RAF's alternative doctrine and procurement between 1934 and 1940

[tomo pauk]

In order not to clog the current thread about the Gloster's fighter, and because it is that time of the year ( ), I'd start the thread about how the RAF's doctrine and procurement should've looked like in the time frame between 1934 and 1940. Fighters, bombers, trainers, transports, plus how to use them and how many to buy to cover the possible threats, all on the technology of the day (yes, changes in techy stuff were happening fast back then). Engines, guns, electronics - what to make and buy and use, what to avoid? Deployment on the Continent once the political decision is made? What to buy abroad, from components to whole aircraft? Cooperation between the friendly countries?

 

[Shortround6]

Deployment on the Continent once the political decision is made?

That assumes France is friendly during that period
although by 1934-35 Germany was taking over from France as the bad guy.

What to buy abroad, from components to whole aircraft?

Well, historically the British weren't buying much of anything from abroad until about 1938.
Except guns.

Cooperation between the friendly countries?

The British were exporting an awful lot of aircraft during the early and mid 30s.


and again the was a lot of stuff going on.
For the British in 1934, they announced one of the first expansion plans that called for 41 new RAF squadrons, however the expansion plans underwent constant revision.

Just found this on the web: HyperWar: Royal Air Force 1939–1945: Volume I: The Fight at Odds [Chapter I]

 

[tomo pauk]

Engine situation:
Merlin family is a given. RR should not waste the time and resources for the Exe, Peregrine is also a distraction at the end. Without these two, Merlin can be perfected/improved even faster. Not sure whether the almost-Griffon can be made for service for 1940, if yes it would be a nice addition.
Bristol - not making the Taurus might improve the Hercules' timetable a few months? Bristol's engines would've benefited if improved superchargers are designed and produced in a timely manner.
Not sure what to do with Napier - Dagger is a meh engine, Sabre is way too late. Have them make Bristol or RR engines under licence?
Armstrong-Siddeley: Tiger is a bad choice for anything, bigger engines never materialized, small engines were good. What to do here, perhaps licence production of the R-1830s instead for the G&R radials?

 

[yulzari]

Engine situation:
Merlin family is a given. RR should not waste the time and resources for the Exe, Peregrine is also a distraction at the end. Without these two, Merlin can be perfected/improved even faster. Not sure whether the almost-Griffon can be made for service for 1940, if yes it would be a nice addition.
Bristol - not making the Taurus might improve the Hercules' timetable a few months? Bristol's engines would've benefited if improved superchargers are designed and produced in a timely manner.
Not sure what to do with Napier - Dagger is a meh engine, Sabre is way too late. Have them make Bristol or RR engines under licence?
Armstrong-Siddeley: Tiger is a bad choice for anything, bigger engines never materialized, small engines were good. What to do here, perhaps licence production of the R-1830s instead for the G&R radials?

With 21st century hindsight Britain only needed two aero engines. The Merlin plus Cheetah. Those two will cover all needs. OT but they could also cover tank and armoured cars too; not to mention MGBs and MTBs.

 

[Shortround6]

I favor keeping the Peregrine/Kestrel and farming it out to a shadow factory.
If nothing else it would have make a nice tank engine
One does wonder if the Vulture could have been saved, but that requires a lot of hindsight. But if you cancel the Sabre you are running out of 2000hp engines.
Sabre?
Vulture?
Centaurus?
Griffon?

Now when do you KNOW when 100 octane fuel is going to show up and when do you KNOW what it will do?
two different things. It took the British until 1943 or so to reach the limit of 100/130 fuel and then they started work on the 150 octane stuff.

But in 1938-39-40 the Griffon was NOT a 1750hp engine. You need 12lbs of boost, not 6lbs or 9lbs.

As far as the R-1830 goes. A lot depends on timing. and back to the fuel, The US introduce 91-92 octane fuel for commercial use before the US 100 octane.
The US P-35s used the -9 engine that used 87 octane and gave 950hp at 2450rpm for take-off, The early P-36s (in 1938) used the -13 engine with new cylinders, 91 octane fuel. almost 100lbs more weight but gave 1050hp at 2700rpm for take-off, Which one did you get the license for?
And can you make the new cylinders/heads on the old machinery?

