Destroyers.....

[RCAFson]

I was aware that section 2 does deal with the 4in gun, but this particular extract refers to all dead times, for both claibres, , not just not just the 4in.


We dont know about the 4.7 twin, but it has the same published rof as the 1936 models. Power ramming still requires hand loading and can involve innefficiencies because of the poor placement of the shell hoppers, so I have to disagree with you. the power rammer might add or improve fireing cycle by 1-2 seconds over the older mounts but that still brings it in at somewhere below 12 rounds per minute. Given that 12 is already an indaequate number, the conclusion whether it be twin mounting or no, remains the same.

If as I suspect the older models at non-optimal elvations can only fire at around 6 rpm, and power ramming improves that practical rof by say 1-2 secs, then you might get 8 rpm. still within the original estimate for practical rof of 4-8 rpm. 4 for the really old versions, 8 for the newer twins.

Sorry, still dont agree with you. Far too rose coloured a view of the RN capabilities in my book.

Look, I've provided abundant data regarding the RoF - 5 rounds in 17 sec for Basylisk in 1930 - 180 salvos from Kimberly at Narvik, most with a 5 sec loading cycle - 15rpm for the 4.7in Mk VIII- 3000 rounds from Illustrious at an average of 12 RPM - 16 RPM from Scylla...all these guns had essentially the same loading tray system, except that the last 4 all have power ramming. It is time for you to get off this pot and accept the facts . There is no rose coloured views here , just a lot of hard digging and research.

and another:

The day by day hum drum of her "working up" period, prior to her joining the Home Fleet at Scapa Flow, would make most uninteresting reading except the mention that she became, by virtue of her latest type radar, exceedingly rapid rate of gunfire (16 round per minute) and high speed, a very efficient ship. An efficiency that was to be a saving grace to her in her hectic times to come.
http://www.naval-history.net/WW2Ships-Charybdis.htm

 

[Glider]

The RN didn't have pom-poms, 20mm and 40mm bofors guns gathering dust that could be used to quickly augment destroyer AA, but they did have lots of older 3in and 4in guns that were not being used - sorry but that is the way it was. A 3 or 4in gun fired over open sights against an aircraft is no more accurate than any other gun fired with the same method; a pom-pom or bofors would have a much better hit probability because of the high RoF.

A lot of truth in this but the 20mm were added pretty quickly, when would depend on the ship and availablity. I don't disagree with your description of the value of the effectiveness of the single 4in added in some destroyers.
What I disagree with, is your position that these were additions to the short range aa guns. All they were were are inaccurate longe range guns, useless against close range fast moving targets.

A slightly amusing aside. There was an obituary in the paper a few months ago. He had served in destroyers during the war and had to live with the somewhat embarrassing nickname 'Annie' all through his naval career. As a young officer he was put in charge of the 4in installed instead of the torpedoes and by absolute fluke shot down a Ju88 with the third shot. Everyone knew this was something close to a miracle and was given the nickname after Annie Oakley. He often said how much he regretted shooting down the Ju88

 

[parsifal]

Look, I've provided abundant data regarding the RoF

And all of it, for one reason or another has been misinterpreted.

5 rounds in 17 sec for Basylisk in 1930

peacetime conditions, optimum elevation, no turret elevation or training to worry about. I bet they were a crack gun crew.

180 salvos from Kimberly at Narvik, most with a 5 sec loading cycle

Not in an AA role. and against targets not really moving at least some of the time. Not relevant to what we are discussing

15rpm for the 4.7in Mk VIII- 3000 rounds from Illustrious at an average of 12 RPM

Ilustrious was armed with 4.5 in guns. a completely differnt kettle of fish and not a destroyer anyway 12 rpm is still too slow to be effective

16 RPM from Scylla...all these guns had essentially the same loading tray system, except that the last 4 all have power ramming.

Scylla was armed with 4.5 inch guns. ive never questioned the rof of the 4.5 gun. Scylla was a cruiser. youve claimed repeatedly that the 4.7 gun had the same loading tray system, but wont recognize or acknowledge that at least one source does not agree with you. Even on the basis of max rof, the 4.5 is rated at 20rpm, whilst the best 4.7s are rated at 12 rpm. how can that be the same?

