Is the Avro Manchester Maligned Too Much And Did It Get Sorted Out?

[pigsty]

23 hours ago, JohnT said:

Your post about two engines for the price of one immediately reminded me of the problems with He177

Not really a fair comparison.  The He 177 engines were two separate IV12s and the troubles came largely from duff cooling and gearboxes.  The Vulture was an X24 that might have been derived from the cylinder banks of earlier engines, but crucially was designed from the start as four of them around a common crankshaft.  That in itself isn't inherently a problem.  Multi-row radial engines had to pull off basically the same trick, especially the R-4360.  Closer to the Vulture, Rolls-Royce also designed the Exe.  It too could be described as a failure, but the few built ran perfectly and possibly the very last Battle in service was powered by one.

 

As others have said, there wasn't the capacity to fix the Vulture to the same standard as the Merlin.  It had far fewer applications at the time it was designed, so not worth the effort at a time when we really needed thousands of reliable engines.  At that time, it was an example of the over-proliferation of ideas without enough control being applied early enough.  (So was the Exe.)  It might have been developed in reserve, to be one of the 2,000hp engines that turned out to be needed later in the war.  But, against the Griffon, and the Centaurus, and even the Sabre*, it just wasn't cost-effective to sort out.  And we wouldn't have needed four engines in that power range.

 

* a bit of a dog at first, yes, but capable of 3,000hp without significant redesign.

[Selwyn]

22 hours ago, Jamie @ Sovereign Hobbies said:

For the Mustang in particular it definitely wasn't that the Merlin was inherently much better as an engine core than the V-1710, but rather that Rolls Royce were deep involved in variable supercharging whereas Allison put their efforts into turbocharging.

 

The P-51A was weak on the single stage supercharged Allison and brilliant on the Mk.IX Spitfire's two speed twin stage supercharged Merlin. The Allison was a perfectly good engine in the P-38 designed for turbochargers though. Had someone decided to try a Merlin X in the Mustang it would have been no better a long range high altitude escort fighter than the A model.

 

A Merlin especially isn't an engine but a lineage. Parts commonality between early and late Merlins is very low.

 

Particular aircraft which did or didn't work with Merlins isn't so much about the size and shape of the engine but about which specific version of the Merlin that aircraft was tried with.

 

The Merlin II in the Battle of Britain could barely crack 1000hp. An engine from a Hornet was producing over 2000hp. Put a pair of Hornet engines on a Beaufighter and it would have outperformed the 1600hp Bristol Hercules engines. 1200hp Merlin XXs (or whatever they were exactly) came up 800hp short on a Beaufighter, which given the base power needed to maintain straight and level flight, is most of the excess power that should have been available for climbing or acceleration.

The P 51A was not weak  on the single stage supercharged Allison, when used for Tac R the aircrew much preferred it to the  Merlin Mustang . The RAF were  still trying to obtain additional  Allison mustangs from the US after D day!  which doesn't suggest a weak engine.

 

Selwyn

 

[Aeronut]

Its often forgotten that the evolution from Manchester to Lancaster is not just about the engines, the airframe evolved as well, and in a typically British cheapskate way to boot. 

The original Manchester tail plane was found to be insufficient and a simple central fin made from a wooden structure covered in fabric was quickly added. This was a 'quick and dirty' solution and gave the Manchester Mk 1 its distinctive profile. The tail plane of the Manchester Mk 1a was modified to do away with the central fin, the span was increased and the fins and rudders increased in height. When the Lancaster was proposed it was recognised that the outer main planes would also need to be increased in span. That said the Lancaster prototype showed its Manchester ancestry by emerging with the Manchester's triple fin tail plane.

What is often not reported is how these increases in spans and fin heights were achieved. The Manchester Mk Ia tail plane, fin and rudder, and the Lancaster outer main plane were not totally new designs, for to save time and reduce costs, the same ribs were retained. There weren't even any new ribs added, they just spaced out the existing ribs along new longer spars and skinned the result.

I know this as my Grandfather was the Jig and Tool Foreman at AVRO's Newton Heath factory and he personally altered the Manchester's jig drawings for the Lancaster's Main Planes on his kitchen table after his 12 hour shift. Well there was a war on.

