Destroyers.....

A general summary of lenlease and USA restrictions on weaon and equipment types:

But in the summer of 940 the hard facts were that the decision as to the standardization on British designs lay with the Americans and that in the main the decision was adverse. The British had therefore to decide whether, notwithstanding all the objections to such a course, they should agree to place orders for American types or whether they should persist in the attempt to secure a separate niche, within the general framework of American munitions production, for the manufacture of at least some weapons of purely British type. Against the latter policy there were two arguments so obvious and decisive that to invoke them seemed almost superfluous. One was that it would mean foregoing the chance of American capital assistance for British orders. On 24th August there was an important meeting between British and United States representatives, the theme of which was 'the adoption of common types so as to create one productive capacity'. Here was renewed Morgenthau's offer to consider financing the manufacture for British orders so long as the United States were satisfied that the type of weapon manufactured for England was the same as the United States Army and Navy had adopted. If the United Kingdom pressed its own types, it did so at the risk of having to pay the whole capital cost as well as purchase the output and with no prospect of later American assistance. The other argument was the Administration's control over priorities and shipments. British supply representatives in America united in underlining the folly of trying to start separate British programmes which would be bound to take second place to production for the United States Services. For example, the better-known aircraft firms would -be unlikely to accept British orders in preference to American. It might, therefore, be necessary to fall back on untried and inexperienced firms. This would hardly be practicable unless the United Kingdom could provide fully equipped production teams, as well as much larger capital assistance. Moreover the United States Government was always in a position to bar British access to American firms, which it did temporarily in August I940 pending a settlement of the question of types. Purvis summed up the whole position as he saw it in a very important cable of 24th August. 'We believe that it is only if (as in the last resort will be inevitable) we agree promptly with the Americans on common types of weapons, so achieving complementary programmer, that we can hope to take advantage of the plan . . . whereby the American Administration finances our capital expenditure . . . or obtain United States consent to . . . priorities on deliveries.' The point about priorities was that the Administration would allow 'British' plants to be built and equipped more quickly than its own if, but only if, the material produced thereby could be diverted in case of need to its own use; also that it might sometimes release to the British material produced under its own contracts if it knew that there would be identical material coming along later on British contracts, from which it could be recouped
Overseas Supply, Hall, p.97-98.
​

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So at one point the US government called a halt to UK orders, if the UK would not agree to ordering US designs and this was when the UK was paying cash...the situation only got worse when lend-lease formally started. So the USN was in a position to veto the production of any RN spec weapons and FC equipment. WE have seen how USN DEs went to sea with no AA or surface FC equipment, even though the UK was outfitting all UK built Hunt class DEs with lightweight and effective FC equipment right from the start. Similarly the RN 4in twin was, IMHO, a better DE weapon than any built in the USA (3in/50 was too light and the 5in/38 too heavy) but while it was produced in Canada it was never built in the USA.

The US got "burned" in the First World War with too many of it's factories tooled up for French and British weapons/ammo that the US didn't want or couldn't use when it did declare war 1917. Granted the US 75mm field gun of 1916 was often called the "crime of 1916" but what the US "standardized" on was the British 18pdr field gun chambered/lined for French 75mm ammo. The US majority of US troops went to war not with the 1903 Springfield but with the 1917 Enfield ( a 30-06 version of the British .303 Pattern 1914) and so on through a variety of weapons. Or weeks/months were lost as factories re-tooled. The US was determined that that would not happen again.

Mistakes were made and the British 4in twin was a better DE weapon than the US 5in but making large numbers means something else not being made and complicating the ammo supply even more than it was.

yes, standardization was very important from a logistic point of view. Having a single calibre for main armament for destroyers and smaller made a lot of sense. If the 5/38 was the best that was available, but didnt quite suit the Escot Destroyers because of its size, it would have been even less satisfactory to have some ships using 4" and some the 5/38. It would still work, but it would place strains on the logistics system, not just in terms of ammo, but also in terms of a whole range of things....training, spare parts, capability. Putting the 5/38 on the DEs was a case of "good enough".


