Rn vs IJN (1 Viewer)

Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules

Equip him with a M1 carbine to compensate for his size...
 
Some of this discussion dates from statements/discussions about if the Japanese were ahead or behind the west or British.
Getting planes from the US means the British were behind.
Of course the British didn't send the newest and best to Far East but that is sort of a different story

And then there is the quality of the crews/and personnel in terms of training/experience.

British were facing a different war than the Americans. The British were defending (and failed) a large land mass with a large coast line. They didn't actually need a large carrier force until they had to retake the lost ground areas.

Carriers are very good at force projection.
Getting airpower into areas were you have do not have ground air bases. If or when you have ground bases then carriers become less important.
The whole Guadalcanal campaign was about a ground air base. One that could not be sunk. And could operate longer range aircraft than most carrier planes.
 
True but the air and carrier part was only as a part example of what could be made available.

If we went through the lot it would be too big a list.

Also, the premise of the thread is RN vs IJN and most of what I have seen is predicated on actual RN losses
up to the start of Japanese aggression so it follows that lend lease would also be a valid inclusion.

The other factor not looked at yet is although in this one the US is not directly involved, a war starting in the area
would mean an immediate change to US military presence across the Pacific. Hawaii and the Phillipines would
see a build up for a start. This would have affect Japanese thinking on the conduct of operations as they would
have to ensure they are ready to respond if things kick off with the US.
 
I'm not sure that not having the USN in the war would have the effects you expect with regard to delivery of assets to Britain.

Escort carriers
On 20 Jan 1941 (while Audacity was under conversion and before lend lease started) Britain requested the USN act as agent in the procurement of 6 escort carriers in the US. After various negotiations, these became BAVG1-6, Archer, Avenger, Biter, Dasher, Charger & Tracker based on the C3 merchant hull with the first 5 hull acquisitions being made on 20 May 1941. The sixth came later with modifications as the prototype for the Bogue class. In Oct 1941 it was agreed that Charger should be retained by the USN as a deck landing training carrier for both USN & FAA personnel then training in the USA.

In July 1941 Britain requested a further 6 escort carrier conversions from the USA. This was turned down with a week as C3 hulls were then in short supply. That resulted in Britain having to commence to plan more conversions from her own home built hulls.

That postion did not change until 11 Dec 1941 (after Pearl Harbor) when the Auxiliary Vessels Board of the USN called for 24 conversions for both the USN and RN (initial Bogue class orders with deliveries from mid-1942). But only 20 C3 hulls could be found. These were split equally between both navies. A further 24 were ordered later in 1942 (eventually split 23 RN & 1 USN)

So without PH is there actually the push required to order that batch of 20 Bogue class? Would the US relent and agree to more C3 conversions having turned the RN down in July 1941?

F4F Martlet / Wildcat
Britain wanted the folding wing Martlet II (from a pre-lend lease order) and waited to get it. But F4F production in 1941 totalled only 323 only approx 60 being for the RN. Grumman production did not begin to exceed 100 airframes per month until May 1942 (which represents a tripling of production from the year before and a 50% increase from the end of 1941). With the exception of a single Lend Lease contract Martlet IV delivered in Feb 1942 the rest of the 220 Martlet IV didn't begin until June 1942 and ran until Nov 1942.

So without US involvement in WW2 how quickly does F4F/Martlet production ramp up? With the USN desperate to revitalise its fighter fleet how is Grumman told to prioritise its production between the two nations (the USN had only retired the last of its Grumman F3F biplane fighters from front line use in 1941 and still had squadrons operating the Buffalo at the time of PH)?
 
I wasn't expecting carriers and aircraft to be available on day one but a start to hostilities in the Pacific is going
to change the US priorities for the area. Supplying extra in 1942 is fine.
 
I suppose it's not to trip visitors, but when I visit these old wooden warships with the lines of smoothbore cannons one thing I always notice is the lack of the in-haul tackle. In addition for hauling in the gun (if recoil not present or sufficent) when runout, the tackle was essential for keeping the gun secure when run-in for stowing/securing or loading. Without the in-haul tackle there is nothing to stop the gun from rolling forward when the ship rolls.

