..... It's not clear to me that data overload was necessarily a large problem.
Some of the most inaccurate claims, for 1942, were made when there was very few attacking aircraft.
Imagine the following scenario in 1945:
A group of kamikaze approaches a USN TG. CAP pursues the kamikazes and shoot down several, but the CAP veer off as the TG opens fire with 5" guns. Some of the CAP damaged kamikazes crash while within the barrage, some of the Kamikazes are actually a fighter escort and they drop to low altitude and withdraw, some of kamikazes simply abort but others are hit by the AA at long range and multiple kill claims arise. Trying to sort out who killed what and how many aircraft were actually shot down is going to be extremely difficult, to say the least.
The problem here comes in defining what we mean by "effective". The main purpose of AA guns was to protect ships not to shoot down planes. Was the 40mm all that effective vs dive bombers for instance? The larger calibers could start intimidating attacking planes at a considerably longer distance and while they might not shoot down as many they could affect the aim and or cause damage that rendered attacks less effective even if they didn't shoot the plane down. Indeed some of the kills by ligher guns may have been made possible by damage caused by the larger ones. Not at all sure there is an easy answer to this one.
Without wishing to be overly pedantic surely the best way to protect your ship or the target is to shoot down the attacking planes, not least because it causes specific loss to the enemy in return for the expense of ammunition?
''Give me a Ping and one Ping only'' - Sean Connery.
Certainly that's the prefered solution if it's achievable. But for instance are you better off taking a good shot at a plane that's already dropped it's bomb or torpedo or taking a poorer one that's still an immediate threat to the ship? Indeed one of the problems with 20mm may have been that it was in many cases a revenge weapon. By the time you got fire on target the bomb or torpedo was away. One of the greatest success of war time OR was a similar case dealing with the Battle of the Atlantic. The success came in large part by the OR team realizing that the real problem was not to "sink u-boats" but to get merchant ships across the Atlantic. While some of their measures did address the latter the initial ones concentrated on the former.
South Dakota has been credited with 20+ AA kills at the Battle of Santa Cruz. Here is her ammo expenditure and Captain Gatch's assessment of the relative effectiveness of the different weapons:
From South Dakota's Action Report:
Rounds fired:
5" = 890
40mm =4000
1.1" = 3000
20mm = 52000
Captain Gatch's assessment of SoDak's relative AA effectiveness (proportion of kill claims):
20mm = 65%
40mm/1.1" = 30%
5" = 5%
Extracts of SoDak's Action Report were included in AntiAircraft Action Summary, July 1942 to Dec 1942 (Information Bulletin No. 22)
This isn't the only action in which SoDak's claims cause some dissention within the fleet. The term "Showboat" was not always used as one of affection. Take care with her claims.
lwd wrote:This isn't the only action in which SoDak's claims cause some dissention within the fleet. The term "Showboat" was not always used as one of affection. Take care with her claims.
I believe "Showboat" was an affectionate term for USS North Carolina.
lwd wrote:This isn't the only action in which SoDak's claims cause some dissention within the fleet. The term "Showboat" was not always used as one of affection. Take care with her claims.
I believe "Showboat" was an affectionate term for USS North Carolina.
Woops ... didn't the SoDak have a similar name then? I understand that there were hard feelings between her crew and others to the point that higher command tried to keep them seperate.
I'm seeing nothing here about the British twin 4 inch .
Developed well before WW2 started , it was used throughout , and thought good enough to equip the " Bay " class AA figates at the war's end , lasting in at least one case until December 1961 , when HMS St Brides Bay returned to the UK from the Far East .
I would guess the weapon's greatest test was in the ferocious air attacks on Allied naval and merchant ships in the Mediterranean theatre from mid 1940 up to the Italian surrender in 1943 .
I dont recall seeing any criticism of it as an AA weapon , although when used as the main gun in destroyers it was weaker when used against surface ships , (due to short barrel and lower shell weight ) , so not a good dual purpose gun .
I think that the same barrel was shipped in a single mount in some destroyers and in the "River class" frigates .
Elsewhere in the forum there seems to be a view that the British twin 5.25 DP mountings where pretty much failures , although they went through the same Mediterranean mill in the Dido class cruisers from beginning to end , and were used for later , modified Didos and for battleship Vanguard , where presumably they could have been replaced by the twin 4.5s as fitted in Renown , Q E , Valiant , and the Carriers .
Can anyone expand on this 5.25 "failure" theme please ?
In the Light automatic department I have to concur with 40mm Bofors and 20mm Oerlikon . I think the Allied 20mm was better because you didnt have to reload every 20 or 30 rounds as with the German weapon .
" Relax ! No-one else is going to be fool enough to be sailing about in this fog ."
hammy wrote:I'm seeing nothing here about the British twin 4 inch .
Developed well before WW2 started , it was used throughout , and thought good enough to equip the " Bay " class AA figates at the war's end , lasting in at least one case until December 1961 , when HMS St Brides Bay returned to the UK from the Far East .
I would guess the weapon's greatest test was in the ferocious air attacks on Allied naval and merchant ships in the Mediterranean theatre from mid 1940 up to the Italian surrender in 1943 .
I dont recall seeing any criticism of it as an AA weapon , although when used as the main gun in destroyers it was weaker when used against surface ships , (due to short barrel and lower shell weight ) , so not a good dual purpose gun .
I think that the same barrel was shipped in a single mount in some destroyers and in the "River class" frigates .
Elsewhere in the forum there seems to be a view that the British twin 5.25 DP mountings where pretty much failures , although they went through the same Mediterranean mill in the Dido class cruisers from beginning to end , and were used for later , modified Didos and for battleship Vanguard , where presumably they could have been replaced by the twin 4.5s as fitted in Renown , Q E , Valiant , and the Carriers .
Can anyone expand on this 5.25 "failure" theme please ?
In the Light automatic department I have to concur with 40mm Bofors and 20mm Oerlikon . I think the Allied 20mm was better because you didnt have to reload every 20 or 30 rounds as with the German weapon .
The 4" twin was a very good AA weapon, with excellent ballistics and a high RoF, unfortunately, it is hard to sort out how well it did because there was always guns of differing calibres firing in the same engagements. The same statement is generally true for the 5.25" gun. I believe that the 5.25" gun was a success and criticism of this weapon appears to be a fairly recent development with comments by Campbell in Naval Weapons of WW2 being taken out of context, as wartime accounts are pretty positive. I think the 5.25 got a bad rap because of the limitations of WW2 era AA FC but the guns themselves appear to have performed well. The pom-pom also appears to have been a good weapon that was hampered by poor firecontrol and the lack of a tracer round prior to 1942, and again, it's performance has been unfairly criticized, IMHO.
I think there is a fairly good summary on navweaps.com. The twin mounts were redesigned for use on Vanguard so probably didn't have as many problems. One criticism was the shell weight being possibly too heavy for one man to have to handle. I know the manually loaded 5"/54 guns intended for Montana and used on the Midway class carriers were unpopular for that reason.
The pom pom had low muzzle velocity, giving it a substandard effective range compared to the 40mm Bofors.