I dont have any problem in stating British Hunt Class Escort Destroyers were generally superior to the USN classes of DEs.

The problem for the RN was quite narrow. It lies with its "Fleet Destroyers". They were supposed to provide muti level defence for high level targets, and that meant being able to counterr threats from the surface, above the surface and below the surface. For a long time British Destroyers had a hard time providing effective fleet defences against air attack. They could defend themselves, and they could defens against other threats, but providing area air defence seems to have been a difficult task for them. Now, whether the USN could do it any better is in disopute, but for me, it seems clear that the USN filled that role better than the RN.

The USN destroyers had a hard time defending themselves off Okinawa - 5 sunk and 16 badly damaged.
Multiple attacks against any ship without aircover or mutual support are going to have a bad day.

That is part of the trouble with using combat results as a comparison. The "opposition" is not consistent. For that matter even the AA defense is not consistent.

The US Navy off of Okinawa was facing what were in effect, primitive guided missiles capable of different attack profiles. A much different threat than conventional aircraft (goal of the pilot was to get home).

Helping the US was the VT fuse which made the 5in/38 up to seven times more effective than using regular time fuses.

The 5in/38 might be remembered a bit differently without VT fuses. However it had the elevation, training and elevating speed (mostly) and rate of fire to make good use of them. Please note that is was more of a happy coincident than good planning, the VT fuse being little more than vague ideas when the 5in/38 was adopted.

Many Of the DD losses occurred because the USN were using radar pickets, some posted as far out as 60 miles from the main body, to provide advance warning of incoming attacks. The Japanese were using their suicide strikes very intelligentlyand were generally approaching from multiple directions and very ow in Altitude. The CAP was not being given enough warning of the approaching strikes, and as a consequence, whilst they were geneerally vectoring to intercept, were simply not given enough time to break up the incoing strikes. Placing radar pickets around the TGs allowed the CAP longer time to deal with the suicide attacks.

Unfortunatly, the down side of this initiative was that the picket destroyers whilst operating in pairs could not generate enough fire to prptect themselves fully. As the Japanese became increasingly desperate, many attacks targetted the Picket ships. Losses amongst these ships was heavy, amounting to about 20% of total USN DD losses for the entire war. However, for the work they were doing, this was judged a reasonable price to pay.

Fraser Rawling spent some time aboard a US Task Force flagship in 1945. I forget which one. What they saw for themselves changed the way they organized the defences of the BPF. The USN Carrier TGs were organized so as to maximize AA defences against high value targets, and theiir CAP was given a lot of time to intercept and engage the incoming strikes. Once within the flak zone they also witnessed the USc DDs providing effective and concentrated cover fire simulataneously from both the DDs main batteries and the 40mm CIWs. The smaller TDs of the USN heavy units meant that USN TGs could be more densely packed than the BPF (around 20% more tightly).....if you attacked a carrier in a USN TG, all the wepons in the support screen of that carrier could fire at you. The result was a very effective defence screen, in which the Destroyer screens played a critical part.

Fraser and Rawlings compared this very tight and effective defence to the efforts of the BPF. The BPF had a generally, man for man, more effective CAP, but it too was not being given enough time to react. The Brits generally used their LIII Sefires for the intercepts down low (and with its heavy firepower, high low level manouverability and climb rates it was probably the best a/c in the pacific for this purpose) whilst stacking their Hellcats and Corsairs further out and higher. But intercpets were still not happening quick enough. generally at the 30 mile range, this was just not enough to break up the typical suicide strike of 20-30 a/c.


Once the attackers did break through, the British admirals noted the inability of their own DD screens to operate as effectively as the US DDs in the area air defence role. There were a number of reasons for this. The low elevation of their main armament, the slow traverse and elevating speed, the unreliability and relative short range of their CIWs, the lack of effective incendiary rounds for them, the inability of the DDs to use both their Main HA armmanet and CIWs together, the inability of DD CIWs to always and uniformly provide cover fire over the core ships. Time and agin in March -April-May, the Kamikazes had broken through the British defences and caused damage to the precious carriers.

