"Chasing Goeben" Topic

I am trying to figure out what ought to happen if you set up Milne / Troubridge versus Souchon on the table.

The maximum range of the British cruisers' guns was about 14,000 yards and that of Souchon just under 20,000. That gives a "safe zone" of about 5,000 yards inside which Goeben can reach a hypothetically pursuing armoured cruiser but not be reached.

At Jutland, where much of the firing was at similar ranges, the incidence of heavy hits was about 3 or 3.5%.

So if Goeben is being pursued by four armoured cruisers, and she has to score at least one hit on each to slow it down, she has to fire about 120 rounds from – presumably – her after turrets. If it takes three or four rounds to do so she has to fire maybe 500 rounds.

Does anyone know how many rounds of 11-inch she would have carried, i.e. did she have 500 rounds in her after magazines? How difficult was it to move ammunition aft from the forward magazines?

Goeben carried 81 rounds for each 28cm gun, tho not all would have been APC ammunition. So, her after magazines would have had 324 projectiles. The rest on the after magazine allotment being HE and practice shots.

link

I'm not sure if the magazines for Goeben's midships turrets were singled or combined, but together they'd have 324 more. Each shot to be moved from the midships aft would have involved 3 parts. The projectile itself of 660ibs and 2 propellant bags of 57 and 174lbs. It is difficult to imagine a chain of hands being able to bring projectiles from the midships magazine(s) at a rate anything like supplies brought from the after magazines..

The modest supply for the forward turret Anton would likely be irrelevant.

At long range hits would be few. But if Goeben could have slowed even 2, it might well have enabled Souchon to turn and tangle withe the others.

Better for Goeben to turn just enough to bring 4 turrets to bear, while still keeping the range open. Beyond doubling the rate of fire, it's much easier to adjust ranging with an 8-round ladder than with 4 rounds. At some point, you'll need to cut back and fire the opposite broadside, but you're still not losing too much relative speed by running 30 degrees off of a direct route.

From Staff, "German Battlecruisers of World War One", page 68, the magazines and shell rooms for the wing turrets were separated by two boiler rooms.

Cosentinoe & Stanglini, "British & German Battlecruisers", page 158, gives the ammo load as 150 per turret for the forward and wing turrets and 180 for the rear turrets, 810 rounds total. That would give 90 rounds per gun for the rear guns.

Contrary to Navweaps, neither book mentions anything other than AP shells.

Hi 4c & HMS Exeter,

Gary Staff, ("German Battlecruisers") indicates that GOEBEN carried 81 x L/3.2 302kg APC for each of her ten 28cm L/50 main battery guns; each of her twelve 15cm secondary guns was supplied with 50 x "L/3.2 AP" plus 100 x "L/3.5 AP nose-fuzed" (which I would interpret to actually translate as "common shell").

Maximum range of GOEBEN's 28cm guns (in 1914) was 18,100m @ 13.5deg, which equates to ~19,800 yds. Range of her 15cm secondary battery was 13,500m @ 20deg, which equates to ~14,750 yds.

Based upon Staff's deck diagrams, I cannot see how transfer of 28cm ammunition from one turret to another would have been practicable.

- – -

Per Campbell, ("Warship 1 Special – Battlecruisers") GOEBEN's official main battery ammunition stowage was confirmed as 81 x 28cm APC per gun, but he goes on to say that "British intelligence" believed this 81 shell figure to be true only for the guns of the wing turrets, with the center-line turrets stowing 96 x APC per gun. FWIW, my guess would be that this (if true) was most likely a later modification of her main battery ammunition stowage arrangements.

Campbell also states that GOEBEN was not fitted with her main and secondary battery semi-directors until late 1916 or 1917. However, the very good gunnery performance of the similarly unfitted German battlecruisers at Dogger Bank (Jan 1915) should be borne in mind -

Seydlitz – 390x 28cm APC expended for "at least 8 hits".
Moltke – 276x 28cm APC expended for "8-9 hits".
Derfflinger – 234x 30.5cm APC + 76x "base-fuzed HE" for 5-6 hits.

