RAF BoB Fighters OTL ATL v Me-109

[yulzari]

Looking at the original thread; what might one have done with the Gladiator? As a supplement to existing fighters.

x6 .303" Brownings were a trialed fit (x2 in the upper wings). Not as many as the Spitfire or Hurricane but a closer group so possibly as many hits.

The Mercury seems to be quoted in the 810 to 825ish bhp area irrespective of 87 or 100 octane. Could more be achieved?

Changing from fixed pitch to variable, or better, constant speed 3 blade propellor? Malta Gladiators used ex-Blenheim engines with 3 blade propellors.

The rate of climb compares with a Hurricane MkI.

The Perseus is an alternative engine that got to 920bhp just before the war and the larger Perseus 100 got to 1,200bhp. It was the alternative to the Mercury in the Lysander so it should go into a Gladiator.

Use of different and smaller airfields could reduce the vulnerability of Fighter Command in the south to air attack on it's bases.

Familiar to older pilots so a sweep out of ex fighter pilots from RAF staff could add some pilot numbers and new pilots could skip OCUs for the conversion to type element as Gladiators would be an easier transition from Masters or Furies.

I see the main flying problem as being difficulty in catching the fast bombers in a stern chase. However bombers, especially in formations, operate at cruising speed and the essence of the RDF/control room system was to place the fighters so that they do not need to do a stern chase except after initial engagement.

Comparatively cheap and does not impinge on existing fighter production until the Tornado/Typhoon needs those production facilities. After the BoB ship them off to Malaya and India for extra reserve squadrons using locally trained staff.

 

[Shortround6]

Ok, lets look at it.

Without major modifications to the Mercury engine was stuck at 840hp at 13-14,000ft. Just like the Merlin III was stuck at 1030hp at 16,250ft. ANY improvement from 100 octane fuel comes below that height, not above. Using 100 octane fuel the Mercury could go to over 900hp for take-off instead of 725hp for take-off. Using a two pitch prop may help even more ( most Blenheim's had 2 pitch props, called CP for Controllable Pitch, they were NOT constant speed). Britain was rather short of constant speed props during the summer of 1940.

So yes you can improve the performance of the Gladiator but not at the altitudes the fights were starting during the BoB.

Perseus was a sleeve valve engine and the Perseus 100 was a post war engine (using Centaurus cylinders) that, while advertised, may never have actually been installed in even a flying test bed. Perseus was in low scale production and might have been available in quantities measured in dozens (steal them from Bothas?), It used the exact same bore and stroke as the Mercury so expecting any major change in power is just not happening.

AS for vast numbers of Pilots having experience with it. It was introduced into service in Feb 1937 (about a year before the Hurricane) but the rate of production was not high and the last planes were not completed until 1940. Eight home squadrons may be the most equipped with it at any one time. It also had a surprisingly high accident rate when first introduced as it handled quite a bit different than the biplanes that proceeded it.

Going back to the start of the thread. When or what causes the 'shortage' of Hurricanes and/or Spitfires? A Factory fire in July of 1940 or in Nov of 1939?
In other words how much time is there to come up with alternative fighter/s? Are we talking about building new fighters with new engines or taking months (or year) old air-frames and re-engining/modifying them in work shops with what ever is handy?

 

[Glider]

I think one Gladiator was fitted with 6 x 303 on Malta but it was destroyed on the ground before it could go into combat. I also think it was fitted with an engine from a Blenheim, but that might have been a different airframe.

 

[tomo pauk]

The Italians installed the DB-601 engine in their CR.42, for sake of experiment. Clocked about 320 mph. So - how about he Merlin in the Gladiator? Unless we install it in the MB-2...

 

[Aozora]

I think one Gladiator was fitted with 6 x 303 on Malta but it was destroyed on the ground before it could go into combat. I also think it was fitted with an engine from a Blenheim, but that might have been a different airframe.

Apparently the modified Sea Gladiator was N5531 "Hope", which was fitted with a Mercury XV and C/S propeller from a Blenheim as well as extra Brownings on the upper wings; N5531 was destroyed with "a bomb smack through the centre section" before she could be flown. (From Malta the Hurricane Years page 370).

 

[yulzari]

IIRC the extra two guns in the top wing was a FAA option so the fittings for the lower guns might be used in a straightforward installation.

In the BoB Plymouth was defended by an RAF flight of Gladiators at Roborough as it was then too small for Hurricanes or Spitfires and the Dockyard held FAA Gladiator spares. So they were in BoB service and had only recently been in use in France.

