Tuesday, July 30, 2013

Challenging 'Inevitable' results in battle - Midway, Force Z, and Ceylon

The probems of assessing the uses and effects of naval airpower in WWII

I have had several interesting comments on my discussion of which aircraft carriers were most effective in WWII and why. I was reasonably impressed by some comments about the efficacy of Dive Bombers vs Torpedo aircraft (thanks to those who made them), and did a little more research along those lines.

What I found was very little definitive argument, and lots of deterministic laziness along the lines of ‘well this happened therefore naturally it was absolutely inevitable that it would happen, and there was never any possibility that anything else would happen’.

I hate this stuff. I have since I played board games on a regular basis and came across all sorts of stupid rules to make things happen the way they did, with no allowance for what could have been. ‘World in Flames’ for instance was great fun, except that it made absolutely no allowance for the very real possibility that Italy could have finished on the Allied side not the Axis side.

Unfortunately the same laziness crept into academic teaching. In one of the courses I taught at Deakin University in the early 1990’s  – War and ModernIndustrial Society – other lecturers were appalled that I could suggest that Italy being on the Axis side was not absolutely inevitable.

So I started combing discussions of naval battles of WWII decided (or potentially decided) by airpower, and assessing the logic of their claims.

Here are a few trite statements that seem to make reasonable sense:

High level bombing against ships was usually pointless. (Sometimes described as trying to drop a billiard ball on a scared mouse.)

The Japanese (or Germans or Italians) had very little success against Allied fleets when even limited fighter cover was available to break up attack waves.

If what fighter cover there was could be drawn down by torpedo bombers, dive bombers had a much better chance.

Japanese fleet fighter cover was often effective against torpedo aircraft, but their sight based interception was usually inadequate to prevent dive bombing attacks.

Once the Allies had effective radar controlled fighter direction for defense, there were very few successful Japanese (or German or Italian) attacks. [German guided missiles and Kamikaze’s are limited exceptions here.]

It takes time to develop the correct techniques for fleet fighter control officers to be effective, and usually the first few attempts were not very effective.

British fighter direction enabled British carriers to operate smaller CAP’. (This had been evident when HMS Victoriousserved with he USN in the Pacific in 1943, where the American Admiral had left Victorious– USS Robin – to run her strength – fighter direction for the fleet – and Saratoga to run hers – strikes by the fleet. It was even more evident in 1945.)

Here are a few trite comments that are arguable:

Dive bombers got through more often, but torpedo bombers were far more likely to knock an opponent out entirely, or put them out of action.

No available Allied fighters could outfight Japanese fighters – particularly Zeros – in 1942. (Seems to concentrate on surprised and outnumbered defenders in the early days and ignore the very good results of the Flying Tigers P40’s in China and RAF Hurricanes in Burma and USN Wildcats/RN Martlets at sea if they were prepared and at height.)

The side with the greatest number of aircraft on their carriers has the advantage. (Seems to ignore the many times the majority of those aircraft got lost; ran out of fuel and crashed; were too broken up by fighters to be effective; or failed to do as much damage as they thought when they did get through. In fact direction and control was far more important than pure numbers. A dozen aircraft at the right place and time repeatedly trumped hundreds wandering around all day.)

Still these often overly simplistic statements give a good start to consider some realities.

Case Study 1. Midway.

The Japanese were entirely reliant on Mark 1 eyeball. The failure of the Japanese scout planes to find the American carriers an hour earlier may well have decided the battle. Note that it was a series of accidents – a plane breaking down, replacement launching late, radio reports not accurate enough, etc – that caused this vital delay, not the actual abilities or techniques of the Japanese recconnaissance units.
The Americans had the beginnings of radar. Admittedly, it was not well used, and the fighter direction was inadequately developed, but it gave them a crucial edge at a vital point. (In all later battles where they used it more effectively the Japanese failed dismally.)

The vital factor was that the Japanese lack of radar meant that when their fighter cover was sucked down after American Torpedo bombers, a group of 32 Dive Bombers won the battle. (Note that, until the last few months of the war, almost every battle won by naval air power was actually won by a relatively small group that got through unnapposed for one reason or another.)

