Dive Bomber Comparison

[renrich]

Quite a number of years ago, I read a book written by a British admiral, (I think he was an admiral but I am certain he was a RN officer) that was a very detailed account of the RN in WW2. He mentioned a number of times how inadequate the RN AA was because of the apparatus for sighting or directing the fire. I wish I could remember the book's name but it was a library book and too long ago for me to remember. I have always marveled at the KGV class's "countersunk" 5.25 inch secondary armament. I thought it was an elegant engineering solution and made the gun houses less vulnerable but it apparently did not make them more effective against EA.

The following certainly is not necessarily proof of anything but in WW2, according to Janes 1944-45, the RN lost 30 cruisers and 12 of those were lost to enemy air action. The US lost ten cruisers and one of those was lost to air action.

The RN lost two capital ships at sea to air action and the US lost none at sea to air action although that comparison certainly is probably not as valid because I can think of no US capital ships exposed to air action without having some CAP protection.

Arguably the Japanese anti shipping aircraft strikes were more effective than the Axis air strikes in the ETO. The Germans had torpedo problems early in the war, almost as badly as the US. The Japanese ship launched and aircraft launched torpedos were pretty reliable.

I don't believe that judging the effectiveness of AA fire based on comparing results against dive and torpedo bombers and those results against Kamikazes makes much sense. It is much easier to hit a target with one's plane than it is to score hits with bombs or torpedos.

 

[Nikademus]

I would just point out that the primary mission for AA is not to shoot down enemy aircraft. That is primarily the responsibility of fighter aircraft. Flaks primary purpose is to throw the attacking aircraft off their aim, and to disrupt attacks.

Actually shooting down aircraft is a primary mission of both AA and Fighter aircraft. The other facets mentioned are also equally important to both types of weapon systems. The problem with judging AA is that too often, people, including the professionals at the time, tend to fixate on outright kills because its a statistic that can easily and quickly be grasped as a measure of "success". This was a major problem for Germany during the Bombing campaign on their cities. The guys in charge on the ground wern't interested in how many planes were damaged, or driven off, or made to make inaccurate runs..they only wanted to know one thing. "how many of the enemy did you shoot down??!!" This helped fuel arguments on downplaying flak development in favor of more fighters. Ironically in the case of Germany, postwar analysis indicated that flak actually ended up shooting down more enemy planes than the Jagdwaffe....even when not factoring in damaged planes later picked off by fighters.

The same tunnel vision impacts CAP analysis at times too. The Illustrious Blitz is a good capsule on that. Malta's AA and CAP defenders didn't score much during the "Blitz" and that overshadowed their primary acomplishment, which was disrupting the attacks enough that only a few hits were scored.

 

[RCAFson]

The following certainly is not necessarily proof of anything but in WW2, according to Janes 1944-45, the RN lost 30 cruisers and 12 of those were lost to enemy air action. The US lost ten cruisers and one of those was lost to air action.

The RN lost two capital ships at sea to air action and the US lost none at sea to air action although that comparison certainly is probably not as valid because I can think of no US capital ships exposed to air action without having some CAP protection.

Arguably the Japanese anti shipping aircraft strikes were more effective than the Axis air strikes in the ETO. The Germans had torpedo problems early in the war, almost as badly as the US. The Japanese ship launched and aircraft launched torpedos were pretty reliable.

I don't believe that judging the effectiveness of AA fire based on comparing results against dive and torpedo bombers and those results against Kamikazes makes much sense. It is much easier to hit a target with one's plane than it is to score hits with bombs or torpedos.

The IAF had a very effective TB from the start in the SM-79 and they had effective torpedoes as well.

The RN faced several problems which the USN, largely, did not have to deal with, mainly that the RN had to supply, protect, and then withdraw large numbers of troops from areas completely dominated by enemy airforces. Many of the RN ships were actually scuttled, rather than sunk outright, but they had no choice but to do so because they were typically well within reach of enemy airforces and devoid of air cover themselves. Malta was a thorn in the side of the Axis, but was also a major headache for the RN, which regularly had to face hundreds of Axis aircraft while trying to run convoys through to the island. The number of sorties that the Axis flew against the RN is also really staggering, when you start to add it all up.

 

[Kurfürst]

This helped fuel arguments on downplaying flak development in favor of more fighters. Ironically in the case of Germany, postwar analysis indicated that flak actually ended up shooting down more enemy planes than the Jagdwaffe....even when not factoring in damaged planes later picked off by fighters.

That's true but don't forget the cost analysis - only a couple of hundred fighters were employed during the most successfull period of the RV (1943), vs literally thousends of Flak batteries scattered all over Germany, most of which could simply not fight the threat due to its immobility, and were damned to a passive role. They were important part of the defense, being always there, yes, and much if not most of the circa million personnel serving them were unfit for normal military duties (teenager kids, Hiwis and the like) but IMHO fighters overall were considerably more cost effective - though in fairness the fighters themselves required a fairly extensive logistic network, ie. fuel, ground crew. Altough the latter is true for the Flak as well, namely, they expended huge amounts of ammunition.

