Dive Bomber Comparison

RCAFson said:

That brings us to something like 65-75 actual kills for the year, and probably only 5 - 10% could have been 5in kills, based upon various expert witnesses, so the USN probably overclaime 5in kills by a factor 8 or 12 to 1! No wonder the 5in has a reputation as some kind of wundergun...unfortunately it was completely bogus, at least in 1942.

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There is no way to tell what % of kills were due to 5". I'm not saying the % was higher, but you haven't quoted any solid source to back up that % (nor does one exist, so please don't spam any more with generic sources everyone else can also look up and try to twist it into such an analysis, no such analysis that we can rely on exists; if people on ships could overstate the enemy losses, they could mistate the loss causes for the real enemy losses just as easily).

OTOH you quoted losses of Axis a/c to RN (and Allied merchant ship) AA, which other more reliable posters have indicated are overstated, but anyway the key point is the same: there's no reliable source as to which of those Axis losses in MTO or North were to heavy AA. Anecdotally at least, a lot seemed to be light AA 'revenge' hits on a/c which completed weapons runs then ditched on the way back or crashlanded at base.

So, did 5"/38's shoot down a mass of Japanese a/c in 1942? no. But I think this is a straw man argument for anyone who has read much about the topic: the issue is the inherent design capability of USN heavy AA v that of other navies, not some claim that it shot down huge numbers of a/c in 1942. Which goes back to my post many pages ago, though a lot of in the interim space is your spam (why not just give links to generic stuff on the web?, I think it's reasonable to take up large amounts of space in a thread with details only if it's something that's not on online in English). Nobody's heavy shipboard AA up to around 1942 shot down a lot of a/c, per any solid evidence.

Joe

JoeB said:

Joe

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I provided expert opinion on the matter, and that opinion does not support a 25% kill ratio in 1942 by 5in guns as stated by the USN in their AA summary. This is a forum for discussion, and lots of information exists on the web to further the discussion, but because it is available on the web it is not inferior to your private sources, and providing data based upon wartime intelligence gives us some insight into what information was available during the war, and therefore, insight into the data upon which opinions as to equipment effectiveness were based.

I quoted losses based upon official sources for combined AA and fighter kills which have actually proven to be relatively accurate and for PQ-18, about 30 of 40 claims have been confirmed, based upon incomplete records. My whole argument, which you appear to be supporting is that automatic AA, was the most potent aircraft killer, and the RN had the best AAA up to and including Oct 1942.

The whole point of the 5in DP design was to shoot down aircraft and the USN made huge trade-offs, especially on destroyers, in terms of weight and cost to do that, and yet the gun was vastly overrated in terms of AA capability. Sorry if that bothers you, but its the truth. I think providing short snippets from lengthy online sources is useful, but that's just my opinion...

Nikademus said:

For continued giggles, here's what i had recorded for AA out of the Pedestal operation (including pre-attack period) via Shores;

8/9

1 x Sunderland

8/11

1 x Ju-88

8/12

2 of 7 lost Ju-88's claimed by AA
1 x Sea Hurricane

Evening attack
1 x Ju-88

Convoy scattered by attacks but only has lost 3 merchants. Night attacks will cause further loss and dispersion. (4)

8/13 attacks on convoy elements

1 x Ju-87 (ita)
2 x Spitfire
3 x S.79

Total estimated AA kill (including friendlies) = 12


AA fire was particularily effective on 8/11 during the morning and afternoon, thwarting the torpedo attack by KG-26 from being pressed home. Coupled with Fighter defense, expertly directed via radar assisted FDO Shores noted that no AK's were lost in the face of large string of attacks by both RA and Luftwaffe to be a good achievement. Unfortunately, the dusk attack by 42 planes (30 x Ju-88, 7 x He-111 escorted by 6 x Bf-110) scored sinking 3 AK's and damaging a Destroyer and two more AK's. This effective attack also had the unfortunate effect of scattering the convoy elements over many miles, setting up the favorable conditions for the night surface MTB and sub attacks that evening.

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I not sure what's so funny, but I ran through the official despatch and made note of the kill claims:

1-Ju88 - FAA

3 x JU-88 - AA

8 - FAA

1 - FAA

1- TB - AA (prob)

1- TB - AA (prob)

1- JU87 - AA (prob)

9 - FAA

1 - JU88 AA (destoyed by blast)

1- ju87 AA

4 - RAF
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27 total including 5 x AA + 3 AA Probables

http://www.ibiblio.org/hyperwar/UN/UK/LondonGazette/38377.pdf

So the despatch seems to actually understate the number of AA kills and total kills, as stated by Shores.