The three British battlecruisers engaged by the above-mentioned German ships officially counted a total of 22 heavy caliber (28/30.5cm) hits suffered among them – LION (16 hits), PRINCESS ROYAL (0 hits), TIGER (6 hits).

Pretty good shooting for the long distances involved (16,000 – 18,000 yards).

- – -

Re armament of Troubridge's 1st Cruiser Squadron (Aug 1914), per Campbell's series of articles in Warship.

DEFENCE
4 x 9.2in Mk XI – 16,200 yds @ 15deg (2crh)
10 x 7.5in Mk II**/V – 14,100 yds @ 15deg (2crh)

BLACK PRINCE
6 x 9.2in Mk X – 15,500 yds @ 15deg (2crh)
10 x 6in Mk XI – 14,310 yds @ 15deg (4crh)

DUKE OF EDINBURGH
6 x 9.2in Mk X – 15,500 yds @ 15deg (2crh)
10 x 6in Mk XI – 14,310 yds @ 15deg (4crh)

WARRIOR
6 x 9.2in Mk X – 15,500 yds @ 15deg (2crh)
4 x 7.5in Mk II**/V – 14,100 yds @ 15deg (2crh)

- – -

Being a long-time devotee of the entire fascinating episode of the flight of the GOEBEN, allow me to recommend what I consider a terrific historical work on the topic – Geoffrey Miller's book "Superior Force" – by far the best I have read on the subject.

FWIW. Hope this had been helpful.

B

Nice info, NCC1717. I have Coesentino & Stanglini, but neglected to consult it.

Haven't heard from you in a while. Hope you are doing well!

B

I also like Geoffrey Miller's "Superior Force" and his other two books on the Med. All three are still available to read free online:

navalhistory.co.uk

Blutarski,

I'm doing fine, thanks. Still changing the WW1 naval game code constantly. See for example the new code overview here:
link

Given that these same AC's (less DofE) were cut to pieces at Jutland by 11" and 12" shells, and given the hammering that the BC's took from 12", 13.5" and 15" shells, and Goeben's sister Moltke from at least 4 15", I doubt 9.2s and 7.5's, even 16 and 14 respectively on the broadsides would have had much chance.

"81 shell figure to be true only for the guns of the wing turrets, with the center-line turrets stowing 96"

It may be a coincidence, but the Navweaps link above lists that for Seydlitz. The total (900) is not consistent with either Staff or Coesentino & Stanglini, both of which give a total of 870 for Seydlitz. Coesentino & Stanglini do not give a turret breakdown for Seydlitz as they do for Moltke/Goeben.

VirtualScratchBuilder:
Agree completely. Gaming this fight that I did some years ago always resulted in the ACs losing badly. In addition to the weight of fire, fire control and range issues, the shell issues (fillers exploding due to impact and shells shattering due to oblique angles) make it difficult for the ACs to damage Goeben.

Not to beat a dead squadron..er horse, but the four ACs all have mixed batteries. That means as many as eight separate batteries trying to range on Goeben (assuming Breslau stays out of range). Judging fall of shot would seem to be a problem.

""81 shell figure to be true only for the guns of the wing turrets, with the center-line turrets stowing 96"

Double-checked and Campbell did indeed write that in connection with MOLTKE/GOEBEN. No specific source reference was provided, however, beyond mention of British intelligence. I did, at this point, have the presence of mind to haul out "German Warships of World War I – The Royal Navy's Official Guide to the Capital Ships, Cruisers, Destroyers, Submarines and Small Craft, 1914-1918", whose data MUST to some degree have been compiled by British naval intelligence. The following appears on pg 32 in connection with MOLTKE/GOEBEN -

quote -
ARMAMENT, cont'd
Magazines and Stowage -
For 11-inch guns, 96 rounds per gun (centre-line turrets)
For 11-inch guns, 81 rounds per gun (side turrets)
- unquote

No further detail or source reference provided.