 

[JoeB]

If it could be possible to compare Med and Pacific in a non national-dick-measuring US v British way (fat chance! ) the only reasonable conclusion would be that the two situations differed too much to make easy and direct comparisons of the AA effectiveness of the ships. But the Brit uber-alles type posters on the internet with 'far bigger air threat in Med' are really being quite ridiculous, as shown by the RN's own operations early in the Pacific War. There were a larger number of *engagements* between Axis a/c and Allied ships in Med througth whole of 1940-43 than there were v Allied ships in the Pacific in the prime of the JNAF in 1942-3, but in order to hope to compare effectivness of defense, you'd have to start by considering air attack effectiveness *relatively* per engagement, rather than the number of attack sorties or sinkings in total. But there's no episode of air attack at all that fully matches the POW/Repulse debacle; and not really any in Med which fully match the smothering with mutiple divebomber hits in the various attacks off Ceylon, either.

But as I said, demonstrating a specific difference in air defense capability based on results in one theater v another, and considering the highly nationalistic prism through which some obviously view these questions...I doubt it.

Just a point on Italian capability. Through basically all of 1940 and into part of 1941, the Italian air threat consisted principally of ineffective medium altitude level bombers. When the Italians introduced torpedo equipped S.79's in late 1940 they had literally 4 a/c in total so equipped, famous for achieving severl hits despite that very small force size. An attack of 40 S.79 sil at once was not until the Pedestal operation in summer of 1942. The Germans didn't use torpedo bombers in the Med during the height of the Anglo-Italian naval war; their torpedo training base was at Grosseto in central Italy from early 42, but priority was given to building capability to use against the Russia convoys. Later on, from Torch landings through summer of '44, German torpedo planes were more active in Med.

Besides limited numbers of S.79 'sil', which were sortie for sortie the most effective Axis antiship a/c in the Med in '40-42, the main threat was from Ju-87's, and Ju-88's acting as divebombers. Ju-88's also acted as level bombers with limited success. German and Italian fighter bombers (Bf109, Re-2001, CR.42) also got a few key hits v British ships but a/c besides S.79 sil, German piloted Ju-87's and *divebombing* Ju-88's the other a/c types were mainly just ramping up the number of sorties. The British formations off Malaya and Ceylon faced more concentrated and purely professional antiship air units than the British faced on average in the Mediterranean, even though they faced cumulatively more attacks and lost more ships in the Med and *some* of those attacks were by highly effective antiship units.

Joe

 

[parsifal]

Actually shooting down aircraft is a primary mission of both AA and Fighter aircraft. The other facets mentioned are also equally important to both types of weapon systems. The problem with judging AA is that too often, people, including the professionals at the time, tend to fixate on outright kills because its a statistic that can easily and quickly be grasped as a measure of "success". This was a major problem for Germany during the Bombing campaign on their cities. The guys in charge on the ground wern't interested in how many planes were damaged, or driven off, or made to make inaccurate runs..they only wanted to know one thing. "how many of the enemy did you shoot down??!!" This helped fuel arguments on downplaying flak development in favor of more fighters. Ironically in the case of Germany, postwar analysis indicated that flak actually ended up shooting down more enemy planes than the Jagdwaffe....even when not factoring in damaged planes later picked off by fighters.

The same tunnel vision impacts CAP analysis at times too. The Illustrious Blitz is a good capsule on that. Malta's AA and CAP defenders didn't score much during the "Blitz" and that overshadowed their primary acomplishment, which was disrupting the attacks enough that only a few hits were scored.

I have to disagree. Ships dont put to sea to sail around the ocean to shoot down aircraft, they put to sea to undertake a mission. It is often the case that ships must sail into enemy dominated seas, and risk air attack, but this is still not the primary mission of those ships.

Fighter aircraft, on the other hand, get airborne for one purpose only, to shoot down enemy aircraft.

It follows therefore that the AA armament of a ship is there to facilitate the mission of that ship. If the carrying out of that mission enables some losses to enemy aircraft, then so much the better, but the primary purpose remains defensive, that is enabling the ship to complete its mission. if ever there was a demonstrable example of what i am referring to, it has to be the tragedy of PQ-17. Once broken up, the Task Force could not mass sufficient volume of fire, and as a result could not successfully complete the task Groups mission.

I'll put it another way....if a ship does not shoot down a single aircraft, but is abale to undertake its mission without loss or damage, that ship, and its AA can be considered a success. If it shoots down aircraft b\ut is prevented from undertaking its stated mission, by sinking, or damage, or scrapping of the mission, the ship, and its AA have failed in their primary mission. If the ship manages to shoot down aircraft, and complete its mission, its a success with a bonus "score", so to speak.

If this accepted, then the RN demonstrates in spades that its AA was adequate. Someone mentioned that the RN lost 30 cruisers in the war whilst the USN only lost ten. Well, this is true, but is a gross misuse of basic statistics. In fact in the time frame that the USN was being shot at, the RN lost only 18 cruisers, and of this only 5 were lost to enemy air attack. in that period the USN lost one cruiser to air attack. However the RN often operated in conditions of enemy control of the airspace, wheras the USN after the end of 1942, usually operated under conditions where the naval units were concentrated, and the the airspace was either under their control, or, at minimum, was under challenge by their own airpower. It is simply invalid to start comparing the losses of one theatre to those in another. The USN enjoyed advantages that the RN was not privy to until very late in the war. In the circumstances where the operating conditions were similar, such as off the coast of japan in 1945, the RN does not appear to have been any worse off with its AA arrangements than the USN. Both took losses to the Kamikaze attacks, and both had significant successes as well.

