Rn vs IJN

[Wild_Bill_Kelso]

True. If the ETO and MTO were not so demanding of ships, the RN's submarines would be very useful against the IJN. Put a dozen RN boats between FIC and Malaya and another doze split between Sarawak and Penang, all with effective ROE, and the IJN's inept ASW should see much of their invasion fleet sunk.

We discussed all this in depth. Most of the RN submarines didn't have sufficient range, they could have done some damage but could not have prevented the fall of Malaya on their own.

 

[Wild_Bill_Kelso]

Well, we are over 30 pages and 630 posts into this discussion.

Yes indeed, we certainly did.

The RN (and Commonwealth) in actual history was fighting very, very out numbered, poorly supplied and pretty much lacking in air cover/support.

Which would go badly for any navy.

In a what if scenario with better air cover/support, better supply and more numbers a lot of mismatch goes away.

Not nearly enough, I think that was very clear from the data which emerged in those 630+ posts

However the match up would not be RN substitutes for USN situation, at least not if the RN has at least some combat experience.
The RNs strengths are not the same as the USN strengths and the RN weaknesses are not the USN weaknesses.

Right. They had a lot more and much more serious problems, like a lack of modern, effective naval aircraft.

With 15-20 RN subs at the start that entire aspect of the naval war gets flipped. Japanese losses due to submarines goes way up (British torpedoes worked).
Night actions get somewhat turned around. Again British torpedoes worked, British had more experience with radar/night fighting than the USN did. Enough better or equal to the IJN???

I think it was very, very clear from that discussion that the IJN was far ahead of the RN at the beginning of the war, as was also made abundantly clear in the naval and air / naval actions early in the war there. IJN had torpedoes with twice the effective range which were more reliable and faster. They had the best naval night optics in the world - so good that they were adapted by both the British and the Americans. And their limitations in ASW are exaggerated. They had a large fleet of destroyers with very well trained crews.

Large carrier battles?
British loose.

Yep

Big daylight BB action?
British don't engage (they aren't going to have the numbers unless the war in Europe is very different).

They may not have a choice

Amount of British air cover/support???

With what? Gladiators? Fulmars? Short ranged Spitfires and Hurricanes?

A big hinge point. If the initial Japanese attacks do not go well they get sucked into a sort of Guadalcanal battle of attrition only in the western DEI/Singapore area sooner than Guadalcanal.

British also get sucked into the same sort of battle, trying to keep land forces supplied in Malaysia and much of the southern DEI. IJA is still somewhat stuck in China.
If the British can get more resources into Burma before the fight starts the British may be able to hold Burma (mosty) and keep the Burma road open.

They threw a lot into Burma and barely managed to hold on to India in the long run, with strong US support

Japanese subs can attack the British supply lines in the Indian Ocean. However the British are better at ASW than the Japanese. It will take a while but the Japanese cannot replace losses as well.

Not better enough, and the British have a huge disadvantage in both carrier and ground based strike aircraft.

Lets look at the basics. The world's navies were set up on the famous 5 : 5 : 3 : 3 : 3 ratio. This scenario has the US (5) sitting it out and with it the US bases in the Pacific, which the Japanese cannot use.
German surface fleet is somewhere between 1 and 2. If Norway happened as historically Germany is barely at 1.
Without the defeat-surrender of France, Italy and France pretty much cancel each other out.

Without a lot of war losses and the need to ride herd on the Italian and German navies the British can out number the Japanese in just about every catagory except carriers.

How much strength does the RN need to hold Burma, Malaya, Singapore and the DEI and get the IJN into a war of attrition that the Japanese cannot win?

RN was catastrophically inferior in aircraft, to the point that the Japanese could launch strikes repeatedly from well beyond the range of RN / FAA strike aircraft, which could not survive engagements with IJN fighters. Nor would they do very well against land based IJN bombers. In surface action, the Japanese clearly have an advantage again. Much bigger battleships. Twice the torpedo range. Better night optics. Better training, probably. I wouldn't be betting on the British and neither would you if you weren't intentionally being contrary.

 

[Wild_Bill_Kelso]

If we can get Weimar to work (keeping Stresemann alive might just do it) and keep Mussolini in check, the Japanese will be facing much of the RN. Though with a lessor threat of Germany between the wars, what does the RN look like?