 
Last edited:
WARSPITER said:
Also, the premise of the thread is RN vs IJN and most of what I have seen is predicated on actual RN losses
up to the start of Japanese aggression so it follows that lend lease would also be a valid inclusion.
Click to expand...
My own scenario involves the British securing NA in early 1940, no Greek adventure and possible co-operation with the French Colonies in NA.
Less RN losses, More RA resources to send east, more RAF resources to send east.
Like QE and Valiant leave for the far east before the frogman attack for instance.

Now the problem is with the US. If the US stays neutral in the Far East what happens to the oil embargo, the triggering event for the Dec attack?
What does the US do that keeps the Japanese from attacking Pearl Harbor and the Philippines, as in what does Japan get from the US.
The Japanese have no idea of how bad the US torpedoes are and how bad the US submarine force actually is.
Does the US insist on the oil embargo but withdraw most of the US subs as a gesture to keep the US from attacking? (like that worked for anybody else the area of Japanese wanted).

In any case, The British lost historically in the first 3 months of the Pacific war. If they had another 4 divisions of men/equipment (and not trainees) and another 400-500 planes could they have hung onto Singapore, Malaya, and the western half of Indonesia (like most of the oil wells). This forces the Japanese into a battle of attrition in areas where the carriers are not quite as important. Sort of a reverse on the British Carriers vs the Italians in the Med. If the British had a few air bases in Algeria for instance need for carriers for the supply runs to Malta would have been much reduced.
Once the British lost everything getting it back was going to be a real problem.


Would the US keep up unlimited Lend Lease or only honor the earlier cash shipments (if that).

At what point do the British realize they cannot depend on the US to keep the Japanese in check?

A lot of butterflies

Japanese technology was not that great.
Or sometimes they concentrated on the wrong stuff.
The answer to floatplane fighters was not better floatplane fighters but bulldozers and some sort of runway matting.
 
Assuming the US keeps the oil embargo but doesn't otherwise get involved, if the Allies manage to hold back the Japanese advance for a little longer, they could've completely destroyed the oil wells and refineries. Resulting in the IJN needing to severely reduce operations so they don't run out of reserves before they rebuild the oil infrastructure in the occupied territories?
 
Admiral Beez said:
This makes me think of today's Ukrainians.
Click to expand...

I think Zelenskyy is spending a lot of time thinking of Czechoslovakia and listening to what people running for office are saying.

---------------------------------

Back on topic:

First, I think it's incredibly unlikely the US doesn't go to war against Japan in the Pacific. The US was already committing quite a lot of treasure against Japan, and the Japanese government -- which was in control of the most aggressive parts of the Japanese polity (Yamamoto was sent to sea so he wouldn't be assassinated by those who thought he was too soft on war, especially with the US) -- was not going to back down in its invasion and subjugation of China beyond Manchuria (even if the government of Japan could manage that; the IJA in China didn't seem to be particularly obedient to Tokyo).

Given that I think it's unlikely the US doesn't go to war against Japan, I think I'll ask (and answer) how I think the RN (and, by extension the RAN) would do against the IJN. In my opinion it's going to depend on the specific tactical situation. For my argument, I'm going to have Italy neutral. The Kriegsmarine will still want to neutralize the Suez Canal, so it will have submarines and aircraft operating out of bases in the South of France (Spain, as historically, also remains neutral). Since there will be far less Axis shipping, the RN will be able to move ships and submarines into the Indian Ocean and Pacific. While the RN made some huge blunders -- Force Z -- against Japan, and its aircraft were largely inferior, the RN had a quite competent submarine service (with reliable torpedoes!) and seemed to be adept at melee combat (see: Narvik) as opposed to the more organized combat the USN seemed to be expecting. My opinion is that in some situations the RN will do quite well; lots of Japanese ships that survived due to defective US torpedoes will get sunk by the RN's working ones, and the RN would probably be more prepared for the IJN's excellent and well-used torpedoes, and in some worse, like any kind of day carrier action. (although it would be interesting to see what happens if those Stringbags come in on a torpedo run during a dark and stormy night against a Japanese carrier?
 