 

[Shortround6]

Comparing the AA ability of either navy in 1945 to the each others ability or even their own ability at earlier periods of the war ignores the large advancements in number of AA guns mounted, types of AA guns mounted, types of mountings used (powered vs unpowered) , fire control and ammunition (VT fuses) .

While I mentioned earlier the RN destroyers armed with a pair of quad .5" MGs and was rebutted by American destroyers with 4-8 .50 cal guns.
this rather ignores the facts that the British main armament of 4.7in guns was rather useless for anti-aircraft work. Older destroyers having a max elevation of 30 degrees and somewhat newer having 40 degrees as a book figure but only obtainable by pulling up sections of the deck grating to allow for gun recoil. A full 40 "degrees was finally achieved but this compares badly to the 85 degrees of the US 5"/38.
Few if any British 4.7 were power operated until the twin mount on the Tribal class. I believe ALL destroyer mounted 5" 38s were power operated.
The British 4.7 had a rate of fire of 10-12 rpm. Most if not all destroyer 5"/38s had a rate of fire of 15-22rpm for a 20% margin of superiority for the US destroyers at worst and double the rate of fire at best.
While the RN was at the forefront in some developments in AA it's very size conspired against it as did the war situation. It is one thing to develop or introduce a new gun or mounting or fire control device, it is quite another to retrofit to a number of ships the size of the RN, especially if the ships are spread around the world and are being worked so hard that they cannot be docked for routine maintenance let alone refits. Combine that with a shortage of manufacturing capacity and AA refits were slow in coming for many ships. Or refits were parceled out in dribs and drabs. A couple of 20mm guns now, a couple of 20mm guns months from now.
The landing of a set of torpedo tubes for either a single 4" or 3" unpowered, local control AA gun was more of a morale booster than an effective AA defense. it also shows that no other AA guns were available.

 

[Nikademus]

I have to disagree. Ships dont put to sea to sail around the ocean to shoot down aircraft, they put to sea to undertake a mission. It is often the case that ships must sail into enemy dominated seas, and risk air attack, but this is still not the primary mission of those ships.

Fighter aircraft, on the other hand, get airborne for one purpose only, to shoot down enemy aircraft.

The same can be said of Fighters. They are there to fullfill a mission which is generally broken down into two or three types; 1) Fleet defense 2) Strike escort 3) sweep. A primary means of acomplishing this is to "shoot down enemy planes" but said missions can be acomplished through indirect means as well, particularily in the case of 2). Same for Anti-Aircraft. The primary mission of AA is to defend said ship/TF. The most direct means to acomplish this is to hit and shoot down enemy planes but in lieu of that, driving off enemy planes is acceptible to ensure survival of the ship and to maintain systems integrity. A problem with the argument that AA is primary an attempt to "ward off" enemy attackers exclusively is that better trained crews are not going to be warded off in general. Highly trained crews with good morale tend to press home their attacks. Similar situation existed in the case of Kamakaze's. Behind such fanaticism, the USN was faced with the challenge of hitting as quickly and hard as it could as even a damaged plane might still hit a ship. Advances in AA technology (including the vital VT fuse) were all about HITTING the enemy planes, not driving them off. IMO, saying AA is primary a means to ward off enemy planes is like saying Anti-ship weapons arn't really there to "hit" an enemy ship but more as a deterrent to sticking around the battlefield. You might indeed drive off the ship, but in the process you are trying your damnest to HIT the enemy ship.

 

[RCAFson]

Comparing the AA ability of either navy in 1945 to the each others ability or even their own ability at earlier periods of the war ignores the large advancements in number of AA guns mounted, types of AA guns mounted, types of mountings used (powered vs unpowered) , fire control and ammunition (VT fuses) .

While I mentioned earlier the RN destroyers armed with a pair of quad .5" MGs and was rebutted by American destroyers with 4-8 .50 cal guns.
this rather ignores the facts that the British main armament of 4.7in guns was rather useless for anti-aircraft work. Older destroyers having a max elevation of 30 degrees and somewhat newer having 40 degrees as a book figure but only obtainable by pulling up sections of the deck grating to allow for gun recoil. A full 40 "degrees was finally achieved but this compares badly to the 85 degrees of the US 5"/38.
Few if any British 4.7 were power operated until the twin mount on the Tribal class. I believe ALL destroyer mounted 5" 38s were power operated.
The British 4.7 had a rate of fire of 10-12 rpm. Most if not all destroyer 5"/38s had a rate of fire of 15-22rpm for a 20% margin of superiority for the US destroyers at worst and double the rate of fire at best.
While the RN was at the forefront in some developments in AA it's very size conspired against it as did the war situation. It is one thing to develop or introduce a new gun or mounting or fire control device, it is quite another to retrofit to a number of ships the size of the RN, especially if the ships are spread around the world and are being worked so hard that they cannot be docked for routine maintenance let alone refits. Combine that with a shortage of manufacturing capacity and AA refits were slow in coming for many ships. Or refits were parceled out in dribs and drabs. A couple of 20mm guns now, a couple of 20mm guns months from now.
The landing of a set of torpedo tubes for either a single 4" or 3" unpowered, local control AA gun was more of a morale booster than an effective AA defense. it also shows that no other AA guns were available.

according to:
USA 5"/38 (12.7 cm) Mark 12
The older models of the 5in/38, on prewar destroyers, and other ships had a rate of fire, of about 12 -15 RPM, and it was only the newer ships with improved fuze setters that could fire faster. According to
Goldplaters, 1500-ton destroyers and 1850-ton destroyer leaders
All USN destroyers prior to 1939 had a close range armament of 4 x .5" MG.
So the RN destroyer close range armament of either 2 x 40mm pom-pom, 2 x quad .5" or 1 x quad 40mm pom-pom and 2 x quad .5" is still superior.

