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Naval wargames in the Great War - rangefinders
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jwduquette1



Joined: 20 Dec 2005
Posts: 90

PostPosted: Sat Jun 17, 2006 9:03 am    Post subject: Reply with quote

Regarding the 15-ft Barr & Stroud range finders on the Queen Elizabeth’s, while their overall hit rate was higher than 1st BCS and 2nd BCS at Jutland, it was considerably lower than 5th BCS (best hit rate during the battle). 5th BS was also somewhat lower than 1st BS, 2nd BS and 4th BS. See John Campbell’s “Jutland, An Analysis of the Fighting” page 355.
I realize correlations are trying to be drawn to similar environmental conditions, but to that end shouldn’t a comparison be made to hit rates of 5th BS to 1st BCS and 2nd BCS during (or any other Grand Fleet elements) during discrete time periods rather the overall hit rates for both during the whole course of the battle. For example what were contrasts in overall hit rates of 5th BS vs. 1st + 2nd BCS between say 5:10PM and 5:48PM. Moreover the time period between the intervention of 5th BS and the period in which Beatty spots the main elements of the High Seas Fleet and begins his turn away. Are the rates similar or was 5th BS grossly out hitting 1st + 2nd BCS during this time slot? Same again for later periods in the battle – for example how did 5th BS gunnery\hit rate compare with say 1st BS, 2nd BS and 4th BS during similar time periods of the battle?

I don’t know the answers to the above questions. I am just curious as to what sort of advantage may have resulted from the 15-ft range finders on the Queen Elizabeth’s when compared with other elements of the Grand Fleet. Best overal shooters are indicated as Barham & Valiant -- so why is the overall 5th BS hit rate second to lowest?

Overall hit rates for the various Grand Fleet Elements at Jutland. From: John Campbell’s “Jutland, An Analysis of the Fighting” page 355.

http://img100.imageshack.us/img100/7290/hitpercentilesjutland20ec.jpg
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jwduquette1



Joined: 20 Dec 2005
Posts: 90

PostPosted: Sat Jun 17, 2006 11:17 am    Post subject: Reply with quote

I just realized that J.Campbell's hit rate for 1st, 2nd and 4th BS should be a bit lower than he has indicated. It should be 3.578, not 3.7.

57/1593 = 3.578

Transposition error.
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NewGolconda



Joined: 17 Jun 2006
Posts: 18
Location: Adealide Aus

PostPosted: Sat Jul 01, 2006 12:20 am    Post subject: hit rates Reply with quote

*I don’t know the answers to the above questions. I am just curious as to what sort of advantage may have resulted from the 15-ft range finders on the Queen Elizabeth’s when compared with other elements of the Grand Fleet. Best overal shooters are indicated as Barham & Valiant -- so why is the overall 5th BS hit rate second to lowest?*

Some of my observations on the issue.

-Campbell’s hit rates are not gospel, in fact, Brooks looking at the battle re allocates several of the hits, some of which, from memory favour the 5BS. Campbell and Gordon are in significant dispute as to just who was firing at whom at a key point in the battle. There might be a good half dozen hits to be moved from the point in which the 5 BS turned north.

- Very few ships or squadrons in either war ever shot very well after being subjected to heavy and accurate fire. The 5BS was subjected to heavy and accurate concentrated fire twice, and this must have effected their efficiency.

-Hit rate is range and condition dependent. It is also significantly effected by being under effective fire from the enemy. When the 5BS had their best opportunity for hitting, ie when they were undamaged, and unengaged or only just being engaged – they were firing at very long range (let us say 19,000-18,000 yards but possibly as much as 22,500 yards if you believe Gordon’s reconstruction (not sure that I do). The most accurate gun fire in the run to the south by the battle cruisers on either side took place around 16,000 yards. Visibility in the run to the south is said to have favoured the Germans, though certainly the oil fuelled QE’s were lest hampered than Beatty’s ships.

- Some of the most accurate gun fire of the battle, the 3BCS and the Grand Fleet squadrons took place from 12,000 yards or even significantly less.

I think you have to first re allocate some of the Campbell hits. Then you need to “normalise” the hit rates. What I get without formalising the process from a combination of Brooks and Campbell is a rough estimate, for British ships;

Given equal visibility and conditions in 1916, equal (grand fleet?) training and due to a range of ballistics (gun calibre) and fire control issues.