FWIW.

B

NCC1717 wrote -
"Not to beat a dead squadron..er horse, but the four ACs all have mixed batteries. That means as many as eight separate batteries trying to range on Goeben (assuming Breslau stays out of range). Judging fall of shot would seem to be a problem."

True words – Concentration firing upon a single target was only practiced by pairs of ship bearing the same armament and operating adjacent to one another in a close-order formation. DEFENCE and WARRIOR conducted such pair fire concentration against WIESBADEN at Jutland.

Following from the Jutland Despatches -

Report of Captain Molteno, HMS Warrior – Official Despatches (p.291)
"Defence" altered course about three points to port and brought the second or third light cruiser, which was closer than the others, to the bearing of Green 80. She then signaled " open fire " and " ship interval 12 seconds."

- – -

Narrative of H.M.S. Warrior – "The Fighting at Jutland" (p.159-160)
At about 5.47 I sighted three or possibly four enemy light cruisers about 20 degrees on my starboard bow, and I now increased speed to 21 knots to close from ½ a mile to Ό of a mile astern of Defence. Defence then altered course about 30 degrees to port, bringthe nearest enemy cruiser – the Wiesbaden – on to a bearing of Green 80 (80 degrees from right ahead on the starboard side) and signaled "Open fire, ship interval 12 seconds". Three salvoes were fired by each of us at extreme range under the concentrated pair ship fire organization which the squadron had worked up, but all the shot falling short, we checked fire, and Defence altered course directly towards Wiesbaden. At 6.1 p.m. the Defence again altered course and brought Wiesbaden on to a bearing 40 degrees on the port bow.
<snip>

[Blutarski note – My best guesstimate is that Abuthnot closed the range from 15,000 yds down to about 8,000 to 10,000 yards.]

Defence and Warrior then opened fire, and the second salvo of both ships hit the Wiesbaden, setting her on fire, and causing a great escape of steam on board her. In a few minutes she was seen to be stopped, but as she was still in a position favourable for firing torpedoes at our battle cruisers, we, Defence and Warrior, continued hitting her again and again with our port guns, closing her to within 6,000 yards before turning away. During this time everything seemed to be happening quite naturally and in order, with nothing surprising nor disconcerting. When both Defence's and Warrior's second salvoes hit the enemy, I remember remarking to the Navigator, "We have never had a practice concentration of fire go off so smoothly and successfully." There seemed to be plenty of time for everything; to give orders, to have them repeated, and to have them reported back executed.

- – -

The best easily available resource concerning concentration fire, as employed and developed in the RN during WW1, is ADM186339 C.B. 3001/194-36 – Progress in Naval Gunnery 1914-1936.

FWIW.

B

Friedman, "Naval Weapons of World War One," diagram on page 139 and text on page 141 indicate the turrets for Moltke and Seydlitz had storage for 8 ready-use shells. This might explain some of the inconsistencies between statements of magazine storage and rounds per gun. I don't know if the ready-use shells were removed from the magazines and returned, or were extra shells beyond what the magazines could hold.

Possibly not relevant to the Moltke, but Friedman on page 135 gives the standard load for the 30.5cm guns and says the British claimed higher numbers. He does not give a source for either but he may be referring to the British intelligence reports.

The reprint of the Royal Navy's official guide to German warships, ISBN 1-55750-303-6, lists magazine storage. Page 66 has, for Moltke, 96 rpg center line and 81 rpg wing. Page 61 has the same for Seydlitz.

Thanks all – much good info. To pick up / respond to some of the points made:

@ HMS Exeter: Looking at Goeben in planform it seems probable that if she were being pursued by a line abreast she could have brought three or even four turrets to bear. The figure of 81 shells per gun therefore may have to reflect six to eight rather than four guns. Even if it's only four, if they fired off all 81 rounds you'd expect about eight or nine hits, which ought to be enough.

