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Dogger Bank -- and\or Gunnery Mechanics
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jwduquette1



Joined: 20 Dec 2005
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PostPosted: Tue Jun 13, 2006 9:37 pm    Post subject: Dogger Bank -- and\or Gunnery Mechanics Reply with quote

Sorry – I moved this to a different thread as I think I was going way off topic and beyond the intent of the Naval Wargames and The Great War – Range Finder Thread. I guess I want to talk about any and all aspects of gunnery mechanics. But, I suppose that is too broad, so I threw up a thread title of Dogger Bank.

This was the bit I was referring to previously about the Lion’s initial shoots at Dogger Bank. Turret-B begins the shoots as Turret-A's sights were awash with spray? Below is a snippet from Lieutenant Commander G.F. Longhurst’s after action report -- Dogger Bank. The bit about A-Turret’s sights being washed down with spray is the second to last para.

Best Regards
JD

Lieutenant Commander G.F. Longhurst, HMS Lion:

“Argo was now getting ranges at 25,000 and thereabout. The enemy were making much smoke, and at first it was thought they were coming towards us.

This was soon noticed as incorrect, and Dumaresq set at 20 to right of our course; our speed 27, theirs 25.

At 8.46 a range-finder cut of 21,500 yards obtained and put on table, these ranges were being reported to conning tower and T.S. by the Gunnery Lieutenant's voice-pipe. Bridge range-finder was also getting ranges, showing short on argo. Captain was on the bridge, Commander in conning tower.

Commander conversed with Gunnery Lieutenant as to possibility of catching the enemy up.

Eventually Gunnery Lieutenant was ordered to fire single shots.

The Gunnery Lieutenant passed the order through to "B" turret: "I am going to fire single, shots, deliberate and slowly, from 'B' turret." "B" turret was selected, since the spray could be seen washing down the sights of "A" turret.

The range-finder was giving ranges just above 20,000 yards. The enemy's ships were making much smoke, but the conditions were good, and high-power spotting glasses were in use. A range of 20,000 yards was passed through to T.S. Def. 8 left. "B" turret report when ready to fire. Point of aim foremast and upper deck. 8.52, "B" turret fired first round by order.”
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PostPosted: Tue Jun 13, 2006 10:03 pm    Post subject: Reply with quote

This is a very nicely detailed report. Was the other quote also from Dogger Bank? I suppose Lion may not have had director fitted at Dogger Bank? There is not a trace of an indication in what you supply here that a director is fitted.

edit: checking a bit, I see Lion did not have a director in August 1914, but she did have one by May 1915. I would take it as an absolute certainty from what you write above that she did not have it at Dogger Bank.

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jwduquette1



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PostPosted: Wed Jun 14, 2006 11:45 am    Post subject: Reply with quote

Hi Tone.

Yes all three of the quotes are derived from Dogger Bank reports. Moore from HMS New Zealand; Lt. G.P. Bowles of A-Turret, HMS Lion; and the above quote from Lt Cmndr G.F. Longhurst, HMS Lion.

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JD
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jwduquette1



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PostPosted: Wed Jun 14, 2006 8:16 pm    Post subject: Reply with quote

I think there was some discussion earlier about the effectiveness or lack thereof of zig-zagging. Again this is more from Dogger Bank:

From Admiral A.G.H.W. Moore:

Quote:
“3. As the enemy zigzag whenever they are being hit, it is most important to practice this at the spotting tables or when doing towed target practice. Rates and Dumaresqs become almost useless under these conditions. Range-finders may help, but spotting must be the primary aid for keeping on the target.
4. There can be no doubt that we should make a turn, in or out, when enemy begins to hit; 2-points would be ample, or at high speed 1-point. Small helm should be used. This has often been practiced and will in no way interfere with our gunnery.”

LATER IN THE MOORE REPORT:

16. The enemy zigzagged very much at first, and frequently threw out the control with marked success; of course he lost ground in doing so, and thus in a measure he gave us back the equal of what he took away.

