RAF after BoB: mid-term strategy, tactics technology?

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On the British 4 engine bombers you have to remember that they were ALL designed to a requirement that they should be able to transport 24 fully armed soldiers in case of need. This means they had rather large fuselages right from the start. Some designers may have placed more importance on that requirement than others.

This might have been true of B.12/36, from which the Stirling came, but not of P.13/36, from which the Manchester/Lancaster and the Halifax by way of the HP.56, which were designed to be smaller overall than the aircraft of B.12/36, twin instead of four engines. On both specs gun turrets were mandatory for defence. The Hali certainly had a large enough fuse to carry troops and was used in that role, but it was somewhat larger than the HP.56 design. Which ever way you look at it, you're not going to get 24 troops in the fuselage of the Manchester/Lancaster! :) Lancastrian maybe, but not the Lanc or Manchester, it'd be standing room only and they'd risk getting bopped in the head by the mid upper turret. That is unless they lay down between the fwd and rear wing spars... nah. There's not much room in there.

There would be a number of imperatives: - guard South-East England just in case the Luftwaffe tries BoB mark II,

Merlin has a point. This would or should be number one priority. A more defensive stance in late 1940 should be applied to all the services across the entire country; shoring up the barricades for the night bombing offensive, at the expense of other commands if need be. As with the rest of you, no leaning into France; a waste of resources. The first priority is night fighter defences. Let's look at the options post BoB:

Blenheim; obsolescent but a necessity since there is a desperate shortage of suitable aircraft, but once these come on line the Blenheims should go to OTUs. Their radar is an advance, but proved faulty in service, plus the Blenheims were so slow, they often couldn't catch the enemy bombers. Bring Blenheim production to a standstill and concentrate on bringing Beaufighters in their place on the production lines.

Beaufighter; not available in large numbers initially, plus, very difficult for pilots used to the benign handling of the Blenheim and Defiant to get used to. There were a large number of crashes at OTU level as a result. This was largely from the Beaufighter Mk.II with its Merlins, whose handling was described as 'evil', but these are also necessary; an evil handling Beaufighter is better than no evil handling Beaufighter in the numbers game. Advanced specific training at OTU level to assist tyro pilots to get round its handling issues. Beaufighters were hampered in service by the radar sets also and the type really didn't get into service in suitable numbers to replace interim types until early '42 as a result of technical difficulties - much effort should be expended to sort electronic issues out to facilitate smoother radar ops for British night fighters.

Defiant: As a result of the Beaufighter's unexpected troublesome introduction into service, the Defiant rose in importance. Although not ideal, it had little or no vices in its entry into night fighter service, plus it was available in numbers. BP had been building Defiants for more than a year or so, so the two squadrons that served in the BoB can be bolstered by fresh production examples used strictly for new night fighter units. Little can be done with the Defiant; it's not going to get any faster and the Daffy Mk.II is also having trouble with its radar, but it's better than nothing. Once Beaufighters come on line, the Defiants can be sent to OTUs (the largest Defiant operator was 60 night fighter OTU).

Hurricane: In my scenario, the Hurricane takes on greater prominence as a night fighter. Since day fighter units are not going to be so busy on offensive ops, I propose that day Hurri squadrons (not all, though) convert to strictly night ops, along with new build Hurricanes, with crews going through OTUs for specialist training. Once the 'thin wing' Tornado/Typhoon is sorted out, it would replace the Hurricane in production altogether, since it was approaching obsolescence by 1942 - 43, and go into service as the RAF's single-seat night fighter.

Mosquito: By the end of BoB the DH.98 prototype had not yet flown, but a spec for a night fighter variant had been issued, so little can be done to the Mossie's timeline that wasn't done in reality. The idea of building the Mossie with a tail turret can be canned for certain!!! Perhaps anticipating a need and establishing production facilities (for engines as well - Canadian Mossies had Packard Merlins) in Canada and Australia from the outset when the type was ordered?

OTUs: More specialist night fighter OTUs are required, with radar operations taking prominence. Experienced aircrews on front line squadrons would naturally be given a tour of the OTUs to facilitate training, and to give them a bit of a rest.