Still cruising around with Sea Gladiators, Skuas, Rocs, Fulmars, Swordfish... with aircraft carriers that carry half as many plans as the IJN ones IIRC.

 

[Wild_Bill_Kelso]

With little scholarly research, I would say the RN would have been a nasty surprise to the IJN. Especially at night.

You may want to go check through the discussion. I really don't mind bringing it all out again. It's important people grasp basic realities.

 

[Shortround6]

what we don't really know is what the British/Americans really knew about Japanese aircraft and ships during the 1930s.
What we have easy access to is old editions of Jane's aircraft and ships but those may not be accurate and/or reflect what the British wanted the public to know and not what the British government knew.

In the 1938 edition (published in late 1938) there is a photo of the navy type 96 shipboard bomber biplane with no details, as in none, zero, bupkis.
There is photo of the Navy type 96 twin engine monoplane (Nell although not named) and details are
Believed to be a product of the Mitsubishi company.
Span 25m (82 ft)
Length 16m (52ft 6 in)
Height 3.7m (12ft 1 in)
empty weight 5000kg (11,000lbs)

that is it.

There is a photo of the Navy type 96 single seat fighter monoplane.
Believed to be a development of the Mitsubishi "Karigane"
with span, length and height given.
No weight, no details of engine or armament or performance.
Only other current warplane was the Army type 94 two seat reconnaissance biplane. With a bit more detail.

The next 7 pages are a collection of trainers, light commercial transports, and few record setting planes and few truly obsolete warplanes like the Kawasaki Army type 93 bomber

Now with post war research we know that this plane was introduced in 1933/34 and was out of production in early 1935, 3 years before that edition of Jane's was published.
Jane's sometimes kept old listing to help keep the page count up but this was the only plane listed for the Kawasaki company. No mention of the Kawasaki Ki-10 Army biplane fighter that entered production in 1935 although a photo of the last of the Ki-11 prototypes shows up labeled as export fighter. There were 4 Ki-11s built and the last one was sold to a Japanese newspaper for liaison, courier and news gathering flight.

Again I have no way of knowing what the British high command actually knew vs what Jane's was publishing but the public information was scanty and several years out of date.

 

[SaparotRob]

It's important people grasp basic realities.

That's crazy talk.

 

[Shortround6]

You may want to go check through the discussion. I really don't mind bringing it all out again. It's important people grasp basic realities.

A big part of the problem is the basic set up of the scenario.

The British cannot win if the US is not part of the battle, case closed.
The British simply do not have the resources to fight Germany, Italy and Japan at the same time.

However if we start trying to figure IF the British can fight only two countries at the same time (Germany/Japan or Italy/Japan) then we can start discussing technical merits and not simply numbers.

That is part of the basic realities.

The basic premise would never have happened as the Japanese did not know how bad the US torpedoes were and the Japanese were not going to leave a US submarine base with almost 30 subs sitting right in the middle of their supply lines with the aid of several hundred fighters, bombers and recon planes while the IJN sailed on their merry way down to Java and Borneo. The US was one of the chief instigators of the embargo's. That is a reality.

If people want to twist the reality to take the US out of the situation for a fantasy battle between the Japanese and the British to show how superior the Japanese were with the British stuck with historically deployment of troops, ships, aircraft we are not going to learn much.

 

[Wild_Bill_Kelso]

A big part of the problem is the basic set up of the scenario.

The British cannot win if the US is not part of the battle, case closed.
The British simply do not have the resources to fight Germany, Italy and Japan at the same time.

However if we start trying to figure IF the British can fight only two countries at the same time (Germany/Japan or Italy/Japan) then we can start discussing technical merits and not simply numbers.

That is part of the basic realities.

Put Germany out of the war (or focusing on Russia first) and France and Italy cancel each other out. I don't think it changes a thing.

The basic premise would never have happened as the Japanese did not know how bad the US torpedoes were and the Japanese were not going to leave a US submarine base with almost 30 subs sitting right in the middle of their supply lines with the aid of several hundred fighters, bombers and recon planes while the IJN sailed on their merry way down to Java and Borneo. The US was one of the chief instigators of the embargo's. That is a reality.

If people want to twist the reality to take the US out of the situation for a fantasy battle between the Japanese and the British to show how superior the Japanese were with the British stuck with historically deployment of troops, ships, aircraft we are not going to learn much.

