Tactics: Spitfire vs Zero

[RCAFson]

As in my longer post recently and others before, high losses compared to what?

First, forget RCAF's obfuscation.
Joe

I had to do a lot of digging around the web to find the answer to the number of bombers shot down by the Darwin Spitfires in 1943:

JBren1

(22-Jan-2009 01:19:46)

I'm quite sure I never said anything about whether those combats occurred over land or water, and once we can agree you're misrecollecting that I ever did...what different does it make?

OK, if it's going to going back and forth endlessly about which generalization about altitude is accurate, let's just review the Darwin combats (only those involving both Spits and Japanese fighters). Losses are air combat unless otherwise noted, repeat, the large number of Spit operational losses are not included here except parenthetically in a few cases. The main source is the, definitive so far IMO, "Soleil Levant Sur L'Australie" by Baza, which covers both sides in detail, first hand accounts up to the big picture. The losses in that and Price "Spitfire V Aces" seem to be basically the same:
March 2 '43: 9 Type 1 Land Attack Planes ('Betty') escorted by 21 Zeroes; 24 Spitfires (7 failed to engage): claims on both sides but no actual losses on either side, starting around 26k ft
March 15: 19 Type 1, 26 Zero; 27 Spitfires: 4 Spits lost for 1 Zero, 8 Type 1's damaged but none lost, Type 1's at ~21k ft.
May 2: 18 Type 1. 26 Zero; 33 Spitfires: 5 Spitfires air combat losses, 9 more operational; no outright Japanese losses though 13 a/c hit*, Type 1's at ~30k ft.
May 9: Millingimbi a/f, 9 Zero, 5 Spitfire: Spitfires surprise Zeroes strafing at low altitude, down 2 for 1 Spit crashland write off.
May 28: Millingimbi, 9 Type 1, 7 Zero; 6 Spitfires: 2 Spits lost for 2 Type 1 lost outright and 1 crashlanded; Spits attack from 23k ft above bombers
June 20, by JAAF: 18 Type 100 Heavy Bomber ('Helen'), 9 Type 99 Light Twin Bomber ('Lily'), 22 Type 1 Fighter ('Oscar'); 46 Spitfires: 2 Spitfires lost for 1 Type 1 Fighter and 1 Type 100, 1 Type 100 and 2 Type 99 force land near base, HB's 29k ft, LB's at low altitude.
June 28: 23 Type 1 , 27 Zero; 42 Spitfires: 2 Spitfires crashlanded, 1 Type 1 crashed on landing. Type 1's bombed from 21k ft, Spits attacked from above.
June 30: Fenton a/f, 23 Type 1 27 Zero; 38 Spiftires: 5 Spitfires lost in combat (+2 operational) for 1 Type 1 lost, Type 1's at 26k ft.
July 6: Fenton a/f, 21 Type 1, 25 Zero; 36 Spitfires: 6 Spits lost in combat (+2 operational) for 2 Type 1 lost and 2 more crashlanded, Type 1's at 21k ft, Spits attacked from above
Sept 7: 3 Type 100 Hq Recon ('Dinah') escorted by 36 Zeroes; 48 Spitfires: 3 Spitfires lost for 1 Zero; J formation at 23k ft.

*the original Japanese records are now available online btw. The operations report ('kodochosho') of 753rd AG (Type 1 'Rikko') for May 2, chart by a/c, shows 6 a/c hit (not 7 as in Baeza and Price), one each by 6, 3 and 2 rounds, 3 by a single round. The 202nd AG (Zeroes) had 7 a/c hit, the chart doesn't specify which ones. I haven't completely reviewed those records yet v Baeza, but no major discrepancies where I have. Baeza's source is a privately published English language monograph summarizing those records.

So in a few cases the bombers were very high (and the Spits knocked down almost none when they were) but generally in the 20's, not unlike the '42 Darwin raids or Henderson Field bombing, and the Japanese occasionally tried extra high altitude there too. The Spits like the other interceptors naturally tried to attack from above (one reason the P-40's engaged lower was they just weren't as good climbers). The altitude and 'loss rate' thing are basically a grasping-for-straws tangents anyway to this topic: a light weight fighter (or whether it's really even important it be light weight) to *take on the Zero*. The Spits over Darwin did poorly *taking on the Zero*, there's no room for factual debate about that. The reasons can be debated, possibly relevant to whether a lighter fighter would do better.