New designs: In July 1940 Spec F.18/40 for a new night fighter was issued, in December it was altered to incorporate a turret - scrap that and continue it without said appendage. The Gloster Reaper was one aircraft conceived to this, but it wasn't progressed with because Gloster didn't have the resources to work on jets simultaneously to setting up production for the Reaper. Jets are obviously important for the future, so that cannot be interrupted. Two options are available here. Another firm, Boulton Paul or Miles perhaps could put the Reaper into production as a twin engine fighter bomber/night fighter, photo recon platform, estimating an in-service date to suppliment Mossies and Beaufighters in 1942, or option two undertake Mosquito production (easier for Miles than Boulton Paul) and can the F.18/40 spec altogether.

Another option is looking to the USA. Traditionally, Douglas Havocs arrived for RAF service since the US didn't have a specialised night fighter in late 1940, but the Havoc was slow, like the Defiant and Blenheim, but it bolstered numbers. Perhaps a Lockheed Lightning night fighter derivative? We are straying into other threads here.

That's the aircraft side of things, obviously greater defensive measures around the country would be put in place to combat the German bombers and deter their use of sophisticated radio nav aids.

Once the bombing offensive - in late 1940 no one could judge when this might happen - the next step in the plan would be to look at offensive elements and improving the RAF's strike capabilities. Traditionally, the German invasion of Russia gave the British some breathing space, so once the bombing offensive against Britain eases, step two can be acted on. This involves improving Bomber Command and crucially, Army Co-operation Command, which takes on increased importance in my scenario.
 
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Another option is looking to the USA. Traditionally, Douglas Havocs arrived for RAF service since the US didn't have a specialised night fighter in late 1940, but the Havoc was slow, like the Defiant and Blenheim, but it bolstered numbers. Perhaps a Lockheed Lightning night fighter derivative? We are straying into other threads here.

By the time you start getting these Lightning NF.IIs you should also be getting some Mosquito NF.IIs. The Mosquito is definitely better for the radar operator.
 
Yep, probably right, but when your back's against the wall and all you have is a handful of Blenheims and Defiants and Beaufighters that don't work properly, you take what you can. The RAF put the Havoc into service despite its inadequacies, so the idea of a night fighter Lightning doesn't sound so bad when attempting to bolster numbers.
 
Bombers. That powerplant would yield a better performer than an early Douglas DB-7 (tough target for Bf-109Es) or B-26 (hard catch for Zeroes), let alone the Beaufort, Maryland or Baltimore. Should do just fine at CBI PTO.
Goes without saying that other engines should be better choices, though.

Sorry, but an R-1830 in a Mosquito airframe is a waste of an airframe.

Mosquito production was, in my mind, restricted by airframe production, not engine supply.


It probably would. We need to have working Griffons prior the summer of 1942, though? Again, what the Napier and Hawker/Gloster to build if we forget Sabre Typhoon? An expedited 2-stage Merlin pretty much negates the need for the 1-stage Griffon.

The XII was faster down low than the F.IX or LF.IX, though maybe not when LF.IX gets +25psi boost.

I suggested earlier, Napiers can have a little longer to perfect the Sabre so they can put it in the Hawker P.1005 unarmed high speed bomber.
 
Sorry, but an R-1830 in a Mosquito airframe is a waste of an airframe.

I've just read a bit about the Argentinian Calquin, really a non-performer. Guess I can shelve the Mossie on Twin Wasps.

Mosquito production was, in my mind, restricted by airframe production, not engine supply.

Probably. If we attempt the increase in Mossie's production, alternative engines could come in handy.

The XII was faster down low than the F.IX or LF.IX, though maybe not when LF.IX gets +25psi boost.

Agreed. In case RR can come out with the 1-stage Griffon some 15 months after the BoB (winter of 1941/42), that would likely give us the 2-stage version for service use in say, Spring/Summer of 1943?

I suggested earlier, Napiers can have a little longer to perfect the Sabre so they can put it in the Hawker P.1005 unarmed high speed bomber.

The Sabre-powered bomber should really be capable to lug an 8000 lb cookie to offer an advantage over the Mossie? The P.1005 have had wings in mid-wing position - would that restrict the bomb bay?
 
Part of the problem with increasing Mosquito production by a LOT, is trying to get the wood for it. With Ecuadorean Balsa wood being used as the core of the sandwich you are rather limited. Balsa trees don't grow in stands or forests of balsa trees but a a bit scattered. Balsa does grow in other countries but Balsa can also vary in weight per cubic inch (CC) quite a bit. Then you have then you have the Spruce outer layers and spars, only certain grades of Spruce will do. long, straight grain and knot free. Also selected by weight to volume ratio.
You can't use Pine or Oak or Elm or............
Canada (and US ?) had the Spruce but doubling wood output was not quite like doubling the output of a mine or smelting. The Trees had to a minimum age to get the growth/grain structure wanted and also couldn't be over a certain age without causing problems.
Now maybe the wood production was not maxed out but just saying you are going to double or triple Mosquito production if you can get the engines might be a lot harder than it looks at first glance.
 