It is time for you to get off this pot and accept the facts .

Ive accepted the source material youve produced. what I have challenged, is your interpretation of those facts. When you get confronted by legitiamte questions and critiques you try every form of bluff bluster and bullying tactics you can think of. Wont work with me. You have not succeeded in convincing me. So what. I have questions you cant answer IMO. We can and should agree to disagree and leave it at that. its a difference of opinion, nothing more. I dont have to get off anything, and i dont have to move away, or accept anything. Im not losing my temper. Im enjoying the debate and the exchange of ideas to be honest. i am sorry if the discussion is upsetting you, seriously I am, but a tantrum is not reason for me to change my opinion. Ive happily conceded a number of points where I think you are are correct, and thats good. ive not denigrated in any way your source material. In fact im impressed with it. The one area where we have disagreed is in the interpretation of the data. get over it. its just a discussion, and opinions on the known data.

There is no rose coloured views here , just a lot of hard digging and research.

Yes, and I have and wil again commend you on the quality of the material you have produced. Well done. Thats not the issue. its the interpretation of the data. Me not accepting your opinion does not or should not affect how you view that material if you dont want to accept my point of view.


Charybidis was a cruiser, armed with the 4.5 in gun which I have already commented on. a different gun, with a different published max rof, and specifically developed to address the known weaknesses of the 4.7 in weapon. Again, if anything just serves to underline or provide background evidence that the 4.7 was not a good DP weapon, in any of its forms.

 

[RCAFson]

And all of it, for one reason or another has been misinterpreted.

peacetime conditions, optimum elevation, no turret elevation or training to worry about. I bet they were a crack gun crew.

5 rounds in 17 seconds = a cyclic rate of 17.6 rpm. OK, then an average crew should be able to do 10 - 12 rpm.

Not in an AA role. and against targets not really moving at least some of the time. Not relevant to what we are discussing

Kimberly certianly did engage moving targets and did so while moving rapidly herself, and again I reduced the AA rof to 10 rpm in my calculations

Illustrious was armed with 4.5 in guns. a completely differnt kettle of fish and not a destroyer anyway 12 rpm is still too slow to be effective

Scylla was armed with 4.5 inch guns. ive never questioned the rof of the 4.5 gun. Scylla was a cruiser. youve claimed repeatedly that the 4.7 gun had the same loading tray system, but wont recognize or acknowledge that at least one source does not agree with you. Even on the basis of max rof, the 4.5 is rated at 20rpm, whilst the best 4.7s are rated at 12 rpm. how can that be the same?

Navweaps states:

Britain
4.5"/45 (11.4 cm) QF Marks I, III and IV
(Marks 2, 3, 4 and 5)
Twin mountings of World War II: 12 rounds per minute per gun

I've produced evidence that the gun could fire at an average of 12rpm for very long periods and up to 16rpm.

Ive accepted the source material youve produced. what I have challenged, is your interpretation of those facts...

While I'm challenging your interpretation of the facts and I supported my contentions with lots of data - I'm not bullying but you'll have to admit that trying to swim upstream against the bull that Navweaps would have us swallow is no easy task.

Charybdis was a cruiser, armed with the 4.5 in gun which I have already commented on. a different gun, with a different published max rof, and specifically developed to address the known weaknesses of the 4.7 in weapon. Again, if anything just serves to underline or provide background evidence that the 4.7 was not a good DP weapon, in any of its forms.

I've produced evidence that the gun could fire at an average of 12rpm for very long periods and up to 16rpm maximum. The 4.7in twin and 4.5in twin gun mountings and loading facilities were almost identical:

4.7in twin - note the fuze setting pedestal located right beside the loading tray.

4.5in twin BD mount (Illustrious)- if the 4.5in BD housing was removing, you'd never be able to tell them apart. The actual loading tray and breech mechanisms are virtually the same, the only real difference is the higher trunnions (pivot point) on the 4.5in twin.