Zigzagging, if full speed is not essential, is certainly to be recommended at very long ranges, but at short ranges with time of flight of 10 or 12 seconds, it does not appear to offer much advantage.”


This is something from Capt. A.E.M. Chatfield’s Dogger Bank post action report:

Quote:
b) That it is absolutely misleading to think hits will be seen, at any rate at long ranges. Shorts are the only guide, and the great value of them must be impressed on control officers. The main object when opening fire must not be the straddle, but to obtain a big volume of fire short, and than work it up by small “ups” till hitting commences. If shots go over they are lost, and very large corrections must at once be resorted to.

Fairly reliable corrections for all ranges are: “DOWN 1,000”, or “UP, 200”.

When being hit, the enemy will undoubtedly alter course towards or away, which will require the larger down corrections in the former case in order to get short, hence the reason for 1000 yards, even after straddling.

c) Spotting is so vital and so tiring that additional spotters in various positions are essential.

Salvos when gunlaying are impracticable, as, owing to interference with aim, the rate of fire becomes a minimum.

Directors must fire rapid double salvos as soon as range is found. DERFLINGER and MOLTKE at the end fired about two salvos a minute, i.e. from their seven turrets, fourteen shots a minute at LION, whose rate of fire at that time was about two rounds a minute.

That no enemy must be left unfired at must be further driven home.

Sights of the 13.5-inch guns and all corresponding instruments, time of flight watches, etc., to be graduated up to 25,000 yards.

If the enemy commences hitting, course should be at once be boldly altered about 2 points in or about three minutes, and than reversed. Care must be taken not to do this before enemy hits, as shots look much closer than they are, and LION was continually straddled, but only hit fifteen times. The small number of hits was probably partly caused by the very small spread of the DERFLINGER”S salvos, which practically acted as on big projectile.

LATER IN THE CHATFIELD REPORT:

All turrets report on extreme value of Evershed training indicators.
All turrets seriously handicapped by spray from the ship’s speed and enemy shorts. “X” also from smoke, and the latter fired very few rounds.


What are Evershed training indicators?
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PostPosted: Thu Jun 15, 2006 9:53 am    Post subject: Reply with quote

This is curiouser and curiouser. He implies here that a director WAS in use, but only briefly. I wonder if he means to refer to directors in ships other than Lion. Even in this excerpt, he reports more elements that suggest local laying and firing (Evershed receivers, individual turrets not firing due to smoke).

An Evershed system is one of transmitters (aloft) and receivers (typically, in director and turret training positions). By pointing a transmitting scope onto the target to be taken under fire, its relative bearing is transmitted in 2 degree resolution (ugh) to receivers. Given such resolution, it was not useful in directing gunfire but it was meant to convey a shared knowledge of the object being targeted. It would be valuable in cases where local laying was occurring and enemy ships were in close proximity to each other -- each turret trainer would have a means of knowing to +/- 1 degree which way he was supposed to point his turret, and this could permit him to avoid training on the wrong enemy ship or to maintain approximate training during periods where he cannot see the enemy at all. This last would be helpful in minimizing time needed to recover when visibility was regained.

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jwduquette1



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PostPosted: Fri Jun 16, 2006 1:23 am    Post subject: Reply with quote

I came across several indications that local control during this period resulted in higher rates of fire. Is it possible this is what was going on? Of course the logical disconnect is if there are visibility issues like smoke or spray that hamper rapid independent fire, why wouldn’t director control be employed? Surely a slower rate of director controlled fire is better than some turrets or individual guns not firing at all.
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PostPosted: Fri Jun 16, 2006 12:44 pm    Post subject: Reply with quote

Local laying was amenable to the highest possible rate of fire, and indeed remained a mode of fire that a ship might resort to from locally laid salvo fire (individual layers would fire "on the bell", or as near it as they could).