Interestingly Hiryu’s first counter strike of 18 Dive Bombers and 6 Fighters was mostly broken up by defending American fighters, but still got 3 hits on Yorktown. But the result was that the defenders were still moved out of place. The next strike of only 10 TB and 6 F, even though detected, could not be intercepted in time, and got 2 torpedo hits, dooming Yorktown.

The counterstrike at Hiryu was only 24 Dive Bombers, but there were only 4 Fighters left to defend. The result was 4 hits.

Interestingly 35 of 41 American Torpedo Bomber’s that attacked the Japanese were lost for no hits, and Dive Bomber losses were thus reduced by the live bait. Whereas the 10 Japanese Torpedo Bombers managed 2 hits for little loss, because the American Fighters had been pulled off by killing 12 out of 18 Japanes Dive Bombers. (It was radar that made intercepting these dive bombers possible, but that did not solve the problem of inexperienced operators not having more fighters in place to face the next attack.)

Nonetheless Midway was a damn close run thing. Both sides were lucky to get shots against no fighter protection.These were the attacks that achieved most of the damage. The only attack that got through fighter protection was the one where the Japanese took 75%+ losses on the first strike from Hiryu against Yorktown, despite the fact that they were doing the much more likely to succeed Dive Bomber attack that time. (And the three hits only caused limited fires which good damage control managed quickly enough to resume flying operations).

So the interesting point about Midway is that the single occasion where the Americans managed to use their fighter direction successfully probably saved Yorktown.

Case Study 2. Malta Convoys.

Let’s look at how fighter direction really works.

The Pedestal convoy to save Malta in August 1942 saw the British use 3 aircraft carriers (Victorious, Indomitable and Eagle) with 100 aircraft (72 of them fighters – 42 Sea Hurricanes, 10 Martlets or F4 Wildcats, and 16 Fulmar) go head to head with 700 Axis aircraft, most of them German. (Another British carrier, the Furious, accompanied the convoy only long enough to fly off reinforcing spitfires for Malta, before returning to Gibraltar, but if the Doolittle raid could be considered a two carrier operation, I suppose this would count as a four carrier operation?)

The convoy battle breaks into 3 parts. The first part is the Western Mediterranean combat where the RN successfully provided air cover against daylight strikes by the Axis. The second part is the night attacks by submarines or surface raiders like motor torpedo boats in the Sicialian narrows that smashed up the convoy and did most of the damage – which happened after the covering force withdrew. The third part sees land base aircover from Malta successfully shepherd most of the survivors through, despite their heavy handicap that the two fighter direction cruisers that were supposed to guide them had both been lost in the night actions. Although the third part has interesting lessons, only the first part really concerns us here.

In the first stage there were several strkes against the convoythat involved 100 aircraft or more, and they came in so often, and from such varied hieghts and directions, that there were almost constant attacks. Nonetheless most attacks were intercepted 25 miles out by goood fighter direction, and, despite the fighter patrols always being very heavily outnumbered, the majority of attacks were broken up. As a result those planes that got through had little success, except for a pair of low flying Italian FB that looked very like Hurricanes trying to land. They got a single ineffective bomb hit on Victorious. She continued ops.

Unfortunately HMS Eagle was torpedoed by a submarine, and only the 4 of her fighters that were airborn could go to the other carriers. This shortage of another deck made the constant fighter patrols harder and harder to keep up by the two remaining carriers. Eventually a combined attack of Dive Bombers and Torpedo Bombers got through during the difficult to defend dusk period, and although Indomitable combed the Torpedo’s, two 1,100 pound bombs put her deck out of operations. (The 11 of her fighters which were airborne that could land on Victorious simply made her deck too overcrowded for effective operations.)

Nonetheless, the only casualty on the convoy at that point was a single merchant ship damaged. So, had Malta been a bit closer, it would have been a fabulous victory that well and truly demonstrated the ability of well directed fighter patrols to take on much larger numbers of enemy aircraft. (The multiple invasions of Italy, the strikes on Tirpitz and the Dutch East Indies oil refineries, and the many USN operations in the Pacific, would demonstrate exactly the same thing again and again later in the war.)

[It is also important to note that the Germans were no slouch in radar themselves. The Japanese were never to catch up with the radar capacity that both sides had at the time of this 1942 battle.]

Case study 3. Force Z and land based fighter cover.