 

[RCAFson]

USS Benham at Eastern Solomons:

Benham opened fire with 5" anti-aircraft barrage"; initial range 5,000 yards (altitude 12,750 feet), and 20 m.m. fire.

1714 -- Enterprise observed to be hit by bombs.

1720 -- Ceased firing.

Of the approximate twenty (20) planes making the attack, which came within range of anti-aircraft batteries, nearly all were shot down in the vicinity of the Enterprise. Several of these planes were fired upon by this ship and adjacent ships in formation. About four (4) were seen to attempt to escape and were pursued by our fighters. The Enterprise appeared to be the sole target of the attack except for four (4) dive bombers, who, attempted to bomb the North Carolina, and were promptly shot down.

There were no casualties to either personnel or equipment of this vessel.

Ammunition expended:

5"/38 - 109 rounds
20 m.m. - 510 rounds
http://www.ibiblio.org/hyperwar/USN/ships/logs/DD/dd397-ESols.html

Some comments - note they they used "barrage fire" A JKMN class could have engaged the same target, but would have had to open fire before 6000 yds and she would have been able to place a barrage over Enterprise (which is what happened) that the DBs would have to fly through. Note the small ammo expenditure. This is the same battle where Crenshaw of USS Maury stated that they were unable to engage the IJN aircraft because of the ineffectiveness of the Mk 33 GFCS.

Some more from the same report:

Comment on material:

There were no material failures.
The main feed pumps are in such a condition, that their reliability is uncertain. Early installation of new main feed pumps, already ordered by Bureau of Ships, is necessary for battle efficiency.
The main generators overheat excessively in tropical waters, when the load of battle requirements is placed on them. An improved cooling system is urgently required.
The open-sight for director pointer is inefficient. An improved design is needed to aid in getting director and guns on rapidly moving air targets.
The temporary installation of number two 20 m.m. gun on the midship deck house, frame 99, enabled that gun to fire effectively, twice as many rounds as guns 1, 3 4.
During the greater part of the first eight months of war operations this ship has been one of a carrier screen. This ship has only four (4) 5 inch and four (4) 20 m.m. guns. In both the MIDWAY and SOLOMON (STEWART) battles the need for additional anti-aircraft guns was readily apparent. It is again recommended that additional 20 m.m. guns, or, 40 m.m. guns, be installed; and if necessary for weight compensation, eight ( 8 ) of the sixteen (16) torpedo tubes now carried, be removed.

Note the very light CIWS for Aug 1942 - a JKMN would have a quad pom-pom and 2 - 4 20mm, and a HA 4in single in the same time frame, but even in 1939 the CIWS of a quad pom-pom and 2 x quad .5in was a superior CIWS.

27 AA claims were made, including 5 by the destroyers while the USNI summary states that maybe 15 were shot down by AA. Lundstrom estimates that about 5 IJNAF aircraft, in total, were shot down by AA. Again the clumsiness of the Mk 33 is pointed out.

 

[Glider]

USS Benham at Eastern Solomons:


Some comments - note they they used "barrage fire" A JKMN class could have engaged the same target, but would have had to open fire before 6000 yds and she would have been able to place a barrage over Enterprise (which is what happened) that the DBs would have to fly through. Note the small ammo expenditure. This is the same battle where Crenshaw of USS Maury stated that they were unable to engage the IJN aircraft because of the ineffectiveness of the Mk 33 GFCS.

More interesting stuff from you, I wish I had a spare day or two to go through your books. One important observation, the USS Benham opened fire at 5000 yards at a target flying at approx 12,500 ft. Looking at the chart you included in posting 123, a JKN/Tribal using the twin 4.7 would have had to cease firing at about 7,500 yards and could only open fire at about 11,000. In other words the chances of being damaged by the 4,7 would be very slim as the destroyer only had about 35 seconds to get the range, and at the point of bomb release the bomber would have been untroubled.