All the Tribal class and the J-K class had 8 or 6 power worked DP twin 4.7" guns with an main armament AA FC system. No German or Italian destroyers had a DP main armament. The IJN destroyers had very little in the way of DP capability and their 5in main armament is described as:
"However, the very slow training speeds and lack of power ramming made these mountings almost useless against the fast-moving aircraft of World War II""
Japan 12.7 cm/50 (5") 3rd Year Type

The more modern RN destroyers were limited to 40 deg elevation but this still allowed for engaging most aircraft throughout some of their attack, and obviously could engage torpedo bombers continuously. According to this source:

"In theory, the 5in gun could counter either horizontal or torpedo bombers; it could not fire nearly fast enough to present any threat to dive bombers,which, ironically, were probably the most lethal threat to fast maneuverable craft such as destroyers." US Destroyers-An Illustrated Design History, Friedman, p203
So it seems that against DBs, a destroyer's best defence was its close range weapons, and here the RN did not seem to be "substandard", so even if their early war/prewar armament was not sufficient, it was still as good or better then everyone else's. The RN also, pre and early war, re-armed older ships as dedicated AA cruisers, and introduced AA sloops with a heavy armament of 4" guns, with 80 deg elevation. The RN began building large numbers of Hunt class destroyers, early in the war, and they all had either 4 x 4 or 6 DP 4in guns, a quad pom-pom and several smaller weapons.

So compared to the USN, it is hard to say if the RN was really behind, but certainly compared to the Axis ships, the RN destroyers are ahead in terms of AA armament and fire control. The RN was certainly ahead of everybody in terms of AA radar fire control.

 

[JoeB]

Besides any doctrinal debate about the role of AA and fighters in repelling air attacks, as a practical matter when both fighters and AA were defending a group of ships, it's usually very hard to disintangle which shot down how many enemy a/c. The total claims almost always exceed the enemy losses, and specific enemy accounts will sometimes allow AA or fighters to be credited pretty certainly, but usually won't.

Same or more so when it comes to evaluating light v heavy AA.

Debates about RN AA fire control on other boards have run up on the rocks over this issue. The boosters of RN heavy AA as underrated present figures for AA claims in Med as if true and as if all from heavy AA. Then the next fall back position is that overall Axis losses weren't so much less than AA claims, but fighters shot down an intdeterminate high % of the a/c and light AA probably did too. And, a high % of Axis bomber losses in attacks on RN in Med (and Malta) were ditching/crashlanding on way back, which were certainly successes of the defense, but very rarely can those cases be nailed down to a single cause with available info. Same is true in Pacific, but I'm not aware of people trying to claim absolute true losses of Japanese a/c v USN defenses, rather than eg comparative effectiveness of USN VT v USN time fuzed 5" fire, or something like that, where it's reasonable to compare relative claims as at least a rough idea.

Only in cases where a/c attacked ships without air cover is it usually possible to evaluate AA claim/loss, and back to the doctrinal type consideration, one could argue that AA's role is to distract and hamper air attacks, or mop up the remnants, as an add to effective fighter cover, and it isn't that relevant how the AA would do on its own against a large scale attack by competent antiship air units unmolested by friendly fighters; that's something that simply had to be avoided.

Joe

 

[RCAFson]

But the Brit uber-alles type posters on the internet with 'far bigger air threat in Med' are really being quite ridiculous, as shown by the RN's own operations early in the Pacific War. There were a larger number of *engagements* between Axis a/c and Allied ships in Med througth whole of 1940-43 than there were v Allied ships in the Pacific in the prime of the JNAF in 1942-3, but in order to hope to compare effectivness of defense, you'd have to start by considering air attack effectiveness *relatively* per engagement, rather than the number of attack sorties or sinkings in total. But there's no episode of air attack at all that fully matches the POW/Repulse debacle; and not really any in Med which fully match the smothering with mutiple divebomber hits in the various attacks off Ceylon, either.

But as I said, demonstrating a specific difference in air defense capability based on results in one theater v another, and considering the highly nationalistic prism through which some obviously view these questions...I doubt it.

Just a point on Italian capability. Through basically all of 1940 and into part of 1941, the Italian air threat consisted principally of ineffective medium altitude level bombers. When the Italians introduced torpedo equipped S.79's in late 1940 they had literally 4 a/c in total so equipped, famous for achieving severl hits despite that very small force size. An attack of 40 S.79 sil at once was not until the Pedestal operation in summer of 1942. The Germans didn't use torpedo bombers in the Med during the height of the Anglo-Italian naval war; their torpedo training base was at Grosseto in central Italy from early 42, but priority was given to building capability to use against the Russia convoys. Later on, from Torch landings through summer of '44, German torpedo planes were more active in Med.

