January 1936: build your RAF

[tomo pauk]

There is a good deal it the timing.
In the time Merlin X was available (pre-war; 2 speed S/C), the service V-1710 'C' was barely in production. By the time the V-1710 'F' was in production (early 1941), the Merlin XX (with Hooker's improvements to the S/C) was already in production for maybe half a year, and P&W was introducing a two-stage R-1830. By the time the V-1710 F with a reliable 9.60:1 supercharger drive ratio is in production (second half of 1942), both Merlin and R-2800 are available with 2-stage supercharger.
Being the 1st and foremost a 'fighter' engine, the single stage V-1710 lacked a bigger supercharger (9.50 in diameter, against Merlin's usual 10.25 in S/C), more than a multi-speed one.

 

[gjs238]

.

 

[swampyankee]

The big problem with many of the aircraft developed isn't the design, but the specifications that led to that design: the Swordfish was a good design to a very demanding specification (for one thing, the aircraft had to be able to be launched by the catapults of non-carriers). The spec probably couldn't have been met by a monoplane.

The specs were, to a great extent, caused by a mix of penury (Tories didn't want to spend any money; Labourites didn't want to spend any on the military) and inter-service politics (which were probably exacerbated by lack of money); the latter probably led to the RN losing a great deal of staff expert on aviation matters, which fed into the specs problem when the FAA was formed.

So, it's 1936, and what do I as the new czar of all the British aviation world?

1) It's better to defend Britain over the fields of Europe: at least the pieces of airplane falling from the sky won't hurt your own subjects. This would require closer defense cooperation with France and Belgium. This means that you'll need aircraft that can fight over at least the parts of Continent, from British bases.

2) Germany had demonstrated its affection for using submarines against merchant ships in a recent war. Assume they'd do so again, so some long-ranged aircraft for MPA would be incredibly useful. The last war had shown that even unarmed aircraft can force submarines to submerge, reducing their mobility.

3) Maybe dive bombers won't work against battleships, but not all ships are battleships, and sinking enemy destroyers, cruisers, and transports is not going to hurt the British war effort.

4) Spend some money on float-less carburetors, better gun sights, etc.

 

[tomo pauk]

The heavy fighter, based around two Merlins, was well within scope of British industry. A 'classic twin', like 'Whirlwind and a half', or a 'metal DH Hornet', or a really materialized Gloster Reaper. A fighter-bomber and a night fighter variant should leave more Mossies for bomber duties.

 

[nuuumannn]

I believe a fair number of my proposals are to prevent some of the "high losses and unecessary deaths of aircrew" as much as they are to increase the operational capability of the Blenheim or turn it into 'super bomber". Better engine out capability means more crews make it back after loosing an engine, and better chances of getting the plane back on the ground in one piece if an engine cuts out on take-off. Better cockpit layout would help there too and doesn't realy cost much in the grand scheme.
It should have been replaced much quicker but the "replacements" were slow in coming. Improve the Blenheim so more aircrew survive until the replacements come and for this "what if" try to make sure the effective replacements come sooner by ditching some of the intermediate designs that took up so much time and weren't that effective. All too many Beaufort crews were lost too.

Problem is, when do you start doing this and what impact would it really have? I don't believe much would change and with the workload Bristol had pre WW2, what gives in its place? A two-speed supercharged Mercury gives the Blenheim what in performance? An extra 10, 20 maybe 30 mph? Still makes it vulnerable and like you've pointed out, there are other issues with it rather than just its low engine output. Still not convinced and with hindsight, I don't believe it would make a huge amount of difference to the type in the long run. RAF losses will still be high on the type. Much of this had to do with how they were used rather than the aircraft itself, but its low performance certainly didn't help. Also, there's is no way you are going to get a torpedo to be carried under a Blenheim! You'd have to strengthen and redesign the undercarriage, then add more powerful engines, Hercules' maybe, get rid of extra crew... wait, that's a Beaufighter...

