DBWI: Manchester with 4 Merlins

[gruad]

[DBWI="Double Blind What If" is when you comment as if you are in the alternate reality and propose the current reality]

The Manchester must go down as one of the worst bombers of WW2. It had coupled engines that failed spectacularly. On one raid 12 planes were lost this way.

Thankfully Beaverbrook took one look at this flying coffin and ordered Avro to produce the Halifax.

But there was a plan by the Manchester's designer, Roy Chadwick, to convert the plane to 4 Merlins and some historians think it might have worked.

I for one disagree. As we know from the Halifax the Merlin was not a suitable engine for a bomber. The Hx only achieved its potential once it was fitted with the Hercules radial engine.

So, yes, good job they only built 200 Manchesters as Avro went on to build 4,000 of the 9,500 Halifaxes built!

Do other members of the forum think this scheme had any chance of success?

 

[Thumpalumpacus]

Well, now I can't find my ass with both hands and a Thomas Guide.

 

[wuzak]

The Manchester must go down as one of the worst bombers of WW2. It had coupled engines that failed spectacularly. On one raid 12 planes were lost this way.

The Rolls-Royce Vulture was not a coupled engine. It was an X-24 - 4 banks, 1 crankshaft.

The Daimler-Benz DB606 and DB610 were coupled engines, where two engines were joined to one prop through a gearbox, in which either engine could be disconnected from the propeller and shut down.

The Manchester also had many other faults, including with the hydraulics, electrics and aerodynamics (hence the third fin on many early Manchesters), most of which were solved before the Lancaster entered production.

 

[wuzak]

But there was a plan by the Manchester's designer, Roy Chadwick, to convert the plane to 4 Merlins and some historians think it might have worked.

I for one disagree. As we know from the Halifax the Merlin was not a suitable engine for a bomber. The Hx only achieved its potential once it was fitted with the Hercules radial engine

There really was no option for a 4 engine Manchester other than the Merlin.

The Hercules wasn't that powerful at the time, and were in short supply.

The Halifax "only achieved its potential" when fitted with later model Hercules, several years after the first proposal to change the Manchester to Merlins.

 

[tomo pauk]

There really was no option for a 4 engine Manchester other than the Merlin.
The Hercules wasn't that powerful at the time, and were in short supply.
The Halifax "only achieved its potential" when fitted with later model Hercules, several years after the first proposal to change the Manchester to Merlins.

Hercules was powerful enough early enough. It powered the Striling many months before Merlins powered the Lancaster.

 

[wuzak]

Hercules was powerful enough early enough. It powered the Striling many months before Merlins powered the Lancaster.

Ok, maybe powerful, but they weren't in great supply (we're talking pre 1940).

And the Halifax was being developed around 4 Merlins since 1937/38.

 

[nuuumannn]

The Manchester must go down as one of the worst bombers of WW2. It had coupled engines that failed spectacularly. On one raid 12 planes were lost this way.

Thankfully Beaverbrook took one look at this flying coffin and ordered Avro to produce the Halifax.

But there was a plan by the Manchester's designer, Roy Chadwick, to convert the plane to 4 Merlins and some historians think it might have worked.

I for one disagree. As we know from the Halifax the Merlin was not a suitable engine for a bomber. The Hx only achieved its potential once it was fitted with the Hercules radial engine.

So, yes, good job they only built 200 Manchesters as Avro went on to build 4,000 of the 9,500 Halifaxes built!

Do other members of the forum think this scheme had any chance of success?

Um, a few things at odds with reality here, firstly, Avro didn't build the Halifax, Handley Page did. Chadwick had nothing to do with it, its designer was George Volkert. The Merlin engined Manchester became the Lancaster, although it was originally known as the Manchester Mk.III.

Next, whilst the Manchester was a bit of a dog, the issues that beset it were largely cured by late 1941 early 1942 and in essence it was a sound design, the fuselage required little change when conversion to the Lancaster took place. That massive 33-foot long unobstructed bomb bay, unique in a WW2 bomber was applied to the Lancaster and enabled enormous flexibility in the types of loads it could carry, the armament remained the same although crew positions changed with a rationalisation within Bomber Command itself. The hori stab increased in length, but not much else apart from a new wing and powerplant and strengthened undercarriage to cope with increased all-up weight. This is why Lancasters got into frontline service relatively quickly after the prototype flew - the production line building Manchesters could make the change to the new type relatively swiftly.

