1933 Wargames - RN attack on Pearl Harbour

[MatthewB]

1929, with the pending completion of HMS Glorious as the third of the Outrageous class, the US and RN intend to test each other's Pacific defences. Notwithstanding the global economic depression, it is decided to go ahead as planned and in 1933 Glorious, Furious and Courageous "attack" Pearl Harbour. Followed by a USN attack on Singapore from the Philippines.

The attack on PH will be a logistical challenge for the RN. The three carriers have a range of 5,800 nmi at 16 knots, but a one way trip from Singapore to PH is 5877 nautical miles. So the attack needs to be staged logistically.

So, the force leaves Singapore for the British Gilbert Islands territory (modern-day Kiribati), 4,200 nmi (11 days at 16 knots) from Singapore. https://www.britishempire.co.uk/maproom/gilbert.htm In advance of the exercise a fuel supply convoy would be in place at Gilbert. Gilbert is only 2,364 nautical miles from Pearl Harbour, and within six days sailing at 16 knots.

Thus RN approaches to within 100 miles of PH and launches a force of 40 Blackburn Ripon torpedo bombers, 40 Fairey III bombers and escorted by 30 Fairey Flycatcher fighters.

1) Blackburn Ripon

2) Fairey III loading up with bombs on HMS Furious and taking off from HMS Glorious

3) Fairey Flycatchers and Fairey III bombers preparing to take off from HMS Courageous

Beyond the carriers, what else would the RN send? In these days before radar, what reasonably realistic notice would the US be permitted to have of the raid. IMO, the learnings on both the British and American sides would be invaluable in the coming decade.

 

[Killer in]

Probably at least one of the Battlecruisers maybe two.

 

[Cryhavoc101]

Escort could be the Hood, Refit or repair and 5 D/E/Hawkins class Cruisers similar to the Special Service Squadron of 1924

All fast ships capable of keeping up with the Outrageous class - allowing the entire force to outrun anything in the USN it cannot outfight

 

[mudhead]

Will the RN - and the aircraft were operated by the RAF - come up with a suitable means of shallow water torpedo dropping?

The IJN started developing the wooden appendages to the Type 91 aerial torpedo in 1936, apparently independently of any external influence.

 

[Cryhavoc101]

Will the RN - and the aircraft were operated by the RAF - come up with a suitable means of shallow water torpedo dropping?

The IJN started developing the wooden appendages to the Type 91 aerial torpedo in 1936, apparently independently of any external influence.

Well the British came up with the Taranto plan in 35 or 38 so the same people would be kicking about a few years earlier.

And the British are quite smart - I am sure that they would think of it.

 

[jsb]

929, with the pending completion of HMS Glorious as the third of the Outrageous class, the US and RN intend to test each other's Pacific defences.

Why are they attacking PH, would it not make more sense to test it in the Atlantic to be less threatening? Some port in eastern Canada would fill in perfectly for both nations to join in or maybe something in the Caribbean?

 

[MatthewB]

Why are they attacking PH, would it not make more sense to test it in the Atlantic to be less threatening? Some port in eastern Canada would fill in perfectly for both nations to join in or maybe something in the Caribbean?

Both are seeing the growing naval power of the IJN, hence the construction of the Singapore naval base and the fortress at Corrigidor, Philippines. At the 1930 Imperial Conference the Australians were clear on this point and wanted assurances that the empire would protect them.

https://en.m.wikipedia.org/wiki/1930_Imperial_Conference

 

[jsb]

Both are seeing the growing naval power of the IJN, hence the construction of the Singapore naval base and the fortress at Corrigidor, Philippines. At the 1930 Imperial Conference the Australians were clear on this point and wanted assurances that the empire would protect them.

https://en.m.wikipedia.org/wiki/1930_Imperial_Conference

If the USN and RN are openly excessing together then this is very different from OTL..... nobody will dare challenge the united English speaking world in early 30s....

WNT is 5, 5, 3, 1.75, 1.75 .... no other combination can equal 10 and everybody knows this.

 

[MatthewB]

If the USN and RN are openly excessing together then this is very different from OTL..... nobody will dare challenge the united English speaking world in early 30s....