Now as an opening point, I will say that Admiral Phillips was a prize idiot, and that I entirely agree with most historians (and most contemporary admirals at the time), who thought he should never have been in charge of this operation. (The fast declining First Sea Lord Admiral Pound was one of his few adherents.)

Why the damn fool didn’t communicate with his land based support at any point is beyond comprehension. Apparently he didn’t want to radio even when he knew he had been seen and was being shadowed? Apparently he thought his land based subordinates would guess where he intended to go and provide aircover? Apparently, though he knew that there was a squadron of fighters tasked to him waiting for instructions, he didn’t even call it when the Japanese strike appeared on radar, or when Prince of Wales was damaged? The captain of Repulse called air support almost an hour later, and it arrived only in time to chase the last Japanese planes away?

If fighter cover had been called, even if only when the attacks actually started, the two case studies quoted above (and the many others that can be identified throughout the whole war) seem to suggest that it would have been successful in breaking up the Japanese attacks enough to make it unlikely that any ships wold have been sunk. Note that in the above cases all attacks that were intercepted were broken up despite fighter escort. The Japanese here had no fighter escort (even though a few Japanese fighters were available and might have had the range).

The Nell and Betty bombers used in this operation were fast and long ranged, but Allied pilots (and indeed Japanese aircrews) recognised their appalling vulnerability to air attack by referring to them as ‘first strike lighters’. Even though the comparatively slow Buffalo fighters operating from land would have had similar problems of interception of dive bombers to those both the Japanese and Americans later experienced, there is little doubt that they would have had very little  difficulty in shooting down quite a few of these incredibly vulnerable aircraft if they attempted low level torpedo strikes. (Note, the low level torpedo strikes were the killers here. The few high altitiude bomb hits were not very effective, and the Japanese simply had no dive bombers available for this action.) The case studies suggest that even if Zekes had escorted the later strikes and managed to shoot down two thirds of the defending fighters, the air attacks would still have been too broken up to be successful.

Case study 4. Force Z and the Indomitable.

It is common knowledge that the aircraft carrier HMS Indomitable was supposed to accompany Force Z, until damaged in trials in the West Indies and delayed. Which has allowed too many people to count to say that it ws a good thing that she wasn’t there, or she would have ‘almost certainly’ been lost too. (In fact it is entirely possible that she would have been too late to get to Malaya in time for this battle even if not damaged, but for this discussion let us go with the supposition of the argument.)

I have long wondered about the supposition that Force Z would have been doomed even with a modern heavily armoured aircraft carrier, with one of the most advanced anti-aircraft batteries, and a force of radar directed fighters.

To quote Professor David Hummer who published BomberVS Battleship in 1998: “During the Second World War daylight bomber attacks without fighter escort were almost never successful – or anyway incured heavy casualties – if the target was defended by high performance fighters, efficient radar, and effective direction of fighter defence by radio.” He uses more than a dozen case studies on every front right through the war to prove this point. (Mind you David Hummer also one of the people who, earlier in the same book, says Indomitable would have probably been lost. Not sure he bothered to proof read his own conclusions, or if he genuinely believed this… I suspect he is just being a prime example of the sort of unthinking laziness I am complaining about)

So lets look at it.

HMS Indomitable was the latest, largest, and most powerful armoured aircraft carrier in the RN. Her radar directed AA batteries alone would have more than doubled Force Z’s anti aircraft firepower. (It is notable that it was Prince of Wales’ radar being inoperable that day which was a major contributing factor to the disaster. Indomitable’s radar systems might have been a useful backup?) Her standard extra destroyer escorts – usually a cruiser too, but possibly not in this case – would not have hurt either.

Indomitable was attacked many times in the war, and hit on several occassions. Two German 1,100 pound bombs actually put her out of flying operations during the Pedestal battle mentioned above (though she steamed away at 28 knots), and a German torpedo also put her into drydock once, though a Japanese Kamikaze just bounced off later in the war. (None of the six Illustrious class armoured carriers were actually sunk, despite all of them receiving bomb or kamikaze or torpedo damage, most of them on multiple occassions. And even after taking 6 hits from German dive bombers and having her flight deck out of operation, Illustrious continued to fight as an anti-aircraft vessel for weeks while initial repairs were completed.)