Last edited:
Maybe it is just me but the Japanese got very lucky in most of their early operations.
Maybe fortune favors the brave but they took an awful lot of risks and came out on top most of the time.

Pearl Harbor, endless debates about what would have happened if the radar reports had been acted on earlier.
Even if there was one less badly damage battleship and 10 more Japanese planes lost?
Every plane (and pilot/crew) lost is a strain on the Japanese in the first few months of the war.

The total fiasco that was the US submarine service in the Philippines.
The near total fiasco that was the US air Defense of the Philippines, some accounts say that 1/2 of the 277 Allied planes were lost in 45 minutes?

Initial Japanese landings Malaya?

Not expecting the Japanese to be stopped cold.
But a few more weeks or 2 months delay could have put the Japanese on the defensive much earlier.

A lot can be blamed on the Allied high command that thought weak forces and poorly equipped and under trained troops would do the the job.
 
The British needed 3 or 4 fewer divisions in Malaya/Singapore/wester half of Indonesia and a radar chain to effectively use the planes they had.

The historic issue is logistics - the roads/rails could support maybe a battalion (1,000 men) in active combat. <Maybe 2 if using both Singapore and Penang.> Everyone else is just another mouth to feed sitting in Singapore waiting to be captured. Train capacity was such that 1 train took company's guns, another took the trucks and a 3rd the men. And that got you 25 rounds/gun - enough for a 1 minute barrage.

It doesn't help that troops from India were sent to Singapore to get them out of India (to keep them from causing trouble at home). So, the Allied troops weren't entirely sure which way they needed to point their guns.

If British are willing to turn Penang/Singapore into Leningrad/Stalingrad 2.0, i.e. hold the Malacca Strait with no concern over civilian lives, they can make a fight of it for IJN. Ideally, RN holds Sumatra too (If Allies hold the Strait, IJA/N can't project air power over Sumatra and Allies stand a chance).

You make IJN run the gauntlet past the coastal guns in Singapore or sail all the way around Sumatra with RN subs awaiting.
 
To keep the Malacca Strait open Britain needed to keep hold of the airfields in north western Malaya, north of Penang, that fell in the opening days. Or render them so damaged to be useless for a long period of time, which given their nature would not have been possible. Places like Alor Star.


When the Japanese finally set about taking Sumatra starting 14th Feb, the day before Singapore surrendered, they started in the South at Palembang, having sailed past the guns at Singapore. From them to about early April they then moved northwards up the east coast of Sumatra to Sabang at the northern tip and then into the Nicobar and Andaman Isands.

After those first few days the only route to reinforce / resupply Singapore was via the Sunda Strait which lies between Sumatra & Java.

While Malacca Strait seems wide they were, and still are, difficult waters to navigate, getting worse as you get nearer Singapore. Sunda Strait is also relatively narrow.
 
swampyankee said:
the RN had a quite competent submarine service (with reliable torpedoes!)
Click to expand...
Needs must, but I wish the RN had not pulled back the twenty odd submarines they had at Malaya until 1940. A half dozen Perisher-commanded boats on patrol off FIC with clear orders to commence offensive ops if Malay waters are violated would have been interesting.
 
Last edited:
Shortround6 said:
Maybe it is just me but the Japanese got very lucky in most of their early operations.
Maybe fortune favors the brave but they took an awful lot of risks and came out on top most of the time.
Click to expand...
This luck became a problem for Japan later on. The Japanese losses in 1942 operations were quite low as to destroyers and cruisers.
When the Unryu class was decided on in 1942 destroyer and cruiser escorts, which are necessary, were not given priority as
not a lot had been lost.

By the end of 1943 destroyer losses were 55. At the same time, destroyer production to the end of 1943 is listed as 23 but may
be a little higher.
1944 / 45 saw another 55 destroyers lost and around 26 replacements announced with only 5 being fleet types . the rest were Matsu
type which was smaller at 1,200+ tons and was mainly armed for AA and ASW work while still carrying four torpedoes (many of this
type were used to help escort convoys).

