Swordfish vs Devastator

[Juha3]

The Luftwaffe (OB from Operation Pedestal) was flying JU87Ds and I know that they were carrying 1000kg bombs, because they hit Indomitable with two of them. In the Fall of 1941 Ju87Bs hit the Soviet battleship Marat with 1000kg AP bombs and there is strong evidence that they used the same on HMS Illustrious in Jan 1941. The JU87R could carry the same bomb weight for short range missions, and due to the operational requirements of the Malta Convoys FAA carriers had to operate within the JU87B radius of action with a 1000kg bomb. I already indicated, in a prior post (#245), that the JU87-R traded bomb weight for extra fuel for long range missions.

Ok, I was thinking on 1941 battles, anyway Peter C. Smith, a dive-bomber enthusiast if there is one, in his Junkers Ju 87 Stuka (Crowood 1998) and Armoured Aircraft Carriers (armouredcarriers.com) agreed that Indomitable was hit by two 250 kg bombs. And what "strong evidence that they used the same on HMS Illustrious in Jan 1941." there is. I have not seen a German report showing the ordinance used in the attacks but Report: (armouredcarriers.com) says that the 6th hit was at first estimated to be made by a 500 kg bomb but then re-valuated to be a 1000 kg bomb, but according to Smith it also was a 500 kg bomb as were the 4th and 5th hits and the 8th [I corrected this, I had missed the one hit of undetermined size achieved during the last attack on 10th Jan. which was the 7th hit] on 16th Jan at Malta.
On Marat, IIRC something what I read decades ago, a few 1000 kg bombs were allocated to some specially selected pilots for the attack, not something to be used by an ordinary pilot flying Ju 87 B.

 

[RCAFson]

Ok, I was thinking on 1941 battles, anyway Peter C. Smith, a dive-bomber enthusiast if there is one, in his Junkers Ju 87 Stuka (Crowood 1998) and Armoured Aircraft Carriers (armouredcarriers.com) agreed that Indomitable was hit by two 250 kg bombs. And what "strong evidence that they used the same on HMS Illustrious in Jan 1941." there is. I have not seen a German report showing the ordinance used in the attacks but Report: (armouredcarriers.com) says that the 6th hit was at first estimated to be made by a 500 kg bomb but then re-valuated to be a 1000 kg bomb, but according to Smith it also was a 500 kg bomb as were the 4th and 5th hits and the 7th on 16th Jan at Malta.
On Marat, IIRC something what I read decades ago, a few 1000 kg bombs were allocated to some specially selected pilots for the attack, not something to be used by an ordinary pilot flying Ju 87 B.

The Ju87s that attacked Illustrious was a specialist anti-shipping unit that was specifically tasked with sinking her. Even If they carried 'only' 500kg bombs this is still double the load of a D3A1 Val, and gave the Ju87 the ability to potentially sink heavily armoured ships, such as Illustrious or damage them severely enough that they would be forced to scuttle. A dive-bomber delivered 250kg bomb could never penetrate the armoured box around her machinery spaces. However, we know that 1000kg bombs were available to the JU87s in Jan 1941 and we know that they could carry them, and that Illustrious was within range of the JU87 armed with a 1000kg bomb.

 

[Ascent]

Some pictures of Illustrious under attack from my Grandfathers collection. He was an RN gunner on a destroyer.

 

[RCAFson]

German account of attack on Illustrious:

"On or about 10 January the Geschwader received news that the British
aircraft carrier "Illustrious" was bound from Gibraltar for Malta.
It was expected to pass in the next few hours the offshore island
of Pantellaria, south of Trapani. It was said to cruise quite
unsuspectingly as if the British ruled the Mediterranean,
proudly ignoring the existence of any Italian Fleet or Air Force,
not to mention the German Stukas on Sicily. It seemed to be a
fine catch for us. It was decided to attack the carrier, taking
it by surprise. Our two Gruppen prepared for action, loading the
500-kg bombs with armor-piercing heads. Soon we were given the
operation order. My friend, the valiant commander of II/Stuka 2,
Major Enneccerus (Brigadier General after the war), flew the
first attack while I was on another mission...