Besides limited numbers of S.79 'sil', which were sortie for sortie the most effective Axis antiship a/c in the Med in '40-42, the main threat was from Ju-87's, and Ju-88's acting as divebombers. Ju-88's also acted as level bombers with limited success. German and Italian fighter bombers (Bf109, Re-2001, CR.42) also got a few key hits v British ships but a/c besides S.79 sil, German piloted Ju-87's and *divebombing* Ju-88's the other a/c types were mainly just ramping up the number of sorties. The British formations off Malaya and Ceylon faced more concentrated and purely professional antiship air units than the British faced on average in the Mediterranean, even though they faced cumulatively more attacks and lost more ships in the Med and *some* of those attacks were by highly effective antiship units.

Joe

It is a question of telling the real story, and it is historically inaccurate to suggest that the Luftwaffe crews were cowards, unwilling to press home their attacks. If they didn't press home their attacks on RN ships, then it suggests that they had powerful reasons to fear for their safety. Which is it?

The Luftwaffe did attack RN ships with great determination, (and it is an real insult to the Luftwaffe and the RN/RCN/RNZN/RAN to suggest otherwise) and flew hundreds of attack sorties, off Norway, Dunkirk, Malta and Crete, so that by June 1941, the RN must have faced a far higher numbers of attacks than the USN, did in 1942-43. Many RN ships were sunk, but they also shot down large numbers of attacking aircraft, mainly with their pre-war outfit of AA weapons, although some 20mm guns were in service by June 1941.

The IJN was able to overwhelm isolated numbers of elderly RN ships in the Indian Ocean and so conducted DB attacks under virtually peacetime practise conditions, where the Luftwaffe DBs often to had to brave the fire of a massed fleet, to press home their attacks. The Luftwaffe often carried 500kg bombs, which were rarely used by the IJN, while Luftwaffe aircraft were, typically, heavily armoured and had self sealing fuel tanks, while the Japanese planes had no crew or fuel protection at all.

As for POW/Repulse, give me an example of a similar encounter by another navy, where large numbers of TBs where able to attack with no worries about CAP and/or a screen of modern cruisers and destroyers.

While you attempt to minimize the IAF TB attacks, you also state that they achieved some successes, so I guess "some" of the IAF crews were "determined". The TB attack against Operation Halberd, was certainly determined, and it also got a very hot reception by RN AA.
Operation Halberd - Wikipedia, the free encyclopedia

 

[Shortround6]

according to:
USA 5"/38 (12.7 cm) Mark 12
The older models of the 5in/38, on prewar destroyers, and other ships had a rate of fire, of about 12 -15 RPM, and it was only the newer ships with improved fuze setters that could fire faster. According to
Goldplaters, 1500-ton destroyers and 1850-ton destroyer leaders
All USN destroyers prior to 1939 had a close range armament of 4 x .5" MG.
So the RN destroyer close range armament of either 2 x 40mm pom-pom, 2 x quad .5" or 1 x quad 40mm pom-pom and 2 x quad .5" is still superior.

The rate of fire also had a lot to do with the ammo hoists so a fair number of the pre-war destroyers (the ones with the base ring mount) could do all right.
The older single 40mm pom-poms are a problem. The British considered them so good they replaced then with the Quad .5in mount which was no great item itself. While these may be considered better close range armament than the American four .50cal guns when you consider that for the British A through I class they were the ONLY effective AA guns on the destroyer, few of these early class (if any) had an AA director an only the H and I class could realistically elevate their 4.7in guns above 30 degrees, things don't look so good.
As a comment on how well the 4.7in guns of the early classes worked as AA guns it may be noted that many of them landed half their torpedo armament in order to mount a single WW I era 12pdr (3in) AA gun in local control which aside from raising the morale of the sailors was just about useless.
Granted the 4 barreled pom-pom gun was great improvement but it was only on the Tribal class and the J class and what few K class that were in service when the war broke out.

All the Tribal class and the J-K class had 8 or 6 power worked DP twin 4.7" guns with an main armament AA FC system. No German or Italian destroyers had a DP main armament. The IJN destroyers had very little in the way of DP capability and their 5in main armament is described as:

I guess it depends on what you call dual purpose. The British thought so much of the dual purpose capability of the J-K class with their power worked twin 4.7in guns that they also landed half the torpedo armament to mount a single 4in gun in local control to beef up the AA capability. It actually wasn't much more use than the 12pdr. Some Tribal Class destroyers landed X mount of the 4.7in guns to mount a twin 4in mount. The fire control director was modified to accommodate the dual ballistics. I think that says something about what was thought of the twin 4.7in as an AA gun.

"In theory, the 5in gun could counter either horizontal or torpedo bombers; it could not fire nearly fast enough to present any threat to dive bombers,which, ironically, were probably the most lethal threat to fast maneuverable craft such as destroyers." US Destroyers-An Illustrated Design History, Friedman, p203

True enough but that page goes on to point out that it was thought that the dive bombers would go after higher value ships and leave the DDs alone (wishful thinking?) and that devoting armament space/weight to heavier machine cannon (the 1.1in mounted on the 1850 ton leaders) would mean a sacrifice in the 5in armament which was planned as as part of the fleet AA defense. The destroyers forming an AA screen around the higher value ships. The US may have gotten the mix of weapons wrong but they were thinking about a STRONG AA gun defense of the fleet to include ALL ships.