Light cruisers to the end of the war numbered about 5 only with one heavy cruiser laid down.

The successes of the initial aggressive expansion plus the carrier losses in 1942 combined to give priority to carrier production
while fleet destroyer and cruiser production got little. By 1944 carriers were becoming more susceptible to submarine and
surface attack as the combined fleet types were not able to be fielded in the required mix.
 
Slightly different IJN figures,

To end December 1943, 43 Fubuki class or later lost, nominal strength from 68 in November 1941 to 48, plus 19 older class destroyers lost, plus 1 conversion to aircraft rescue ship, nominal strength from 55 in November 1941 to 35

In 1944/45 there were 48 Fubuki class or later lost, nominal strength from 48 end December 1943 to 9 at surrender, including 3 considered badly damaged, 26 older classes lost, nominal strength from 48 end December 1943 to 9 at surrender, including 4 considered badly damaged.

Matsu class did not start arriving until April 1944, with 32 built and 13 lost, 2 of the survivors badly damaged. While the Nashi is listed as a war loss it was raised in 1955 and put back into service.

Larger destroyer production was 10 in 1942, 12 in 1943, 7 in 1944 and 2 in 1945, which can be compared with 41 built January 1935 to end 1941, or just under 6 a year on average.

The IJN stopped building light cruisers in 1925, the mid 1930's Mogami class were rebuilt as heavy cruisers in 1939/40, the pair of captured Chinese light cruisers built in the early/mid 1930's were not that much bigger than a Fletcher class destroyer. Then came 3 training cruisers in 1940/41, then 5 modern light cruisers during the war.

Carriers, The CV/CVL/CVE classification is a bit arbitrary, 9 CV/CVL pre war, 9 builds plus 2 conversions from seaplane tenders, 4 survivors, CVE 1 pre war, 20 built including conversions, 17 survivors. 5 CVE built in 1942, 8 in 1943 and 6 in 1944.

Now for Hindsight on the hindsight.

The R class were designed to be better gun platforms, less beam, more draught, half the installed power of the Queen Elizabeths and around 2,000 tons lighter. The hindsight is knowing when the war was coming and limits on new guns and armour, if you wanted modern fast battleships you needed to use relevant parts of the older ones. The twin 15 inch turrets came in at between 770 tons and 855 tons (Vanguard), so up to 3,440 tons, the 14 inch turrets on a King George V came in at 4,000 tons, the lower weight would make keeping to 35,000 tons easier, an extra mounting harder. Also the recycling program would veto the rebuilding program (except Hood (1938/9) and maybe Renown (1937/8) and Repulse 1939/40), with the commissioning of 1 extra mounting plus the 4 spares plus the 3 on the monitors allowing the front line strength to be kept up (of course ignoring where the armour for the first two ships are coming from, how about the Illustrious class, and yes it is a half joke.) And continuing on our merry way, we recycle all the 15 inch gun ships except Hood, say an average of 3 years build time, half hull, half outfitting, 12 ships, 4 slips, 6 years for each slip/outfitter to do 3 ships, 1937 to 1942, with 6 done by end 1940, 6 slips 4.5 years, all done by mid 1941, or at least the end of the year. Ship design locked in by end 1936, extra 15 inch mounting and guns ordered as another spare in 1935, plus some armour, relevant slips brought into service (Renown and Repulse were around 800 feet long, KGV 750, Vanguard 815, Hood 860). All adequate for what the RN actually fought, or was likely to fight, apart from the Yamato class.

However apart from Ramillies preventing Scharnhorst and Gnesienau attacking HX.106 the 4 surviving R class do not seem to have had an impact on operations beyond making up the battleship numbers. In any case the real hindsight answer is pairs of Ark Royal class from 1938 to 1940, the 1938 treaty upping the carrier limit by 10,000 tons like the battleships along with the overall carrier tonnage limit, allowing 4 non armoured hangar around Implacable displacement laid down as the 1941 and 1942 carriers.