Joe

Best light-weight monoplane fighter to take on A6M2 fighter? - The Air Forces - NavWeaps Discussion Boards - NavWeaps Discussion Boards - Message Board

So by my count that makes 5 IJN/IJA fighters and 14 bombers lost to the Spitfires.

Andy01
(24-Sep-2008 01:41:45)

I took at look at the numbers to try a get a better picture of what happened:

Japanese escorted bomber Sortie loss rates:
Spitfires:
119 bomber sorties / 14 destroyed = 11.7%

114 fighter sorties / 4 destroyed = 3.5%

Kittyhawks:
221 bomber sorties /12 destroyed = 5.4%

202 Fighter sorties / 10 destroyed = 5%

The Spits inflicted a much higher bomber loss rate but a slightly lower fighter loss rate.

These numbers are as accurate as I can find, but I invite corrections.

Hellcat Vs Zero - Aircraft Carriers - NavWeaps Discussion Boards - NavWeaps Discussion Boards - Message Board

So the Spitfires actually downed more bombers than the P-40s, at least according to the above, which I can't verify since no sources are given. Apparently the Spitfires also downed more recon aircraft, so overall probably more than the p-40s.

 

[FLYBOYJ]

So the Spitfires actually downed more bombers than the P-40s, at least according to the above, which I can't verify since no sources are given. Apparently the Spitfires also downed more recon aircraft, so overall probably more than the p-40s.

So you're basing this on a post from another board who gives no references for his numbers?

Thanks parsifal!

 

[Nikademus]

Yes I'm curious too.

Joe, what's the crux of your opinion on the Pacific airwar comparing Commonwealth vs US results?

Were the P-40 Wildcat just better aircraft to fight the Japanese vs Spitfire Hurricane?

Or were the CW not as good as US? Inexperienced pilots? Poor training? Poor tactics?
Poor planning on choice of missions?
What was the reason for the disparity?

There's no simple answer. Citing a recent thread that touched on Burma in 1943, the RAF itself was puzzled at the disperity in results in comparison to other Theaters and the USAAF experience. Best one can do is theorize. After my own study, I tend to agree with the RAF's "troubleshooter" , w/c Paul Ritchie who felt that training and tactics were largely responsible for the disperity given that on technical grounds there was no real reason why the Hurricane (the focus of the study as it was the primary fighter in the Theater at the time) should suffer such a disparate loss ratio.

Comparisons with the USN/USAAF experience are tricky, especially in the former case. I don't feel its fair to make such a comparison because i consider the USN active VF's (carrier based) to be a small, elite organization compared to the much bigger RAF. USN VF's benefited from the "personal touch" so to speak in that while their pre-war/early war training was not all that much (if at all) better than other organiztions, their gunnery training was much improved operationally courtasy of C/O's such as Thatch, a disciple of proficient gunnery which included deflection shooting. RAF training was accelerated during the course of the war in order to get bodies into the cockpit and has been cited in books by Christopher Shores in more than one case as being a factor in the greater losses suffered by RAF units compared to some USAAF units....even when flying the same plane. Tactics also factored, influencing ratio exchanges in N.A., themselves not all that disparate from the Burma experience until addressed.

Geography and mission profiles also factored and were different in some cases. In 1942, the F4F's had limited types of engagements as i see it. The only sustained campaign involving it was at Guadalcanal, an air campaign that was primarily defensive in nature with the F4F's flying and fighting over their base. Further advantages included knowing pretty much when the enemy had to attack and of course "where". The range to the target was effectively beyond the operational [safe] range of the Zero [often having to fight with drop tanks attached] and contributed to the loss, wear and tear, and exhaustion of the pilots.the activation of the small airfield near Shortlands late in the campaign did little to address this situation. Under these circumstances i'm not suprised the ratio was competetive. Contrary to alot of opinion, i think the fact that the Zero drivers were able to win slightly on the vaunted exchange ratio under these circumstances to be remarkable. Remarkable but ultimately futile....the Japanese could care less about such things....mission success was the goal....and in that they were thwarted continually.