Alvis was initially set up to make 15 G & R engines a week(?) or less.
However Alvis during the war expanded to 21 dispersed factory sites and employed 3160 people overhauling RR engines, assembling DH propeller hubs and servicing US aircraft engines in service with the RAF.

A big problem with the Bristol engines is that they may have had cooling problems. They didn't seem to take much over boosting (neither did most American radials) and the Taurus was notorious for overheating. Just like the American radials the Hercules needed major changes for every large jump in power, The post war engines used lot of new materials, process and changes in the size of things like main bearings.

 

[Shortround6]

With 21st century hindsight Britain only needed two aero engines. The Merlin plus Cheetah. Those two will cover all needs. OT but they could also cover tank and armoured cars too; not to mention MGBs and MTBs.

Sunderland with Merlin's?
Or Sunderland with 12 Cheetahs? Two rows on six on the upper wing Dornier X style

I am not sold on Merlin's for MGBs and MTBs, The Packards that were used were 41 liter engines, about 50% larger than Merlin. As the boats gained weight the larger engines had more reserve of power. you could make the Merlins work but at what cost in overhaul life or breakdowns?

 

[yulzari]

Sunderland with Merlin's?
Or Sunderland with 12 Cheetahs? Two rows on six on the upper wing Dornier X style

I am not sold on Merlin's for MGBs and MTBs, The Packards that were used were 41 liter engines, about 50% larger than Merlin. As the boats gained weight the larger engines had more reserve of power. you could make the Merlins work but at what cost in overhaul life or breakdowns?

The concept is all about production simplicity. Sunderland with Merlins? Well why not if they are available. The Cheetahs are for trainers and light transport etc. Ditto for boats and tanks. Pile them high and sell them cheap. What else do you need. Not want but need? But this is all hindsight. At the time everyone had different ideas of what was going to be needed.

 

[Shortround6]

Not want but need?

In some cases you are better off making what you have tooling for rather than build new tooling to build large numbers of the same engine in different factories.

And in some cases you may be better off using specialty engines rather than trying to hammer square pegs into round holes just because they are cheap.

If your are running you factory/s at 2 or 3 shifts you aren't going make things much cheaper.

The British may have gotten a bit too boutique with some of their tank engine selections (two/three of them?) but in the 1930s and early war the tanks were using commercial bus and truck engines, they were cheap. The armored cars used commercial engines too.
Tanks work better with a lot of torque rather than horsepower. Especially if the transmissions use limited gear ratios. A flat torque curve allows for less shifting
The British did make some questionable choices for some of their tanks but trying to use Merlins in 1940-41 was probably not the answer.
The Cheetah was not quite big enough to substitute for the Liberty. The Cheetah being a 13.65 L engine. It was too big for the light tanks and armored cars and not quite big enough for Crusader and bigger tanks. The Liberty may have been a mistake in hindsight. But a 27 liter engine in a 20 ton tank meant the driver didn't have to work hard at keeping the engine in the powerband with the 4 speed transmission. German MK III and MK IVs used an engine of about 12 liters and used more gears to keep the engine on the torque peak.
The Merlin was too much of good thing at times in the Cromwell. It gave a speed of 40mph in the early ones but the crew got beat up driving cross country and even on roads the running gear took a beating. Later versions were re-geared to do 32 mph in the interest of longer life for the running gear.

Shermans with radial engine engines used a 16 liter engine and 5 speed transmission. The Shermans with V-8s had 18 liter engines.

The US could not retool engine factories to make just a few engines and used quite a selection of engines because it was easier than retooling.

for MTB/Motor Launch engines the 2nd most popular engine for British craft after the Packards were Hall-Scott Defenders that were V-12 35.7 liter engines. They were lower in power and heavier but they lasted longer. (they also didn't need aviation fuel)

 

[EwenS]

The US Ordnance Board realised in mid-1941 that it would not get the numbers of medium tanks needed in a relatively short space of time if it waited to retool factories to build the R-975 radial engine in the numbers required. Speed was of the essence. So it asked both GM & Chrysler to come up with new tank engines with the required power and torque.