Fraser and Rawlings came up with solutions for these problems, and they followed closely the US pattern (but taking into account the limits of their own wepons) . The TD limits of the Capital ships were ignored to allow the 2 pounders of the escorts to get cover over the carriers, the inability of the 4.7s to fire at those close ranges was accepted. The British admirals pushed for the installation of 40mm Bofors to replace the 2 pounders which by then was all but an obsolete weapon ( wthe replacement of the 2 pounder with the 40mm Bofors was happening progressivley by wars end),. But it was also acknowledged that the BPFs best defences against the Kamikazes were the airborne CAPs, and in the current situation they were not being given enough time or space to have full effect. It was very quickly realized that pickets similar to the US sytem were needed. However, unlike the Americans, who saw their better armed DDs as having some chance at self defence the british never considered placing unprotectd DDs alone in the picket screen. Instead they intended (or may have actually done it) to form two picket screens, each centred around a cruiser and 2 x DDs with 2-4 fighters flying constant air patrols over them

The 20mm gun was being replaced progressively by the Bofors but the pom-pom was also being used in the new power single mounts on many new built destroyers. Given equal firecontrol to the Bofors, the pom-pom was an effective weapon against Kamikazes and much better than the 20mm.

USN picket destroyers were generally their later classes, which being much larger than RN destroyers had no equivalent in the BPF, especially as the Battle class were delayed in entering service. In any event using DDs as pickets was a bad idea, that the USN could get away with because they had so many destroyers by 1945.

Without seeing their action reports, I cannot comment of the performance of RN destroyers during the Kamikaze attacks, but Kamikazes certainly did penetrate the dense screens to hit USN CVs, often with disastrous results.

I think you will find that some of the USN DE's were used as picket ships, it wasn't just the latest Fletcher and later classes of destroyers.

The USN got away with it as you put it, because their ships had a good chance of surviving. Its also worth remembering that the USN were not just protecting the CVN but often very vulnerable CVL and invasion fleets. The pickets detected the incoming attackers and directed the fighters to intercept. Often the attacking aircraft picked on the destroyers because they couldn't get to the main targets the fleet and knocking out the radar pickets was a valid tactic.

Re
In any event using DDs as pickets was a bad idea,
Clearly if you are going to withdraw the pickets then the defending forces are are going to have less time to respond to the threat. The less time you have to react, the attacks will be closer before being intercepted. The more concentrated and organised the attack, the more attacking aircraft are going to get through and the higher the losses.

What would be a good idea?

Glider said:

I think you will find that some of the USN DE's were used as picket ships, it wasn't just the latest Fletcher and later classes of destroyers.

The USN got away with it as you put it, because their ships had a good chance of surviving. Its also worth remembering that the USN were not just protecting the CVN but often very vulnerable CVL and invasion fleets. The pickets detected the incoming attackers and directed the fighters to intercept. Often the attacking aircraft picked on the destroyers because they couldn't get to the main targets the fleet and knocking out the radar pickets was a valid tactic.

Re
In any event using DDs as pickets was a bad idea,
Clearly if you are going to withdraw the pickets then the defending forces are are going to have less time to respond to the threat. The less time you have to react, the attacks will be closer before being intercepted. The more concentrated and organised the attack, the more attacking aircraft are going to get through and the higher the losses.

What would be a good idea?

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I think the ideal would be a CLAA such as Dido or Atlanta class as even lightly armoured ships were nearly impossible to sink via kamikaze strikes. The other possibility would be old BBs outfitted with a very heavy CIWS. However, the USN really "got away with it" because they considered their DDs expendable, much as the RN did in Norway and the Med. For the USN Okinawa was "the tip of the spear" where they concentrated the bulk of their fleet, whereas for the RN it was a secondary theatre until after the German surrender, and by then the RN had shot it's bolt, militarily speaking, since they had been at war for 2 1/2 years longer than the USN. Although if the bulk of the 1945 RN had been concentrated around Okinawa they would have had the ships to expend as well.