 

[Shortround6]

The difference in speed would be nonexistent at higher altitudes, 13-18,000ft. Use the high gear from the fully supercharged engine and a low gear about the same as the moderately supercharged engine. Better performance at low altitude though. British turrets, while ahead of the rest of the world (mostly) seemed to suffer a disconnect. They had fighters with eight .303s and were planing on 20mm cannon and yet thought single drum feed .303 guns were adequate defense?
or twin .303s on the big bombers?
All I am hoping for is fewer operational losses and perhaps more crews getting back with damaged aircraft. Having more power and less drag (a prop that fully feathers) may mean much higher speeds/climb when on one engine.

as to the torpedo, Most sources give 1320lbs as the bomb load for the Blenheim, which includes eight 40lb bombs hanging on a pair of racks, one behind the other, under the fuselage behind the bomb bay. They also carried enough fuel for 1400 miles. Torpedo weighed about 1700lbs. Use 56imp gallons less fuel and weight problem is solved. Not the range of a Beaufort but a lot better than a Vildebeast which is what you are replacing. BTW the max take-off weight for the MK V Blenheim was 17,000lbs so they did beef up the landing gear at some point.
With the extra power at low level from the 2 speed supercharger it may be possible.

 

[tomo pauk]

Now that we've beaten the fighters and twin-engined bombers to death, what about heavy bombers. When is a good time to introduce 4-engined stuff? The 1st ones can rely on Pegasus/Perseus/Mercury engines, even the A-S Tiger can be useful here. Would still need either escort (but won't get it?) or to operate during the night. Next gen bombers can use Merlins and Hercules, while the 1st gen can do MPA work.

 

[nuuumannn]

British turrets, while ahead of the rest of the world (mostly) seemed to suffer a disconnect. They had fighters with eight .303s and were planing on 20mm cannon and yet thought single drum feed .303 guns were adequate defense?

Experience during the war taught the British that .303s were inadequate, they took their time about introducing the .5, although both Boulton Paul and Frazer Nash built .5 in gun armed turrets early on, they weren't put into production.

If you are going to reinvent the Blenheim, I'd get rid of the turret and save yourself some weight. It was not powered.

Regarding torpedo aircraft, the Beaufort spec was hampered by the fact that the Air Ministry wanted a crew of four, hence its bulky size mid fuse area. Originally it was designed based on the Blenheim, so for your theoretical non-existent Beaufort scenario, you could use the Blenheim as a basis for a torpedoplane, but ignore the four crew requirement; the Beaufighter only had two, but that was in wartime and experience had meant that aircrew could multi task, but again, what to power it with? I still don't accept a revamp of the Blenheim as it was; it's not really worth the effort, I'm afraid - using hindsight as a judge. The only thing would be to reinvent it from scratch. Structurally it wouldn't be strong enough to carry a torpedo; you'd have to redo the lower fuselage under the wing and remove the bomb bay for strengthening.

Sorry Tomo.

Next gen bombers can use Merlins and Hercules, while the 1st gen can do MPA work.

The thing is, you are describing the Whitley and Wellington. You could come up with alternatives to B.12/36 (Stirling) and P.13/36 (Manchester and HP.56). B.12/36 also produced the Supermarine heavy bomber (Type 316, then 317), construction of which was cancelled after Woolston was bombed during the war, which destroyed work on the aircraft, leaving the troublesome Stirling. Firms that conceived bombers to this include AW, whose design looked a bit like a four engined Whitley, the Boulton Paul design was technically advanced, Bristol and Vickers. The Air Ministry stated that this spec was (quote) "of outstanding importance..." and were happy with the Short and Supermarine designs, but the death of Mitchell left a bit of uncertainty in their minds, leaving the S.29 as the favoured aircraft. Because of Short's haphazard means of manufacture - although common to most British firms, the Stirling took a long time to conceive and was plaqued with production issues and wasn't that great a performer when it did get into service, so perhaps a better Stirling?

The next spec P.13/36 is for a medium bomber to suppliment the former, but in effect it kind of evolved into another heavy. By this time, both specs stipulated powered turrets for defence. It also had the rather straining requirement of being able to be catapulted from the ground with a full bomb load (!) Thankfully, this was later relaxed, although I've seen pics of Manchesters sitting on test rigs, though I don't know if it was ever done. Engine options are the restriction here, the stipulation was for Vultures and HP dropped the twin Vulture HP.56 for four Merlin HP.57, mainly because of a possible shortfall of engines. This also meant that Chadwick and Dobson at Avro planned a four engined Manchester from early on, so as an insurance plan, get that going simultaneously to the Vulture engined one. We know HP are going to have trouble with their Halifax, which means it would be another two to three years after it flies for the first time before the issues are sorted.