...Now this aircraft carrier was for the Supreme Command of the Luft-
waffe a matter of prestige, also a precedent. It had to be sunk
under all circumstances. If the Supreme Command of the Wehrmacht
could have reported the sinking of an aircraft carrier by German
Stukas, both friend and foe would have sat up and taken notice.
So commenced our attacks, with heavy losses, against the aircraft
carrier in La Valetta. In La Valetta more than 90 AA batteries
of all calibers spit their fire against us, the attackers. At
the same time a strong unit of "Hurricanes" seriously interfered
with us on the approach route and after our departure. In prac-
tically every sortie I lost three or four of my old-battle-tested
crews--an irreparable loss. It was just impossible to replace
those thoroughly trained and experienced pilots and their back-
seaters. During those actions the carrier was hit by four 1,000-kg
bombs, the heaviest a JU-87 could carry. Still we did not succeed
in sinking it, though she must have suffered terrible inner damage...

from:
"CONVERSATIONS WITH A STUKA PILOT"
CONFERENCE FEATURING
Paul-Werner Hozzel
Brig. General (ret.). German Air Force
AT
The National War College
November 1978" pages 44-45.

 

[Juha3]

German account of attack on Illustrious:

"On or about 10 January the Geschwader received news that the British
aircraft carrier "Illustrious" was bound from Gibraltar for Malta.
It was expected to pass in the next few hours the offshore island
of Pantellaria, south of Trapani. It was said to cruise quite
unsuspectingly as if the British ruled the Mediterranean,
proudly ignoring the existence of any Italian Fleet or Air Force,
not to mention the German Stukas on Sicily. It seemed to be a
fine catch for us. It was decided to attack the carrier, taking
it by surprise. Our two Gruppen prepared for action, loading the
500-kg bombs with armor-piercing heads. Soon we were given the
operation order. My friend, the valiant commander of II/Stuka 2,
Major Enneccerus (Brigadier General after the war), flew the
first attack while I was on another mission...

...Now this aircraft carrier was for the Supreme Command of the Luft-
waffe a matter of prestige, also a precedent. It had to be sunk
under all circumstances. If the Supreme Command of the Wehrmacht
could have reported the sinking of an aircraft carrier by German
Stukas, both friend and foe would have sat up and taken notice.
So commenced our attacks, with heavy losses, against the aircraft
carrier in La Valetta. In La Valetta more than 90 AA batteries
of all calibers spit their fire against us, the attackers. At
the same time a strong unit of "Hurricanes" seriously interfered
with us on the approach route and after our departure. In prac-
tically every sortie I lost three or four of my old-battle-tested
crews--an irreparable loss. It was just impossible to replace
those thoroughly trained and experienced pilots and their back-
seaters. During those actions the carrier was hit by four 1,000-kg
bombs, the heaviest a JU-87 could carry. Still we did not succeed
in sinking it, though she must have suffered terrible inner damage...

from:
"CONVERSATIONS WITH A STUKA PILOT"
CONFERENCE FEATURING
Paul-Werner Hozzel
Brig. General (ret.). German Air Force
AT
The National War College
November 1978" pages 44-45.

Interesting, but Stukas got only one hit during their attacks on HMS Illustrious at Malta. Plus one or two damaging very near miss(es)while flying 44 sorties on 16 (causing the 8th hit) and 42 sorties on 19th (one or two near misses). Now Valletta situates only under 100 km south of Sicily and Germans knew the exact position of Illustrious, so they could keep the rear gunner and simply took 100 - 120 kg less fuel, same goes to Marat. But in open sea shipping strikes one needs some fuel reserves for possible search for targets, so IMHO your scenario that Ju 87 is worth of 4 Vals as load carrier is not very realistic, at least when talking on Bs and Rs. D model was fairly different animal, capable to carry even 1,800 kg bomb for short range sorties, but I don't have just now time to study it closer.