WNT is 5, 5, 3, 1.75, 1.75 .... no other combination can equal 10 and everybody knows this.

Japan quit the WNT in 1936. With these 1933 Anglo-American war games being planned from about 1930, Japan may have renounced the WNT in 1933 or earlier, citing clear provocation. Japan will be quickly building carriers.

Just wait four years later until the 1937 war games (provoked by Japan’s invasion of China) when France and the Netherlands join in. France sends the newly commissioned Dunkerque, heavy cruiser Algerie and four of the 45 knot Le Fantasque class destroyers to join the RN fast CBG. The Dutch focus on submarines, sending all five of their new K-XIV class https://en.m.wikipedia.org/wiki/K_XIV-class_submarine plus six older boats and the necessary tenders.

 

[Cryhavoc101]

Japan quit the WNT in 1936. With these 1933 Anglo-American war games being planned from about 1930, Japan may have renounced the WNT in 1933 or earlier, citing clear provocation. Japan will be quickly building carriers.

What impact might that have on the RN and USN?

Can the Japanese build them any quicker than they did?

They are limited to 6 long slips IIRC and they are modernising most of their 10 Battleships/Battlecruisers during this period

As I understand it they were pretty much maxed out.

 

[MatthewB]

With both the RN and USN clearly focusing on carrier warfare we might not see the three Yamatos started in 1937. Instead those slips go to carriers. Also, the Nagatos were modernized from 1933-1937, the very period that the RN and USN are conducting carrier ops.

 

[jsb]

With these 1933 Anglo-American war games being planned from about 1930, Japan may have renounced the WNT in 1933 or earlier, citing clear provocation. Japan will be quickly building carriers.

IF the "Anglo-American" are a thing any hope of wining at sea for anybody not speaking English is gone before it starts and walking from the treaties simply invites them to be flooded under the tidal wave of warships that will be laid down by USN/RN.

 

[fourthmaninaboat]

A few quick points here for people. Firstly, these exercises are probably taking place in the Mediterranean or Atlantic, with some other harbour standing in for Pearl. The RN never carried out major fleet exercises like the one proposed ITTL in the Pacific, even ones aimed at Japan. Instead, suitable stand-ins, typically in the Mediterranean, were chosen - for example, in 1928, Alboran Island was used as a stand-in for Singapore. Secondly, the RN/RAF probably wouldn't need to hurriedly develop techniques for attacking ships in shallow harbours. This had long been understood as a key role for naval aviation in the RN, with plans for using carriers with torpedo to attack ships in harbour dating back to 1914 at the earliest. The RN's first exercise featuring carrier aviation centred round an attack on elements of the Home Fleet at anchor in Portland Harbour in 1919, and later exercises continued the theme. Finally, this doesn't represent a considerable break in British naval policy; the RN had been using grouped carriers from 1929, with Courageous, Glorious and Furious operating together in a number of exercises. I doubt that this exercise would cause a change in Japanese procurement priorities, beyond the obvious need for expansion caused by Anglo-American cooperation.

The RN's exercises of the 1920s and 30s suggest that they would probably deploy the three carriers supported by whatever battlecruisers are available, a cruiser squadron, and two destroyer flotillas. As to what the outcome is going to be? The defending force is likely going to have very little warning. Without radar, the only real way to spot a raid is visually; but spotting a raid over water is unlikely without plenty of picket ships and scouting aircraft. With these, you might get up to an hours warning, without (to simulate a surprise attack), the first warning you get will be when they attack. With 36 torpedo aircraft, you could expect maybe 12 to 18 hits on stationary ships; bombing accuracy would likely be similar. Torpedo aircraft would target the battleships, while bombers would target cruisers and destroyers. It's hard to tell what the effects would be, but with that many torpedo hits, there would likely be a few sunk battleships; how many depends on how they were distributed across the force.

 

[MatthewB]

Firstly, these exercises are probably taking place in the Mediterranean or Atlantic, with some other harbour standing in for Pearl.

No, we’ve already established that this is a Pacific exercise, with a reasonable premise that massive military investments in Singapore and The Philippines can justify the occasional large scale multinational naval op. The Singapore Strategy was all about sending a fleet when needed, so it makes sense to send a fleet to test the strategy, and while there to exercise with willing allies.