Oh yes, with the flight deck layout of the USS John F Kennedy or USS America, since there was no engineering reason against that generation of carriers having angled flight decks, deck edge lifts and mirror landing systems with Fresnel lenses, once the ideas were thought of. Makes for a much more efficient carrier. To continue, call the lawyers if necessary to "allow" Courageous and Glorious replacements, all the others were eligible, while the WWI service meant all the heavy units before Hood were over age (2 years war service = 1 year peace) in the late 1930's. Put the older carriers into reserve to have them emerge as escort and training carriers in wartime. Essentially figure out a way to make the pre war building limits either machinery or hull steel, not armour, naval guns or money, we know what WWII cost.

Easy when you know how it turns out, the rise of carriers, the aborting of most battleship programs by the war. Meantime back in the reality of people trying to anticipate the future as of the second half of the 1930's the chance the new generation of battleships would have much superior guns to the 15 inch was quite real, Iowa versus Vanguard in firepower, though it seems Vanguard was the better sea boat, so try fighting in a storm, yet by that stage the fire control electronics and keeping them working were probably more important.

While over in IJN land (sea?, ocean?) cancel the Yamato class, redirect the resources and imagine the allied problems if another pair of Shokaku class turned up in late 1941 instead, followed by another pair in mid 1942. Bah humbug (to get into the spirit of the season, leaving a discussion of presents' quality and humbug pronouncements feed back loops for another time), just send the USS Nimitz, yet the best thing they could have done was send their text books, trained people and engineering answers to the Manhattan project and next generation combat aircraft and weapons design and manufacturing teams, not blown the IJN force to pieces at the slight risk of being sunk. After all the 1930's probably could not make many of the materials for the spare parts, nor the parts to the precision required, as a potent weapon Nimitz would have had only a few shots, better to use the flight hours, radar operating hours etc. elsewhere.
 
Last edited:
There are 2 problems for the Japanese in the 1930s for cruisers & destroyers.
1. The Treaty limits set in the 1930 London Treaty
2. The size of Japanese shipbuilding industry and its ability to react to its leaving the Treaty system

Treaty system
Under the 1930 Treaty, Japan was only allowed:-
12x8" cruisers total 108,400 tons being the Furataka, Aoba, Myoko & Takao classes at their declared Washington tonnages which couldn't be replaced before 1946; and

100,450 tons of cruisers with up to 6.1" guns. It had to remove from service everything up to and including the Kuma class by the end of 1936 in order to have the tonnage to build the 4xMogami & 2xTone that it planned for its 1931 & 1934 Programmes (all at their initially planned 8,500 ton declared displacements). None of the other light cruisers were replaceable under the Treaty before 1942.

Japan left the Treaty system at the end of 1936, having given due notice in Dec 1934. But until that point it couldn't breach the Treaty too blatantly.

Given the various problems it had with its ships in the early 1930s it couldn't rush into designing new ships. The actions it did take included:-

1. Upgunning the Mogamis from 15x6.1" to 10x*8"along with a host of other modifications between 1937 & 1940.
2. Upgunning the Tone class to 8x8" while under construction
3. Retaining the 2xTenryu & 5xKuma class in the fleet.

Under the 1930 Treaty Japan would have been allowed to retain 3xKuma class as training ships along with the battleship Hiei. Retaining these in the active fleet probably accounts for the building of the much smaller & cheaper Katori class in subsequent programmes.

Japan left the Treaty system because the other Powers wouldn't give it what it wanted. It asked for parity with the USA & Britain, but would have settled for about 80%. Instead it was being restricted to about 60%.

Subsequent Building Programmes
Japan's planning was done on the basis of multi year Programmes. And as war approached and changes got made, they become ever more confusing.