[Graham Boak]

The Merlin III which powered most BoB fighters was capable of some 1300hp on 100 octane - which was about the same as the early Hercules on the same period Beaufighter.  The Merlin XX was only a little more powerful but had a second gear giving better performance at altitude.  It was the Merlin XX in RR power eggs that was used on the Beaufighter and the Wellington.  It was also offered and tried on the Mosquito but DH's tailored installation gave superior performance.  At this period (1940/41) there was no great difference in power between the two engines.  The Hercules went on to develop more power than the single-stage Merlins, but that wasn't where RR were putting the emphasis on development.  If you want to compare the Hornet with a radial-engined fighter than you need to look at the Centaurus-powered Fury and the Tempest II, there being no equivalent British twin.  You could perhaps consider the Tigercat?

 

The point about the Allison in the early P-51s was that it lacked power (=weak?) at the higher altitudes that the RAF believed were necessary for their fighters, so was rejected as an air superiority fighter and as an interceptor.  That didn't prevent the combination being very effective lower down, hence its use in the FR role.  Horses for courses.  It has been said that the Allison was smoother running than the Merlin.

[Ex-FAAWAFU]

18 hours ago, pigsty said:

And we wouldn't have needed four engines in that power range.

No, we wouldn't - but that's the same argument as the oft-produced "why are <insert Model company name here> producing yet another Bf109/Spitfire when we already have other great kits?"  The Merlin wasn't going to make any money for Napier or Bristol, any more than the Halifax made money for Avro.  The British aircraft industry was still extremely fragmented at this stage - simply because they were almost all (obviously) companies that had only been in existence for about 30 years (often a lot less).  Yes, there was a war on, and all that, but companies still needed to make money to fund development of other projects.  The Air Ministry don't escape blame, either; they had a great tendency to specify too many concurrent things in different projects (some would argue they still do, albeit under a different name!), and the companies had to build to at least approximately meet the spec, or not get the contract.

[Aeronut]

42 minutes ago, Ex-FAAWAFU said:

 The British aircraft industry was still extremely fragmented at this stage

But was it?

I have the letter from Roy Dobson (AVRO's Managing Director) congratulating my Grandfather on his BEM in the 1944 Birthday Honours list. What confused me was the fact that it is on Hawker Siddley headed paper.

[Graham Boak]

The Hawker group contained Gloster as well as Avro before WW2, I'm not sure when Armstrong Whitworth and Blackburn came into the mix but the latter was postwar, I believe.  However they still retained individual design teams, despite having production of the more successful Hawker designs farmed out among them.  Something which certainly kept the smaller companies afloat.  The AM was concerned between the wars about ensuring that enough British companies survived to ensure a viable industry for the expected war, which goes someway to explain the multiple projects and the shared production.  This did require some "cossetting" of the chosen companies, something that was resented by newcomers but prevented successive collapses.

 

Given how the B-50 evolved from the B-29, or the P-36/P-40 range, not to mention the Yak fighters, what makes the British companies uniquely "cheapskate"?  Using what you've got as a firm base in order to advance is fairly standard engineering practice.

[EwenS]

There were a lot of companies involved each with their own design teams but several were under the same overall ownership.  For example

 

Hawker Siddeley Aircraft was formed in 1935 and by 1939 included:-

Hawker Aircraft

Armstrong Siddeley (engines)

Armstrong Whitworth

Avro

Gloster Aircraft Company

Air Training Services

In 1945 they added Victory Aircraft and renamed it Avro Canada.

In the industry consolidation of the late 1950s and early 1960s they added De Havilland, Folland and Blackburn.

 

The other major aircraft builder at the time was Vickers-Armstongs (Aircraft) Ltd which comprised Vickers aviation interests and those of Supermarine. In 1960 these merged with Bristol, Hunting and English Electric to form BAC.

 

In common with a lot of British Industry in the 20th Century management skills were not of the best resulting, in the aviation industry, in companies effectively competeing with themselves and with a lot of relatively small factories scattered around the country.  While this may have been good, to a degree, in wartime it was not sorted out postwar.

 

The one company that remained fiercely independent was Handley Page.  As a result it lost out on all govt business after about 1960 and then went bust.