One of the things that bugs me on Alt History boards are the contrarians; those who tell us why something wouldn’t, couldn’t or shouldn’t have occurred. There’s no convincing or persuading the contrarian, no attempt at providing a reasonable premise or back story is sufficient.

 

[fourthmaninaboat]

No, we’ve already established that this is a Pacific exercise, with a reasonable premise that massive military investments in Singapore and The Philippines can justify the occasional large scale multinational naval op.

One of the things that bugs me on Alt History boards are the contrarians; those who tell us why something wouldn’t, couldn’t or shouldn’t have occurred. There’s no convincing or persuading the contrarian, no attempt at providing a reasonable premise or back story is sufficient.

The massive military investments in Singapore IOTL didn't cause the RN to begin exercises in the Pacific, so it's hard to see why it would here. That said, working with the USN is an equally big break with RN policy, so hey. In any case, my second paragraph was an attempt at examining how it would work, putting my objections aside.

 

[Cryhavoc101]

The massive military investments in Singapore IOTL didn't cause the RN to begin exercises in the Pacific, so it's hard to see why it would here. That said, working with the USN is an equally big break with RN policy, so hey. In any case, my second paragraph was an attempt at examining how it would work, putting my objections aside.

Could such an exercise be carried out in the Pacific as per the OPs suggestion if the 'impact' of it was intended for Australia and New Zealand - "look see we can come in force to your aid" - the Sending of 2 BCs, 3 CV, 5 Crusiers and up to 16 DDs to the region an example of the RNs ability to project power

Otherwise yes I suspect any Anglo / American war game to take place in the Caribbean if not the Med

 

[MatthewB]

Yes, that’s the point. Britain has just completed the Singapore naval base, and the strategy dictates a sizeable fleet be sent out when needed. We’re doing some test runs of that strategy in 1933 and 1937.

 

[jsb]

Could such an exercise be carried out in the Pacific as per the OPs suggestion if the 'impact' of it was intended for Australia and New Zealand - "look see we can come in force to your aid" - the Sending of 2 BCs, 3 CV, 5 Crusiers and up to 16 DDs to the region an example of the RNs ability to project power

Yes they could its just matter of budget, they would rather spend it on more new ships or refits than sail round the world.

Otherwise yes I suspect any Anglo / American war game to take place in the Caribbean if not the Med

Yes, that’s the point. Britain has just completed the Singapore naval base, and the strategy dictates a sizeable fleet be sent out when needed. We’re doing some test runs of that strategy in 1933 and 1937.

This is the big part its one thing for RN to test Singapore but doing any large exercise with USN isn't about "the 'impact' of it ... for Australia and New Zealand" its about the impact on US isolation and reforming the alliance that won the end of WWI....

 

[WaterproofPotatoes]

With both the RN and USN clearly focusing on carrier warfare we might not see the three Yamatos started in 1937. Instead those slips go to carriers. Also, the Nagatos were modernized from 1933-1937, the very period that the RN and USN are conducting carrier ops.

The IJN in this period OTL strongly believed in a Mahanian decisive battle. To this end, they needed some fast ships, some submarines and carriers, and some big battleships. The fast force (the Kongo class battlecruisers and their B-65 planned replacements) would attack the approaching US fleet at night, after said fleet had been harrassed by carrier aircraft and subs. Then, the qualitatively superior Japanese battleships would decisively defeat the approaching US fleet.

The Gun Club was a powerful force in each major navy and will prove challenging to overcome, especially as a mock raid isn't exactly Tsushima or Trafalgar.

 

[jsb]

The IJN in this period OTL strongly believed in a Mahanian decisive battle. ...Then, the qualitatively superior Japanese battleships would decisively defeat the approaching ... fleet.

The Gun Club was a powerful force in each major navy and will prove challenging to overcome, especially as a mock raid isn't exactly Tsushima or Trafalgar.

The problem with the OP is that the IJN will sit in the corner of the planning room wondering how they fight a decisive battle with a mixed force of 20-25 battleship from RN/USN when they only have 9.......