What we can learn is that the RN ships air aircraft were unable to cope with the IJN equivalent. We don't have to write an alternative reality screenplay to do that. Just sweeping away the BS which crops up here routinely. That's my only goal.

 

[Shortround6]

Put Germany out of the war (or focusing on Russia first) and France and Italy cancel each other out. I don't think it changes a thing.

It changes quite a bit. A lot more British ships in the far east fleet. A lot more troops/equipment and training in the ground forces. And more numbers of aircraft and more modern aircraft for the RAF in the area.
British had 15 subs at Singapore in 1939, they pulled all of them to Med well before 1941 is just one instance.

What we can learn is that the RN ships air aircraft were unable to cope with the IJN equivalent. We don't have to write an alternative reality screenplay to do that. Just sweeping away the BS which crops up here routinely. That's my only goal.

The RN (and Britain in general) had planned a force structure to contest the Japanese in the Far East. They had not planned to have to guard the entire Atlantic coast of France, Convoy routes through both the the North and South Atlantic and Indian Oceans and fight or contain the entire Italian fleet AND deal with Japan at the same time.

The British pulled forces from the Far East and/or delayed reinforcing the area while they dealt with other things. They were counting on the US to help counter the Japanese.
If they KNEW the US was going to back down and not try to contest the Japanese expansion in time The British may have been able to move more forces to the area. Or sent less stuff to Russia or not gone into Greece or...............................

 

[Greg Boeser]

That's crazy talk.

 

[ThomasP]

Part of the problem with the ATL scenario is that in the OTL the UK switched focus during the time the Ark Royal was being constructed. Aside from the construction of 4-5 repeat/improved Ark Royals we do not really have any idea of what the UK would have done differently if the focus had remained on Japan and the PRTO as the next battleground.

We can make some basic guesses, maybe the base at Singapore gets finished sooner? A better carrier based fighter?

I think we can assume that the Chain Home radar would have arrived in the PRTO in a big(ger) way.

What else?

 

[Wild_Bill_Kelso]

Speculating as to what alternative weaponry might have been produced may be an interesting exercise, but it's not really the point I was focusing on. I think you could put most of the RN fleet in the Pacific in 1941, 1942, 1943, and they will still lose. Aircraft carriers matter. A lot of people down the IJN during WW2, but it's clear they were at worst the second strongest navy in the world.

 

[ThomasP]

It is not just a case of alternate weaponry. If the UK's focus had not changed, there would - of necessity - have been strategic/operational doctrine differences as well. The change of focus led to doctrine changes, and the changes in doctrine caused the switch from repeat/improved Ark Royals to the Illustrious class - as one example.

In the OTL the 1940-43 RN was less capable than the IJN in an open ocean war, and hence in the OTL would probably have lost - barring the long war of attrition. On the other hand, put the Japanese in the Atlantic, North Sea, and Mediterranean - what then?

Continuation of the pre-Ark Royal doctrine might very well have resulted in a scenario more similar to the Atlantic, North Sea, Mediterranean theaters - only in the PRTO.

 

[Wild_Bill_Kelso]

Well that's reasonable. There are limits to what you can do in speculation on such a vast scale, but it could also be interesting. I guess my big question would be what prospects were there for better carrier aircraft.

 

[RCAFson]

True. But if Ark Royal was designed to fight Japan in the IPTO, it would be good to consider the aircraft Japan was using and had in development. The only fighter envisioned for Ark Royal seems to be the Skua, which while having four .303 mgs vs. the A5M's two, does not seem like a competitive match. And the Skua is significantly slower than the B5N and the IJN's Bettys and Nells. Not a good fleet defence fighter, but there's no folding-wing fighter from the British that can fit down Ark's narrow lifts until the Fulmar and later Seafire. Fulmar vs. Zero, poor bastards in the FAA fighter.

The IJN entered the war in Dec 1941, not Sept 1939. The Fulmar was envisaged for the Ark Royal from late 1937 and a production contract was issued on 5 May 1938. Production began in early 1940. The IJN was not in a position to fight a carrier based naval war in Sept 1939 as they only had 3 fleet carriers in service; 3 more came into service from late 1939 to late 1941.