The issue was that none of the RN guns could really fire in continuous aim, but if you permitted each layer to fire when his gun was ready and when he saw his wires coming on, you missed the bare minimum number of shot opportunities, and indeed they could chase the target somewhat in elevation to anticipate when the gun would be ready. I don't think, myself, that this would be such a great speed gain, but apparently it was worth repeated mention at least.

For director fire, "rapid director" was usually the quickest form of fire undertaken when the team was sure of both range and rate (the two being right meant they could be confident of several successive straddles). I think the idea in rapid director was that the guns would all try to become ready as quickly as possible and the director layer would fire as often as he could. This came at a total disregard for how many guns discharged in each volley -- you might get none at all, and you might get all of them. I'd have to double check the definition to be sure.

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jwduquette1



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PostPosted: Sat Jun 17, 2006 8:04 am    Post subject: Reply with quote

I went back through this, and perhaps I am misinterpreting what is implied by “rapid independent”; or I am reading too much into the phrase. I assumed what Beatty was implying was that rapid independent was local controlled fire, and that it somehow resulted in a greater rate of fire. Your thoughts?

This is from: J. Brooks, “Dreadnought Gunnery & the Battle of Jutland. The Question of Fire Control.”. Cass Series, Routledge 2005 (pg 227)

Quote:
“Even before the war, Beatty's battlecruiser orders had emphasised the importance of maximising the rate of hitting and had recommended breaking into rapid independent after the first or second straddle.62 Now Beatty responded, with the same complacency that he had shown after the Dogger Bank:

Yes indeed it was a terrible disappointment the battle practice of Lion and Tiger... The other three were not bad but undoubtedly as you say we could do with much more practice at sea... I do not think you will be let down by the gunnery of the battle-cruisers when our day comes.

... on the subject of rapidity of fire [I] feel very strongly . . . and think we should endeavour to quicken up our firing... the Germans certainly do fire 5 to our 2.”

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PostPosted: Sat Jun 17, 2006 9:46 am    Post subject: Reply with quote

I believe that rapid independent is all guns in local laying and firing, with each gun firing being taken at every opportunity. Range and deflection would be common to all guns (by transmission from TS), but salvoes would not result and pointing errors would differ between guns.

I think the result was fastest possible fire from those guns that could see the target, but with consequent weakness in spotting and loss of coherence in salvo pattern. I think most documents suggesting its periodic use acknowledge that after a short while it would have to be suspended so that the range, deflection and rate could again be verified by salvo fire and methodical spotting.

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lflelli



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PostPosted: Thu Feb 14, 2008 7:21 pm    Post subject: Reply with quote

A little late but if anyone is still reading this topic:

In "Naval Gunnery" by Captain H. Garbett R.N. published in 1897 there is a description of an instrument known as the "Gun Director". Unlike later directors, it does not transmit bearing and elevation data to the guns. It is a telescopic sight situated in the conning tower and allows the operator to simultaneously fire the guns. The guns having to be trained and layed based on information relayed to them by other means.

Garbett says: "... in consequence of the increased rapidity of fire from turrets, barbettes, and quick-firing guns, its value has much diminished, and its use been greatly curtailed, ..."

However, by the time of the Battle of Dogger bank the importance of salvo firing had been recognized. Salvo fire was required for effective spotting.

My (somewhat unsupported) hypothesis is that to get coherent salvos the guns had to be fired simultaneously. Maybe, what Chatfield is referring to when he says: "Directors must fire rapid double salvos as soon as range is found." is this earlier type of Director fire - essentially a simple centralised firing mechanism.

Lou
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PostPosted: Thu Feb 14, 2008 9:07 pm    Post subject: Reply with quote

Hi, Lou -- great to hear from you.

In the WW1, the Chatfield quote cited likely refers to what should be done when range is found and the rate is likely correct (or should be assumed correct, as the positive hypothesis is rewarding indeed), as it would maximise the number of rounds fired in 2-3 salvoes with the range being fairly correct for all.