So it seems that against DBs, a destroyer's best defence was its close range weapons, and here the RN did not seem to be "substandard", so even if their early war/prewar armament was not sufficient, it was still as good or better then everyone else's.

Granted the German and French 37mm guns wer a bit of a joke but the German 20mm guns had to be worth something even if they are the early slow firing models.

The RN also, pre and early war, re-armed older ships as dedicated AA cruisers, and introduced AA sloops with a heavy armament of 4" guns, with 80 deg elevation. The RN began building large numbers of Hunt class destroyers, early in the war, and they all had either 4 x 4 or 6 DP 4in guns, a quad pom-pom and several smaller weapons.

True but a few special AA ships per task force is not quite the same thing. And considering that from the Benham class on 2 US destroyers could come close to putting up as much heavy AA fire as one converted British AA cruiser

So compared to the USN, it is hard to say if the RN was really behind, but certainly compared to the Axis ships, the RN destroyers are ahead in terms of AA armament and fire control. The RN was certainly ahead of everybody in terms of AA radar fire control.

There are two problems with fire control and radar, one is development and the other is deployment. While the RN may have been a leader in development it tended to fall down in deploying systems that worked well at the beginning of the war and because of the war situation and the size of the British fleet retrofits came slow and hard causing many older ships to fight on without the modern equipment. Things did get better for the British while for the axis navies things usually got worse, their improvements came even later and in even smaller numbers. US also had 2 years to learn from the British what worked and what didn't before more than a few of their ships got into a shooting war.

 

[RCAFson]

As of Sept 30 1939 (by my count using data from the web)the USN had:

8 farragut
18 mahan
4 Gridley class
8 bagley
5 benham
43 destroyers with DP 5" guns in commission, although some of these might not have been fully completed.

The RN had
16 Tribals
10-JK class
6 sloops (including 3 Egret class with 4 x 4" twin mounts)
4 AA cruisers
36 light ships with DP armament.

So the USN had a slight lead. We can debate the efficacy of DP guns against DBs, but it is doubtful that they were very effective, and the RN probably should have installed automatic weapons rather than 3"/4" HA guns, in place of the torpedo tubes. Of course the RN learned these lessons the hard way but did pass on all the info gained to the USN. Again no German or Italian destroyer ever had any DP main guns.

There are two problems with fire control and radar, one is development and the other is deployment. While the RN may have been a leader in development it tended to fall down in deploying systems that worked well at the beginning of the war and because of the war situation and the size of the British fleet retrofits came slow and hard causing many older ships to fight on without the modern equipment. Things did get better for the British while for the axis navies things usually got worse, their improvements came even later and in even smaller numbers. US also had 2 years to learn from the British what worked and what didn't before more than a few of their ships got into a shooting war.

I have already detailed how the RN had 56 ships (and many others with type 279/280/281) outfitted with Type 285 radar by Sept 28 1941, when no other navy had a single operational AA FC radar in service.

While only the Tribal and JKclass had quad pom-poms in Sept 1939, all RN capital ships and many modern cruisers had quad or octuple pom-poms as well, at a time when the USN depended almost universally on the .5" single MG, on almost all its ships.

True enough but that page goes on to point out that it was thought that the dive bombers would go after higher value ships and leave the DDs alone (wishful thinking?) and that devoting armament space/weight to heavier machine cannon (the 1.1in mounted on the 1850 ton leaders) would mean a sacrifice in the 5in armament which was planned as as part of the fleet AA defense. The destroyers forming an AA screen around the higher value ships. The US may have gotten the mix of weapons wrong but they were thinking about a STRONG AA gun defense of the fleet to include ALL ships.

And this was the thinking current in the RN as well, which led to the decision to retain a 40 deg elevation on the twin 4.7in gun, as this elevation was sufficient to provide 4.7in AA fire to protect ships being escorted by destroyers.
4.7 inch QF Mark XII - Wikipedia, the free encyclopedia

 

[Juha]

RCAFson
the 4.7" guns of Tribals, Js and Ks had max 40deg elevation, the US DDs in your list had 5"/38s with max 85deg elevation, a bit difference, especially when fighting against dive-bombers. That's why Js and Ks sacrificed ½ of their TTs to get even one real H/A gun aboard. In Tribals, which had only one quadruple TT anyway, Y-turret was changed to a 4" twin mount. So I would say that USN had significant lead in DP armed DDs. AA protection by guns with only 40deg elevation was a dubious asset, even high flying level bombers would have been out of reach when it really mattered ie when they approached their bomb-release point.

On automatic AA British had a lead, IIRC only US leaders had 2 quad 1.1" AAA mounts and their twin 5" mounts were LA type.

Juha

 

[RCAFson]

RCAFson
the 4.7" guns of Tribals, Js and Ks had max 40deg elevation, the US DDs in your list had 5"/38s with max 85deg elevation, a bit difference, especially when fighting against dive-bombers. That's why Js and Ks sacrificed ½ of their TTs to get even one real H/A gun aboard. In Tribals, which had only one quadruple TT anyway, Y-turret was changed to a 4" twin mount. So I would say that USN had significant lead in DP armed DDs. AA protection by guns with only 40deg elevation was a dubious asset, even high flying level bombers would have been out of reach when it really mattered ie when they approached their bomb-release point.