In Aug 1941 GM was contracted to take two of its GM 6-71 Diesel truck engines, (already in use on the Valentine), and couple them together via a common transfer case. It had a prototype engine running by Oct and production diesel engined M3 Grants and Lees began rolling off the Baldwin Loco production line in Jan 1942. By April 1942 diesel engined M4A2 began rolling off the production lines.

Chrysler opted to take 5 of its 6 cylinder "Royal" petrol engines and connect them to a single crankcase to produce the Chrysler A57 Multibank engine. It ran in prototype form in Nov 1941 and was installed in 109 M3A4 tanks in early 1942 built at the Chrysler run Detroit Tank Arsenal. That factory then went on to produce 7,499 similarly engined M4A4 Shermans by Sept 1943 at which time a decision was made to drop the engine altogether. The US Army found them unreliable and difficult to maintain. Most M4A4 ended up in British hands and the problems were mastered. This was a 20l engine.

The final medium tank engine was the Ford GAA V8 which began to be fitted in M4A3 Shermans from June 1943.

All 3 of these engines provided more power than the original R-975 radial. But all involved changes to the layout of the engine compartment and, in the case of the A-57 engine, a lengthening of the hull.

The same thing had happened with the M3 Stuart light tank. To get the volume sought, the Continental W-670 petrol radial had to be supplemented by the Guiberson T-1020 diesel. The Cadillac V8 was then introduced with the M5 from April 1942.

 

[EwenS]

It is worth taking a look at the RAF around this jumping off point. Nearest OOB I have is April 1932. Numbers relate to number of squadrons.

U.K. based:-
Hawker Hart 4
Boulton Paul Sidestrand 1
Fairey Gordon 2
Fairey IIIF 1
Vickers Virginia 5 (incl 2 Reserve units)
Handley Page Hinaidi 2
Handley Page Hyderabad 1 (Reserve unit)
Armstrong Whitworth Atlas 3
Bristol Bulldog 6
Hawker Fury 3
Avro Tutor 1
Westland Wapiti 9 (1 Reserve & 8 RAuxAF)
Hawker Horsley 4 (incl 1 Reserve)
Hawker Audax 2
Supermarine Southampton flying boat 3
Various SARO flying boat types / Blackburn Iris 1

Total 48 squadrons (incl 5 Reserve & 8 RAuxAF)

Middle East (Egypt, Trans-Jordan, Iraq, Malta, Aden):-
Armstrong Whitworth Atlas 1
Vickers Victoria 2
Fairey IIIF 5
Fairey Gordon 1
Westland Wapiti 3
Short Rangoon flying boat 1

Total 13 squadrons


Far East (India, Singapore):-
Westland Wapiti 5
Hawker Horsley 1
Supermarine Southampton 1

Total 7 squadrons

The Horsley & Audax are variants of the Hart. Later in the 1930s it spawned the Demon fighter, Hartebeest, Hardy and Hind.

1932 saw Specs issued for what became the Battle, Hampden and Wellington. 1933 for the Sunderland. 1934 for the Whitley, Hurricane & Spitfire. 1935 for the Warwick, Defiant, Anson, Harrow, Blenheim. These are amongst many others for updated versions of earlier aircraft.

So the RAF problem is twofold. It needs to expand and it needs to modernise the aircraft types in use. And all this needs to happen quickly. And all during a period of rapid aircraft development. New types take time to develop. So production of variants of older types are required to fuel early expansion. 1934 the best fighter was the Fury II, 223mph 4x.303 MG. By 1939 the Spitfire 355mph & 8x.303 MG. It was the same with bombers.

And all this has to happen against the background of a peacetime economy (with the related peacetime working hours I.e no multi-shift working) and funding, and of a nation that, with the horrors of WW1 still fresh in the mind, is reluctant to get involved in rearmament and the prospect of a repeat. And of an aviation industry that, having been starved of orders since WW1, needs to expand its workforce, and factory facilities while converting to new construction methods requiring workforce training.

