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Jul 15 17 5:17 PM
Jul 15 17 5:40 PM
Jul 15 17 7:35 PM
Phil Gollin wrote:This is NOT just a British problem. .
The British data just doesn't exist in quantity. The US data is NOT reliable. German, Italian and Japanese data doesn't seem to be available in quantity. These are facts, not people trying to bias the data.
As someone who has bothered to poke around UK archives I can confirm that the main RN and Vickers ordnance and gunnery archives have GONE. Yes, the MAIN reports, minutes, etc... that were printed for service use have mainly survived, but the DNO files have not. They are not in the TNA : PRO, IWM, Priddy Hard, "Explosion", Vickers or any other archive. There are many (but NOT all) "Reports of Proceedings" but most do not include the gunnery report (usually sent separately through DNO channels). This is NOT a conspiracy by Andy, or anyone else.
With your supposed standard of required proof we (ALL of us, including you) may as well just never write anything more about WW2 Naval Anti-Aircraft actions.
Jul 15 17 7:58 PM
No, it's entirely possible to do meaningful analysis of data sets that are limited in many many ways, as long as you can correctly characterise the data. The requirements you quoted are necessary if you want to do something like engineering or physics, but this is /history/, and the goal isn't anything like six nines reliability, or even 95% confidence intervals - the goal is some level of enhanced understanding of past events, and the standards for data analysis are far more lax than you appear to be demanding.
I'm not going to claim that Andy is a saint or even that he's not attempting to reinforce strongly held personal opinions, but you're attacking him for even /trying/ to accumulate historical data on this question.
It's pretty obvious to me that what he's doing is digging through whatever primary sources he can find and posting the snippets that appear to be relevant - this is exactly what someone doing historical research will /do/, except that he's posting things here rather than making personal notes. I have no idea if the sources he's using are good, if his selections are relevant, or if he's ignoring information that doesn't fit his preconceived notions, but none of what he's posting seems on the face of it unreasonable as data points. Maybe he'll eventually build up a large enough collection of data to be able to provide meaningful answers to the questions he's obviously interested in, despite the limitations of the source material.
Jul 15 17 8:09 PM
ChrisPat wrote:Hence I'd think shrapnel would fill the error space better than HE. Considering the shells as shotguns firing at the target ac the shrapnel has a tighter choke and the targets are flying along the spread.
Jul 15 17 8:27 PM
Andy01 wrote:At Bougainville, where we have very good numbers, 17 IJN aircraft were attacked with ~2600 5in rnds. That's ~150 rnds/aircraft. On 15 Feb 1942 Exeter and Hobart attacked 91 aircraft with ~1000 rnds of 4in. That's ~11 rnds/aircraft.
Hobart fired 600 rnds versus ~60 aircraft ( on 16 occasions ) from June to Sept 1940, or ~10 rnds/aircraft.
Jul 15 17 8:31 PM
Albert wrote:An alternative perspective might be that Andy is unearthing data which challenges some commonly held beliefs about American equipment being markedly superior, and surprisingly , or not, the US fan boys don't like it !!I don't think it is necessarily 'Anti American' to question common perceptions and often touted historical claims . In a world increasingly influenced by fake news, providing hard data that supports an alternative view will help promote discussion and foster analytical reasoning.
Jul 15 17 8:53 PM
Steve Crandell wrote:Note 4 in the navweaps entry for the 5"/38 barrel life:
"During the Okinawa campaign, so much 5"/38 ammunition was expended in such a short period of time that concerns were raised regarding excessive barrel wear. Two Fletcher class destroyers, USS Hall (DD-583) and USS Richard P. Leary (DD-664), which had both expended about 4,270 rounds per gun, were ordered to fire practice rounds to determine the effects of barrel wear on accuracy. The exercise found that the range patterns were 260 yards at 6,000 yards (240 m at 5,500 m) and 470 yards at 12,000 yards (430 m at 11,000 m), which were both within the nominal accuracy specifications."
This is from the description of the 4"/45 of WWII (1938 to 1945) marks:
"These guns were noteworthy as having "neither long barrel life nor particularly high accuracy" - John Campbell. This was blamed on the use of projectiles with a too-short parallel section which led to poor centering at the muzzle."