Guess that a 30% increase of the production would gave a boost to the Allied cause. That, and more emphasis on bomber versions.

Back to the engines a bit - wonder whether it would be of use to develop the 2-stage version of the Hercules? Bristol was experimenting with 2-stage supercharging pre-war (setting the world record in process), though the systems were quite bulky then.
 
The Sabre-powered bomber should really be capable to lug an 8000 lb cookie to offer an advantage over the Mossie? The P.1005 have had wings in mid-wing position - would that restrict the bomb bay?


The P.1005 was designed from the beginning to carry 4000lb, rather than the Mosquito's 1000lb (changed to 2000lb early on).

The data sheet shows 1 x 4000lb, 2 x 2000lb and 4 x 1000lb bombs. The Mosquito with bulged bomb bay could carru only 2 x 1000lb bombs, and early experiments with the normal bomb bay had 1 x 1000lb and 2 x 500lb.

I doubt that the P.1005 could have taken the longer and larger in diameter 8000lb HC bomb.
 
Good source for info on British bombs. Bombs

8000lb HC was 38in diameter and either 131.5 or 159in long depending on tail, The 4000lb HC was 30in diameter and 110in long. Lancasters had to use bulged bomb-bay doors to handle the 8000lb HC bomb.
 
Now maybe the wood production was not maxed out but just saying you are going to double or triple Mosquito production if you can get the engines might be a lot harder than it looks at first glance.

Yet they built over 7,000 Mosquitoes and not to mention other wooden aircraft, such as the Oxford, Magister etc. I honestly don't think it would have been too much of an issue, to be honest. A lot more of the world was forested back then than what it is now. The issue with the Mossie was that there weren't enough of it to go round.
 
Thought that it would be better to discuss a bit about Hercules vs. Merlin here:

Merlin 45 1,190hp @ 23,000ft. Weight 1,385lb
Merlin XX 1,430hp @ 11,000ft. 1,460hp @ 6,500ft. Weight 1,450lb
Hercules VI 1,545hp @ 15,500ft. 1,750hp @ 6,500ft.. Weight 1,845lb.

The Hercules has more power than the equivalent period Merlin, but also more weight and drag. Plus there would need to be significant revisions to the fuselage since the Hercules is nearly twice as wide. Also, the prop centreline will be lower so the prop diameter will be restricted and the extra hp may not result in extra thrust.

The Merlin 45 was good for 1515 HP at 11000 ft, corrected for altitude it gives ~1300 HP at 15500 ft, and ~1130 HP at 20000 ft. IOW, some 250 HP less than Herc VI at 15500 ft, and some 200 HP less at 20000 ft. The weight of cooling system need to be added for the Merlin - 350 lbs? We might recall that BMW-801C was some 200 lbs heavier than the Hercules, making 1360 HP at 15100 ft (the restricted BMW 801D was in the ballpark). The heavy Fw-190s (even before the restrictions on the 801D were lifted) were still faster and with greater RoC than the lightweight and more sleek Spit V.
As for changes required to the Hercules Spitfire to work - Lavochkin and Kawasaki were capable enough to pull that out, the people at Supermarine are at least as good. As for the prop - the 4-bladed can be used, like the one installed at the Spitfire VI. Part of the drag can be cancelled out by deletion the underslung radiator.

The Spitfire with such power should be able to at least hold it's own at all altitudes against the Fw-190 (prior late 1942, by then we should have had 2-stage Merlins around) and Bf-109F-4, a thing that the Spitfire V has been unable to do. At lower altitudes, it would be a far tougher machine, especially vs. the Bf-109.
 
Don't forget that you have much more blockage behind the prop with the Hercules than the Merlin.

Also, Beaufighter with Merlin XX was faster than with Hercules.
 
Also, consider that the Fw 190 had a much better installation of the radial than was the case in the UK at the time. It wasn't until the Tempest II in 1944/45 that the British caught up.
 
Don't forget that you have much more blockage behind the prop with the Hercules than the Merlin.

Fair enough. Seems like the La-5 and Ki-100 managed to deal with that problem.

Also, Beaufighter with Merlin XX was faster than with Hercules.