The only major difference to an ex Gauntlet pilot would probably have been the flaps, canopy and radio. Out in the Middle East Gauntlets and Furies were still being used into 1941; albeit in tiny numbers.

 

[Shortround6]

The only major difference to an ex Gauntlet pilot would probably have been the flaps, canopy and radio. Out in the Middle East Gauntlets and Furies were still being used into 1941; albeit in tiny numbers.

From Wiki so usual disclaimer

"The Gladiator's introduction into RAF service was difficult. Although it was well liked by pilots, the accidents during operational training were so numerous that a small replacement batch of 28 Mk IIs was hurriedly produced. Most accidents were caused by pilots being caught out by the fighter's increased wing loading. Moreover, many aviators had still little experience in landing aircraft with such a wide flap area. The new Gloster biplane stalled more abruptly with the tendency to drop a wing. The Gladiator proved even easier to enter a flat spin, and great skill was needed to recover it."

Now it may not be as bad as that and a few hours of training before going into combat might have gone along way to into easing a pilot into it. However, thinking that you can grab pilots from bomber/transport squadron squadrons who flew Gauntlets and Furies 2-5 years earlier and stick them into Gladiators as an emergency solution might not turn out well. Or thinking that pilots posted to the "new" Gladiator squadrons need less operational flying time after leaving advanced training than pilots posted to Hurricane squadrons. British weren't giving their pilots enough operational (flying service type fighters) training as it was before sending them into combat.

 

[Aozora]

IIRC the extra two guns in the top wing was a FAA option so the fittings for the lower guns might be used in a straightforward installation.

In the BoB Plymouth was defended by an RAF flight of Gladiators at Roborough as it was then too small for Hurricanes or Spitfires and the Dockyard held FAA Gladiator spares. So they were in BoB service and had only recently been in use in France.

The only major difference to an ex Gauntlet pilot would probably have been the flaps, canopy and radio. Out in the Middle East Gauntlets and Furies were still being used into 1941; albeit in tiny numbers.

In a slightly different context, Hawker Hectors of 613 Sqn were used to dive-bomb and strafe gun positions around Calais in late May 1940: 12 sorties were carried out over two days in support of Lysanders that were dropping supplies to the British troops; two Hectors were damaged by flak (Alex Crawford Hawker Hart Family, MMP 2008, pages 98-103):

 

[vikingBerserker]

Wow, I had no idea they had been used during the war. Great info!

 

[merlin]

Some of these look attractive at first glance but a bit deeper look reveals the problems. For instance the Supermarine 313 was a larger plane than the Whirlwind, was supposed to use lower powered engines (The Goshawk?) and yet go faster? Something seems off.

The '313' whilst having bigger dimensions was supposedly going to be much lighter than the Whirlwind, also it was offered with an alternative engine - the Aero Engines (Hispano) 12Y engine -just a thought while not bigger than the Peregrine, would it have been more reliable, and therefore a viable alternative engine for the Whirlwind?

 

[merlin]

Wow, I had no idea they had been used during the war. Great info!

Yes, but what a perverse tragedy the RAF resort to that, while the Henley was wasted as a target tug!

 

[Glider]

The '313' whilst having bigger dimensions was supposedly going to be much lighter than the Whirlwind, also it was offered with an alternative engine - the Aero Engines (Hispano) 12Y engine -just a thought while not bigger than the Peregrine, would it have been more reliable, and therefore a viable alternative engine for the Whirlwind?

Just a point and that is the Peregrine was as far as I am aware a very reliable engine. I read a report from the squadron leader when he was being pushed to declare the squadron operational during the BOB. He listed a number of problems but engines weren't one of them.

 

[Shortround6]

The '313' whilst having bigger dimensions was supposedly going to be much lighter than the Whirlwind, also it was offered with an alternative engine - the Aero Engines (Hispano) 12Y engine -just a thought while not bigger than the Peregrine, would it have been more reliable, and therefore a viable alternative engine for the Whirlwind?

What "Aero engines 12Y engine?" a licensed Hispano or imported? There may have been a suggestion that some company build a license Hispano but it came to nothing.

The "unreliability" of the Peregrine has been much over blown. A few early minor troubles including taxing with flaps (which controlled the radiator airflow) in the wrong position leading to ground over heating, but the early troubles were soon solved. Until you get to the 12Y-45 the Hispano does NOT offer more power than the Peregrine at altitude.

