Have the IJN mallet the RN in 'Operation C' - Indian Ocean Raid

[Fuzzy Dunlop]

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Have the IJN be completely successful in their 'Operation C' Pearl Harbor type mission in completely malleting the RN. This means have the RN completely removed from the Indian Ocean as a fighting force with all three carriers and virtually all battleship/cruisers and destroyers sent to the bottom.

What would be the consequences of this defeat?

These are the combat forces of both parties taken from Wikipedia

RN

3 x Carriers
5 x Battleships
7 Cruisers
15 destroyers
7 submarines
100 plus aircraft

IJN

6 x carriers
4 x battleships
11 x cruisers
23 x destroyers
5 x submarines
350 aircraft

Much obliged

 

[Peg Leg Pom]

Japanese scouts locate Sommerville's fleet. Game over.

 

[Carl Schwamberger]

View attachment 751566
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Have the IJN be completely successful in their 'Operation C' Pearl Harbor type mission in completely malleting the RN. This means have the RN completely removed from the Indian Ocean as a fighting force with all three carriers and virtually all battleship/cruisers and destroyers sent to the bottom.

Going over different scenarios for battle, or series of engagements and using the average number of damaging hits in the Japanese air attacks per sortie it looks tough to get to total destruction. The scenarios that get the Brit fleet, actually two separate combat groups, into a position for total destruction run counter to conditions created by Sommervilles assumptions and intent for the battle and his plan as executed. The are possible, but you have to alter the British commanders decisions by a wide margin.

At the other end of the spectrum Sommervilles intent works sort of. The Japanese suffering significant damage from a night torpedo bomber attack, before the get a grip on Sommervilles fleet. The are able to defeat Sommerville as required by the OP, but Nagumos fleet slinks backing Singapore missing several key ships. and large holes bleeding oil and smoke in the others.

What would be the consequences of this defeat?

Given odds of severe losses to the Japanese fleet & odds of average losses the likely outcome is the crippling losses to the KB that came with the Coral Sea battles & Midway start earlier here. That has knock on effects on how the carriers are used for the remainder of 1942 and beyond. As it was the Japanese lost approx 25 pilots in this operation, on top of another 25 lost in the Pearl Harbor operations and some 35 in other operations 7 December through April. While not crippling the 70-80 pilots and navigators lost in these first five months were near irreplaceable. Doubling the loss for Op C puts you over 100 key air crew lost from the KB & insufficient green replacements from school training in Japan.

 

[mack8]

I pondered on this scenario some time back, iirc if the scout that shadowed Cornwall and Dorsetshire would have flown another 10 miles on his course before turning back, he would have spotted Somerville. As a result of the rearmament muddle from the morning, Cardiv 5s B5Ns were ready to go at 14.00, but were stood down once the CAs were sunk by Egusa. Presumably at this time the B5Ns from Akagi, Hiryu, Soryu would have been ready too, plus the D3As from Shokaku and Zuikaku. So if the scout spots Somerville, oh boys he's in trouble.
The japanese would have available to launch something like 88 B5Ns and 32 D3As, probably in two waves, with a plentiful Zero escort. So the 2 RN CVs and Warspite are probably dead there and then. I don't know off the top of my head how close to Somervile was the R force (and also where was Hermes), but as the japanese found Somerville if they sniff around further they may find the Rs too, probably they will get attacked the next day. They can't run away from Nagumo's 30kt force. Any cripples, at least BBs, can be dispatched by the Kongos and CA/DDs with Nagumo, if Nagumo chose to let them do it.

KB will really cover itself in glory in such a scenario, but they will take significant losses. I never got the impression that RN's AA and fighter defences were as good as the USN at this stage of the war (which wasn't that brillian yet), the RN Fulmars and Hurricane and the Wildcats will be probably eaten alive by Zeros, leaving the AA to do what it can.

I guesstimate that if they attack both the CVs and the R force, they will probably lose something like 15-20 B5Ns and 10-15 D3As, plus say 6 Zeros to all causes, with others damaged and OOC temporarily. This may affect the upcoming Coral Sea and Midway, but haven't pondered yet how, one or the other maybe postponed possibly, or maybe not, KB could still gather enough planes for Shokaku and Zuikaku to go in SOPAC, while for Midway they really have to scrounge even harder but still imo doable (Junyo, Ryujo and Zuiho, even Zuikaku - assuming Coral Sea goes about the same- could be pilfered for planes/pilots, though possibly one of them is left home since there wouldn't be enough planes)

But boy imagine the shock in London after loosing 2-3 CVs and 2-3 or even more BBs plus smaller units in two days.