Indomitable also had highly skilled fighter operations officers, who had managed to learn a lot from the many battles fought using radar interception and fighter guidance in the Mediterranean. Her 21 fighters (12 Fulmar and 9 Sea Hurricanes) were the same models that proved so effective in the Pedestal convoy against air strikes very similar to the ones force Z faced… with four differences.

First, the Axis had 700 aircraft operating against Pedestal, the Japanese a little over 100 against Force Z.

Second, the Axis had plenty of fighter suppport. The Japanese had none.

Third, the Axis strikes came in waves all day against a very slow convoy on a completely predictable course. The Japanese strike had spent hours looking around a vast area before giving up and then accidentally stumbling over the fast moving battleships on the way home.

Fourth, the Axis arrived in groups of up to 100 a time. The Japanese attacks dribbled in. 8 Nells at 1100, 17 Nells at 1130, another 6 at 1140, then several Betty’s at between 1215 and 1240.

[I suppose the fifth factor to consider might be that even though operation Pedestal was escorting lots of slow and vulnerable merchant ships, it was nevertheless a large and well organised fleet of dozens of warships, not a smallraiding force of less than half a dozen. Later fleet actions all tend to show that the bigger and more powerful the fleet being attacked, the less results are achieved for a given number of attackers.]

Returning to the attack on Force Z:

It is hard to imagine that working radar would have let there be any element of surprise in the attack.

It is hard to imagine how 20 fighters could not have broken up these waves of attack if fighter direction officers using radar had intercepted them 25 miles away?

It is hard to imagine that the extra squadron of fighters from shore would not have been called by experienced fighter direction officers. (British carrier doctrine was experienced enough by this stage of the war to let the carrier force commander make aircover decisions without asking the admiral in charge of the fleet… something US carriers would also get around to… after Coral Sea and a couple of other learning experiences.)

It is very hard to imagine that the integrated Force Z would have been as vulnerable with a co-ordinated air defence. (On the way to the Far East, Prince of Wales had fought a convoy through to Malta in company with another battleship and an aircraft carrier - Rodney and Ark Royal. Despite Axis efforts, the co-ordinated force had good enough fighter direction that attacks were broken up and came in piecemeal, allowing the Prince of Walses to shoot down several Axis planes during very similar raids… quite a difference a bit of air support makes.)

Now perhaps Prince of Wales would still have been damaged by the lucky shot that hit her steering early in the battle. (Steering is always the weak point of a battleship… ask Bismarck.) but even with no air cover she was still fighting when Repulse was sunk an hour later. With Indomitables aircover, fighter direction, and anti-aircraft firepower… plus extra fighter cover from land?

The more analysis I read of the effect of even limited aircover on the effeciency of attackers, the more I think that the statement, “Indomitable would almost certainly have been lost too”, is just lazy thinking.

 [I do note that Hummer suggests that the Japanese had 25 Zeke’s available which were not used. He says, ‘as they surely would have been’, had the Japanese known there was a carrier present. Surely the Japanese knew the British had fighter cover available? They certainly can’t have been assuming Phillips was too stupid to call for it? And perhaps the fact that the strike of Nell’s and Betty’s – with over 3000 miles range each -  found Force Z accidentally on the way back from hours of fruitless searching may be a consideration on whether the Zeke’s – about 1000 miles range normally, or 1,600 with the later drop tanks - were actually likely to be there? At least until the very last strikes? More laziness?]

It is interesting to note that although everyone is very impressed by what the Japanese Naval Air arm achieved when there was no , or little, airborne opposition, the results when there is any airborne aopposition are suprisingly different.

Pearl Harbour, Force Z, and the Darwin raid are good examples of what can be achieved when there is very little airborne opposition. (Though it is interesting to note that Nagumo’s best reason for not mounting a third strike at Pearl Harbour was that the casualties of the second strike had doubled even as results declined, and if this had continued losses would have possibly outwieghed the net benefit of another strike. I, and many others, disagree: but it was a very reasonable point.)

By contrast the raids on Ceylon and Midway demonstrate that any airborne defense drastically reduced the effectiveness of the raiders. The first strike on Ceylon at Colombo – anywhere between 70% and 90% of the size of the first strike on Pearl Harbour depending on whose figures you accept – achieved trivial results by comparison. The airfields were not knocked out, port infrastructure was hardly touched (though the bombing of the insane asylum instead of the fuel tanks might have contributed to this failure), and only an old destroyer and an armed merchant cruiser were actually lost. This despite the fact that the radar had been down for maintainance, so most of the defending fighters were caught on the ground.