 

[Juha3]

The Ju87s that attacked Illustrious was a specialist anti-shipping unit that was specifically tasked with sinking her. Even If they carried 'only' 500kg bombs this is still double the load of a D3A1 Val, and gave the Ju87 the ability to potentially sink heavily armoured ships, such as Illustrious or damage them severely enough that they would be forced to scuttle. A dive-bomber delivered 250kg bomb could never penetrate the armoured box around her machinery spaces. However, we know that 1000kg bombs were available to the JU87s in Jan 1941 and we know that they could carry them, and that Illustrious was within range of the JU87 armed with a 1000kg bomb.

What was the range of Ju 87 B-2 with a rear gunner and a 1,000 kg bomb? And HMS Indomitable was badly crippled by two 250 kg hits and three near misses.

 

[RCAFson]

Interesting, but Stukas got only one hit during their attacks on HMS Illustrious at Malta. Plus one or two damaging very near miss(es)while flying 44 sorties on 16 (causing the 8th hit) and 42 sorties on 19th (one or two near misses). Now Valletta situates only under 100 km south of Sicily and Germans knew the exact position of Illustrious, so they could keep the rear gunner and simply took 100 - 120 kg less fuel, same goes to Marat. But in open sea shipping strikes one needs some fuel reserves for possible search for targets, so IMHO your scenario that Ju 87 is worth of 4 Vals as load carrier is not very realistic, at least when talking on Bs and Rs. D model was fairly different animal, capable to carry even 1,800 kg bomb for short range sorties, but I don't have just now time to study it closer.

I don't expect him to know the details of all the hits, only of the ordnance that was carried. The luftwaffe knew the position of Illustrious when she was first attacked by Stukas and it was less than 100nm miles from the Luftwaffe bases in Sicily and no further than when Illustrious was in Malta Harbour. This map shows the distances involved and the risks that the RN had to run to escort a convoy to Malta:

https://images.squarespace-cdn.com/...MshLAGzx4R3EDFOm1kBS/IMG_0469.PNG?format=750w

In this interview the Stuka Squadron Commander that attacked Indomitable states that they carried 1 x 500kg and 2 x 250kg bombs each:

 

[Schweik]

It looks like Indomitable was indeed hit by two 500 kg bombs dropped by Stukas of StG 3. The same unit also scored four hits on the HMS Warspite during the earlier operation Excess, but it too failed to sink. Later the same Stukas managed to damage the light cruiser HMS Southampton badly enough that it was scuttled. They never sunk any capital ships as far as I could determine.

This is footage of the actual attack here:



And yet, unlike HMS Hermes in the Indian Ocean, the Stukas couldn't sink Indomitable. Apparently at least in part because even with bombs twice as big (possible due to the very short range at the time of the strike) they got comparatively much fewer hits. Apparently 40 250kg or smaller bombs was fatal whereas 2 x 500kg bombs were not. Indomitable went on to survive till the end of the war and was flying Seafires and Albacores from 1943, then Hellcats and Avengers in 1945....

Hermes was an older design, but the key factor in the difference is the ability of the bombers to score hits. Air defense was similar though it is possible that Indomitable was flying 12 x Martlets at the time of Pedestal, which would have been more effective air defense than the Fulmars.

 

[ThomasP]

Additional differences relative to survival that should be noted:

Hermes was ~1/2 the displacement of Indomitable and built along heavy cruiser lines, while the Illustrious/Indomitable class was built along capital ship lines.

The Hermes had only a 1" flight deck, while the Illustrious/Indomitable class had a 3" armoured deck, with a 1" hanger deck on the Illustrious group, or the 1" of both hanger decks (I think) on the Indomitable.

Do not misunderstand, I do not think the Illustrious/Indomitable class would have survived an attack equal to the one against Hermes. I doubt that any carrier operational in WWII would have survived that many hits, unless it was due to luck.

 

[RCAFson]

It looks like Indomitable was indeed hit by two 500 kg bombs dropped by Stukas of StG 3. The same unit also scored four hits on the HMS Warspite during the earlier operation Excess, but it too failed to sink. Later the same Stukas managed to damage the light cruiser HMS Southampton badly enough that it was scuttled. They never sunk any capital ships as far as I could determine.