 

[USS_Ward]

I never got the impression that RN's AA

Actually its been kind of agreed that outta the 3 major navies of WW2 (USN, IJN, RN) the RN had the best light-medium AA at least in the start of WW2 (so pre- 40mm bofors/20mm Oerlikon spam. ) The 40mm pom-pom was a decent AA platform, eons better then the IJN's 25mm and USN 1.1 " guns. Downside is theres no tracer rounds (so less psychological effect of seeing hot lead flying past your head while making a bombing run) and also something about the humidity in the tropics fucking with the powder or something along that lines, which obviously reduced the overall effectiveness.

Still relying on AA as your first choice of defense is obviously a poor tactical choice and thats where the RN is kinda at a lost. Being that none of the FAA aircraft are a true match for their IJN counterparts, on top of smaller airwings of the RN carriers.

 

[Coulsdon Eagle]

Actually its been kind of agreed that outta the 3 major navies of WW2 (USN, IJN, RN) the RN had the best light-medium AA at least in the start of WW2 (so pre- 40mm bofors/20mm Oerlikon spam. ) The 40mm pom-pom was a decent AA platform, eons better then the IJN's 25mm and USN 1.1 " guns. Downside is theres no tracer rounds (so less psychological effect of seeing hot lead flying past your head while making a bombing run) and also something about the humidity in the tropics fucking with the powder or something along that lines, which obviously reduced the overall effectiveness.

Still relying on AA as your first choice of defense is obviously a poor tactical choice and thats where the RN is kinda at a lost. Being that none of the FAA aircraft are a true match for their IJN counterparts, on top of smaller airwings of the RN carriers.

I suggest studying how effective RN AA was during the Battle for Crete. IMHO I believe IJN aircraft losses would be lower than predicted.

 

[jsb]

I suggest studying how effective RN AA was during the Battle for Crete. IMHO I believe IJN aircraft losses would be lower than predicted.

Did the AA not mostly work at least to prevent hits, even if it did not shoot down aircraft at Create until they started to run out of ammo?

 

[Carl Schwamberger]

Actually its been kind of agreed that outta the 3 major navies of WW2 (USN, IJN, RN) the RN had the best light-medium AA at least in the start of WW2 (so pre- 40mm bofors/20mm Oerlikon spam. ) The 40mm pom-pom was a decent AA platform, eons better then the IJN's 25mm and USN 1.1 " guns. Downside is theres no tracer rounds (so less psychological effect of seeing hot lead flying past your head while making a bombing run) and also something about the humidity in the tropics fucking with the powder or something along that lines, which obviously reduced the overall effectiveness.

Still relying on AA as your first choice of defense is obviously a poor tactical choice and thats where the RN is kinda at a lost. Being that none of the FAA aircraft are a true match for their IJN counterparts, on top of smaller airwings of the RN carriers.

The one advantage the RN has here is better fighter direction. they had the radar & were more experienced than the USN at using it. May not save the fleet, but the Japanese suffer more in sinking it.

 

[Coulsdon Eagle]

Did the AA not mostly work at least to prevent hits, even if it did not shoot down aircraft at Create until they started to run out of ammo?

That was my point. They shot down few attacking aircraft. Now, with a far more coherent & sizeable attack force, I can't see the RN AA doing any better.

 

[Carl Schwamberger]

I pondered on this scenario some time back, iirc if the scout that shadowed Cornwall and Dorsetshire would have flown another 10 miles on his course before turning back, he would have spotted Somerville.

I have a map back at the desktop that shows the relative positions of the fleets when the cruisers were spotted. Unfortunately cant recall the distance between them nor Sommervilles heading. All I can recall clearly is his intent to avoid a day battle & use the sight strike capability of his air wing. That caused him to zig zag, east in the late afternoon & evening to search and hopefully strike, back west in the morning to open distance. But that does not tell us the exact relative location & courses at the moment concerned here.