2. As mentioned in Part III, the U.S.S. RICHARD P. LEARYin conjunction with the U.S.S. HALL, fired an offset practice [at 6 and 12k yds-AH]on 27 May to determine gun errors in 5"/38 guns having highE.S.R. No photographs were possible due to overcast weatherbut accurate triangulation made observation of pattern reliable.The average E.S.R. in the LEARY were 4,300 with a high gun of4,750. The HALL has ESR of about 3,250. No star gauge read-ings were available; visible wear had appreciably smoothed thelands for two calibers at the beginning of the bore and subsequentmeasurement showed a wear of approximately .023". In thepractice, two effects of erosion were noticed; the deflection offull salvos varied from 5 to 15 mils; the range pattern foreither full or partial salvos averaged 400 yards with somechanges in M.P.I.I believe that guns fired on firesupport missions do noterode as much as they would for a similar number of roundsfired more rapidly under ordinary surface or air action con-ditions, probably because the guns do not become so heatedwith the slower rates of fire.
All four guns had over 2,500 ESR before the bombardment; thisrequired setting the I.V. dial to its lower linit ( 2450 fps ) andan initial ballistic of OUT 250 to hit. Gun No. 2 however, did nothave the large bore-erosion characteristic of the other guns, andtherefore had to be controlled separately, This gun was placed intostarshell designation ( elevation ) and its sight angle was correctedat the rangekeeper in order to depress that gun the required amount.This procedure proved fairly effective in these bombardment as no wildshots were observed.
Jul 15 17 8:54 PM
Jul 15 17 8:57 PM
sergeante wrote:Andy01 wrote:At Bougainville, where we have very good numbers, 17 IJN aircraft were attacked with ~2600 5in rnds. That's ~150 rnds/aircraft. On 15 Feb 1942 Exeter and Hobart attacked 91 aircraft with ~1000 rnds of 4in. That's ~11 rnds/aircraft.Okay... What are the circumstances of each engagement? For example, how many other ships were around Exeter and Hobart that might also have been firing? Which American ships are we talking about? American destroyers, for example, would have had 4 or 5 5"/38 guns to bear on a broadside, while the British cruisers had either 2 or 4 4-inch of somewhat lower rate of fire. What was the nature of target presentation? The number of rounds you can fire per engagement is generally a function of guns available x the rate of fire x length of engagement. If the enemy all comes at once, or in two or three large groups, that limits their exposure. (But, as I have mentioned earlier, increase your chance to hit per shot, provided they are all in tight formation(s).) Hobart fired 600 rnds versus ~60 aircraft ( on 16 occasions ) from June to Sept 1940, or ~10 rnds/aircraft.A single ship, in a number of small, probably short engagements. How many other ships were firing at the same aircraft during those engagements? How many rounds did each of them fire?See, you're not completing the entire statistical picture, or even coming close.
Jul 15 17 9:12 PM
Quick math. The Hornady small arms ballistic calculator...
Jul 15 17 9:13 PM
Andy01 wrote:Most of the information regarding your questions can be found by re-reading the relevant posts.
Jul 15 17 9:49 PM
sergeante wrote:Andy01 wrote:Most of the information regarding your questions can be found by re-reading the relevant posts. Link me back, or at least provide topic names and post #s.
Jul 15 17 10:54 PM
Jul 15 17 11:25 PM
Jul 15 17 11:34 PM
Blutarski wrote:Now Pouts!
Apparently everyone got it wrong.
Jul 16 17 7:35 AM
Andy01 wrote:Post #Bougainville - 90Exeter-Hobart at Java - 146Hobart posts - 150 - 162Coral Sea - 168colombo -198
Jul 16 17 11:44 AM
Jul 16 17 7:57 PM
Steve Crandell wrote: My impression from reading your posts over an extended period is that you have decided that HAA was not worth having and that all enemy aircraft over 1,000 yds from one's own ship should be ignored.
Jul 16 17 7:59 PM
Andy01 wrote:I'm not sure I quite follow your reasoning regarding Bougainville. I'll reply in more detail tomorrow.
The attacks were made by 7 formations attacking sequentially; 4 formations each of 6 and 7 B5Ns [level bombing] and three formations of 23 [8 damaged] , 27 [13 damaged] and 17 [ ~15 damaged with two crash landing] G3Ms and G4Ms for 93 sorties.Some clarifications. Hobart had 4 x twin 4in but no radar until after Coral Sea. Exeter had 4 x twin 4in and Type 279 radar. She might have used Type 279 radar FC at Java but would mean losing the air warning function also provided by Type 279 so I can't state definitively if Exeter used her radar for FC or reserved it for air warning. I would hazard a guess that she did use it against the last two TE bomber raids.
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