Hello RCAFson
How understated total kills, according to your link to TheLondon Gazette Supplement p 4505 the despatch Chapter 56, FAA fighters claimed 39 certain kills, from Shores we know that RAF claimed at least 14. So even without AA claims the total was clearly over known Axis losses. RN lived up its reputation and stubbornly escorted some of the merchantmen to Malta in spite of very heavy losses to subs, MTBs and heavy air attacks. But shows that that RN AA was clearly better than that of USN? Almost at same time on the other side of globe USN AA shot down at least 8 out of 23 attacking Bettys and spoiled aims of the rest so that they got only one hit on DD Jarvis plus one mortally dam Betty crashed on a transport. Betty was much more vulnerable than LW medium bombers but not necessarily very much more vulnerable than the Italian standard torpedobomber S.79. Both Tagaya (in his Osprey Rikko units book) and Lundstrom agree in the AA kill number. IMHO USN AA did very well, shooting down ⅓ of attacking force and spoiling the aim of almost all others.

Juha

Juha said:

Hello RCAFson
How understated total kills, according to your link to TheLondon Gazette Supplement p 4505 the despatch Chapter 56, FAA fighters claimed 39 certain kills, from Shores we know that RAF claimed at least 14. So even without AA claims the total was clearly over known Axis losses. RN lived up its reputation and stubbornly escorted some of the merchantmen to Malta in spite of very heavy losses to subs, MTBs and heavy air attacks. But shows that that RN AA was clearly better than that of USN? Almost at same time on the other side of globe USN AA shot down at least 8 out of 23 attacking Bettys and spoiled aims of the rest so that they got only one hit on DD Jarvis plus one mortally dam Betty crashed on a transport. Betty was much more vulnerable than LW medium bombers but not necessarily very much more vulnerable than the Italian standard torpedobomber S.79. Both Tagaya (in his Osprey Rikko units book) and Lundstrom agree in the AA kill number. IMHO USN AA did very well, shooting down ⅓ of attacking force and spoiling the aim of almost all others.

Juha

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Sorry, I should have stated that my numbers were from the Pedestal diary of events on pages 4506-4512.

According to your sources how many armoured 2E Luftwaffe TBs with self sealing fuel tanks were shot down by RN AA over PQ-18 on Sept 13 and 14 1942? I count 7 for the 13th and 15 for the 14th according to:
Nordic Aviation During WW2

13 Aug 3 plus 2 went missing and one overtuned during landing and suffered 80% dam, plus 1 He 115 missing, easier target because slower.
14 Aug 3 plus 7 missing plus 1 lost to unk reason at Nordkap, 1 90% dam in wheels up landing because of combat dam plus 1 He 115 because of AA and 2 He 115 lost to unk reasons and 1 He 115 missing. And then of course 3 to fighters and the bomber losses.

Those if I counted correctly.

BTW LW itself counted that it lost in Sept 42 23 torp bombers due enemy action and one without enemy action.

Juha

RCAFson said:

I not sure what's so funny, but I ran through the official despatch and made note of the kill claims:

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Sigh.....the "giggles" comment refers to the continued comparison between convoy battles like Pedestal and PQ-18 and Santa Cruz. IMO, its rather silly to make in-depth comparisons given the conditional differences. Just trying to inject a little light heartedness.

The link you provided keeps crashing my Adobe viewer but i saw enough to see "London Gazette" which suggests a wartime acessment. The figures i posted are post-war estimates. All in all, i'd say AA did a good job in helping break up/thwart attacks based on Shore's research. Its not all about outright kill losses but as in wartime this seems to continue to cause tunnel vision.

Nikademus said:

Sigh.....the "giggles" comment refers to the continued comparison between convoy battles like Pedestal and PQ-18 and Santa Cruz. IMO, its rather silly to make in-depth comparisons given the conditional differences. Just trying to inject a little light heartedness.

The link you provided keeps crashing my Adobe viewer but i saw enough to see "London Gazette" which suggests a wartime acessment. The figures i posted are post-war estimates. All in all, i'd say AA did a good job in helping break up/thwart attacks based on Shore's research. Its not all about outright kill losses but as in wartime this seems to continue to cause tunnel vision.

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Yes, I agree that it is hard to find truly tactically equivalent battles. In the final analysis it comes down to examining the hardware and trying to assess it's capabilities.

The link was to the Hyperwar site and the despatch was concerning some of the major Med convoy battles. The last part of the section on Pedestal contained a diary of events which states observed rather than claimed kills and it was quite close to Shores's research. If the link is crashing your web pdf viewer you might try download the document and read it from your HDD. It and the other despatches make for fascinating reading, as they contain the official version of events as written by the senior officer in command, however in some cases they are written post war and seem to have been cross checked with available Axis records.

How long after the war were the various marks of the 4.7 in retained in service. How long after the war was the 5/38 retained in service. I think the last Gearing was not finally retired until 1980, or thereabouts. I think the 4.7 basically disappeared in 1945, because the 4.5 DP was a far better proposition.

The 5/38 was replaced because there was no automated version of the gun, AFAIK. The new turrets in the Charles F Adams class were 5/54, with autoloader as I recall, just as an example.