The pickets were used as a way of detecting air raids - conventional and Kamikaze at a distance from the main fleet.
I would suggest that some of the pilots given their lack of training would attack the first target they found - the pickets.
If they tried to attack a carrier of any sort or troop ships etc, they would have to try to evade the CAP and an intense AA barrage - giving them less chance of success.
I believe the USN had in its plans to build radar stations on land so that the pickets could be moved back to a safer location?
Also, a change in top brass made a shift in emphasis from detecting aircraft to laterly destroying them.
This change in emphasis would probably put the destroyers at greater risk?

Part of the problem with many books dealing with WW2 destroyers is that they praise the USN for developing a HA 5in gun, and damn the RN for not doing so, but then in the same breath admit that the HA 5in guns were useless against dive-bombers or other close range attacks:

On the other hand, US pre-war destroyer designs did not include provision for many automatic AA weapons, partly because the slow development of the 1.1in machine gun made this a moot point for many years. The 5in gun was considered useful for breaking up horizontal bombing formations, and perhaps for dealing with torpedo bombers flying at low level (eg by firing into the water to create splashes); but it was useless as a counter to the two other major airborne threats, the dive bomber and the strafer. Against the latter, most pre war destroyers were armed with the .5in warer-cooled machine gun. The l.lin weapon was intended to deal with dive bombers, but pre-war destroyers generally limited by treaty to 1500 tons could not accommodate it, the only exceptions being the 1850-ton destroyer'Leaders'. By 1937 many people in the feet wanted the 1.1in gun aboard destroyers, but that appeared impossible until the design of the large Fletchers. 'Impossible' turned out by 1941 to mean rather 'impossible unless some other weapons were sacrificed', and much of the story recounted here is the story of the variety of 'trade offs' made between traditional destroyer weapons and the weapons required for close range air defence.
Destroyer Weapons of WW2, Hodges, Friedman, p106.

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So the RN developed the Tribal and JKN class DDs with DP 4.7in guns to engage level bombers and torpedo bombers and equipped their destroyers with an extremely heavy CIWS (by pre-war standards) of 8 .5in MGs and 4 x 40mm pom-poms (which the USN considered superior to the 1.1in) and then receive very faint praise for their efforts.

The 20mm gun was being replaced progressively by the Bofors but the pom-pom was also being used in the new power single mounts on many new built destroyers. Given equal firecontrol to the Bofors, the pom-pom was an effective weapon against Kamikazes and much better than the 20mm.

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This is in direct contrast to the recommendations of Fraser and rawlings. They found the Pom Pom to be severely limited on the DDs attached to the BPF. It lacked effective range, lacked effective Tracer capability and was too prone to james. They wanted the Bofors AND the POM PoMs replaced with the bofors. they were provided

USN picket destroyers were generally their later classes, which being much larger than RN destroyers had no equivalent in the BPF, especially as the Battle class were delayed in entering service. In any event using DDs as pickets was a bad idea, that the USN could get away with because they had so many destroyers by 1945.

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They were only "generally the later classes" because the later classes greatly outnimbered everthing else. Tough break for the BPF, but the ships in the British Fleet, such as the Q classes were only as old, or even newer than some of the Fletchers serving in the Picket lines.

Without seeing their action reports, I cannot comment of the performance of RN destroyers during the Kamikaze attacks, but Kamikazes certainly did penetrate the dense screens to hit USN CVs, often with disastrous results.

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Youve got the reports submitted by Rawlings and Fraser, which give a detailed ccount of their performance to the Admiralty. And we know from the results of those attacks in that time period the level of success they enjoyed (time and again Kamikazes broke through....so too did the Americans, but they appear to be suffereing much heavier levels of attack). Against even single attackers, the BPF destroyers were unable to bring 4.7 fire to bear, could not use their CIWs at all times, and were unable to bring mutually supporting combined fire to bear over the Carriers. Saying you need to see the actual battle reports is a cop out in my opinion. Their commanding admirals already submitted some good details of their performance, you just choose not to take any notice of them.