This is footage of the actual attack here:



And yet, unlike HMS Hermes in the Indian Ocean, the Stukas couldn't sink Indomitable. Apparently at least in part because even with bombs twice as big (possible due to the very short range at the time of the strike) they got comparatively much fewer hits. Apparently 40 250kg or smaller bombs was fatal whereas 2 x 500kg bombs were not. Indomitable went on to survive till the end of the war and was flying Seafires and Albacores from 1943, then Hellcats and Avengers in 1945....

Hermes was an older design, but the key factor in the difference is the ability of the bombers to score hits. Air defense was similar though it is possible that Indomitable was flying 12 x Martlets at the time of Pedestal, which would have been more effective air defense than the Fulmars.

Hermes had no CAP over her at the time of the IJN attack. A total of 14 Fulmars were despatched in two formations but they arrived after Hermes had been hit and was either sunk or sinking. The Fulmars then attacked the remaining 30 or 40 Vals which were in the process of attacking several merchant vessels and their escorts. Hermes did suffer multiple hits, but certainly not 40. The Fulmars shot down 4 Vals whilst suffering two losses.

Hermes was one of the first purpose built carriers but was only 10,000 tons with almost no armour and no Side Protection System (SPS). Illustrious and Indomitable were heavily armoured 23000 ton modern carriers whose armoured flight deck and hangers were designed to withstand 500lb AP bombs delivered by divebombers and whose SPS was designed to protect her machinery from torpedoes and the effects of near miss bomb hits, which are deadly to ships without an SPS, as a near miss will typically stave in the hull allowing flooding of the machinery spaces.

Neither Warspite or Valiant was hit during operation Excess. This is the official damage summary:

"WARSPITE 10th Jan., 1941- One Near WARSPITE was operating off Malta when a near miss bomb burst off the starboard side
No major damage was caused to the hull structure but the starboard lower hawse pipe was split, the anchor damaged and the peravane chains severed.

Fighting Efficiency - Not impaired.

Bomb, judged
to have been 1000kgm

VALIANT 10th Jan., 1941
Five near misses with 500kgm direct action fuzed bombs.

VALIANT operating off Malta, suffered superficial splinter damage from five near miss
bombs. The yoke on the starboard rudder was loosened and dropped 3/16 inch.

Fighting Efficiency - Not impaired" from: HM Ships damaged or sunk by enemy action.

However during the Crete operation on 22 May Warspite suffered heavy damage from a 250kg SAP bomb via an Me109 fighter bomber attack.

 

[Schweik]

Additional differences relative to survival that should be noted:

Hermes was ~1/2 the displacement of Indomitable and built along heavy cruiser lines, while the Illustrious/Indomitable class was built along capital ship lines.

The Hermes had only a 1" flight deck, while the Illustrious/Indomitable class had a 3" armoured deck, with a 1" hanger deck on the Illustrious group, or the 1" of both hanger decks (I think) on the Indomitable.

Do not misunderstand, I do not think the Illustrious/Indomitable class would have survived an attack equal to the one against Hermes. I doubt that any carrier operational in WWII would have survived that many hits, unless it was due to luck.

Understood, good points. My main point is that other factors like range and how accurate the bombing is also matter quite a bit in assessing the effectiveness of a bomber (and what was needed for a bomber to destroy targets), not just the bomb load. This has been a debate that has come up over and over on this forum in many threads. Some people think bomb load was the only real measure of a bomber. The Stuka was a very accurate bomber by WW2 standards, that's why it remained in use for so long after it's slow speed and other limitations made it obsolete, but it did also have a very short range compared to pretty much all 'modern' naval aircraft by the time of Pedestal, no matter how you try to spin it.

And nearly every one of the Japanese bombers were exceptionally accurate as well, based on their combat histories, at least when they still had their highly trained crews. Not just the D3A but also the land based strike aircraft like the G4M and G3M and many of the Army types as well. B5N Kates even sunk some ships with level-bombing attacks in that Indian Ocean raid, a very rare accomplishment by WW2 standards.