One further question....what was the maximum elevation that the 4.7 could be loaded. The 5/38 could be loaded from quite high angles of elevation.....

parsifal said:

How long after the war were the various marks of the 4.7 in retained in service. How long after the war was the 5/38 retained in service. I think the last Gearing was not finally retired until 1980, or thereabouts. I think the 4.7 basically disappeared in 1945, because the 4.5 DP was a far better proposition.

The 5/38 was replaced because there was no automated version of the gun, AFAIK. The new turrets in the Charles F Adams class were 5/54, with autoloader as I recall, just as an example.

One further question....what was the maximum elevation that the 4.7 could be loaded. The 5/38 could be loaded from quite high angles of elevation.....

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LoL, I've learned more about naval guns than I really wanted to know...but from what I've learned 4.7in gunned destroyers were phased out fairly rapidly in the RN, but survived somewhat longer in the RCN in the Tribal class. Several L-M class destroyers with the Mk XI 4.7in/50 served in the Turkish navy until about 1970. The Mk XI gun fired a 62lb round to better than 21000 yds.

There were a variety of different QF 4.7in guns. All QF versions used a loading tray and could be loaded at all angles. The 4.7in/40 Mk VIII gun was used on the Nelson class battleships and a few others and featured 90 degree elevation. The Mk IX and XII guns were used on the A through I, O, Q through W, Tribal (1937), J, K, N and Abdiel Classes. The last variant of this gun was given the Mk XXII mounting which gave it 55 degree elevation, but the weight penalty was substantial, going from 8.8 tons for the first 40deg elevation version to 11.6 tons for the 55 deg version per mount. The powered Mk XX twin 40 deg mount weighed 25.1 tons. For reference a USN 5in/38 open mount started at 13 tons, while the 5in twin DP enclosed mount weighed in at 43 tons on a destroyer while the LA twin 5in weighed 34 tons, and the weight saved allowed the destroyers that had the LA twin, to carry 2 x quad 1.1in mounts.

The 4.5in gun had much better ballistics than the 4.7/45 as it fired a heavier, modern shell. With VT ammo and better FC with faster computers, a HA gun made more sense, but also the newer twin 4.5 designs featured an enclosed mounting that was probably a nice feature for a peacetime navy.

RCAFson said:

LoL, I've learned more about naval guns than I really wanted to know...but from what I've learned 4.7in gunned destroyers were phased out fairly rapidly in the RN, but survived somewhat longer in the RCN in the Tribal class.

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I think you will find that the RCN Tribals were armed with 8 x 4in which tells you something about the standard 4.7in.

The 4.5in gun had much better ballistics than the 4.7/45 as it fired a heavier, modern shell. With VT ammo and better FC with faster computers, a HA gun made more sense, but also the newer twin 4.5 designs featured an enclosed mounting that was probably a nice feature for a peacetime navy.

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Correct which is why the 4.7in left service almost immediately after the war. The 5in L38 survived in the USN and US Coastguard in serious numbers for decades after the war, which tends to prove the point.

parsifal said:

How long after the war were the various marks of the 4.7 in retained in service. How long after the war was the 5/38 retained in service. I think the last Gearing was not finally retired until 1980, or thereabouts. I think the 4.7 basically disappeared in 1945, because the 4.5 DP was a far better proposition.

The 5/38 was replaced because there was no automated version of the gun, AFAIK. The new turrets in the Charles F Adams class were 5/54, with autoloader as I recall, just as an example.

One further question....what was the maximum elevation that the 4.7 could be loaded. The 5/38 could be loaded from quite high angles of elevation.....

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I don't think it was a matter of how long the 4.7 was retained in service as much as how fast the or how many times the British tried to "improve" the 4.7 during the war.
The 4.7 disappeared by 1948-49 because the RN had shifted to the 4.5 back in 1942-43, in the sense that all new constructed ships would have the 4.5. From the Savage/'S" class and after. At the End of the war with the newer ships armed with 4.5s and the older ships with armed with 4.7 being mostly worn out and needing repairs/refits it only made sense for the 4.7 armed ships to be the ones to go in the down sizing.

Of, course in 1941 or so when the drawings started for the designs the British didn't have the war experience to tell them that higher elevation guns and higher rate of fire weren't worth the cost

Glider said:

I think you will find that the RCN Tribals were armed with 8 x 4in which tells you something about the standard 4.7in.

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They were converted to destroyer escorts around 1950, and the 4.7in guns were replaced by twin 4in at that point. The twin 4in might have been a better all round mount, but it was also much lighter and this probably helped to counteract the overall weight and top-weight growth.

RCAFson said:

They were converted to destroyer escorts around 1950, and the 4.7in guns were replaced by twin 4in at that point. The twin 4in might have been a better all round mount, but it was also much lighter and this probably helped to counteract the overall weight and top-weight growth.

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We can all this one a draw as the last 4 RCN vessels were built with 8 x 4in.