RCAFson said:

Part of the problem with many books dealing with WW2 destroyers is that they praise the USN for developing a HA 5in gun, and damn the RN for not doing so, but then in the same breath admit that the HA 5in guns were useless against dive-bombers or other close range attacks:

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Remembering that all HAA was useless against dive bombers before the proximity fuse.

So the RN developed the Tribal and JKN class DDs with DP 4.7in guns to engage level bombers

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Remembering that the RN only had approx 35-40 seconds to engage the level bombers and couldn't touch them when they dropped their bombs
This is worth considering when the proximity fuse arrives. The RN 4.7 still only has 35-40 ish seconds to fire whereas the US 5in can give now effective fire down to the last second.

and equipped their destroyers with an extremely heavy CIWS (by pre-war standards) of 8 .5in MGs and 4 x 40mm pom-poms (which the USN considered superior to the 1.1in) and then receive very faint praise for their efforts.

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This bit I do agree with

Note to one and all. The advantage of destroyers is that they were considered expendable by all navies.

parsifal said:

This is in direct contrast to the recommendations of Fraser and rawlings. They found the Pom Pom to be severely limited on the DDs attached to the BPF. It lacked effective range, lacked effective Tracer capability and was too prone to james. They wanted the Bofors AND the POM PoMs replaced with the bofors. they were provided


They were only "generally the later classes" because the later classes greatly outnimbered everthing else. Tough break for the BPF, but the ships in the British Fleet, such as the Q classes were only as old, or even newer than some of the Fletchers serving in the Picket lines.


Youve got the reports submitted by Rawlings and Fraser, which give a detailed ccount of their performance to the Admiralty. And we know from the results of those attacks in that time period the level of success they enjoyed (time and again Kamikazes broke through....so too did the Americans, but they appear to be suffereing much heavier levels of attack). Against even single attackers, the BPF destroyers were unable to bring 4.7 fire to bear, could not use their CIWs at all times, and were unable to bring mutually supporting combined fire to bear over the Carriers. Saying you need to see the actual battle reports is a cop out in my opinion. Their commanding admirals already submitted some good details of their performance, you just choose not to take any notice of them.

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Here's the Despatch from Fraser and Rawlings:
http://www.ibiblio.org/hyperwar/UN/UK/LondonGazette/38308.pdf

I can't find any real criticism of RN AA or weaponry. Here's a few pertinent excerpts:

One Judy and another unidentified enemy
plane flying low were engaged by destroyers of
4th Destroyer Flotilla on the screen, one being
hit by gunfire. Corsairs and Hellcats closed the
Judy and shot it down in flames after it had
jettisoned its bomb. The other, plane was seen
in flames on the horizon about five minutes later
and is considered to have been destroyed by
the 4th Destroyer Flotilla. A second Judy
orbiting the Fleet at about 10 miles range was
intercepted by Corsairs and Hellcats and
splashed.
Most regrettably one Seafire was shot down
by gunfire of the Fleet, during the raid: the
•pilot was not recovered



10. Air attack on the Fleet. On those occasions on which hostile aircraft have penetrated
the fighter defence's of the Fleet the sky has
been in general overcast, whilst there has been
a longstop CAP essentially maintained over
the Fleet under the cloud base.
There has never been a group at which to
fire,. not more in fact than a single aircraft;
thus there has been little opportunity to use
heavy artillery: gunfire has 'been in the main
restricted to flak, and, as this is little deterred
•by alterations of course, and because the time
between the enemy descending through the.
cloud base and his arrival onboard is small, it
has been my practice, unless necessary to
operate aircraft, to keep the Fleet almost
continuously under rudder during such attacks.
The U.S. Fleet, I understand, do the same...