One of the realities of WW2 aviation is that many, arguably most bomber designs were pretty ineffective at their main job (bombing), because they couldn't hit their targets often enough. Bombing accuracy was typically abyssmal. Even unusually accurate bombers like the Stuka only hit their targets a small percentage of the time. This was true both for Strategic bombing and Tactical bombing of the type so important in Naval War.

No doubt Indomitable was a tough ship and aptly named. It was apparently also hit by a torpedo later in the war launched from an SM.79 and survived that too.

 

[Schweik]

Neither Warspite or Valiant was hit during operation Excess. This is the official damage summary:

"WARSPITE 10th Jan., 1941- One Near WARSPITE was operating off Malta when a near miss bomb burst off the starboard side
No major damage was caused to the hull structure but the starboard lower hawse pipe was split, the anchor damaged and the peravane chains severed.

Fighting Efficiency - Not impaired.

Bomb, judged
to have been 1000kgm

VALIANT 10th Jan., 1941
Five near misses with 500kgm direct action fuzed bombs.

VALIANT operating off Malta, suffered superficial splinter damage from five near miss
bombs. The yoke on the starboard rudder was loosened and dropped 3/16 inch.

Fighting Efficiency - Not impaired" from: HM Ships damaged or sunk by enemy action.

However during the Crete operation on 22 May Warspite suffered heavy damage from a 250kg SAP bomb via an Me109 fighter bomber attack.

You are right about Warspite, my bad for trusting a Wikipedia article - it was apparently four claims of strikes by the Stuka pilots, but no actual hits.

Interesting that Warspite was also at the site of the battle off of Ceylon, though she saw no action.

 

[RCAFson]

Understood, good points. My main point is that other factors like range and how accurate the bombing is also matter quite a bit in assessing the effectiveness of a bomber (and what was needed for a bomber to destroy targets), not just the bomb load. This has been a debate that has come up over and over on this forum in many threads. Some people think bomb load was the only real measure of a bomber. The Stuka was a very accurate bomber by WW2 standards, that's why it remained in use for so long after it's slow speed and other limitations made it obsolete, but it did also have a very short range compared to pretty much all 'modern' naval aircraft by the time of Pedestal, no matter how you try to spin it.

And nearly every one of the Japanese bombers were exceptionally accurate as well, based on their combat histories, at least when they still had their highly trained crews. Not just the D3A but also the land based strike aircraft like the G4M and G3M and many of the Army types as well. B5N Kates even sunk some ships with level-bombing attacks in that Indian Ocean raid, a very rare accomplishment by WW2 standards.

One of the realities of WW2 aviation is that many, arguably most bomber designs were pretty ineffective at their main job (bombing), because they couldn't hit their targets often enough. Bombing accuracy was typically abyssmal. Even unusually accurate bombers like the Stuka only hit their targets a small percentage of the time. This was true both for Strategic bombing and Tactical bombing of the type so important in Naval War.

No doubt Indomitable was a tough ship and aptly named. It was apparently also hit by a torpedo later in the war launched from an SM.79 and survived that too.

The IJN Vals were not exceptionally accurate and we have to remember that attacking nearly unarmed merchant vessels allowed aircraft to drop from very low altitudes. This is a summary, from Lundstrom, of the very similar attack on USS Sims and the tanker Neosho, which had a maximum speed of only 14 knots.

"By 1115, Lt. Cdr. Takahashi determined there definitely was no American carrier nearby and released the carrier attack group and its escorts to return to the carriers. His dive bombers would attack the oiler and accompanying destroyer. At 1126 he began his attacks. He led four carrier bombers against the destroyer Sims, and they scored three direct hits on the radically maneuvering tincan. The remaining thirty-two carrier bombers made slow, deliberate dives against the Neosho and inflicted at least seven hits, including a flaming crash by one of the Zuikaku carrier bombers. Noon found the Neosho adrift without power and perilously listing 30 degrees to starboard. Only her extensive compartmentation and tanks kept her afloat. For the loss of one carrier bomber, the Japanese had sunk one destroyer and fatally crippled a fleet oiler. "

Unlike Hermes, which sank rapidly, the crew of Neosho had time to assess the damage and number of hits. 32 bombs dropped and ~7 hits on a lightly armed 14 knot tanker versus ~35 bombs dropped and 6 hits on Illustrious moving at 24 knots and having some degree of CAP and a lot more flak. Hermes was probably hit ~10 times.