Refresh my recall: is Garbett an American? I do not recall offhand (if I know at all) what director system he is referring to.

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lflelli



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PostPosted: Thu Feb 14, 2008 10:37 pm    Post subject: Reply with quote

Tone,

Garbett was Royal Navy. I won't attempt a description of the "Gun Director". I'll scan the relevant pages and email them to you if you wish.

I know I'm probably not making much sense but please bear with me a little longer :roll:

This is my interpretation of Chatfield's report:
1) The Lion does not have a Director tower installation.
2) Chatfield says: "Salvos, when gunlaying are impracticable, as, owing to interference with aim ..." Clearly this is not "Director Fire". What interference? My guess (and only a guess) is that if you ask four guns to fire in local mode, each turret will fire at slightly different times. As you point out:

Quote:
and indeed they could chase the target somewhat in elevation to anticipate when the gun would be ready.


That means that each gunner's sight will roll on target at different times. The problem here is that the first gun to fire will spoil the aim of subsequent shots due to blast, smoke and spray from water on the decks.

Chatfield then goes on to say: "Directors must fire rapid double salvos as soon as range is found.". My interpretation of what he's saying is that once you have obtained the range (by single shots as salvos are "impracticable") you can switch to full broadsides. However, because of the mutual interference issues as above, this broadsides should be fired by all guns simultaneously to keep the pattern tight.. This is done via the "Gun Director" (in the Garbett definition of Director). My feeling is that if guns were being discharged simultaneously via a common firing switch prior to 1897, then I don't see why it could not have been done in 1914.

Of course this was all academic as practice proved that finding the range and keeping it was far more difficult than anticipated. Chatfield's statement about broadsides when you have the range is probably an optimistic 1914 viewpoint which did not work out. In practice the much more sophisticated "Director" (in the Percy Scott definition of the word) was required to find and keep the range.

Again, let me stress that I'm simply throwing out ideas here with little in the way of hard data to back them up - I simply have too much spare time on my hands :) Now I'm off to scan the chapter from Garbett's book.

Regards,
Lou
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PostPosted: Thu Mar 20, 2008 3:08 pm    Post subject: Reply with quote

I'm sort of puzzled by the remark that a range of 21,500 yards was "put on the plot", as the Mark IV* table plotted from 2,000 to 20,000 yards at this period (later it was adapted to go to 28,000 yards). However, I think I see how it was done -- it had two places where the range pencil could be mounted to permit it to draw in the 5 inch margins of the plot if truly needed. I'm guessing that this was paired with a means for similar slack in the range cut typewriter and that this was used to permit the extra play.

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jwduquette1



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PostPosted: Wed Mar 26, 2008 10:14 am    Post subject: Tiger Gunnery Training, 1918 Reply with quote

I thought the attached scans might be an interesting addition to this thread on gunnery. These are photocopies of archival materials I recently obtained from the UK. It is a rather extensive report on gunnery training\exercises conducted in early 1918 by the Grand Fleet. This set of pages is from one of the Tiger’s exercises. The commentary on the first two pages is interesting. However, I’m not sure I fully understand what is going on in the plot for this set of shoots, and would be interested in reading peoples comments on how to interpret this thing.

Best Regards
JD













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Last edited by jwduquette1 on Tue Apr 08, 2008 11:35 am; edited 1 time in total
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PostPosted: Wed Mar 26, 2008 12:43 pm    Post subject: Reply with quote

This is fascinating by the very second sentence, which implies that they were averaging estimated inclinations sent to the TS, and having the rate control officer apply this to set his dumaresq and decide on the rate to be used. I knew that a conclusion of Jutland was to move away from trusting the rangefinders to tell them anything useful and to concentrate on inclination, but this is a wonderfully clear indication of how they put this into practice.

.... reading...

Also, to see just below that they are using bearing transmitters to send inclinations to the TS. A clever strike against those who might claim the RN was not inventive at seeking expediencies to speed innovation ahead of a world doctrinal and equipment inertia!

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