At 1142 another Zeke dived steeply on H.M.S.
INDOMITABLE whose close range weapons
and those -of HM.S. QUALITY hit him hard
and often. The aircraft burst; into flames and
crashed into the sea about 10- yards off the
starboard bow of the ship' <my note: Quality had pom-poms and 20mm guns>

...Airborne opposition in the target areas — there
was none, whilst airborne attack was confined
to small groups of Kamikaze, who split up 30
or 40 miles from the Fleet and in their approach
through cloud, formed, difficult targets, either for
fighter interception or for gunfire...

...At about 1100 three small groups of bogeys
were detected to the westward, and were soon
.followed up by a fourth. - Probably 16 -to 20
enemy aircraft were . employed with some
acting as decoys. Fighters engaged one
group working round to the southward, but one
Kamikaze group penetrated to the carriers and
was first detected when a plane was seen diving
on the Force. Analysis shows that this group
escaped detection either because, in the absence
of the Bombarding "Force, too many' of the
reduced number of radar sets were fully
engaged-tracking the diversionary planes' and
too few acting as warning sets, or else because
they made a very low approach followed by a
'very high climb at about 15 miles range.
There were no bandits on the screen within
20 miles when at 1131 a Zeke was seen diving
from a great height on to H.M.S. FORMIDABLE and engaged by gunfire.
A.C.I thereupon manoeuvred his Force under wheel at
high speed by successive emergency turns.
Though reported hit by close range weapons
from' -his target, the Kamikaze crashed into the
flight deck of H.M.S. FORMIDABLE near-the
•island structure arid started a large fire in
the deck park of aircraft. • A.C.I manoeuvred
the formation to keep in close touch with the
damaged) ship, whose speed was temporarily
reduced to 18 knots...

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In fact the BPF did use pickets, and they generally used a CL and DD together.

That USN picket destroyers were larger than their RN counterparts is a fact, but the main point is that a larger hull always allows for a much more capable CIWS and it is difficult to make valid comparisons between ships of greatly different displacement and dimensions. I have no doubt that, in terms of treaty limited designs, RN destroyers were superior to their USN counterparts in terms of overall balance between AA and surface fire.

Glider said:

Remembering that all HAA was useless against dive bombers before the proximity fuse. Remembering that the RN only had approx 35-40 seconds to engage the level bombers and couldn't touch them when they dropped their bombs
This is worth considering when the proximity fuse arrives. The RN 4.7 still only has 35-40 ish seconds to fire whereas the US 5in can give now effective fire down to the last second.
This bit I do agree with

Note to one and all. The advantage of destroyers is that they were considered expendable by all navies.

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At 9000ft ( at which altitude, and at a speed of 150 knots (172mph),IIRC, IJN level bombers scored hits on PoW, Repulse and Hornet ) a 240mph bomber could be engaged for about 50 seconds with a 40deg 4.7in and about 65 seconds at 6000ft so, as the altitude of the level bomber decreases to increase it's accuracy, so to does the time under fire.
Remembering that high altitude level bombers posed little threat to manoeuvring ships at sea, it doesn't make sense to optimize a destroyer for that threat alone, at the expense of a large reduction in surface firepower and a strong CIWS which was the only counter to divebombers. I have argued that the optimal compromise between gun elevation and weight increases occurs at around 55degs, which the RN adopted for the last variants of the 4.7in single and first version of the 4.5in single but IMHO 40degs with a heavy CIWS is better than 85degs with a handful of HMGs for a CIWS and a 50% reduction in main armament.

Your looking and quoting the wrong report.

I refer you to JR Webb – The British Pacific Fleet Experience and Legacy 1944-50 In the Chapter titled "Air Defence" for the period March to May he says the following

"British AA defence procedures had grown out of the RNs pre- war experience and it operations in European waters. Before the outbreak of war the RN had doubted defensive fighters could be directed to successful interception due to the speed at which air attacks could develop, and this led to little attention being given to this role. The development of RDF and its potential to assist a fleet in dealing with air attacks was clearly demonstrated in the fleet exercises of 1939 and the fighting instructions issued shortly after included fleet dispositions to optimise its effect.