On automatic AA British had a lead, IIRC only US leaders had 2 quad 1.1" AAA mounts and their twin 5" mounts were LA type.

Juha

DBs are not the only type of attack, but even then the 40 deg guns could still engage Dbs attacking other ships, and as Friedman states, 5" calibre guns are little threat to DBs anyway. Yes, I agree that until VT ammo was available automatic weapons were the preferred way to deal with DBs and the RN should have added more of these in preference to a not very effective HA 4" gun.

OTOH, 30 of the RN ships (16 Tribals, 10 JK class and 4 AA cruisers) had a quad pom-pom, versus only .5" mgs on the USN ships. From other reading it seems that the quad 1.1" which was to have armed the USN destroyer leaders (which had no 5" AA FC) was delivered very late and was not ready by Sept 1939.

 

[parsifal]

The debate occurring at this point seems to revolve around whether the fighting in Europe was as determined and as proficient as those that occurred in the Pacific. An ancilliary question is whther the RN faced a relatively tougher or easier or about the same level of difficulty in the fighting in the med 1941-2 as the USN did a year later. The nearest analogy I guess would be to compre the fighting around Malta and Crete to that which occurred in the Solomons from March through to say November 1942.

I cannot answer whether the Germans and Italians were any more or less proficient than the Japanese in their aeronaval attacks. According to Bragadin, in that period the Italians were responsible for 40% of the tonnage losses to the RN and the merchant service as a result of their torpedo squadrons. People tend to denigrate their efforts because there were no big ships sunk by air attack, but as I recall after December 1941, they were responsible for the sinking of one of the five British cruisers by air attack, the Germans responsible for two, and the the Japanese for two. They sank more merchant tonnage in the med than the Germans. Our view of them is often coloured by their lacklustre belif and use of high level bombing. Once the uselessness of this was relaized, and steps taken to rectify the problem by using aerial torpedo attacks, which began in earnest from January 1941, they remained a potent force

The abilities of the germans in aeronaval capability started the war in a fairly lacklustre fashion, but they too developed specialist ant-shipping units that proved quite devastating. They were slow on the uptake in terms of torpedo bombing, but they more than madde up for this with their divebombing capabilities.

The Japanese had an undoubted prowess in anti-shipping capabilities, but as training levels slumped, there was a marked drop in their skill levels. The Vals scored a hit ratio above 80% in the Indian Ocean, as Joe (and myself) have pointed out. However by 1944, it is estimated that this accuracy had slumped to less than 10%. I would expect a similar drop in proficiency for the other major weapon systems like torpedo squadrons. They countered this slump in training by introducing massed kamikaze attacks, which resulted in a marked increase in USN ship losses.

It is very difficult and not entirely valid to try to compare the ferocity and effectiveness of fighting in one theatre to that which existed in another. If you want to compare the scale and ferocity of the fighting in the mediterranean with that in the pacific, then in my opinion you have to at least compare battles in similar time frames, then make some estimation of the relative merits of the crews and equipment involved, and finally try to determine the tnumbers and effectiveness of those systems.

Most of these variables are simply unknown, or so objective as to be beyond quantification. But in one area i have no doubts. Comparing the numbers of enemy aircraft involved, there is no question that the RN faced a far greater number of enemy aircraft thgan their American counterparts, at least in the beginning. The attacks against the "Excess" group of convoys were resisted by 226 Luftwaffe aircraft, and about 100 RA aircraft (but only about 30 of these can be considered effecetive). I believe the RN forces operating off Crete were faced by about 700 German aircraft not including the transports. These were just the aeronaval units of the two FliegerKorps. During the Pedestal convoys, the RN faced more than 700 axis aircraft, though the axis faced the perrennial problem of being unable to concentrate their forces

The Japanese part of the equation is complicated by the intervention by her carrier based air units. These were usually countered by the presence of American based carrier planes, but it was during these short, sharp engagement that the majority of the damage was done to the USN. At other times the numbers of aircraft involved was far less than those
being employed by the Axis in the Med, so from that single standpoint, there is absolutely no doubt that the scale of fighting was much more intense in the med than in the SW pacific. Later things did change....there were more Japanese forces committed, and the intensity of the battles increased accordingly, but I think this is not a valid comparison.

 

[Nikademus]

The debate occurring at this point seems to revolve around whether the fighting in Europe was as determined and as proficient as those that occurred in the Pacific. An ancilliary question is whther the RN faced a relatively tougher or easier or about the same level of difficulty in the fighting in the med 1941-2 as the USN did a year later.

The Med fighting saw more surface battles than any other Theater and while there were no carrier vs carrier air battles, the proximity of large land based air assets more than made up for this. The need to continually provide convoys on both sides kept the air forces and navies busy. The intensity at times matched anything seen in the Pacific with the exception of large carrier airstrikes. A major difference was in the Pacific clashes tended to be more sporadic but violent while in the Med it might be seen (very roughly) as a more of an even tempo over a longer period of time.