The carrier fights are a seperate type of battle.....and represent one day skirmishes between elite groups of fighter pilots vs. a sustained attritional campaign. This coupled with some advance warning on what they were facing, + their own high level of training spared them the stilted exchange rate suffered by the USAAF and other allied forces at the start of the war (it should be noted that the USAAFFE P-40 drivers did no better than the RAF Hurricane force in Malaya). Still, they suffered a 2:1 exchange in favor of the IJN at Coral Sea, not unreasonable but proof IMO that the IJN VF's were to be taken seriously and that their prowess did not depend entirely on fighting an "unprepared enemy" Further exchanges in the next three carrier battles remained competetive but again largely one day affairs. Under such circumstances between opponents of high skill and training (and experience), a competetive exchange ratio is only to be expected.

1943 is, as mentioned already....more puzzling. The USAAF experience improved while the RAF continued to struggle. Why? ultimately i think rigid tactics coupled with a continued influx of green pilots combined with a more dispersed geographical area and mission profile contributed. In the South Pacific by 1943, the IJNAF had been worn down and continued to fight a two front war based largely in a concentrated area around Rabaul and Bouginaville. While the tap of experienced pilots for Japan had not yet been exhausted this was countered by an increasingly poor tactical and operational situation, facing two air forces that were re-equipping with 2nd generation aircraft and benefiting from increasing logistical support vs. targets closer to their targets vs. the Japanese. Reviewing Eric Bergerud's work on the S.Pac fighting, it was emphasized that while the IJNAF continued to be reinforced with a large number of fighters, the paper strength often listed belied the true situation and helped explain the puzzlement of the Japanese leaders themselves as to why things were not going better.

 

[Freebird]

So you're basing this on a post from another board who gives no references for his numbers?

It's an interesting hypothesis though, one that I had wondered myself.

If Joe or anyone else has different (or sourced) numbers for bomber losses it would be nice to see.

I get the impression that the British/CW placed more importance on protection of airfields than than the US (as the British were protecting their own territorty), the Americans simply concentrated on Japanese kills. Ultimately, this strategy was successful, as attrition wasted the Japanese air forces

 

[FLYBOYJ]

It's an interesting hypothesis though, one that I had wondered myself.

If Joe or anyone else has different (or sourced) numbers for bomber losses it would be nice to see.

I get the impression that the British/CW placed more importance on protection of airfields than than the US (as the British were protecting their own territorty), the Americans simply concentrated on Japanese kills. Ultimately, this strategy was successful, as attrition wasted the Japanese air forces

I actually agree...

 

[JoeB]

Example 1. The source is Japanese Army Operations In the South Pacific: Translated by Steve Ballard, Australian War Memorial. This is a translation of the war history series Senshi Soshu, which I am sure Joe is familiar with. This volume covers from the invasion of Rabaul in January 1942 through to the destruction of the South Seas Force in January 1943.

Example 2: This is from an admittedly secondary source…"The Pacific War" by John Costello. It is significant, however in that it was one of the first pieces that tended to rely on decrypted intercepts more than unit summaries in compiling the narrative.

Putting all of that aside, however, the narrative include a chapter on the Marianas Turkey Shoot. Commenting on the operations of the 1st Air Fleet, at page 480 it describes how Kurita was advising Ozawa that he had retrieved over 500 aircraft from the dispersal area in the Carolines, and from those units that had been transferred south as a result of the crisis on Biak. In fact over 1/3 of the 500 aircraft he listed as still on the effective list had been lost. Most scholars believe this was a deliberate deceit by Kurita, I am not so sure, but the facts remain, he was no longer in command of the numbers he said he was controlling. I believe that many aircraft had in fact been lost in the long over water flights, many more were destroyed on landing, or shot down.

3b Kurita maintained the delusion, however, sending off unsubstantiated, and what appear to be deliberately deceptive reports of winning the battle and eliminating much American strength.

4. Joes accounts are referring to squadron level records, in which it is harder to argue the confusion and ignorance argument. Difficult, but not beyond the realm of possibility

1. That volume is the Army's history of operations in that period and place. It has some references to the Navy's operations, but is not a statement about Navy's internal information.

2. As I mentioned in previous post, I compared Japanese loss accounts from US comms intercepts, as given in Wilson's "Seek and Stiike" history 75 Sdn RAAF for some incidents, to the kodochosho for same incidents and did not find major disagreements. Same for the more complete treatment in "Revenge of the Red Raiders" by Gaylor et al about 22nd BG, which references various other Japanese records in addition to kodochoso for some of same incidents mentioned in Wilson. Nor have I heard of any other case where comms intercepts info about Japanese losses is seriously at odds with written records, which even under the thesis of 'understated losses' wouldn't logically be the case, since the intercepts are of what local units reported by radio to higher Hq, which would presumably contain the same falsifications if there were any.

