Repulse/prince Of Wales Sinking

[Brian Kennedy]

Was today, and I actually had no idea that it happened 3 days after Pearl Harbor. Probably cemented the ascendancy of the airplane as much or more than Pearl did. RIP.

[Markus Becker]

 

. Probably cemented the ascendancy of the airplane as much or more than Pearl did. RIP.

Yes, but without justification though. The triple A of Force Z was utter shit. Edited December 11, 2018 by Markus Becker

[MiloMorai]

 

. Probably cemented the ascendancy of the airplane as much or more than Pearl did. RIP.

Yes, but without justification though. The triple A of Force Z was utter shit.

 

 

What ships did have good AAA?

[Josh]

Pretty much no one that early in the war. US ships probably doubled their AAA per ship by war's end. I think things like Iowa and Essex had nearly 70 40mm and similar numbers of 20mm.

[Ken Estes]

The increases in USN AAA were exponential. We commissioned battleships in 1941 with only four quads of 1.1 inch, and some .50 cal., no 20mm.

Edited December 11, 2018 by Ken Estes

[Josh]

I knew most of the mounts were the ineffective 1.1 inch, but I had no idea how few there were. The 40mm / 20mm were giant leaps qualitatively as well. I feel like a level torpedo run would probably have been a death sentence by defensive fire by 1945.

[Markus Becker]

 

What ships did have good AAA?

 

 

The new KGVs and the rebuild old ones like Warspite and Renown. British cruisers weren't bad too and even British destroyers were getting somewhere. The RN was doing ok in the Med provided ships stuck together

 

But Force Z was really the B-team by RN standards. Repulse had more or less 1920's AA-armament, the DD had a minimal self defence capability and cruisers were absent entirely.

[rmgill]

By the end of the war, the BB's with Radar directed 5"/38s firing PD fuzed projectiles along with director controlled 40mm and manually controlled 20mm were hell on aircraft. The same scenario with Force Z having the late war tech would have been VERY Different. The new 5"/54s had even more range.

Radar Director controlled guns with PD have reach and a very low firing count to hit an aircraft.

iinm, even some British BB's were sent stateside for AAA upfits.

Edited December 11, 2018 by rmgill

[shep854]

Then came the Divine Wind, and 40mm/20mm guns became immediately obsolete, as only catastrophic destruction of an attacker was considered acceptable.

Edited December 11, 2018 by shep854

[rmgill]

This is something I'm sure I've seen an analysis paper somewhere out there on the subject showing data on hit rates early war and late war with the different methods and weapons (possibly back in my misspent days on Sci.Military.naval?) Here's a reddit thread that digs deeper into this with some citations that seem to be somewhat old and stale links..

https://www.reddit.com/r/AskHistorians/comments/33sa2x/effectiveness_of_shipborne_antiair_in_wwii/


Looking down through the thread...here we go...

https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/a/antiaircraft-action-summary.html

Antiaircraft Action Summary · World War II
October 1945
Headquarters of the Commander in Chief
UNITED STATES FLEET

 

During the 8 months of 1945, when approximately half of the war's kills were made, rounds per bird dropped off. Except for those attacking the fast carrier force, many enemy planes were outmoded types, comparatively slow and operated by unskilled pilots. Gunners had improved in accuracy as a result of increased experience in action and increased training.

The 40 mm. developed into the most effective weapon in the fleet. The 20 mm., which was the most important weapon during the first 2 years of the war, was passed by both the 5-inch and 40 mm. in the percentage of planes knocked down during 1944 and 1945.

Five-inch guns destroyed 30 percent of all "sures" during the war. VT-fuzed projectiles, used in only 35 percent of 5-inch rounds, were responsible for 50 percent of 5-inch kills.

The indicated performance of the 3"/50, which boasts a lower R. P. B. than even the 5-inch VT, is considered a statistical casualty as a result of poor reporting by ships.

The 6"/47, lacking an AA. computer and VT fuzes, was used but rarely against aircraft. It was responsible for two "kills." Both a computer and VT fuzes have been developed for this weapon.