Regarding MPA, perhaps a long range four engined aircraft from scratch?

 

[Greyman]

If you are going to reinvent the Blenheim, I'd get rid of the turret and save yourself some weight. It was not powered.

Definitely powered.

 

[nuuumannn]

Well slap my thighs and call me Susan. Thanks Greyman.

 

[parsifal]

youll be right susie

 

[Shortround6]

Experience during the war taught the British that .303s were inadequate, they took their time about introducing the .5, although both Boulton Paul and Frazer Nash built .5 in gun armed turrets early on, they weren't put into production.

If you are going to reinvent the Blenheim, I'd get rid of the turret and save yourself some weight. It was not powered.

Regarding torpedo aircraft, the Beaufort spec was hampered by the fact that the Air Ministry wanted a crew of four, hence its bulky size mid fuse area. Originally it was designed based on the Blenheim, so for your theoretical non-existent Beaufort scenario, you could use the Blenheim as a basis for a torpedoplane, but ignore the four crew requirement; the Beaufighter only had two, but that was in wartime and experience had meant that aircrew could multi task, but again, what to power it with? I still don't accept a revamp of the Blenheim as it was; it's not really worth the effort, I'm afraid - using hindsight as a judge. The only thing would be to reinvent it from scratch. Structurally it wouldn't be strong enough to carry a torpedo; you'd have to redo the lower fuselage under the wing and remove the bomb bay for strengthening.

British had pretty much figured out that the .303 was lacking in effectiveness well before the war. Which is why they were working on the 20mm canon. What is puzzling is that when they were trying to build fighters with eight .303s that fired at 1200rpm each (or close) it seemed like they thought a single .303 Lewis gun (600rpm) was adequate to defend the bomber/s even though they had often used twin Lewis guns and many WW I bombers/flying boats against much less sturdy fighters.
Now maybe the Lewis guns were 'place holders' until they could get enough Vickers 'K' guns (900-1000rpm) and the Lewis guns were free, being left over WW I guns stored in warehouses.
Granted the power mountings/turrets offered much better tracking/aiming than the old hand powered mounts but if you are going to the weight/complexity of a turret saving weigh by leaving out a 22-30lb gun and around 30-45lbs of ammo /drums seems like a poor trade off.

While powered the Blenheim turret may have had only 180 of traverse. Of course many hand held mounts, while they could traverse over 180 degrees on the ground were very limited in effective traverse in the air as the slipstream buffeted the gun/s and tried to push them back into pointing at the tail. That or you used a large, high drag wind defector/s.

Hampden's gun mounts were not powered and please notice the sophisticated method of keeping the gunner form shooting up his own aircraft
Early Hampdens had single guns.
British also seemed to think that a single fixed .303 Browning was adequate defense from the front on the faster, more maneuverable bombers. Try to imagine a squadron of bombers in formation all bobbing and weaving about as the pilots tried to get their gun sights on attacking fighters
Hampden, BTW, is an alternative for long range torpedo bomber. It was certainly used as such but perhaps not until later in the war?

For some roles the Blenheim flew getting rid of the turret would have been an advantage. Like nightfighter, of course designing a new belly pack for the guns instead of going on to make hundreds of that thing made by railroad apprentices (even steam locomotives had curves) would have helped also.

There is nothing you can do to a Blenheim to make it a decent warplane in 1943/44 when the last were coming out of service but there was a lot that could have done earlier. Better landing gear and landing gear doors were fitted. A better turret was fitted (although it certainly didn't lower the drag). Better propellers could have been fitted, not so much for performance (although they would have helped) as for crew safety/survival.
Trying to take existing Blenheims and turn them into torpedo bombers (like existing Blenheims were turned into fighters) probably wouldn't have worked. But building a run of torpedo bombers in the factory with suitable modifications may have worked. And if you are going to keep the Blenheim around, making a Blenheim X that used similar construction to the Beaufort (more aluminum and less steel) might not have been out of the question.