@ emckinney: so as there is about a two-mile "safe zone" in which Goeben can hit but not be reached she could, presumably, yaw to either side and fire broadsides. At 23 knots it would take a CA six minutes to come within range so Goeben could have fired probably half a dozen observed broadsides in that time, then resumed her previous course.

@ Blutarski – the score percentages for Dogger Bank fit well with my guess of 3% to 3.5% hit rate. On your figure for the range of the 9.2-inch, Navweaps reckons the range was indeed 15,000+ yards but that the weapon was only "calibrated" to 14,000 which I assume means you couldn't elevate it reliably for the longer ranges? Thanks for the book tip BTW.

@ virtualscratchbuilder and NCC1717: yes, it seems to me that one 11-inch hit on a CA could easily have proven fatal. In an actual battle, I am convinced at least one of the four CAs would have exploded, and Goeben might have escaped pretty much unscathed. That said, you don't fight her in the expectation of defeating her. The operational aim would have been to get her to thrash her machinery, exhaust her coal and shoot out her magazines. This would make her a much less potent threat thereafter. The political aim would have been to discourage Turkey from joining the war – her value would have been less and even if resupplied with ammunition Turkey would have been sent the message that if she sortied again she could expect frenzied attack.

Here is a ‘historical fiction' account of the origin of the British intelligence on Moltke's 28cm magazine load.

Design documents for the Moltke class specify the following magazine loads (as reported by Cosentinoe & Stanglini, "British & German Battlecruisers", page 158):

150 per turret for the forward and wing turrets and 180 for the rear turrets, 810 rounds total.

A British intelligence agent in Germany learns the total rounds (810) and the number of 28cm guns (10) and transmits this information to Britain. An analyst there divides 810 by 10 and documents the number of rounds per gun as 81.

A British intelligence agent in Germany learns that the center-line magazines have 30 more shells than the wing magazines (180 vs 150) and transmits this to Britain . This is incorrect, since only the after center-line magazines have 180 shells. An analyst in Britain reasons that 30 additional shells per magazine is 15 additional rounds per gun, giving 81 + 15 or 96, for the center-line magazines. He fails to reconsider the original assessment of 81 rounds per gun. This information is included in the report send to the fleet, and later used by Campbell, Friedman and Navweaps, and reprinted (1992) by Naval Institute Press (the reprint has a forward by Friedman).

4th Cuirassier:

Good points. Achieving the operational aims of burning up her coal and emptying her magazines seems possible. To trash her machinery would probably require AP shells that worked. Some holes in her funnels might slow her a bit.

Hi 4c,

@ HMS Exeter: Looking at Goeben in planform it seems probable that if she were being pursued by a line abreast she could have brought three or even four turrets to bear. The figure of 81 shells per gun therefore may have to reflect six to eight rather than four guns. Even if it's only four, if they fired off all 81 rounds you'd expect about eight or nine hits, which ought to be enough.

Looking at the fates of the armored cruisers and first generation battlecruisers lost at Jutland -
INDEFATIGABLE – blew up after about 15 minutes under fire.
INVINCIBLE – ditto.
DEFENCE – ditto
BLACK PRINCE – ditto
WARRIOR – foundered as a result of uncontrollable progressive flooding combined with failure of her propelling machinery. Lucky ship, as the crew largely survived.

At Coronel, both MONMOUTH and GOOD HOPE suffered major cordite "events" and sank (Waiting with great anticipation for Mark Bailey's upcoming book on Coronel).

Moral to the story, IMO – none of the armored cruisers had the armor to resist a major caliber hit and any such hit that involved a magazine, handing room, working chamber, turret, ammunition lobby, or munitions passageway for the secondary battery was likely to result in a cordite explosion. Their boilers and machinery were equally vulnerable. We are talking, of course, about ranges up to 13,000-14,000 yards for 28cm hits.

@ emckinney: so as there is about a two-mile "safe zone" in which Goeben can hit but not be reached she could, presumably, yaw to either side and fire broadsides. At 23 knots it would take a CA six minutes to come within range so Goeben could have fired probably half a dozen observed broadsides in that time, then resumed her previous course.