The 15in ships have an effective range (chance of scoring multiple hits) of something like 19-20,000 yards. (15ft range finders, oil firing, 15in guns.)

The 13.5in ships have an effective range of something like 16,500-17,000 yards. (9ft range finders on conning tower mountings).

The 12in, 4crh fitted ships, with brand new directors but manual plotting have an effective range of 15,000 yards or less. (9ft range finders on vibration prone foretop mountings).

On the question of the specific benefit of the 15ft range finder. Of some note is the mad rush to broader and broader range finder base lengths in the 20’s. Brooks makes the interesting point that 9ft or 15ft mattered much less than if they were used correctly. The ideal for use with the British FC system was for them to get four “cuts” a minute, while at the run to the south for a range of visibility, speed, smoke and vibration issues they were lucky to get one “cut” per minute. I think if I was going to build a gunnery “hot rod” battle cruiser in 1916, of more value than a 15ft range finder would be to argo mount two 9ft instruments, one on the conning tower, and one at the after control position. Sure there were many more instruments in the turrets, but then “notes from the turrets –at Dodger Bank” indicates in North Sea conditions, given spray and visibility, an observer so situated was lucky to see anything at 16,000 yards, bar smoky bands on the horizon.
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jwduquette1



Joined: 20 Dec 2005
Posts: 90

PostPosted: Sat Jul 01, 2006 10:17 am    Post subject: Reply with quote

Hi NewGolconda:

Thanks for the in depth. I have Brooks’ work on “Dreadnought Gunnery & The Battle of Jutland”, although I will admit that I have not read it cover to cover. I haven’t read the chapter on Jutland as yet. Does Brooks criticize Campbell’s hit distribution in “Dreadnought Gunnery” or is this something he has detailed in a separate paper or article?

Regarding the hits that are in dispute, five or six hits swapped here or there will not change the overal hit ratios by much. Historians will never agree upon such things. They like to argue -- so they do. Campell has 5th BS firing 1099 shells with a hit ratio of 2.64%. Adding six more hits takes the overal hit rate to 3.18%. This still isn't showing a clear advantage of the 15-ft range finder over the hit rates associated with 3rd BCS or 1st, 2nd and 4th BS. And yes there are many additional factors associated with hit rate -- which is precisely point. I suppose I'd prefer to have a 15' RF to a 9' RF, but the RF in and of itself is only one piece of the puzzle. Than again maybe I would prefer to have an expert manning a 9' RF than a novice manning a 15' RF. I think the point here is that RFs are not the sole key ingrediant that makes or breaks hit rate.

Thanks
JD
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tone
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Joined: 29 Oct 2004
Posts: 479
Location: Boston

PostPosted: Sat Jul 01, 2006 11:19 am    Post subject: Reply with quote

Hi Golconda... glad to see you check in as I have seen your posts in the Henneman forums and saw your registration some time ago here. Welcome!

I think the issues you cite are most cogently summarized that the inequitable conditions under which ALL shooting was ever conducted, whether regarding them from vantage points of vibration, mist, spray, lighting, background, smoke of own or enemy ship, etc, etc and etc again is what makes most efforts to judge one group's expertise or equipment or biorythms in relation to another's pretty much an opportunity to select your favored mode of self-deception. Indeed, if this were a clinical drug trial, the first step taken by any reputable researcher with the data would be to throw it out and design a GOOD experiment capable of determining the efficacy of the agents under review!

The dominant theme in the reports I've read is that few cuts were taken, or that those taken could not form the basis of a reliable plot at all. I conclude, without venturing into trumped up claims to certitude, that failing to produce usable rate plots on tables amenable to using the data collected from every RF on board would imply that a true course plotting mechanism wed to a single instrument would have been even worse. I think I'd like to learn more about the RN's conclusion as the Dreyer table committee met and thinking on the post-war FC mechanisms was was underway was that it was better to focus on target inclination that rangefinder data.

That said, I have been sorting out some data I have on how many RFs each ship had at different dates, and if it would be helpful, I could look and see what suggestions I have as to how many were on ships at Jutland.

tone
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