The RN had developed its method of defending vessels at sea from air attack under the particular circumstances of the (ETO). But whereas AA fire from 2 pdr and 20mm guns could interfere badlly enough with a pilots aim to make his chances of hitting with a bomb or torpedo more difficult in that TO, in the PTO, when faced with suicide planes these weapons showed a marked inability to actually destroy the aircraft. This was seen as a major problem by the commanders on the scene. Kamikazes would approach at high speed and would not veer off if damaged. The Americans had found that their 40mm guns could break up attacking planes and the british discovered for themselves that (their weapons) could not. The british discovered that they had a desperate need for (the Bofors) to replace their inadequate and underpowered LAA. Fraser wrote

"The armament of our Destroyers has been designed primarily from an anti-ship point of view and generally speaking they are as the Americans would say 'not able to look after themselves"

Indeed, when Fraser came to write his report on the lessons learned by the BPF in the Okinawa campaign he said

"The standard of AA gunnery by our destroyers was low which could be offset by training and requipment ….."

Webb again

"Although armoured decks had saved the BPFs carriers, it was abundantly clear that Kamikaze attacks required a change in tactical thinking. Rawlings acknowledged that the kamikaze attacks had placed a premium on fighter interceptions being carried out at maximum possible range…..he wrote in his report

"Operations were revealing that US pattern defensive dispositions were superior to our own, but a conventional US pattern AA screen (was difficult for us)….there were difficulties in providing fire support over the main body (by our Destroyers). "


Webb
"Rawlings partially addressed this by adopting a new screen disposition, which was more densely packed (to attempt to allow the escort to place supporting fire over the main body). Speaking after the actions of 9 May, Rawlings stated "The object of these new dispositions were in evolved in response to our experiences and had the object of giving better protection to the carriers during suicide attacks." But these new dispositions led to station keeping and manoeuvre inflexibility and led to Rawlings advocating the re-equipment with 40mm Bofors as the chief LAA as well. Secondly".

Webb then comments on the BPFs efforts to develop effective picket forces.

"The USN had utilised radar to a greater extent in their light forces than the RN. Radar equipped ships were utilised as advanced warning pickets. These pickets were seen as central to the BPFs overall air defence response to Kamikaze attacks. Each picket was initially to contain 4 DDs and 4 Fighters was stationed 40-60 miles from the fleet to cover an arc of 180 degrees in the most likely direction of attack. These DDs were specially equipped with radar and fighter direction equipment, but the BPFs response was technologically inferior to that of the USN. The Directorate of air warfare and flying training decided in July to fit out cruisers to perform the same function and provide similar levels of defence to the picket line. Cruisers were considered better able to protect themselves and the existing fleet destroyers radar was not efficient enough in his assessment. The Director Of radio Equipment at the time commented that the number of aircraft involved was swamping the Action Information Organization (AIO) and radar identification . despite the fact that the RN had assisted earlier in the war, in the introduction of AIOs (CICs in the US parlance) the clear superiority of US C&C in this field was another example of the Americans being able to bring to bear more resources to develop an idea faster and better than the RN could ever hope to achieve".

In commenting on the improvements to air defence Webb states that the BPF still lagged behind the USN, but the improvements that had been achieved were cause for some satisfaction. "The AA defence of the TF had also seen important improvements. In mid-May Rawlings reported to Fraser, advising that the BPF had been devoting much of its exercise time and resources to the introduction of new air defence technologies, techniques and procedures, with pleasing results. In particular he drew attention to the new VT fuses. He wrote

"We do depend on this VT fuse now. All our recent training has been centred around them. The improvements in equipment, radar, fighter direction (have achieved astounding improvements)"

Webb
"The British had been developing VT fuses for use in bombs and rockets , but had convinced themselves the technical problems in making such fuses rugged enough to be fired from a gun were at that time (too difficult)

parsifal said:

Your looking and quoting the wrong report.