When Hiryu came into service in late 1941, this was her aerial complement:

12.1939

16 A5M2

20 D1A2

38 B4Y1

 

[ThomasP]

The info I have:

standard displacement increased to from 22,000 tons to 23,000 tons (you can do a lot with 1,000 tons)
different elevator arrangements - still the same basic size elevators but having one platform that serves both hangars
improved machinery, more efficient (basically similar to the Illustrious class) including improved rudder arrangements
improved internal arrangements and compartmentalization
improved/increased emergency services
heavier catapults (accelerators)
crash barriers
primary AA moved to the gallery deck (for better coverage of airspace)
some rearrangement of armour
still 64x large or 72x medium size folding wing aircraft

Plus by the early-war you would have had:

various radars including air search and AA FC
fighter control center, similar to those onboard the Illustrious class in the MTO
outriggers for additional aircraft (probably 5x) as in Illustrious class
increased light and/or medium AA

 

[RCAFson]

Japan attacked in Dec 1941 precisely because it seemed that the Axis was winning and the RN had suffered massive losses. So we have two possible scenarios here, one where the RN has been terribly bled and the British Empire and Commonwealth (BEC) is engaged in a life and death struggle in the ETO/MTO or one where the the BEC has not gone to war in the ETO/MTO and the RN has been free to expand as per it's prewar plans and the BEC could devote it's entire resources to fighting Japan.

If we look at the non-war BEC in Dec 1941 and compare it's scientific, economic and military resources with Japan, we can see that the odds are tilted heavily in favour of the BEC and it's very likely that Japan would not have attacked.

In Dec 1941, the BEC was working on the world's first atomic weapon development program; TUBE ALLOYS. BEC industrial and technological development was far ahead of Japan, but the BEC couldn't fight all the axis powers combined without Allies. In a straight fight between the BEC and Japan, the war ends badly for Japan.

 

[EwenS]

...... Aircraft carriers matter........

Not so much inter-war. Look at how much effort went into the Treaty era limiting the power and numbers of Battleships and extracting the max from what was available to navies when compared to other types. Until WW2 carriers were not that numerous in any navy. On 3 Sept 1939 the numbers for the RN/USN/IJN in service were 6 (Argus, then classified as an auxiliary, wasn't reactivated as a training carrier until Nov 1939)/5/6. And of those 1/2/2 had entered service in 1937-39. On order/under construction you have 6 (the armoured Illustrious / Implacable classes) / 2 (Wasp & Hornet, with funding for a third) / 2 (Shokaku & Zuikaku)

For all the power displayed by Japanese carriers in the first 6 months of the Pacific WW2 it is usually forgotten that the Kido Butai wasn't formed until 10 April 1941. Until then then they generally operated their carriers singly or in pairs. On one occasion in 1932 Kaga briefly joined Hosho & Ryujo with their small air groups for operations off China.

Inter-war US doctrine was to operate carriers singly. They were seen largely as one shot weapons. Hopefully putting an enemy's carrier(s) out of action before themselves being lost. It was early 1942 before they deployed a group of two, and even then it was more like two single carrier groups operating in close proximity than a single group with carriers at its core.

Britain experimented with multi carrier groups in exercises in the Med in the early 1930s but never had enough to make it a permanent feature when it had world wide commitments. Through most of the 1930s the core of the RN carrier fleet was Furious, C& G with Eagle & Hermes alternating between periods in the Far East and refit or reserve and Argus in reserve / refit from 1932.

 

[EwenS]

The IJN entered the war in Dec 1941, not Sept 1939. The Fulmar was envisaged for the Ark Royal from late 1937 and a production contract was issued on 5 May 1938. Production began in early 1940. The IJN was not in a position to fight a carrier based naval war in Sept 1939 as they only had 3 fleet carriers in service; 3 more came into service from late 1939 to late 1941.

When Hiryu came into service in late 1941, this was her aerial complement:

12.1939

16 A5M2

20 D1A2

38 B4Y1

And the Fulmar was ordered as an "interim two-seater front gun fighter ... (for quick production)..."