 

[Glider]

An observation on the Twin 4.5 and the Twin 4.7 mountings. There was one significant difference between them, the twin 4.5 used a fixed shell and the twin 4.7 a seperate shell. This must have made fairly major changes in the loading arrangements

 

[RCAFson]

An observation on the Twin 4.5 and the Twin 4.7 mountings. There was one significant difference between them, the twin 4.5 used a fixed shell and the twin 4.7 a separate shell. This must have made fairly major changes in the loading arrangements

Not really. With the one piece shell, the entire round was placed into the loading tray. With the separate round the cartridge and then shell were placed in the loading tray. as you can see from the photos, the loading tray is much the same for both. Fuzing the separate round is probably easier.

BTW, I found the photos here:

Vickers Photographic Archive

 

[RCAFson]

More interesting stuff from you, I wish I had a spare day or two to go through your books. One important observation, the USS Benham opened fire at 5000 yards at a target flying at approx 12,500 ft. Looking at the chart you included in posting 123, a JKN/Tribal using the twin 4.7 would have had to cease firing at about 7,500 yards and could only open fire at about 11,000. In other words the chances of being damaged by the 4,7 would be very slim as the destroyer only had about 35 seconds to get the range, and at the point of bomb release the bomber would have been untroubled.

In this particular action, very few ships actually sighted the IJN aircraft prior to their dive (they were tracked on radar but lost as about 16000 yds) SOP for the RN would have been an "umbrella barrage" over the carrier, which seems to be what happened:

The Enterprise radar lost track of the enemy group when it came within its minimum range, but, on the basis of previous tracking, radar plot reported at 1709 that "the enemy planes are directly overhead now!" In spite of this warning and the excellent visibility, the first plane was sighted after it already had entered its dive. Effective enemy plane camouflage and the fact that the first dives were made on the Enterprise from the port quarter, out of the sun, probably accounted for this belated visual contact. In the case of the Enterprise, the first plane was sighted at 12,000 feet by a 20-mm. battery officer. Although the target was well beyond effective range, he promptly opened fire with one gun, thus calling the ships' attention to the attacker and giving them a point of aim.
HyperWar: The Battle of the Eastern Solomons [ONI Combat Narrative]

I checked the 4.7in engagement drawing carefully, and I get minimum range of about 6000 yds for 12750 ft altitude, but yes, potentially, there would be a few thousand yards where the destroyers would not be able to engage the aircraft with predicted fire, prior to the barrage.

 

[parsifal]

I propose that we leave this sub debate about British and US DDs to one side. weve done it to death, and stil cannot reach agreement. I would like to discuss the destroyer techs of some of the lesser navies like the Russians and French

I dont know much about them, so would hope that other memebers step in and give us some insights.

Fire away gentelemen

 

[Glider]

I checked the 4.7in engagement drawing carefully, and I get minimum range of about 6000 yds for 12750 ft altitude, but yes, potentially, there would be a few thousand yards where the destroyers would not be able to engage the aircraft with predicted fire, prior to the barrage.

I was allowing time fior the shell to arrive as the 6,000 yard is the last shell burst. However the chart is very clear in that the time between the earliest shell burt and the last shell burst is about 35 seconds. It would be the shortest and least effective barrage fire in history.

 

[Glider]

All I kniow is that the italian destroyers had similar weapons as the British 4.7 (none DP) and the 20mm was quite well thought of. The French weapons looked quite modern even by todays standards but were very, very unreliable.

 

[parsifal]

Soviet destroyers were based loosely on Italian Destroyers, but the Soviets upgunned themn to a 5" calibre. The first interwar design, the Leningrad class were a bad design, but thereafter there were gradual improvements, such that by 1945, they were considred quite good. The Soviet Destroyers did some good work in the Black Sea and in the far north. In the Baltic they suffered pretty heavily from mines mostly. They dis carry out a number of Dunkirk style evacuations, but with heavy losses. I vaguely recall they undertook the evacuation of the Hango peninsula in Dewcember 1941.


The Russians actually had two categories of Desytroyers, which we might classify as leaders and then destroyers. DD Tashkent was an example of a Leader, and was, by most accounts, an exceptionally well designed ship.

 

[RCAFson]

In Which we Serve

This wartime film is a fictionalized account of HMS Kelly - but it was filmed on a J-K class destroyer and if you watch closely it shows how the 4.7 twin was loaded. The film also features very accurate naval terminology and is an invaluable introduction to understanding how Commonwealth destroyers were fought.