Edited December 11, 2018 by rmgill

[Ken Estes]

The RN did not fix the 5.25" issues until postwar, HMS Vanguard, not with the KGVs, nor the AA cruisers. [the army's 5.25" battery at Gibraltar was also fixed]. The 4.5" mounts and FCS OTOH performed well in the war.

 

The USN 5" 54 likewise required postwar evolution. In any case, none of the WWII training and FCS systems for directors and gun mounts could handle jet aircraft of the late 40s, hence the need for missiles.

 

 

In 1946 US testing with nuclear weapons delivered by air against a target array of ships anchored in the Bikini Atoll (Operation Crossroads) demonstrated that modern warships could survive atomic attack. The two tests employed 21-kiloton fission bombs like those dropped on Nagasaki in 1945, the first an aerial burst, the second a shot positioned 90 feet underwater in the center of the 95-ship target array. While several ships sank, most survived relatively intact even at close range and the Navy took heart in the evidence that mobile and somewhat dispersed task forces could survive atomic munitions, provided personnel remained within the ships’ hulls and structures. New self-washdown equipment would be required to decontaminate the ships’ exteriors from radioactive fallout.

....

In each case, the mainstay operations of naval forces were confirmed as viable in the atomic age. However, the new turbojet aircraft, the presumed delivery method for atomic ordnance, posed increased dangers for defending ships and would require new weapons and techniques to counter. Already in hand were new rapid-fire automatic cannon with radar-directed fire-control systems that had been developed to combat the kamikaze attacks of the latter part of the Pacific War, and these were first incorporated on board ships laid down in 1949. However, the real dynamic for coordinated antiaircraft warfare in the fleet would combine improved radars, jet fighters from aircraft carriers, and guided missiles, all under development since 1945, and the Navy began converting cruisers to employ these missiles in 1952, the first entering service in 1955.

 

 

[shep854]

Weren't the semi-auto 3" guns of the late '40s originally designed with the kamikazis in mind?

[Ken Estes]

Hi Shep, the 3"/50 with the power-driven loader begin service in 1946 [in quantity from 1948] and replaced the 40mm on something less than a 1 for 1 basis until 1950. Development objective was based upon the Kamikaze, with the idea that only shells with proximity fusing could be effective, and 3" was the smallest gun in service with the VT fuse. Recognizing jet aircraft as the new threat led to the fully automatic 3"/70 being designed but it had teething problems in the USN and had little use; the RN and RCN were more successful with it when they slowed the rate of fire.

 

The WWII AA directors and FCS remained much less effective vs post war jet aircraft because the slew rate of the gun mounts and directors could not be improved.

[shep854]

Thanks, Ken. It's a shame the USN didn't get the bugs worked out; they always seemed to be handy weapons. At least the Italians developed a workable system.

[DougRichards]

Hi Shep, the 3"/50 with the power-driven loader begin service in 1946 [in quantity from 1948] and replaced the 40mm on something less than a 1 for 1 basis until 1950. Development objective was based upon the Kamikaze, with the idea that only shells with proximity fusing could be effective, and 3" was the smallest gun in service with the VT fuse. Recognizing jet aircraft as the new threat led to the fully automatic 3"/70 being designed but it had teething problems in the USN and had little use; the RN and RCN were more successful with it when they slowed the rate of fire.

 

The WWII AA directors and FCS remained much less effective vs post war jet aircraft because the slew rate of the gun mounts and directors could not be improved.

 

It should be remembered that there were land based 75mm AA of the same vintage, with the same goals. That is the T22, T23, with carriages T18, T18E1,T19, T19E1.

 

The idea was similar, auto loading, using VT fuze, and a high rate of fire and on carriage radar. The WW2 land based guns only fired at 2,300ft/sec, and later types - the M51 'Skysweeper' at 2,800ft/sec.

 

Whilst my source does not mention the naval weapon, one would have hoped that the Army and Navy could have worked together on this project.