The first couple of chapters here give some background to the drivers of expansion.

HyperWar: Royal Air Force 1939–1945: Volume I: The Fight at Odds

Edit. Just seen Shortround6 has also referred to this.

 

[yulzari]

In some cases you are better off making what you have tooling for rather than build new tooling to build large numbers of the same engine in different factories.

And in some cases you may be better off using specialty engines rather than trying to hammer square pegs into round holes just because they are cheap.

If your are running you factory/s at 2 or 3 shifts you aren't going make things much cheaper.

The British may have gotten a bit too boutique with some of their tank engine selections (two/three of them?) but in the 1930s and early war the tanks were using commercial bus and truck engines, they were cheap. The armored cars used commercial engines too.
Tanks work better with a lot of torque rather than horsepower. Especially if the transmissions use limited gear ratios. A flat torque curve allows for less shifting
The British did make some questionable choices for some of their tanks but trying to use Merlins in 1940-41 was probably not the answer.
The Cheetah was not quite big enough to substitute for the Liberty. The Cheetah being a 13.65 L engine. It was too big for the light tanks and armored cars and not quite big enough for Crusader and bigger tanks. The Liberty may have been a mistake in hindsight. But a 27 liter engine in a 20 ton tank meant the driver didn't have to work hard at keeping the engine in the powerband with the 4 speed transmission. German MK III and MK IVs used an engine of about 12 liters and used more gears to keep the engine on the torque peak.
The Merlin was too much of good thing at times in the Cromwell. It gave a speed of 40mph in the early ones but the crew got beat up driving cross country and even on roads the running gear took a beating. Later versions were re-geared to do 32 mph in the interest of longer life for the running gear.

Shermans with radial engine engines used a 16 liter engine and 5 speed transmission. The Shermans with V-8s had 18 liter engines.

The US could not retool engine factories to make just a few engines and used quite a selection of engines because it was easier than retooling.

for MTB/Motor Launch engines the 2nd most popular engine for British craft after the Packards were Hall-Scott Defenders that were V-12 35.7 liter engines. They were lower in power and heavier but they lasted longer. (they also didn't need aviation fuel)

I should reiterate that the two engine scheme is pure hindsight and presumes the armed forces to be clairvoyant soothsayers at the start of the OP period. The actual decision makers were mere humans and have no reason evident to them to make the two engine decision.

 

[Reluctant Poster]

In some cases you are better off making what you have tooling for rather than build new tooling to build large numbers of the same engine in different factories.

And in some cases you may be better off using specialty engines rather than trying to hammer square pegs into round holes just because they are cheap.

If your are running you factory/s at 2 or 3 shifts you aren't going make things much cheaper.

The British may have gotten a bit too boutique with some of their tank engine selections (two/three of them?) but in the 1930s and early war the tanks were using commercial bus and truck engines, they were cheap. The armored cars used commercial engines too.
Tanks work better with a lot of torque rather than horsepower. Especially if the transmissions use limited gear ratios. A flat torque curve allows for less shifting
The British did make some questionable choices for some of their tanks but trying to use Merlins in 1940-41 was probably not the answer.
The Cheetah was not quite big enough to substitute for the Liberty. The Cheetah being a 13.65 L engine. It was too big for the light tanks and armored cars and not quite big enough for Crusader and bigger tanks. The Liberty may have been a mistake in hindsight. But a 27 liter engine in a 20 ton tank meant the driver didn't have to work hard at keeping the engine in the powerband with the 4 speed transmission. German MK III and MK IVs used an engine of about 12 liters and used more gears to keep the engine on the torque peak.
The Merlin was too much of good thing at times in the Cromwell. It gave a speed of 40mph in the early ones but the crew got beat up driving cross country and even on roads the running gear took a beating. Later versions were re-geared to do 32 mph in the interest of longer life for the running gear.