You can watch it online or download it here:
In Which We Serve : Noel Coward, Anthony Havelock-Allan, and Herbert Smith : Free Download Streaming : Internet Archive

"follow TBI" = follow target bearing indicator"

 

[Glider]

Until laer in the war Russian ships lacked almost all modern electrical equipment, radar, sonar nearly all of it had to come from the USA or UK. Another problem was very poor training, a captain would get a a medal if his ship was at sea for three days and nights. One very telling statistic was that the Russian navy (excluding submarines and MTB's) didn't sink a single ship in the entire war including Merchant ships.

The Italian Navy had a similar problem but the ships were well designed and well manned. The problem with the Italian navy was poor senior officers, the crews on the ships often fought with considerable courage. Some of the ships had unusual but effective design features. The Gabbiano class of corvettes could switch to electric engines to assist when hunting submarines, as far as I am aware this was unique to the Italian Navy.

 

[parsifal]

The opportunities for the Russians to sink ships were pretty restricted. There were plenty of RN ships that didnt sink a single ships either. And three days at sea in the baltic and/or the Baltic is a very long time.

I also know that not sinking a single ship is highly doubtful. For many years it was historical "fact" that not a single ship was lost to Soviet Submarines. But Of all places in the Kriegsmarines day by day war diaries (online and comppiled post war) I have found entries that quite a bit of Axis shipping was intersepted and sunk by Russian submarines in all three operational areas. Hayward, in wrinting his book about the Lw operations on the southern front, talks of how the LW was forced to divert resources to combatting Soviet Naval activities. He furthe mentions 9I think, that Soviet destroyers had sunk a number of small Axis (italian I think?) MAS boats based at makeshift bases trying to isolate Sevastopol.

So whilst i too have seen such statements, and cant be 100% certain about thye actual truth, do have my doubts about the veracity of those claims.

The italians make another interesting study. I think their overwhelming problem was the faulty leadership at the top,, followed closely by their lack of oil and the poor co-operation with the RA. I do not believe the italians particulalry needed a carrier, but they did need a dedicated naval co-operation unit to support naval operations. They lacked radar, or moree precisely a general fitout of radar and a doctrine on how to use it. Thay did have sonar, from the middle of 1941. They had some patchy equipment, some good, some not so good. Their chief naval guns for DDs were the 120/45 and 120/50 by Ansaldo and OTO, both based on Armstrong designs. The latter weapon came in a twin power mounting, with centralised hoists. The guns were fully enclosed, and spaced only 22 in apart which caused severe dispersion problems. The gun mounts were originally designed as hand cranked, but came in too heavy, so had to be electrically powered. They also started life as hand rammed, but were fitted with a mechanical loader from 1926, which was gradually imporoved over time. However the power rammers were a severe restriction on the operation of the turret, according to Campbell. Apparently the rammers would not operate above 30 degree elevation which meant that the guns (even though rated as elevating to 45 degrees, could not be loaded above 30 degrees. These guns (not the mounts) were a very close relative if somewhat lighter, to the british pattern 4.7in, but had a sustained rate of fire of 7 rounds per minute. hmmmm.

Italian torpedoes were based on the whitehead pattern , and were reliable, on par designs. They has an aerial torp at the beginning of the war far supeior to that in use in Germany, so from 1941 the Germans began using the italian types over their own, until after 1942.

Some accounts say the optics for the Italian guns was not good, but Im pretty sure that claim is bogus. What was missing for these guns were crews properly trained in nightime gunnery Wartime expereience also shows a marked reluctance for Italian destroyers to enter any smokescreen . This affected their performance during several battles.

Both the 120/50 and the larger 135 mm guns were meant to have a DP functionality, but operational experience showed that they could not fulfil that role. Hmmm again. The larger 5.3 in gun was eventually redesigned for the new carrier Aquila to have AA capability. manufacture AA ammuntion for it, but the gu was originally intended as a DP weapon.

 

[Juha]

... They dis carry out a number of Dunkirk style evacuations, but with heavy losses. I vaguely recall they undertook the evacuation of the Hango peninsula in Dewcember 1941.