The 1937 Programme (intended to cover the next 6 years construction) included 2 training cruisers of the Katori class amongst the 66 ships listed (based around the first 2 Yamatos & the 2 Shokakus).
The 1939 Programme (based around a second pair of Yamatos & Taiho) included a Katori class training cruiser, plus 4 Agano class (design started Oct 1937) & 2 Oyodo class cruisers.
The 1940 Supplementary Programme included a 4th Katori class training cruiser which was suspended while under construction in Nov 1941 and was later scrapped.
A 1941 Programme planned 2 Ibuki class 8" cruisers (and the first Unryu class carrier)

That was the sum of the pre-war cruiser plans. A further 6 light cruisers were included in the various 1942 Programmes at different times.

But longer term planning by the IJN in Nov 1938 called for another 25 cruisers to be built in 2 phases through to completion in 1950. That would have included the 2 Ibukis, and 8 new 8" cruisers. The rest would have consisted of 4 modified (faster to accompany the planned Shimakaze class destroyer flotillas) Aganos, 8 new design AA cruisers and 3 cruiser flagships for the sub flotillas. This plan was then modiified over the coming couple of years. But with the exception of the Ibukis no steel hit the slipways.

Capacity of Japanese industry
And this is where the problems arise. There does not seem to have been a large enough number of suitably sized slips/dry docks to build everything planned quickly enough.

The Aganos were intended as replacements for the old light cruisers as leaders of the destroyer flotillas. Initially 2 were to be built at Kure Navy Yard, 1 at Yokosuka Navy Yard and 1 At Mitusbishi Nagasaki. Because of the pressure on these yards from other projects only the Yokosuka ship was built as planned. So 3 of the 4 Agano class were allocated to the Sasebo Naval Yard. But they had to be build consecutively on the same slip. So construction stretched from the laying down of the first ship in June 1940 to the launch of the last in April 1944 for completion that Nov. Build times of the 3 ships did not vary significantly (28,25 & 24 months respectively).

Oyodo was ordered in 1939 and was supposed to be laid down in June 1940 at Kure Navy Yard. But pressure of work delayed that until Feb 1941. The second ship was to be laid down on the same slip in Sept 1941. Delays to Oyodo delayed the sister Niyodo, and in Nov 1941 her construction was postponed and then cancelled altogether in Aug 1942.

The laying down of the Ibukis was delayed, as the Aganos had priority for the limited capacity available. Warship 300 / Ibuki was laid down on 24 April 1942 at Kure Navy Yard. Construction was stopped at the end of June only to be restarted at the end of July to clear the slip for aircraft carriers. She was launched in May 1943 and work suspended in July while consideration was given to converting her to a fast oiler or a carrier. Aug 1943 it was decided to convert her to a carrier and she was towed to Sasebo in Dec for conversion work to commence. Her sister, Warship 301, was laid down at MItsubishi Nagasaki on 1 June 1942. Construction stopped on 30 June and, as she was less advanced that Ibuki, she was scrapped to allow the carrier Amagi to be laid down in Oct.

This is one version of Japanese shipyard capacity in terms of slip size that I have seen on the net.


150m = 492ft
175m = 574ft
200m = 656ft
225m = 738ft
250m =820ft
275m = 902ft
300m = 984ft

An Agano cruiser was 174m (571ft) long
Oyodo was 192m (629ft) long
Ibuki class cruiser was 200.6m (658ft) long
An Unryu class carrier was 227m (746ft) long

While the Japanese had big carrier plans in 1942 (lead ship + 15 Unryu class, 5 improved Taiho) they prioritised the Unryus and knew full well that the modified Taihos couldn't possibly be completed until 1947/48.

Destroyers
Similar Treaty problems arose with the destroyers as there were also limits on overall tonnage. But Japan prioritised them once it exited the Treaty system.
 
You must log in or register to reply here.

Users who are viewing this thread

Total: 2 (members: 1, guests: 1)

Similar threads

IJN Kaga....
Replies
0
Views
461
Lucky13
IJN Akagi....
Replies
0
Views
566
Lucky13
S
Battlecruisers vs Cruisers
2 3 4
Replies
62
Views
4K
Peter Gunn
A
Italian vs. Japanese WW2 Tanks
2 3
Replies
47
Views
5K
machine shop tom
Smith vs. Smith
Replies
0
Views
1K
Timppa
Menu
Log in
Register