 

[EwenS]

The info I have:

standard displacement increased to from 22,000 tons to 23,000 tons (you can do a lot with 1,000 tons)
different elevator arrangements - still the same basic size elevators but having one platform that serves both hangars
improved machinery, more efficient (basically similar to the Illustrious class) including improved rudder arrangements
improved internal arrangements and compartmentalization
improved/increased emergency services
heavier catapults (accelerators)
crash barriers
primary AA moved to the gallery deck (for better coverage of airspace)
some rearrangement of armour
still 64x large or 72x medium size folding wing aircraft

Plus by the early-war you would have had:

various radars including air search and AA FC
fighter control center, similar to those onboard the Illustrious class in the MTO
outriggers for additional aircraft (probably 5x) as in Illustrious class
increased light and/or medium AA

Ark Royal came out heavy, despite a lot of welding being used in her construction. Designed for 22,000 tons standard displacement on completion she was 22,585 tons (declared under WNT rules at 22,500 tons). But there were discrepancies between the calculated weights (as noted above) and those revealed by actual inclining experiments. The latter brought her out at 22,870 tons with full ammunition load. Some of the early 1934 figures showing her at 22,000 tons included only 75% of both ship and aircraft munitions (but space was provided for the full load). That was coupled with a hope that weight could be saved during construction. This was done for a number of British ship designs of the period. So there is less margin to play with than might be assumed (data from Friedman "British Carrier Aviation").

As for aircraft numbers, and remembering that was driven by hangar capacity, the final design dated 3 May 1934 was given as 48 torpedo bombers and 24 fighter/recce aircraft for a total of 72. The latter were to be the Hawker Osprey. But by 1938 it had already become apparent that due to increasing aircraft size she could not accommodate those numbers. Friedman quotes estimates of 40-44 Albacores and 12-22 Skuas (52-66 total) but some of the larger combinations meant permanent stowage on the lower lift platform. 60 was considered the max for sustained operations and maintenance and the hangar fire curtains were arranged accordingly. On the outbreak of war she carried 42 Swordfish (4 squadrons) and 18 Skuas (2 squadrons) for a total of 60.

Quite what her capacity would have been with an Albacore/Fulmar Air Group is open to question as these were 3-4 ft longer than their predecessors. Her air group seems to have dropped to about 54 when she replaced the Skuas with Fulmars, but it is not clear if that maxed her hangars out. One problem in assessing her capacity is that, unlike the Illustrious/Implacable classes, the lifts occupied floor space within the hangar, so how longer aircraft might have fitted in/around those I've never managed to work out.

Increasing the hangar width from 60ft to 62ft would have helped come 1940 in view of the decision that the folded width of fighters should be 13ft 6in (Firefly, Firebrand F.I and Seafire III/XV/XVII all met that requirement) which allowed 4 abreast stowage in the hangar with adequate working room.

No change to the power of the machinery was necessary. Designed for 102,000shp and 30 knots but on trials at deep load she made 103,000shp and 31.2 knots. Illustrious was designed at 111,000shp for 30 knots. Only with the demand for more speed from the Implacable in 1938 to 32knots, (which has never been fully explained) did a new 4 shaft machinery layout have to be used to produce 148,000shp. Increasing speed by a few knots around that speed point comes with a significant cost.

Accelerator/catapult power was not so important in an era when free take offs were the norm. But in 1938 the BH.I as upgraded was capable of launching 12,000lb at 56 knots in zero wind (having started at 8,000lb in 1935). The prototype BH.III of 1940 (as fitted to Illustrious in 1940) was capable of launching 11,000lb at 66 knots in zero wind. The BH.III was then upgraded as WW2 went on. These figures were comparable with USN catapults of the same period.

Ark Royal was the first RN Carrier to be fitted with a crash barrier (sources differ as to whether this was fitted on completion or during 1939).

Increased compartmentalisation comes at a cost in space and weight terms. It can lead to inefficiencies in actually operating the ship as was found in the Midways. Ark's biggest weakness was the routing of the boiler uptakes across the ship so close to the waterline. That was something that was not realised until she was lost but then quickly acted on in terms of modifications to carriers built or building and to the design of the Audacious class.

I don't follow your armament comment. An early design for Ark had 16 single 4.7" AA at lower hangar deck level. It was March 1935 before the twin 4.5" was adopted with the 8 mounts being placed on the upper gallery deck at a cost of 150 tons. The spacing was to reduce blast interference between mounts. Friedman notes "Presumably it was impossible to place twin mounts on the lower hangar deck." Sponsons for them would have then had to be larger and more liable to damage in heavy seas.