 

[mack8]

I did found a quite useful map too, showing the position of Force A, Force B and Nagumo. It looks like Somerville was sailing obligingly TOWARDS Nagumo right at the time he could have been spotted and attacked by KB. Force B was right behind him, 135nm astern at 17.00PM
https://www.alamy.com/indian-ocean-...-world-war-2-1961-old-map-image242587558.html
I also found out that Hermes was detached to Trincomalee on the 3rd, so it could have possibly escaped if Nagumo does not attack Trincomalee on the 9th.
Also the wiki article on C sakusen is an excellent source to see how close Somerville got to Nagumo in the afternoon, as close as 100-120nm! Spitting distance as far as KB aircraft are concerned.

 

[Carl Schwamberger]

Thats the map Im referring to, but I cant magnify the one in the link to where I can read the date/time indicators. It does confirm Sommerville was for a uncomfortable time in striking distance.

 

[Carl Schwamberger]

But boy imagine the shock in London after loosing 2-3 CVs and 2-3 or even more BBs plus smaller units in two days.

Im wondering if this leads to another of the series of delays in the GYMNAST/TORCH operations. It would do a lot of damage to the RN reputation, no matter how badly the Japanese fleet is damaged.

 

[mack8]

Is this better?

 

[mack8]

Im wondering if this leads to another of the series of delays in the GYMNAST/TORCH operations. It would do a lot of damage to the RN reputation, no matter how badly the Japanese fleet is damaged.

Also possibly Wasp and the two South Carolinas remain in the Atlantic for longer to prop up the RN, with consequences for what happens in the Pacific summer/autumn ( Assuming KB still loses at Midway, though i don't want that in any ATL scenarios i ponder! However as with C sakusen, it's relatively easy to see how Midway could have flipped too, or at least not have KB lose that badly, but i digress)

 

[Carl Schwamberger]

Also possibly Wasp and the two South Carolinas remain in the Atlantic for longer to prop up the RN, with consequences for what happens in the Pacific summer/autumn ( Assuming KB still loses at Midway, though i don't want that in any ATL scenarios i ponder! However as with C sakusen, it's relatively easy to see how Midway could have flipped too, or at least not have KB lose that badly, but i digress)

So much of this depends on the Japanese losses. Its a wild variable.

 

[mack8]

Here is also a very interesting treatment of KB search patterns in 1942, actually it's about Midway but has info on C sakusen too, especially the drawings are most interesting.

A Question of Estimates: How Faulty Intelligence Drove Scouting at the Battle of Midway

New scholarship and interpretations point to a new understanding of two of the most perplexing questions of one of the most debated naval battles in history—why the seemingly unstoppable Japanese carrier force suffered a devastating defeat at Midway in June 1942 and how we interpret the battle...

digital-commons.usnwc.edu

 

[Dilvish]

The Combined Fleet message board (Tully'w Port) associated with CombinedFleet.com has a section devoted to Operation C:

Indian Ocean (Operation C) - Tully's Port

The Combined Fleet Articles of Interest section also has several articles about the Indian Ocean raid, including one about the loss of the RN cruisers.

Articles

 

[Dilvish]

My thoughts. KdB's dive bombers sink Cornwall and Dorsetshire, while a second strike goes after the carrier force. Both CVs and Warspite are hit and sunk or crippled. A third strike formed from the dive bombers that sank the cruisers, return to finish off cripples and go after any other ships they can find. Does Nagumo order KdB to close in for a gun battle? I think he is aware that there are still British battleships around somewhere.

The KdB will take heavier aircraft and aircrew losses. They can still do the Coral Sea operation, and the historical results may still happen. I don't believe that the IJN will be able to scrape up enough planes and aircrew to field all seven front line carriers that they did for Midway and the Aleutians. I don't see the Midway operation taking place. Plus, after beating up the RN in the Indian Ocean, is the need to defeat the USN as important? The Allies will still be reeling from the losses in the Indian Ocean. Another thought, would Nimitz and other USN commanders be as willing to risk their carriers at Midway?

 

[tonycat77]

Erasing the RN east of the suez would have large butterflies for the Indian independence movement.
RN was the symbol of imperial power since time immemorial.