Shermans with radial engine engines used a 16 liter engine and 5 speed transmission. The Shermans with V-8s had 18 liter engines.

The US could not retool engine factories to make just a few engines and used quite a selection of engines because it was easier than retooling.

for MTB/Motor Launch engines the 2nd most popular engine for British craft after the Packards were Hall-Scott Defenders that were V-12 35.7 liter engines. They were lower in power and heavier but they lasted longer. (they also didn't need aviation fuel)

The Liberty was used because that's what Christie used in his pioneering tanks which the British and the Russians used as the basis for some of their tank designs. Reintroducing the Liberty into production after 20 years has to rank as one of the stranger decisions. The Meteor was a Rolls Royce developed expedient to correct this mistake. Rolls Royce became heavily involved in British tank design not just engines in WWII.

Christie M1931 - Wikipedia

en.wikipedia.org

The R-975 Sherman was considered to be underpowered. Note that the US kept the Ford V-8 versions for itself and send only R-975s and Chrysler multibanks to the British. Diesel powered variants went to the Russians and the Marines.
From: The Chieftain's Hatch: ETO Equipment Reviews, Pt 2
"Using personnel preferred this engine to the air cooled radial type engine because of its higher horsepower and torque outputs."
Also note the following from the same reference with regard to the fabled Ford V-8 crankshaft:
"Crankshaft: It was necessary to scrap 35% of the crankshafts of engines returned to the base shop for rebuild because the journals were scored so badly that they could not be reclaimed by regrinding. It is recommended that improvement in engine design to reduce bearing failures be considered."

 

[tomo pauk]

On the guns. Browning in .303 was decent. Cannons' armament was too late, while a HMG was not dopted.
Me - I'd stick with the Browning, adopt one of the Vickers HMGs, and make a deal with Oerlikon for 20mm cannons, since those were available early enough.

 

[Reluctant Poster]

Engine situation:
Merlin family is a given. RR should not waste the time and resources for the Exe, Peregrine is also a distraction at the end. Without these two, Merlin can be perfected/improved even faster. Not sure whether the almost-Griffon can be made for service for 1940, if yes it would be a nice addition.
Bristol - not making the Taurus might improve the Hercules' timetable a few months? Bristol's engines would've benefited if improved superchargers are designed and produced in a timely manner.
Not sure what to do with Napier - Dagger is a meh engine, Sabre is way too late. Have them make Bristol or RR engines under licence?
Armstrong-Siddeley: Tiger is a bad choice for anything, bigger engines never materialized, small engines were good. What to do here, perhaps licence production of the R-1830s instead for the G&R radials?

The real problem for Rolls Royce was the diversion into the ramp head design for the Merlin. This wasted a huge amount of time and effort. The Merlin would have been built with separate heads from the beginning if not for this. If Royce had lived for a few more years, I'm sure Elliot would not have had the freedom to go off the deep end.

Ramp Head Merlin

Without the ramp head fiasco Roll Royce may have had time to develop Snowy Grouch's beloved direct fuel injection.

 

[EwenS]

The R-975 Sherman was considered to be underpowered. Note that the US kept the Ford V-8 versions for itself and send only R-975s and Chrysler multibanks to the British. Diesel powered variants went to the Russians and the Marines.
From: The Chieftain's Hatch: ETO Equipment Reviews, Pt 2
"Using personnel preferred this engine to the air cooled radial type engine because of its higher horsepower and torque outputs."
Also note the following from the same reference with regard to the fabled Ford V-8 crankshaft:
"Crankshaft: It was necessary to scrap 35% of the crankshafts of engines returned to the base shop for rebuild because the journals were scored so badly that they could not be reclaimed by regrinding. It is recommended that improvement in engine design to reduce bearing failures be considered."

It is true that the US Army kept the Ford engined M4A3 for itself, but that is not the whole story.

The US Army standardised on the R-975 powered M4/M4A1 for their front line units until well into 1944. Other versions were used by Stateside training units before many entered a remanufacturing programme from late 1943. After July 1944 the M4A3 supplemented them.