3. As with other cases the natural question is, the true figures determined how? quite possibly by seeing later that individual unit records didn't agree with what a commander had reported in aggregate. The discrepancy certainly isn't established by comparing to American claims, nor comms intercepts of the same misleading statemetns. Plus, two other factors enter into that situation and period which don't apply in earlier periods: lack of complete and fully organized record keeping at unit level (we can see in '42 and '43 ops that every engagement reported on Allied side is specifically reported on Japanese side, not true by mid 1944). And, this case is also dealing with overall numbers of serviceable a/c, not specific plane and pilot losses in combat. It can include all kinds of anomalies like existing but unserviceable a/c that don't apply in the more 'grass roots' cases.

3b. Highly incorrect reports of damage inflicted on the enemy not in dispute. That wasn't limited to the Japanese, and in other cases also the extent of overstatement is such to suggest it was at least partly deliberate.

4. IMO it's unlikely beyond a reasonable doubt, nothing is 100% certain, again I don't see why that's beyond the 100% barrier for the Aussie records either. Again, especially wrt mission reports which list each pilot by name on 500 mile each way missions. For the losses in such reports to be seriously inaccurate, more pilots would have to have failed to return. That's the part that's not plausible. For defensive missions there's always more room for debate about a/c recorded damaged and what really happened to them, and that can lead back in to the issue in point 3. Another random example is the first really successful P-39 combats v Zeroes Aug 26 1942 in NG, as the Zeroes took off from Buna. 2 Zeroes each of Tainan and 2nd group are listed as lost or written off, one other 2nd AG machine hit 10 times. That a/c was still there when the Allies took Buna field later in Dec '42, a Model 32, IIRC first 'Hamp' captured. Japanese personal accounts confirm it was the same plane. This wasn't a misreporting, but somebody who wants to strictly credit the P-39 with all possible successes might add it in. But faking the non-loss of a missing pilot seems to me exponentially more difficult and less likely, especially unlikely for the Japanese if we want to do 'the culture thing', to deny someone who died in combat that honor by just losing them in the records. I think it's very close to the 100% certainty mark that the 3 pilot KIA's in 202nd are all there were.

Joe

 

[Freebird]

3b. Highly incorrect reports of damage inflicted on the enemy not in dispute. That wasn't limited to the Japanese, and in other cases also the extent of overstatement is such to suggest it was at least partly deliberate.

4. IMO it's unlikely beyond a reasonable doubt, nothing is 100% certain, again I don't see why that's beyond the 100% barrier for the Aussie records either.

From Joe's numbers, there may be some minor discrepancies, but it seems pretty clear that no matter how you massage the numbers it isn't going to change the end result - the Hurri P-40 lost more fighters than the Japanese did, and the Spit V wasn't much of an improvement over the Hurri, if any. (and may well have fared worse)

Joe, do you have numbers for # of japanese bomber kills in these same missions? Do the numbers match up with RCAF's?

There are some other things I'd like to know about the numbers you posted (28 Spits for 4 zeros, 19 P-40 for 8 zero)
How many of the allied losses resulted in the pilot killed?
Further, did any of the Japanese pilots make it back to friendly territory?
Were all of these combats over friendly Allied territory?

The 49th FG's combats over Australia in 1942, with numbers of fighters present and fighter losses, Darwin area v 3rd AG except as noted. Numbers of Allied a/c in contact includes contact with any enemy a/c in the attacking formation.
Source: Baeza
March 14, 1942 (Horn Island): 12 P-40's v 12 Zeroes (4th AG); 1 P-40 and 2 Zeroes lost
March 30: 8 P-40's v 12 Zeroes; 1 P-40 lost, 1 P-40 belly landed
April 4: 9 P-40's v 6 Zeroes; 2 P-40's damaged by Zeroes, downed by own AA on approach (right after Zeroes strafed the field)
April 25: 11 (making contact, of 50) P-40's v 14 Zeroes; 1 P-40 belly landed on a beach, repaired, 1 Zero lost