When they did take off, the 41 defending fighters lost half their number, but clearly managed to disrupt the attackers quite significantly. The limited opposition the Japanese actually faced clearly had very impressive effects on reducing their results.

By contrast the second and much smaller wave was directed againt the two British cruisers – Dorsetshire and Cornwall – discovered while the first attack was going on. These strikes had no airborne opposition, and therefore had complete success, with quite outstanding accuracy.

The second attack at Trincomalee a few days later achieved remarkably similar results to the Colombo attack. There were less fighters availble – only 23 in fact – but they were in the air and achieved similar effects to the 41 at Colombo. For losses of half their number, the attacks were broken up enough to be limited in effect. There was more damage to the dockyards (with no mental asyluym to be a distraction this time), but the harbour and shipping were hardly touched. The worst losses were the planes undergoing refit or repair on the ground at the airfields and naval base, many of which were destroyed.

With spooky similarity, the second strike was again diverted by the discovery of nearby warships: this time the ancient little aircraft carrier Hermes and her destroyer escort a bit further up the coast. (Note that this same pattern would of course be followed again, at Midway.)

The second, and smaller, strike had the traditional success that attended an unapposed air attack, and easily sunk both ships, again with remarkable accuracy. The fighters that might have intercepted were delayed in being dispatched, and arrived too late to intefere. (They may have been too late anyway, but it is interesting to note that even light fighter coverage would have certainly reduced the effectiveness of the attacks… though probably not enough to save the elderly and very vulnerable Hermes.)

It is interesting to note the differences in effectiveness between the fighter intercepted strikes by bigger forces, and the unapposed strikes by smaller forces. It cannot be that, on both occassions (as at Midway a few weeks later), the Japanese pilots had lost the skills that served them at Pearl and Darwin completely during the first strikes, and magically rediscovered them an hour or two later. The pathetic results achieved in the first strikes, compared to the impressive – almost clockwork – results of the second strikes, make clear statements about the effectiveness of any sort of air interception.
Most notably the air defence at Colombo, even though caught on the ground, and losing half its numbers when it did get in the air, made the results of the Colombo raid almost laughably small.

Case Study 6. The ‘almost but not-quite’ Battle of Ceylon

This leads to another interesting series of ‘inevitable’ statements that can be analysed.

The whole purpose of the Japanese Indian Ocean raid in April 1942was to try and catch the British Eastern Fleet and defeat it before it was fully assembled. (The RN had 2 more carriers and 4 more batteships were on the way to reinforce the 3 and 5 respectiveley already present.).

The fundamental Japanese problem was that they faced a two front naval war (as well as a 3 front land war – counting China and later Russia). Having failed to complete the job at Pearl Harbour, this raid ws their one and only attempt to knock out the other threat axis before turning back to face the Pacific again.

However Admiral Nagumo made the same mistake as at Midway. The first strikes went after harbours, rather than find the ships which are the real point of the operation and strike them. As a result, although the second and later strikes at Colombo, Trincomalee and Midway all succeded in knocking out major Allied warships, they didn’t come close to the major naval victory that was required to save their position long term.

Nonetheless book after book, and article after article, claim that it was lucky that the Japanese did not find the British Eastern Fleet, because it would “certiainly have been destroyed”, or “there could only be one outcome”.

These statements are, again, nicely deterministc, but again, very lazy. They assume that something would automatically have happened, despite the evidence that the same authors quote in every other case study they use?

Basic point is that the Eastern Fleet only had 3 aircraft carriers (2 modern armoured and the old Hermes) and although it had 5 battleships, half a dozen cruisers and a score of destroyers, they were mostly older and less well eqipped vessels. Therefore, it is argued, they could not have withstoood the Japanese striking force which contained five carriers and four modernised battlecruisers. (The minor niggling point here being that the ship vs ship odds were far more in the British here favour than the ship vs ship odds were at Midway, but the same authors don’t seem to have a ‘inevitable defeat for the USN’ line going there? Perhaps because reality demonstrated that theory is nothing like ‘inevitable’?)