The initial 1,690 Ford GAA V8 engined M4A3 built by Ford (all the Shermans that Ford built) June 1942-Sept 1943 were retained as training tanks in the USA until those engine bugs were sorted. Those vehicles only began to appear on the front line late in 1944 after being remanufactured. The M4A3 was declared "suitable for overseas supply" in June 1943. It was then Feb 1944 before the Ford engines again appeared in new production tanks and July 1944 before they began to appear on the frontline.

Britain received all variants except the M4A3. The diesel M4A2 (over 5,000) being the second most used version after the M4A4 and followed by the M4A1 and finally the M4. It was only from Feb 1944 that all new, as opposed to remanufactured, M4A2 went to the USSR.

 

[Shortround6]

I should reiterate that the two engine scheme is pure hindsight and presumes the armed forces to be clairvoyant soothsayers at the start of the OP period. The actual decision makers were mere humans and have no reason evident to them to make the two engine decision.

The two engine solution isn't a good one even in hindsight. You are getting rid of a number of factories that are already tooled up to make truck and bus engines, Tooling is already paid for. Will the two engine solution pay for the retooling ?
Will the Cheetah actually work?
Cheetah's of over 300hp (?) were supercharged. There were lower powered versions without superchargers.
The Cheetah's of much over 300hp used 80 or 87 octane fuel. M4s with radial engines used 80 octane.
I don't have the specs for British armor but a lot of the US halftracks, armored cars and other non-Sherman based armor used 70-72 0ctane fuel.

Do you really want to pull maintenance on Cheetah engine in an armored box?
The upper end of the valve train (rocker arms) were lubricated with a grease gun.
Doable with aircraft cowl (still a pain in the neck) but a radial engine in an armored box with limited access hatches?

US radials used oil supplied the main oil system.

The Humans didn't know that 100/130 fuel and higher were going to show up allowing them to keep using the Merlin.
Having extra engine factories also spread the risk out. While the Germans did do a lot of damage during the BoB and Blitz the factories were not hit as badly as some people thought they would be. Spreading production out (and even types of engines) were looked as insurance on both bomb damage and a development gone wrong (RR ramp head?)

Putting all the eggs in one basket was never a real good idea.
In the US some of the alternatives, like tanks, made it into small scale production but never were issued for overseas service (some were used for training) and get skipped over in quickly histories. The US did NOT stop making tanks with the M4.
See the M7 Medium (canceled with 3000 on order)
See also the T23 medium (250 built) with an electric transmission. They did borrow the turret for the 76mm armed Shermans.
Think about that one, 250 German tanks would have shelves worth of books devoted to them. For the US it was a foot note. (or 2-3)

 

[tomo pauk]

The real problem for Rolls Royce was the diversion into the ramp head design for the Merlin. This wasted a huge amount of time and effort. The Merlin would have been built with separate heads from the beginning if not for this. If Royce had lived for a few more years, I'm sure Elliot would not have had the freedom to go off the deep end.

Ramp Head Merlin

Without the ramp head fiasco Roll Royce may have had time to develop Snowy Grouch's beloved direct fuel injection.

Yes, not straying into that blind alley would've improve the supply of reliable Merlins early on.
About the fuel metering - adoption the pressure-injection carbs already before the war would've also allowed for some performance gain ( the Spitfire V gained 10 mph and 1500 ft in ceiling once the float-type carb was replaced by a 'fuel pump'). Add the more streamlined exhausts for another 6-7 mph, and the Hurricane I is now good for 330+ mph, and Spitfire I/II at 370-380 mph. Hurricane might also benefit from a better radiator set-up, perhaps in the 'beard' position (it helped XP-40 and Typhoon, plus already the Battle is with it).

Now that I'm blabbering about the fighters: no Gladiator, no Defiant; Hurricane to be produced by Hawker and Gloster; Spitfire to be produced by Vickers-Supermarine, Boulton Paul and Westland (sorry, Whirlwind lovers). Lease machinery from Castle Bromwich factory to B-P and Westland. Supermarine needs to came out with ribs that have far less pieces than it was the case historically, so the manhours to make Spitfire are reduced.