 

[Schweik]

In that same raid they hit a destroyer three out of four times that was trying to evade! That is extremely unusual accuracy for bombers in WW2. They generally could hit the larger capital ships (and big equivalents like the Neosho) but smaller warships like Destroyers were considered very hard to get.

Since this whole thread has now become Indian Ocean / Pacific vs. MTO Theater, I would be delighted to compare the bombing accuracy of the D3A "Val" which was indeed one of the most accurate bombers of WW2, with that of the Stuka (also one of the most accurate bombers, but not quite in the same league in the naval role) in detail.

I'm also glad to expand that to the other Japanese bombers and compare those to the Italian and German types.

Against the Hermes, Cornwall and Dorsetshirte the D3A had a hit accuracy of better than 80%.

 

[RCAFson]

Against the Hermes, Cornwall and Dorsetshire the D3A had a hit accuracy of better than 80%.

The official damage summary states 19 direct hits (9 + 10) on Cornwall and Dorsetshire out of 53 bombs dropped. This was excellent bombing but not 80% accuracy and there's no reason to suppose that the attack on Hermes was more accurate (the damage summary states she "was repeatedly hit"). Remember it was the same crews that were attacking Neosho a month later. BWOC to the attack on USS Sims, 26 Vals attacked USS Edsall, on 1 March 1942, which was limited to about 26 knots and managed to score one direct hit, which stopped her and allowed pursuing IJN ships to sink her with gunfire.

On 11 May 1942, 31 x JU88s sank 3 RN destroyers (one was scuttled) each suffering at least one hit.


When we look at very small sample sizes, we often get skewed results, but typically anything over 25% is exceptionally accurate.

 

[Schweik]

My understanding is that the 80% figure (specifically 82%) includes the strikes on all of the RN ships they hit in that one day engagement . I agree about the small sample size skewing results, that 82% number is often and prominently mentioned in conjunction with the D3A though it's not something I cherry picked for this debate.

The source cited for the number is listed as Francillon, René J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970 (2nd edition 1979

The wikipedia article says the Hermes was attacked by 32 "Vals" escorted by 9 A6M, and that they were intercepted by 6 Fulmar II fighters from 273 Sqn RAF, plus another six from 803 and 806 arrived afterward. They also sunk RFA Althelstone, the corvette Hollyhock, the oil tanker SS British Sereant (which had less luck than Neosho) and the Norwegian SS Norviken and the HMAS Destroyer Vampire.

The article says the Japanese lost FOUR D3A in this attack and the British lost two Fulmars.

 

[RCAFson]

My understanding is that the 80% figure (specifically 82%) includes the strikes on all of the RN ships they hit in that one day engagement . I agree about the small sample size skewing results, that 82% number is often and prominently mentioned in conjunction with the D3A though it's not something I cherry picked for this debate.

The source cited for the number is listed as Francillon, René J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970 (2nd edition 1979

IJN claims cannot be used as a basis for hits scored. We have to look at bombs dropped vs hits reported by the vessels engaged.

At Coral Sea 31 Vals attacked Lexington and Yorktown and scored 5 hits yet:

"The Japanese believed they had dealt mortal blows to at least one and probably both American flattops. Indeed, Takahashi at 1125 radioed that they had sunk the "Saratoga." The strike crews claimed a total of nine torpedo and ten bomb hits on the "Saratoga," and two torpedo and eight to ten bomb hits on the Yorktown. Actually, as we have seen, they had not hurt Task Force 17 nearly so badly. Now the Japanese would have to fight their way back out the cordon of defending aircraft, already embroiled in several melees with escort Zeros." (Lundstrom)

Yet claimed 18-20. The IJNAF was notorious for making greatly inflated claims.