 

===============================

 

Actually just checked a few things: Army and Navy were trying to do the same thing, but didn't work together: why does that not surprise me?

 

USN worked with RN, but seemingly didn't talk with the Army.....

Edited December 12, 2018 by DougRichards

[shep854]

When they worked, those 3" mounts were impressive! First five min of video:

[Ken Estes]

 

Hi Shep, the 3"/50 with the power-driven loader begin service in 1946 [in quantity from 1948] and replaced the 40mm on something less than a 1 for 1 basis until 1950. Development objective was based upon the Kamikaze, with the idea that only shells with proximity fusing could be effective, and 3" was the smallest gun in service with the VT fuse. Recognizing jet aircraft as the new threat led to the fully automatic 3"/70 being designed but it had teething problems in the USN and had little use; the RN and RCN were more successful with it when they slowed the rate of fire.

 

The WWII AA directors and FCS remained much less effective vs post war jet aircraft because the slew rate of the gun mounts and directors could not be improved.

 

It should be remembered that there were land based 75mm AA of the same vintage, with the same goals. That is the T22, T23, with carriages T18, T18E1,T19, T19E1.

 

The idea was similar, auto loading, using VT fuze, and a high rate of fire and on carriage radar. The WW2 land based guns only fired at 2,300ft/sec, and later types - the M51 'Skysweeper' at 2,800ft/sec.

 

Whilst my source does not mention the naval weapon, one would have hoped that the Army and Navy could have worked together on this project.

 

===============================

 

Actually just checked a few things: Army and Navy were trying to do the same thing, but didn't work together: why does that not surprise me?

 

USN worked with RN, but seemingly didn't talk with the Army.....

 

 

Quite true, Doug, and Rich's new book he is preparing details this shameful lack of cooperation/coordination in WWII, especially on ordnance items. It may have dawned on them at some point postwar, for I discovered that the unusual turret power systems of the T43/M103 heavy tank were derived from naval gun mounts. Of course, there is always the possibility that industry did the expanded search for solutions....

 

Skysweeper and the 3"/50 semiauto AA guns did look amazingly similar but alas it appears coincidence alone.

[Jeff]

Let's not forget the training level of the Japanese pilots at the start of the war, they were arguably the best in the world. How many other air forces could hit maneuvering warships from level bombers? Also, the state of damage control (the ships and the men) early in the war was pretty bad.

[Stuart Galbraith]

The Germans were pretty lousy at it initially. They apparently didnt do any training at all to hit moving ships with their JU87's. A curious omission for a nation obsessed with dive bombing.

[Dawes]

During the Battle of the Santa Cruz Islands, USS South Dakota (BB-57) was credited with downing 26 enemy aircraft, which I think was a record for the war (for a BB anyway).

Edited December 26, 2018 by Dawes

[Ken Estes]

I think that has been corrected to a much lower number, but I'm away from the references I'd need.

[Markus Becker]

Let's not forget the training level of the Japanese pilots at the start of the war, they were arguably the best in the world. How many other air forces could hit maneuvering warships from level bombers? Also, the state of damage control (the ships and the men) early in the war was pretty bad.

They did hit Repulse(?) with a bomb or two but the hit ratecwas lousy, the bombs did little more than scratch the paint and for the RN the third year of the war had begun. They much improved their AA during that time and certainly their DC too.

[Colin]

The 3/50 continued in Service with the RCN till the late 80's

[lucklucky]

Let's not forget the training level of the Japanese pilots at the start of the war, they were arguably the best in the world. How many other air forces could hit maneuvering warships from level bombers? Also, the state of damage control (the ships and the men) early in the war was pretty bad.

All air forces.

 

The issue is investment return, how many hits vs flights mode+bombs dropped.

[Nobu]

26 claimed AA kills of IJN aircraft for USS South Dakota

 

Considered together with the number of total USN AA kills available online of:

 

127 versus actual kills of approximately 25

 

Extrapolates mathematically to about 5 actual AA kills relative to USN overclaims