 

[Shortround6]

On the guns. Browning in .303 was decent. Cannons' armament was too late, while a HMG was not dopted.
Me - I'd stick with the Browning, adopt one of the Vickers HMGs, and make a deal with Oerlikon for 20mm cannons, since those were available early enough.

The British adopted the Browning because they were planning on mounting guns in the wings, trying to mount eight guns around the engine in a single engine fighter was not going to work.
The Vickers was very durable, what is not was reliable. It simply could not be mounted (except during supply shortages) where the crew could not reach it.
That did not change when they enlarged it to take the .5in Vickers round.
The .5 Vickers was heartily disliked as an AFV gun. It jammed just as much as the .303 Vickers, it took up more space in the turret/s making it harder to work on. It needed more force operate the charging system. (Crank in the side)
The tank boys may not have liked the 15mm BESA anymore but it was somewhat more powerful.
The other big Vickers was truly big.

.5in Vickers. then the .5in HV (for the class D gun) and the .50 Browning for comparison.
The Class D gun with that long cartridge was a very heavy gun (about 20lbs heavier than the .50 Browning) and it was slower firing. Since it used the same mechanism, just larger, it didn't get rid of the jamming problem/s.

The British became interested in the 20mm Hispano in 1936. Granted it took a while to sign any contracts/agreements. The Hispano was not fully sorted out and need help.

But I am not convinced the 20mm Oerlikon gun/s were fully sorted out either in the mid 30s. There seems to have been changes to both the rate of fire and the veleocity in some of the guns between 1934 and 1937(?) and actual sales (aside from samples) were small and to a few minor countries (test/trial samples were looked at by a number of countries).

The RN had rejected the 20mm Oerlikon gun in 1934 but had told Oerlikon in 1937 that if they could increase the veleocity and make it simpler to maintain they would be interested.
The new sample guns showed up in early 1939 and were adopted with the RN ordering production guns from Oerlikon. The British got around 100 guns by the time France fell and shipments were cut off. Just before France fell the British took delivery of production drawings and got them to Britain. After considerable difficulties the first British production guns were ready in the fall of 1941. The Duke of York (commissioned Nov 1941) may have had the first 6 guns.

 

[tomo pauk]

But I am not convinced the 20mm Oerlikon gun/s were fully sorted out either in the mid 30s. There seems to have been changes to both the rate of fire and the veleocity in some of the guns between 1934 and 1937(?) and actual sales (aside from samples) were small and to a few minor countries (test/trial samples were looked at by a number of countries).

Oerlikon's cannons were sorted out enough for French and Germans to buy the licences for the S and FF, respectively. The L type has also it's appeal.

The RN had rejected the 20mm Oerlikon gun in 1934 but had told Oerlikon in 1937 that if they could increase the veleocity and make it simpler to maintain they would be interested.

Who helps the fastest, helps the mostest.
Instead of waiting for a super-duper perfect cannon, let's have imperfect cannons for installation on the fighters, while Oerlikon is doing the improvement for Phase 2. Merlin in the nose allows for carrying twice the firepower vs. what the French fighters had. Lower rate of fire = longer fire duration.

 

[K5083]

Transferred from the F5/34 thread




"Shortround6 has it right. The RAF had no clue of what to do with the aircraft they had even if the war they planned for had come to pass. They did not plan to have the LW across the channel inside escort range. They did not plan to support the army except with Lysanders. They thought they were going to destroy German industry and morale with a bunch of mediocre twins which could not survive by day or find their targets by night. They recognised no role for a fighter other than interception.

In terms of simple single-seat fighters there was no magic in designing a decent fighter IF you had a competitive engine. Stick to basics, keep it simple. You do need to know who you are going to fight and when the war will start. A year out and you have a MS406 when you need a D.520."


But mainly there's no point in getting deep into technical things if the doctrine isn't right. The RAF was not prepared for war. The Air Staff had the intelligence form Spain but did not use it, preferring to stick to their delusions.