 

[Schweik]

In the strike against Hermes, 18 D3A pilots from Shōkaku struck first, and claimed 13 hits, then Zuikaku's 14 pilots attacked, also claiming 13 hits. After that, the Hermes was already sinking, so only 11 of Hiryū's 18 attacked the carrier and they claimed 9 hits. Lt. Zenji Abe and FPO 1/c Tamotsu Akimoto of Akagi were the last two to attack, both claiming hits on the sinking carrier. The other 12 bombers from Akagi broke off their attack.

The remaining 7 bombers from Hiryū, seeing that Hermes was already doomed, then joined 12 more from Akagi to attack HMAS Vampire, which was split in half and "torn apart" according to the British report, with three direct hits and five near misses according to the RN report. This ship also sunk very quickly and of the 19 D3A which attacked, only 15 were able to drop bombs before it disappeared into the water in a series of violent explosions. So four D3A from Hiryū and Akagi flew back to their original target and dove on the now definitely sinking hulk of the Hermes, scoring four more hits (and these were confirmed by RN survivors floating in the water who were later picked up by the hospital ship)

After that 18 aircraft from Sōryū arrived and since Hermes was half underwater, they flew off to look for more targets, which they soon found and they were the ones which sunk Hollyhock, Athelstane, and Norviken. This was when the four D3A were shot down by 14 Fulmars, as this group was caught without their escorts. One more D3A from this group crashed while landing on the Sōryū.

So that's actually a total of 40 hits claimed on the Hermes, plus 3 on the destroyer Vampire and an unlisted number on three other ships. You are right we can't take all the claims at face value, but the damage was rather telling. Hermes sunk so fast that many of the D3A which were intending to bomb it had to find other targets.

 

[Schweik]

In other words, after HMS Hermes was attacked by the first 32 D3A dive bombers, it was done. The precise number of hits may be up for debate, they would have to examine the wreck on the bottom of the Indian Ocean and count the holes. But that was sufficient to sink it, and it sounds like it did have some fighter protection at the time.

I think they could have scored many more hits, and in fact they hit it several more times after it was already sinking, but there was no point in further belabouring the issue.

In the direct comparison with Pedastal, the IJN does not come across as the inferior opponent.

 

[RCAFson]

In the strike against Hermes, 18 D3A pilots from Shōkaku struck first, and claimed 13 hits, then Zuikaku's 14 pilots attacked, also claiming 13 hits. After that, the Hermes was already sinking, so only 11 of Hiryū's 18 attacked the carrier and they claimed 9 hits. Lt. Zenji Abe and FPO 1/c Tamotsu Akimoto of Akagi were the last two to attack, both claiming hits on the sinking carrier. The other 12 bombers from Akagi broke off their attack.

The remaining 7 bombers from Hiryū, seeing that Hermes was already doomed, then joined 12 more from Akagi to attack HMAS Vampire, which was split in half and "torn apart" according to the British report, with three direct hits and five near misses according to the RN report. This ship also sunk very quickly and of the 19 D3A which attacked, only 15 were able to drop bombs before it disappeared into the water in a series of violent explosions. So four D3A from Hiryū and Akagi flew back to their original target and dove on the now definitely sinking hulk of the Hermes, scoring four more hits (and these were confirmed by RN survivors floating in the water who were later picked up by the hospital ship)

After that 18 aircraft from Sōryū arrived and since Hermes was half underwater, they flew off to look for more targets, which they soon found and they were the ones which sunk Hollyhock, Athelstane, and Norviken. This was when the four D3A were shot down by 14 Fulmars, as this group was caught without their escorts. One more D3A from this group crashed while landing on the Sōryū.

So that's actually a total of 40 hits claimed on the Hermes, plus 3 on the destroyer Vampire and an unlisted number on three other ships. You are right we can't take all the claims at face value, but the damage was rather telling. Hermes sunk so fast that many of the D3A which were intending to bomb it had to find other targets.

The same or smaller numbers of Stukas (or SBDs, or Skuas or bomb armed Albacores or Swordfish) were quite likely to have achieved the same results. None of these ships represented difficult or hard to sink targets and the end result is not surprising or exceptional.