July 30: 27 (making contact, of 46) P-40's v 27 Zeroes; 1 P-40, 1 Zero
August 23: 18 (making contact, of 36) P-40's v 27 Zeroes; 1 P-40, 4 Zeroes*
Total: 174 P-40 sorties in contact w/ 221 Zero sorties; 19 P-40's downed (including belly landings, not including own AA) v 8 Zeroes downed

The Spit Wing combats in 1943:
Source: Price, Baeza, kodochosho
March 2 1943: 26 Spits v 21 Zeroes (not all in contact either side, but no losses)
March 15: 19 (making contact, of 26?) Spits v 26 Zeroes; 4 Spits, 1 Zero
Total 242 Spit sorties in contact w/ 201 Zero sorties, 28 Spits air combat loss/crashlanding only** v 4 Zeroes downed

 

[parsifal]

FB

According to Wildcats earlier post, total Spitfire losses were 46 aircraft. These losses are from March through to the end of July (I think, you can check his earlier post).

According to the source I posted, the RAAF lost 30 Spits end of March through to June.

The figure Joe is posting is actually being conservative viz Allied losses.


Joe you mentioned the possibility of some creativity on the allied side. In my opinion, I dont think there is any doubt about that. Caldwell after the debacle of the 1st Fighter wing came under a lot of pressure and criticism over the losses. I think if he could hide losses, he would have, judging by his subsequent behaviour.

You misread the intent of my posts. I was not defending the allies, I was merely questioning the accuracy and truthfulness of the reports on which all these conclusions are being drawn. it matters not to me whether they are allied or Japanese, I just believe the Japanese, for whatever reason, had a greater propensity to be innaccurate

 

[Wildcat]

How many of the allied losses resulted in the pilot killed?

For Spirfire losses and pilot outcome see post 75 on page 5 of this thread

Further, did any of the Japanese pilots make it back to friendly territory?

Highly doubtful. Japanese aircrew shot down over Northern Australia faced two options - capture or death

Were all of these combats over friendly Allied territory?

In regards to the Spitfire wing, yes. I believe so with the 49th as well.

 

[renrich]

This thread seems to have moved rather far afield from the original subject so I would like to move it a little further. I believe that many of us have seen the statistics that the Hellcat had a fifteen to one kill ratio in the Pacific and the Corsair had an eleven to one and similar info about all the other types during WW2. We "know" that the Hellcat had 270 losses to EA in the PTO and the Corsair had 189. I am not sure if these numbers came from "Naval Aviation Combat Statistics" published in June 1946, but I feel sure that the numbers about the US losses are fairly accurate. However, after reading Lundstrom, "The First Team" and his other book and reading "Bloody Shambles" which seem to have thoroughly tried to reconcile Allied statistics with Japanese records, I have strong reservations about the number of Japanese aircraft downed by Allied AC in the Pacific and the CBI. These reservations extend to generally accepted info about Axis losses and kills in the ETO.

I guess where I am going with this is that as far as shoot downs are concerned in WW2, I feel pretty confident that the loss figures recorded by the US, Britain, Germany, Japan, Italy of their own aircraft are pretty accurate but I am becoming skeptical about the shootdowns claimed by those countries of their adversaries. In other words, it appears that the air war in the PTO and CBI, especially as far as air to air kills was not nearly as one sided overall as we have been led to believe. Obviously, the kill ratios during 1944-45 Kamikaze raids were one sided but I question the overall number of kills claimed by the Allied fighters during those raids.

Bottom line to me is that during WW2 as a whole the Japanese dedicated fighters competed very well with their Allied counterparts with the Allies having an edge which was not as great as we have been led to believe. I suspect that was true in the ETO also.

 

[Freebird]

For Spirfire losses and pilot outcome see post 75 on page 5 of this thread

Thanks Wildcat!

This thread seems to have moved rather far afield from the original subject so I would like to move it a little further.

However, after reading Lundstrom, "The First Team" and his other book and reading "Bloody Shambles" which seem to have thoroughly tried to reconcile Allied statistics with Japanese records, I have strong reservations about the number of Japanese aircraft downed by Allied AC in the Pacific and the CBI. These reservations extend to generally accepted info about Axis losses and kills in the ETO.

Bottom line to me is that during WW2 as a whole the Japanese dedicated fighters competed very well with their Allied counterparts with the Allies having an edge which was not as great as we have been led to believe. I suspect that was true in the ETO also.