The strength of the ‘inevitable’ case is the air strength of the five Japanese carriers in the main strike force – Akagi, Horyu, Siryu, Shokaku and Zuikaku (Kaga had been forced home for refit, and to replace her significant aircraft and aircrew losses from several months of non-stop operations). Between them they had a theoretical 300 aircraft available (how many were down for maintanance is still uncertain, but Kaga was obvously not the only one to have served for several hard months straight, lets be generous and say 80%-90% operable), to face the 200 odd on the British side.

The 3 British carriers of course had far less aircraft than the 3 American ones did at Midway. In fact Hermes was really an escort carrier and was not available at the time a fleet action almost happened, so it really comes down to the 88 aircraft on Victorious and Indomitable VS the 250-275 on the five Japanese carriers.

This is where stements of ‘inevitability’ sound convincing. For if Nagumo could get a straight fleet action in daylight of 270 aircraft against 88, he was unlikely to lose.



A few problems with this.

First, British intelligence knew he was coming, and Admiral Somerville had waited in ambush for 3 days. Only delays by the Japanese meant that Somerville returned to port even as the Japanese arrived and were spotted by the reconnaissance patrols waiting for them. So, as at Midway, Japanese surprise was not an option.

Second, Somerville had absolutely no intention of facing the superior Japanese air numbers in daylight. Not least because his slow biplane strike aircraft would have been even easier to kill than the equivalent American Devestator torpedo bombers were at Midawy. (Actually this is unfair to the Devestator’s, as the much vaunted and much more survivable Avengers were also smashed out of the sky for no actual result at Midway. Without massive fighter protection, no torpedo bomber managed to survive to attack successfully, anywhere, any time during the Second World War.)

Somerville, the very experienced leader of the world’s first successful Fast Carrier Task Force – Force H of Ark Royal, Renown and Sheffield with their destroyers – in the Mediterranena and Atlantic for two years of combat, knew the limitations of his forces well.

Instead Somerville planned to use the strengths of his fleet and aircraft, principally radar. (Somerville was a radar specialist who had headed Admiralty developments of radar in 1939-40.)

Somervilles carriers and battleships had years of experience with radar, and radar interception, and radar fighter direction, and radar equipped aircraft mounting strikes. As a result, the Royal navy was the only force that had vast experience of radar fighter intecrception, and the only force that could mount radar directed night airstrikes.

Whereas the Americans and Japanese both lost many aircraft during the war because they did not get home before dark, the British had no trouble in mounting night strikes at Taranto and against the Bismarck at sea before returning to their carriers. (Which meant their obsolescent strike aircraft – Sworfish and Albacores – were probably more likely to succeed in getting through at night than anyone else's obsolescent strike aircraft – Kate’s, Judy’s, and Devestator’s for instance – were to succeed against fighter defences during the day!)

There are lots of ifs and buts possible here, but lets go with the straight scenario.

On the Easter Sunday when the Colombo strike was launched, Somerville was heading with his Force A (armoured carriers Victorious and Indomitable, modernised battleship Warspite, two cruisers and several destroyers), to meet the two other British cruisers – Dorsetshire and Cornwall – heading south from Colombo. The plan was to join up and be in position for a night strike on Nagumo’s fleet as it withdrew south after the Colombo raid. A couple of hundred miles behind Force A was Force B, 4 old battleships, more cruisers and destroyers, which Somerville hoped to rendevous with at first light (or retire on at night if Nagumo got frisky with his fast battlecruisers).

When the second Japanese strike (80 dive bombers) was diverted to strike Dorsetshire and Cornwall, they appeared on Somervilles radar. But the cruisers radio messages had not got through, so Somerville did not send fighter support.

Some writers (like Harmer) say that if he had realised what was going on, he would have faced the dilemma of sending fighters and revealing his presence, thus risking the Japanese finding his fleet by day and sinking it: or abandoning the cruisers.

This perspective misses a few points.

First, there is no question Sommerville would have sent support if he had known. He was that kind of man, and his record of such actions in the Mediterranean was clear.

Second, given all we have looked at above, there is considerable question whether the dive bomber attacks would have succeeded so well if support had been available. Certainly they would have suffered casualties.