The Manchester certainly had issues with its engines, which were not coupled, but by the time the Manchester Mk.Ia was in service in numbers had already been fixed and the engine displayed good reliability. The Vulture was discontinued by Rolls-Royce because of rationalisation of production of the Merlin since more aircraft were powered by it. Next, the Manchester's electrical issues were largely solved by the time the Lancaster entered production as has already been said here.

One of the problems that beset it was severe vibration when the Nash & Thompson FN.7 top turret turned, which induced vibration due to airflow around the turret when turned, the simple answer was to get rid of it in the Manchester Mk.III. The stability issues were fixed by increasing the height of the vertical stabilisers which were first applied to the Manchester Mk. III prototype BT308, (which became the Lancaster prototype) and then retrofitted to the Manchester Mk.Ia and the centre fin was removed.

Let's also put the Manchester into context, it was among the first big all-metal bombers being built around the world; in the late 1930s there weren't that many and it was thoroughly new and innovative, with largely electrical systems and a full armament of power-operated turrets, which was unique; Only the Wellington had full armament in power turrets at that time (the early Whitleys had an unpowered Armstrong Whitworth turret fitted to them). The Manchester was the first large all-metal modern bomber that Avro had designed and built, it was only the second all-metal modern aeroplane Avro had built, the first was the Bristol Blenheim under licence. Up to that time, the most modern aircraft Avro had built was the Anson, which was based on the 1920s Fokker F.VIIb in technology, with a tubular fuselage covered in fabric and wooden wings. It didn't even have hydraulics.

So, given all that and the immediate success of the Lancaster as soon as it entered service, the Manchester proved a worthy foundation for Britain's most successful bomber of WW2. As for the Handley Page Halifax, it was a dud for different reasons.

 

[glennasher]

I think it was Guy Gibson who said (paraphrasing), regarding the Manchester, "The actual kite's alright, but the engines suck", or words to that effect. Or, it was someone he was talking with, either way, the point was made.

 

[pbehn]

I think it was Guy Gibson who said (paraphrasing), regarding the Manchester, "The actual kite's alright, but the engines suck", or words to that effect. Or, it was someone he was talking with, either way, the point was made.

The Lancaster was blessed by the shelving of the Vulture engine, even if it had reached projected power outputs it would still be a twin engined plane, loss of one engine would always be a disaster, it would never have been a "heavy" bomber.

 

[nuuumannn]

Yup, the Manchester wasn't classed as a heavy bomber at any rate. It was built to P.13/36, which was a medium bomber specification, whereas B.12/36, to which the Short Stirling was built was the heavy bomber specification. Of course, that massive bomb bay could carry a load to match the Stirling's, but its range was considerably depleted.

 

[wuzak]

The Lancaster was blessed by the shelving of the Vulture engine, even if it had reached projected power outputs it would still be a twin engined plane, loss of one engine would always be a disaster, it would never have been a "heavy" bomber.

Agreed, the airframe was too big and heavy for just two Vultures, at the design power of 1,800hp+. Even at 2,500hp, which the Vulture achieved in testing, it was too big and heavy.

What then of a 4 Vulture Manchester?

The main problem with the Vulture was that it was underdeveloped. It was a few years behind the Merlin in that sense (early Merlins weren't that great either).

 

[pbehn]

Agreed, the airframe was too big and heavy for just two Vultures, at the design power of 1,800hp+. Even at 2,500hp, which the Vulture achieved in testing, it was too big and heavy.

What then of a 4 Vulture Manchester?

The main problem with the Vulture was that it was underdeveloped. It was a few years behind the Merlin in that sense (early Merlins weren't that great either).

Even if it produced a reliable 3,500, that would just mean a higher pay load and more stuff inside. I presume it used more fuel than a Merlin so a four Vulture engined Lanc. would be higher performance and less range and unable to use the performance in a bomber stream.

 

[Koopernic]

Manchester III BT308. was a version powered by four Merlin engines with increased wingspan; also, the three fins and rudders of the Manchester I were retained. This variant was the first prototype of the later Avro Lancaster.

The original Manchester had two fins. The central fin was added to overcome a lack of sufficient directional stability.
I believe the fins in the Lanchester were simply enlarged and the central fin deleted.

 

[wuzak]

Manchester III BT308. was a version powered by four Merlin engines with increased wingspan; also, the three fins and rudders of the Manchester I were retained. This variant was the first prototype of the later Avro Lancaster.

The original Manchester had two fins. The central fin was added to overcome a lack of sufficient directional stability.
I believe the fins in the Lanchester were simply enlarged and the central fin deleted.

Late production Manchesters got the enlarged tail fins/rudders and, IIRC, larger tailplane, which would be used on Lancaster production.