 

[tomo pauk]

A little bit about the engines - what about an alternative to Hercules and Centaurus? A Twin Mercury maybe - 50 liter engines have a certain charm

 

[Shortround6]

You mean something like this?

Alfa Romero built about 150 but never did get them to work right.

Doubling engines was a lot harder than it appears at first glance.

 

[Juha]

...Hampden, BTW, is an alternative for long range torpedo bomber. It was certainly used as such but perhaps not until later in the war? ...

From 42 to early 44 IIRC, also some 23 TB Mk Is were given to Russians who used them appr, a yea r in Barents Sea area.

juha

 

[Greyman]

While powered the Blenheim turret may have had only 180 of traverse.

The turret rotated 60 degrees port/starb and the gun cradle rotated 40 degrees. So basically 100 degrees either direction.

 

[nuuumannn]

Trying to take existing Blenheims and turn them into torpedo bombers (like existing Blenheims were turned into fighters) probably wouldn't have worked. But building a run of torpedo bombers in the factory with suitable modifications may have worked. And if you are going to keep the Blenheim around, making a Blenheim X that used similar construction to the Beaufort (more aluminum and less steel) might not have been out of the question.

Yep, you're right, it wouldn't have. Starting from scratch is your only option, but, I still don't believe the Blenheim had any more mileage in it. Via the Beaufort, the Beaufighter is where your attention should be going. it can be argued that the Beaufighter is what the Blenheim should have been in the first instance. Powerful, able to carry a significant load and a variety of stores, two crew, versatile etc... This is the thing; if improvements to the Blenheim make it a bit better, then how does it match up with the Beaufighter or is Bristol just duplicating effort?

 

[Shortround6]

The improved Blenheims are to hold the line until the Beaufighters show up, Not replace the Beaufighter. That is the only mileage I would try to get out of them. Hold the line with fewer losses, Then go into their training role.

The British tried to stretch the Blenheim with the Bisley or MK V version but 1942/43 was too late for improved landing gear and a two gun turret without some sort of change to the engine, which it did not get. Just 100 octane and a bit more boost which the earlier ones already had.
And the constant idea that shipping 2nd rate planes off to the mid or far east was acceptable.

 

[nuuumannn]

The British tried to stretch the Blenheim with the Bisley or MK V version but 1942/43 was too late for improved landing gear and a two gun turret without some sort of change to the engine, which it did not get. Just 100 octane and a bit more boost which the earlier ones already had. And the constant idea that shipping 2nd rate planes off to the mid or far east was acceptable.

The Blenheim V had disappointing performance and was disliked by its crews; it was consdered unsuitable for European operations, so was sent out to Africa. It entered service three months after the Blenheim IV was withdrawn from the European theatre. Bristol went a bit far with it and tried desperately to make a better Blenheim, which, let's face it, couldn't really be done in a 1940s context - as I've hinted at all along. The Buckingham was Bristol's answer to a Blenheim replacement. Here's where the chain of events gets a little lengthy. The Buckingham was developed from a day bomber project called the Beaumont to spec B.2/41 and this supplanted an earlier spec B.7/40, to which Bristol offered a bomber variant of the Beaufighter powered by Griffons or Hercules. Obviously, by the time the Buckingham had flown (4 February 1943), the Mosquito was proving its excellence and had better performance than the Bristol product.

The Beaufighter was available in 1940/41 as a fighter, but obviously, troubles meant that its development was prolonged, despite numbers in service growing through 1940. The Mk.II went some way to address the Hercules issues, but introduced problems of its own. If Bristol had discontinued Blenheim production and brought the Beaufighter onto former Blenheim production lines around 1940, more Beaufighters would have been available within two to two and a half years of the beginning of the war, possibly earlier. By then the majority of the Hercules issues were dealt with and the Beaufighter VI was entering service and Coastal Command had a decent torpedo bomber.

 

[yulzari]

With the large Vickers commitment to geodesic construction, could a 4 engined Warwick have superceded the Wellington instead of Wellingtons being churned out to the end of the war? The Pegasus is being suoerceded by Hercules so perhaps initially a x4 Pegasus or Twin Wasp or Tiger installation and Hercules thereafter.