Some fun with numbers: (Source: O'Hara)

Surface Engagements by Ocean/Sea

Atlantic: 49
Artic: 8
Baltic Black Seas: 5
Indian Ocean: 14
Pacific: 36
Med: 55

enemy warship tonnage sunk by Nation:

Italy: 145,800
Germany: 169,700
UK: 161,200
US: 33,900

(Luftwaffe accounted for 30% of Allied warship losses compared to 9% Regia Aeronautica)

Italian aerial torpedo squadrons were late in being started and was stunted by limited availability of torpedoes, crews initially had little training but proficiancy rose up slowly. High attrition though eventually led to loss of proficiancy but one that was matched by an increase in numbers available. As mentioned, while they scored little against warships, they were a major threat to merchants in convoy along with "special weapons" (MTB's etc).

German airpower proved more effective than Italian airpower in terms of Allied warship losses.

All in all, the Med was no picnic.

 

[parsifal]

The Med fighting saw more surface battles than any other Theater and while there were no carrier vs carrier air battles, the proximity of large land based air assets more than made up for this. The need to continually provide convoys on both sides kept the air forces and navies busy. The intensity at times matched anything seen in the Pacific with the exception of large carrier airstrikes. A major difference was in the Pacific clashes tended to be more sporadic but violent while in the Med it might be seen (very roughly) as a more of an even tempo over a longer period of time.

Some fun with numbers: (Source: O'Hara)

Surface Engagements by Ocean/Sea

Atlantic: 49
Artic: 8
Baltic Black Seas: 5
Indian Ocean: 14
Pacific: 36
Med: 55

There were no less than 43 operations in which carriers saw combat as well in the med. Most were small, but some were quite significant in size. The source for that is an old book on carrier operations , by Norman Polmar, written in collaboration with Minoru Genda, Capt Eric Brown and Professor Langdon. I am not including operations where nothing happened. In every one of those operations there were risks, and usually losses for someone. I also used David Browns two volume work on Carrier operations, and Barnetts general work on the RN operations.

By comparison, in the swpac , in that first year of the wear, there were less than a quarter as many operations, though the big ones were all bigger than the RN operations, at least in numbers of aircraft involved. Note I am NOT including operations outside the theatre, or Japanese operations. Its hard to count all the Japanese operations, as their carriers were everywhere in the first three months of the war. when did one operationstop and another start???

I would have to disagree that either the Med or the Pacific were not driven by carrier operations, or at least aeronaval operations. In the med, as the British learnt to their cost, resupply operations and operations in enemy controlled airspace all required the use of a carrier, in order to be successful. When carriers were not on hand, the British did little better than the Italians, except at night. Their greatest successes, and arguably even their final victory at sea in the med was directly linked to their successful carrier operations. The same arguments can be mounted for the Pacific....whilst there were many more surface engagement in the solomons, mostly at night, the most strategically important battles were all fought by carriers. Without carriers, the US in particular would not have been able to win at guuadacanal, and guadacanal was the cornerstone to the later victories.

 

[Nikademus]

I would have to disagree that either the Med or the Pacific were not driven by carrier operations, or at least aeronaval operations.

Not sure if this is in response to me, so i'll clarify. The surface battle comparison number was posted to emphasis the point (made very well by O'Hara's recent tomb on the subject of the Med), that the Med was a serious Theater of operation yet it tends to either go under the radar (at least in the U.S.....Europe is a different matter), or is heavily discounted because, as you alluded too, the quality of the opposition (i.e., the Italians) are disparaged. Back in warships1.com days in the 1990's, when one would occasionally compare USN performance to UK performance, say at night.....an inevitable response would be "Oh but look who they were fighting!" Ironically, as shown....more surface battles were fought there than anywhere else. These battles may not have been the size of a Leyte Gulf......but it wasn't beer and pretzels either.

I agree that carriers played a key role in the Med for the UK. Without them first and formost.....Malta could not have been kept running and from a military standpoint their presence was a constant source of concern for the RM. In a way, it dovetails nicely with the position of Bergerud in his study of South Pacific air operations. In it he de-emphasised the importance of carrier vs carrier clashes vs. that of land air battles which were much more steady and prevalent (compared to the two clashes CV vs CV of which the overall result was largely a draw in the big picture) In the Med....carriers were a vital component to countering the large proximity of land based air forces and also provided the means by which the UK land based air forces could be continually replenished and kept up to strength so that the RAF could stay in the battle both offensively and defensively.

 

[BombTaxi]

Comparing the Med and the Pacific is apples and oranges anyway. The RN were fighting an essentially defensive campaign, keeping the seaways open to resupply Malta and NA and maintain the integrity of the Suez Canal. Offensive ops were mainly dedicated to supporting these essentially defensive aims, or later to interdicting Axis attempts to resupply thier own forces in NA.

By contrast, the USN was primarily engaged from day one in a pre-planned campaign designed to get them from California to the Japanese Home Islands. Their only defensive actions were early on, at Coral Sea and Midway. Very different warfighting philosophies were in play too. The USN saw carriers as the primary striking arm of the fleet, whereas the RN still saw carriers primarily as scouting tools and, in the Med, as large aircraft transports. The difference is shown in early-war CV and air group design; USN carriers were designed to rapidly transport large, strike-orientated air groups to the point of engagement as rapidly as possible, whereas RN carriers emphasised greater protection of smaller vessels, carrying small air groups in which almost every aircraft (e.g Skua, Albacore, Swordfish, Fulmar and Firefly) had a secondary reconnaissance capability.