Good points.
I've started a new thread, so that we don't drag this one too far off-topic

http://www.ww2aircraft.net/forum/aviation/pilot-claims-vs-actual-enemy-losses-discrepancy-25866.html

 

[renrich]

Many thanks FB!

 

[Glider]

I know that this posting isn't just about Spitfire and Zero tactics but believe it may be of interest.

There are a number of new pieces of information and personally I found the use of depth charges on land to be novel, to say the least.

I was able to look at the report produced by the RAF when they investigated the air situation in Burma and China. I am afraid the copies I took are not worth posting onto the site. However the following is a summary.

Japanese Pilots and Tactics
Para 54 The main Japanese type is the Oscar with a small number of Tojo's
Para 55 The Japanese seldom fly faster than 200mph to make the most of their agility.
Para 56 Pilots from the JNAF seem to have a slightly higher standard of flying. Recently the Japanese have started to use the finger 4 formation but the no 2's stay very close to the no 1 which limits the advantage that might be gained.
Para 57 No suicide attacks have been noted
Para 58 The Japanese have been instructed not to attack high flying fighters. When in an attack Japanese tactics have been normal and shooting has been moderate. A deterioration in tactics has been noticed and put down to a general reduction in the quality of the Japanese pilots but there are a number of able experienced leaders.
Para 59 Japanese pilots have often used aerobatics in combat
Para 60 Japanese pilots have used dummy combats to lure fighters away from the bombers they are escorting
Para 61 Japanese no 2's will sometimes deliberately straggle inviting an attack from the rear whereupon the leader will loop onto the attacker.

Allied Types
Para 62 The Hurricane is completely outclassed by the Japanese fighters and is confined to ground attack in which its specialised bombing technique has made it a remarkable success.
Para 63 The Spitfire is a success defensively but limited range prohibits full offensive ability

Allied Tactics
Para 66 Allied aircraft avoid in fighting as the Japanese have a clear advantage in manoeuvrability. Allied aircraft (except Hurricane) have the advantage in level and dive speed, zoom and in the case of the Spitfire climb.

Bombing
Para 80 Hurricanes attack using a 40 degree dive, 11 second delayed bombs are then released at minimum height pulling out at tree top level. Ony Hurricanes' can do this type of attack as they don't gather as much speed in the attack and don't 'mush' when pulling out.
Para 81 Other types do a dive bomb attack
Para 82 These types of attack can be used due to the almost non existent fighter opposition and light flak.

NapalmPara 88 Very effective it was noted that on the Irrawaddy during four months of heavy fighting only 20 prisoners were captured. After a Napalm attack an unprecedented 300 prisoners surrendered.

Rocket Projectiles
These are little used in direct support but experiments are in place using delayed fuses to see if they can penetrate bunkers covered with teak. They are very effective against river and other transport targets

Depth Charges
These are used on land to clear jungle and camouflage from potential targets. Its effective but gives warning so is only used in certain situations.

Bazooka Rockets
These are very ineffective and General Chennault wants these replaced with RP as targets are plentiful in China where there is little cover and movement can be seen

 

[renrich]

Informative post, Glider, thanks to you. The info in your post is backed up in less detail by Shore's book.

 

[Wildcat]

There are a number of new pieces of information and personally I found the use of depth charges on land to be novel, to say the least.

Interesting post indeed. Although seldom talked about, the RAAF in the Pacific had also been using depth charges against enemy positions, off the top of my head, mainly by Beaufighters. Apparently they were quite effective against native huts in enemy occupied villages. Another improvised weapon used by RAAF Kittyhawks (and a few times by Spitfires) was the dropping of full drop tanks on the enemy. The follow up aircraft would then strafe the tank creating a kind of poor man's napalm attack.
Stockpiles of captured Japanese aerial bombs were also put to good use by Aussie Beauforts!

 

[fastmongrel]

Depth Charges
These are used on land to clear jungle and camouflage from potential targets. Its effective but gives warning so is only used in certain situations.

How was the Depth charge fused to explode on land, was it fitted with a contact fuse. I cant imagine the depth charge had a fuse pocket capable of taking an airforce fuse.

 

[Glider]

No idea but a contact fuse would be the most logical approach. The other thing I noticed was the use of delay fuses on rockets to penetrate before exploading. In both cases necessity is probably the mother of invention