 

[merlin]

What "Aero engines 12Y engine?" a licensed Hispano or imported? There may have been a suggestion that some company build a license Hispano but it came to nothing.

The "unreliability" of the Peregrine has been much over blown. A few early minor troubles including taxing with flaps (which controlled the radiator airflow) in the wrong position leading to ground over heating, but the early troubles were soon solved. Until you get to the 12Y-45 the Hispano does NOT offer more power than the Peregrine at altitude.

Quite frankly - I haven't got a clue, I was just going by what I read in Butler's Secret Projects.

Re: engines in general - does it mean that the Merlin DB 601 - were the only 1940 engines capable of high-altitude combat performance?? Whilst Bristol learnt a lot from the Fw-190 engine, was there anything to learn from other earlier LW engines from shot down aircraft!??

My imagination wondered, with the Gloster F.5/34 (Grendell) - joining the Hurricanes in France, With the Gloster 'twin' (Guardian) being utilized for photo-recon (faster than the Blenheim), but suffers after being pressed into ground-attack a'la Breguet 693. Following the Fall of France some squadrons are re-equipped with the B-P P88a (Dante) - with Bader being admonished after swopping the cannon for MGs!!

 

[Shortround6]

Re: engines in general - does it mean that the Merlin DB 601 - were the only 1940 engines capable of high-altitude combat performance?? Whilst Bristol learnt a lot from the Fw-190 engine, was there anything to learn from other earlier LW engines from shot down aircraft!??

The Merlin III offered the best performance at altitude of engines commonly available in the Summer of 1940, with the Merlin XII and XX staring to come online in the fall. However the Merlins were installed in larger, heavier aircraft than the 109 was so the combination of the Merlin III and Spitfire/Hurricane and the DB 601/109 worked out about the same.

You can always learn something from captured engines even if it was not as ground shaking as the BMW 801 engine installation ( the FACT that an air-cooled engine could come close to a liquid cooled engine in terms of drag was ground shaking to a lot of people.) Even things like piston ring alloys were analysed to compare with the capturing countries products to see if there might be room for improvement. The German fuel injection systems were looked at pretty closely but rejected for a number of reasons. Some had to do cost, both actual money and time/labor to manufacture.

 

[RCAFson]

The Merlin III offered the best performance at altitude of engines commonly available in the Summer of 1940, with the Merlin XII and XX staring to come online in the fall. However the Merlins were installed in larger, heavier aircraft than the 109 was so the combination of the Merlin III and Spitfire/Hurricane and the DB 601/109 worked out about the same.

You can always learn something from captured engines even if it was not as ground shaking as the BMW 801 engine installation ( the FACT that an air-cooled engine could come close to a liquid cooled engine in terms of drag was ground shaking to a lot of people.) Even things like piston ring alloys were analysed to compare with the capturing countries products to see if there might be room for improvement. The German fuel injection systems were looked at pretty closely but rejected for a number of reasons. Some had to do cost, both actual money and time/labor to manufacture.

A number of Spitfire IIs (~50) and Hurricane IIs (~30) were in service by Sept 22 1940.

Merlin XII production was probably delayed mainly due to Spitfire II airframe production problems.

 

[Edgar Brooks]

Yes, but what a perverse tragedy the RAF resort to that, while the Henley was wasted as a target tug!

The Henley was designed as a light bomber, carrying just two defensive guns; the wings might have utilised the same jigs as the Hurricane, but the Henley airframe had nowhere near the capability of that aircraft.

 

[merlin]

The Henley was designed as a light bomber, carrying just two defensive guns; the wings might have utilised the same jigs as the Hurricane, but the Henley airframe had nowhere near the capability of that aircraft.

I think you'll find my comment is a reply to post 208 - so yes the Henley was designed as a light-bomber top speed 292 mph, Hector max speed 187 mph, armament 1 x Vickers gun + 1 x Lewis gun, and 2 x 112 lb bombs; whereas the Henley as similar machine-guns, it carried two 250 lb bombs internally, wing points for over-load of another two - as per the spec.
Hence, my comment!!

 

[ohogain]

What the heck is OTL and ATL?

Doesn't compute.

Glad you asked. I would like to know as well. Thanks.

 

[fastmongrel]

OTL = Official Time Line ie what actually happened.

ATL = Alternate Time Line ie what might have happened if certain changes had been made at certain times in History.