Third, it is almost incomprehensible that Nagumo did not search in the direction the two cruisers were going anyway? Again we ask, what the hell he thought he was doing if not searching for the fleet that was his main target? Did he just assume they were running away without considering any other options? (Just another sample of him being a far poorer admiral than many people give him credit for.)

Fourth, if Nagumo had realised that there must be British carriers to the south, would he have launched a strike in the vague direction and hoped for the best (as was tried and failed so often in the Pacific conflicts)? Or would he have launched search aircraft while he prepared another strike (as sometimes happened in the Pacific)?

If his search aircraft had found the British carriers (without being interecepted by radar directed fighters), would it have been too late in the day to do anything other than launch the dusk suicide attacks that failed so dismally for both the Japanese and the Americans later in the war?

If some of Nagumo’s strike or strikes (say the third or fourth strikes of the day… so how big? Later wartime actions had these strikes at no more than 30 aircraft at a time….), had found the British carriers, would the radar directed fighter interception have been any less effective than they were aginst much larger strikes in the Mediterranean?

If some (probably dive bombers) had got through, and had managed some hits on the British armoured carriers, would their 500lb bombs have had any effect? (Given that it usually took 1,100b bombs to damage the armoured carriers, and most later hits by bombs or Kamikaze’s simply bounced off.)

Would the inevitable reports by overexcited Japanese pilots of burning or sinking British carriers (see any action of the whole war), have enticed Nagumo to stay in the area for more strikes in the morning… which is exactly what Somerville wanted?

Or would Nagumo’s strikes/reconnaissance have missed the fast force A completely and either found nothing, or found the slow Force B further away instead… with the same implications for suicidal dusk attacks one way and possible night strikes the other?

Note that even without Nagumo knowing Somerville was there, Force A’s aircraft found Nagumo’s fleet at 6pm. Unfortunately Nagumo was heading North East by then, and constant patrolling overnight did not find him before he was well out of range.

All this is failry whimsical speculation. But the more you read about all the other naval air actions of the war, the more you realise just how much difference radar made. When the Japanese and the Americans were both stumbling around trying to find each other, the accidental sightings and even more accidental chances of so many aircraft from this large strike and so many from that smaller strike actually finding anything to attack is quite incredible. By contrast the minute the Americans have a fraction of radar ability, Japanese results spiral downwards at a remarkable pace. (In fact in direct proprtion to how American results spiral upwards!)

Why wouldn't radar have had the same effect in the Indian Ocean?

If Nagumo had had the fortune to find the British fleet before he started his other strikes; and if his planes had been able to find it in large enough groups; and if radar fighter direction didn’t work as well as in the Mediterranean; and if the resulting damage to the armoured carriers had been greater than any other sample of damage I can find in the other battles where Japanese naval aircraft found American carriers: then Nagumo might have won a great victory.

But that’s a lot of if’s.

At the other end, if Nagumo had realised the British were there, or manouvred for a dawn strike, or just continued south instead of north east, then would a night strike by Somervilles aircraft have worked? 

The impressive results at Taranto argue the British aircraft and crew were good enough, but that was against parked ships. (Though admittedly well prepared, unsuprised, and heavily defended ones.) The multiple hits by very few aircraft on Bismarck at high speed at sea (in dreadful weather and/or at night) from both Victorious and Ark Royal argue that the much larger and less easy to miss Japanese fleet would have been fairly vulnerable. (Interestingly most wartime actions reveal that the bigger the fleet by day the better its defenses work, but the bigger by night the more vulnerable to air or torpedo boat attack.)

Frankly it is not reasonable to suggest that either side was likely to score a Midway style knockout blow in such circumstances. Either would have to have a lot of things run in their favour to do so. But then again, a lot of small suprises running together is what actually happened at Midway isn’t it?

What you can say is that, given the ship VS ship and aircraft VS aircraft odds, and the technological gaps, the US victory at Midway was somewhat less likely than the British achieving at least a Coral Sea like standoff at Ceylon. (In fact if radar is as vital as most of the discussions suggest, there was considerably more chance of a British victory at Ceylon than was reasonable to expect of a USN victory at Midway.)

But that is just speculation.

Nonetheless it all gives more reason to be very suspicious of statements of ‘inevitability’. Likely is one thing, but certainty is quite another.

Midway shows that.