I refer you to JR Webb – The British Pacific Fleet Experience and Legacy 1944-50 In the Chapter titled "Air Defence" for the period March to May he says the following...

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I see Webb stating his opinion of the pom-pom, but with no supporting evidence for that statement, which runs counter to Campbell and to commonsense; multiple pom-pom hits would tear apart any IJN aircraft just as Bofors hits would, albeit the Bofors would require fewer hits but then a quad pom-pom has a greater volume and density of fire, than a twin bofors MK V, which weighed about the same. The USN's own experience showed that the Bofors could not be relied upon to stop kamikaze aircraft, and we've all seen film footage of kamikaze's penetrating USN screens to hit their carriers even after being hit by 5in and 40mm fire. Fraser's and Rawlings statements regarding the nature of kamikaze attacks and their ability to evade detection seems to indicate that the armament of RN destroyers was not the problem, and if the USN had superior radar or CIC, this is not a reflection on RN destroyers.

Webb is wrong about UK development of the VT fuze - UK development of VT fuzes to fit AA guns proceeded before and after turning over their technology to the USA via the Tizard mission, but part of the quid pro quo of giving VT technology to the USA was that the development and output of north american VT fuze production would be shared with the UK, with the RN receiving 2nd place in priority after the USN. Consequently, the development of VT fuzes received lower priority in the UK than previously, since two full development programs in the UK and USA would have been a huge duplication of effort. The Deadly Fuze has a good summation of the UK effort.

Its not just webbs opinion. he is fleshing out and reaffirming those held by Rawlings and Fraser, and quote them to support his statements . And campbell does not say what you are claiming he does. In fact whilst Campbell does say alot about the technological operation of the weapon, he is pretty silent about its value (the 2pounder) .

He does say, however that the type had serious problems with relatively low muzzle velocity, though some mountings and later gun types in the family did addresse this at least partially. As to common sense, well, thats a matter of opinion really, but a genuinely friendly piece of advice, I would not start running around spriuiking that this or that source lacks common sense. What do you think the other contributors would say if they were asked who was lacking common sense (and experience) in this debate....... for what it worth I think I am lacking in common sense and judgement for even getting mixed up in this debate..... .

The Pom Pom could not operate as effectively as the bofors because of the limits of the gun. It was not a good area defence weapon at all really, which is why is was obsolete by wars end. It was shorter ranged and the loadout of the ammunition more restricted. It had some serious relaibility issues. Pom Poms, whilst better able to provide some cover fire over high value targets than a 0.5 or 20mm cannon, , were still too restricted in their effective range (at least in the DD fit outs) to do this job as effectively as the longer ranged and more lethal Bofors.

no-one is saying that the 5/38-bofors combinination was completely effective. The USN thought it needed a heavier punch than either could deliver,m which is why they spent so much time and effort working on a 6" DP weapon. Determined Kamikazes could still penetrate the screens even with Bofors and 5/38 blazing away as hard as they could. But the british Admirals at the scene thought they had greater capability than their own equipment, which they saw as part of the problem, along with, as you say, the shortcomings in their DD radar fitouts.

There is some information on the philosophy of RN DD design with respect to anti-aircraft guns at http://www.royalnavalmuseum.org/documents/SB45_Autumn2012.pdf. It is too short but seems interesting.

A great find IMO

Dosent confirm that either side of this debate is completely correct. My opjnion on its key points.....the RN was correct and adequately armed in the pre-radar age, though its choice of weapons was poor. It relevantly quotes Friedman...."Norman Friedman, in 'British Destroyers and Frigates' (2006) writes 'Once war broke out, it became painfully obvious that the 40˚ 4.7" gun, was an inadequate AA weapon' (p34). Yet later (p113) Friedman acknowledges that wartime experience tended to confirm the pre-war view that arming destroyers with 'High Angle' main armament imposed a significant weight penalty for no real benefit".

This commentary would suggest that by 1945, the USN and the theory of air defence had bypassed the RN and its oudated equipment.