If it was - how much was the difference? What about the RoC? BTW, there was a reason for calling the handling of the Merlin Beau as 'vicious' - the lack of power was really felt?

Also, consider that the Fw 190 had a much better installation of the radial than was the case in the UK at the time. It wasn't until the Tempest II in 1944/45 that the British caught up.

150 extra HP should cater a good deal for imperfections of engine installation. We can recall that an usual BMW-801 installation was not perfect either - the internal air intakes cost a good deal of aircraft performance; Hercules used external intake.
The Hercules Spitfire should still be a good deal lighter than Fw-190, that wold yield benefits in RoC and (though less) in speed.
 
Fair enough. Seems like the La-5 and Ki-100 managed to deal with that problem.

I would imagine that they were less compromised by the landing gear than the Spitfire was.


If it was - how much was the difference? What about the RoC? BTW, there was a reason for calling the handling of the Merlin Beau as 'vicious' - the lack of power was really felt?

I don't think it was a lack of power. Probably more to do with the shift in CoG and slightly different aerodynamics.

Not sure on the RoC.

150 extra HP should cater a good deal for imperfections of engine installation. We can recall that an usual BMW-801 installation was not perfect either - the internal air intakes cost a good deal of aircraft performance; Hercules used external intake.
The Hercules Spitfire should still be a good deal lighter than Fw-190, that wold yield benefits in RoC and (though less) in speed.

The 150 extra horsepower would struggle to overcome the extra drag, IMO. This also affects RoC.
 
Also, Beaufighter with Merlin XX was faster than with Hercules.

Over 20,000 feet. Under those heights the Hercules Beaufighters were generally 20-30 mph faster.

What about the RoC?

Data Sheets say:

Time to 15,000 feet
Mk.I - Herc III: 9.5 minutes
Mk.I - Herc XI: 8.7 minutes
Mk.II - Merl XX: 8.8 minutes
Mk.VI - Herc VI: 7.8 minutes
 
It wasn't until the Tempest II in 1944/45 that the British caught up.

The Fw 190 is often credited with being partially responsible for the design on the Centaurus installation in the Tempest and Fury, but Hawker were working on that installation on the Tornado in 1940 and I've never seen anything official to state the Fw 190 connection.

The Merlin Beaufighter's issues were concernign the shift in CG forward and also its asymetric handling. On the ground, if pilots were not careful, advancing the throttles, even gingerly caused the aircraft to ground loop. Part of its reputation came from the fact that OTU pilots experienced on Blenheims and Defiants got used to rather benign handling and the Beau Mk.II was a little much. This caused many accidents.
 
It wasn't until the Tempest II in 1944/45 that the British caught up.

The Fw 190 is often credited with being partially responsible for the design on the Centaurus installation in the Tempest and Fury, but Hawker were working on that installation on the Tornado in 1940 and I've never seen anything official to state the Fw 190 connection.

The Merlin Beaufighter's issues were concernign the shift in CG forward and also its asymetric handling. On the ground, if pilots were not careful, advancing the throttles, even gingerly caused the aircraft to ground loop. Part of its reputation came from the fact that OTU pilots experienced on Blenheims and Defiants got used to rather benign handling and the Beau Mk.II was a little much. This caused many accidents.
 
The Fw 190 is often credited with being partially responsible for the design on the Centaurus installation in the Tempest and Fury, but Hawker were working on that installation on the Tornado in 1940 and I've never seen anything official to state the Fw 190 connection.

The Tornado's installation in 1940 was different to the Tempest's in 1944.
 
If you were converting the Spitfire to a radial engine, a fully-worked installation like that on the Fw 190, La 5 or Tempest II would be nice, but by no means essential. As far as I can tell the Ha-112 installation in the Kawasaki Ki-100 was a very hasty lash-up, with extra fairing being tacked onto the fuselage behind the air and exhaust exits. Despite this, the new fighter was 300 kg lighter than its inline progenitor, and had correspondingly better performance and handling. So a quick-and-dirty conversion of the standard Hercules power-egg installation to fit the Spitfire firewall, with some tin stuck on behind to make it look nice, would be a pretty good start.

Although the dry weight of a Hercules is about 500 lb greater than a single-stage Merlin (or about 300 lb more than a two-stage), once the weight of the cooling system is also considered, there really can't be much in it weight-wise. And the Hercules is of course shorter than a Merlin, so installed on the same firewall in a Spitfire V would give pretty much the same balance.
 

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