knowledgeable LW chaps can correct) on 2 August 1941. The two prototypes proved extremely unpopular among all who flew them. The first production He 177A-1s went to I/KG 40 in July 1942 for operational trials, one particular raid was carried out on 28 August against Bristol. The first of the production He 177A-3s delivered in late 1942 to a training unit, I./KG 50, which was sent to the Russian front for resupply duties. The rest is outside of the scope of this thread, but the point has been illustrated; in just over a two year period, the Manchester went from its first flight to the Lancaster entering service, while the He 177, which flew after the Manchester, within the same time period still had not entered full squadron service in its intended role at all. And that's not mentioning wing spar issues, in-flight engine fires, which of course also plagued the Manchester.

The He 177 had promise, but was plagued with technical issues that were tackled through various modifications, which took place over a considerable period of time. In fact its career is similar in some respects to the early career of the Halifax, which suffered from considerable issues, although not leading to engine fires, but lives were lost through rudder over balance, it's major curse. Between its first flight on 25 October 1939 and the Halifax I entering service in November 1940, the vastly improved Halifax III, which had all the issues of the earlier variants countered, entered service in February 1944 after a considerable number of variants and sub-variants rolling off the production lines in small production numbers as HP desperately attempted to cure the aircraft's many problems.

The over-promotion of wrong people was not endemic to the LW, though.

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Aint that the truth, but the German military and industrial hierarchy did suffer a considerable degree of inflexibility that hampered co-operative efforts between services that, had they not existed, things might have been more fortuitous for them (but thankfully were not for us). Hitler did insist on 'Divide and Rule' and a bunch of sycophants by his side, mind you, there were numbers of those in every military hierarchy.

Anyhoo...

nuuumannn said:

Thanks Wuzak, I read that the Vulture wasn't a Royce design in one of the RRHT books I have, so who was responsible for its conception since it was a departure from normal RR practise? Doesn't say in the book.

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While it was departure from normal RR practice in that it wasn't a V-12, it wasn't exactly totally radical. Most of teh features were common to the V-12s of the time - single block and head, parallel valves, etc.

It also wasn't on its own as an X engine. In response to the Curtiss D-12 RR designed the F (became the Kestrel) and the Eagle XVI. The latter was an X-16 of similar displacement to teh Kestrel. Airframe manufacturers preferred the V-12 though Royce preferred the X-16.

At the same time that the Vulture was being developed, Rowledge was designing the Exe - even further from Rolls-Royce's standard practice, being air-cooled, sleeve valve and an X-24.