Yes, KBF, Soviet Baltic Fleet, DDs participated the evacuation of the Hango peninsula

The Russians actually had two categories of Desytroyers, which we might classify as leaders and then destroyers. DD Tashkent was an example of a Leader, and was, by most accounts, an exceptionally well designed ship.

Taskent was built in Italy and was mostly Italian design

 

[Juha]

I never said that the RN thought that 40 degs was enough!

What I've been saying is that 40degs is not useless and that most air attacks could be engaged by destroyers with 40 deg guns - anyone who takes the time to read Lundstrom and First Team will know that in almost every case USN destroyers with 40 deg elevation could have provided the exact same AA support as they did in 1942. The problem is that most people seem to think that aircraft simply materialized directly over destroyers (but only RN destroyers), and they were helpless if they couldn't shoot straight up! Of course this is complete nonsense.

It certainly was a sign of desperation, to add single 3in or 4in guns - the problem being that the 20mm oerlikon was not yet in UK or Cdn production, nor was the Bofors 40mm in a naval mounting, and the quad pom-pom was in very tight supply, whereas these 3in and 4in guns were sitting around gathering dust...and so they were hauled out of storage and added to RN Fleet destroyers. Later in the war, most of these ships had the gun removed and replaced by TTs once again along with a greatly strengthened CIWS.

I agree that from Tribals onwards RN DDs had reasonable AA capacity against TBs and level bombers attacking at fairly low altitude but the problem was that the high level bombers, usually not dangerous but IJNAF bombers had fairly effective bombing tactic against ships, after flying through the zone inside which the British early war DDs could fire at them could made the final stage of their attack completely unhindered by fire from those DDs, same goes with the dive bombers. Even late war RN DDs had fairly weak CIWS when compared to USN Fleet DDs Allan M. Sumner and Gearing classes had 12 40mm Bofors and some 12 20mm Oerlikons, those which had landed a TT mounting had 16 Bofors. Even KM DDs after Barbara mods had heavier CIWS than late war RN DDs and as had the late war IJN DDs with 20-28 25mm AAA guns, even if IJN 25mm was fairly light AAA gun and the 3x25mm mount had its problems. Of course KM needed much more AA defence than RN in Europe in 44-45.

Juha

 

[Juha]

...Here's Delhi's service record:
HMS Delhi, British light cruiser, WW2

note how she was tucked away in the Irish Sea during HARPOON and PEDESTAL. Hardly what you'd expect if she was supposedly the best AA ship in the RN...

As you see, in June 42 Delhi was escorting QE, very high value ship which was probably in troop transport mission.
According to Roberts' British Cruisers of WW Two RN evaluaded gunnery trials of Delhi as highly successful.

Juha

 

[RCAFson]

I agree that from Tribals onwards RN DDs had reasonable AA capacity against TBs and level bombers attacking at fairly low altitude but the problem was that the high level bombers, usually not dangerous but IJNAF bombers had fairly effective bombing tactic against ships, after flying through the zone inside which the British early war DDs could fire at them could made the final stage of their attack completely unhindered by fire from those DDs, same goes with the dive bombers. Even late war RN DDs had fairly weak CIWS when compared to USN Fleet DDs Allan M. Sumner and Gearing classes had 12 40mm Bofors and some 12 20mm Oerlikons, those which had landed a TT mounting had 16 Bofors. Even KM DDs after Barbara mods had heavier CIWS than late war RN DDs and as had the late war IJN DDs with 20-28 25mm AAA guns, even if IJN 25mm was fairly light AAA gun and the 3x25mm mount had its problems. Of course KM needed much more AA defence than RN in Europe in 44-45.

Juha

Most of the time IJNAF carrier aircraft were engaged in attacking USN capital ships, mainly carriers, and a 40deg gun could still place a barrage over the ships being attacked. Of course there were several occasions when USN destroyers were caught alone and sunk by IJNAF DBs, 5in/38 HA guns not withstanding.

These late war USN DDs were quite a bit larger than equivalent RN destroyers as were the IJN and German Narvik class.