I'm not sure that any of the ships of 1st Cruiser Squadron actually possessed a speed advantage over GOEBEN; Geoffrey Miller's book argues that Troubridge's armored cruisers were capable of no better than 20 kts versus 22 kts (24 kts for brief spurts) for GOEBEN.

@ Blutarski – the score percentages for Dogger Bank fit well with my guess of 3% to 3.5% hit rate. On your figure for the range of the 9.2-inch, Navweaps reckons the range was indeed 15,000+ yards but that the weapon was only "calibrated" to 14,000 which I assume means you couldn't elevate it reliably for the longer ranges? Thanks for the book tip BTW.

I have encountered mention of the "calibration" issue in other connections: at Dogger Bank, it was said that the British 13.5in guns were "calibrated" to 17,000 yds; at Jutland it was implied that the 15in guns were "calibrated" up to 20,000 yds. My belief is that this was related to their Dreyer FC tables and did not prevent the guns from being fired at greater ranges. Still trying to get to the real details at the bottom of this.

@ virtualscratchbuilder and NCC1717: yes, it seems to me that one 11-inch hit on a CA could easily have proven fatal. In an actual battle, I am convinced at least one of the four CAs would have exploded, and Goeben might have escaped pretty much unscathed. That said, you don't fight her in the expectation of defeating her. The operational aim would have been to get her to thrash her machinery, exhaust her coal and shoot out her magazines. This would make her a much less potent threat thereafter. The political aim would have been to discourage Turkey from joining the war – her value would have been less and even if resupplied with ammunition Turkey would have been sent the message that if she sortied again she could expect frenzied attack.

Troubridge's best chance versus GOEBEN (IMO) would have been a close range ambush at night, supported by his DDs and CLs, whereby he could take up a "down-moon" position against a dark horizon. The decisive aspect of the fight (theoretically) would be determined by torpedo attack.

I think that would be a really interesting scenario to put together ….. although one wrong move on the part of either player would conceivably bring the entire scenario to an end in very few moves.

B

"The decisive aspect of the fight (theoretically) would be determined by torpedo attack."

Agree, but Troubridge's coal burning Beagle class DDs with their 21" 'short' Mk I torpedoes will be less likely to get into range undetected than newer oil fired DDs with longer range weapons.

@ Blutarski

Interesting points. I agree that Troubridge's CAs would not have lasted long. Cradock clearly absorbed the message that declining battle was not acceptable, and duly got himself honourably destroyed.

To be clear, the scenario I'm assuming is the worst-case one for Troubridge, where he is spread out in line abreast for search purposes and finds Goeben ahead of him in daylight. Goeben withdraws, and uses her speed advantage to keep Troubridge out of range, but under fire.

In this situation Goeben may be able to train four turrets aft depending on how widely dispersed Troubridge's line is. If so it seems clear that she had enough ammunition to hand to destroy his force, based on the gunnery performance of similar ships elsewhere.

For economy of ammunition use, I am supposing that Souchon might have turned 90 degrees to either side at some point. This would allow all ten guns to fire. As she is now no longer drawing away, Troubridge's ships would now be able to close the range. But it would take five or six minutes to get inside the maximum range of their 9.2, 7.5 and 6-inch guns assuming they have 5,000 yards to cover at 20 knots. So Goeben gets about five minutes to fire full salvoes, then turns away again, re-establishes her previous lead in around 90 minutes, and does it again.

The only way this fight makes any military sense is if the pursuit can go on long enough for Goeben's coal state to get critical, or she maybe suffers a mechanical breakdown. If that happened early enough, Troubridge's four CAs might catch up enough to do some hard-to-repair-in-Istanbul damage.

Absent that slim hope, all the reasons for attempting to fight Goeben are political, reputational, or something else, but they're not based on a sound reading of the prospects of success.

Troubridge saved his men's lives; it's conjecture whether expending them would have brought about some other benefit. What does seem clear is that there was no role at all by 1914 for CAs to speak of. They couldn't defeat anything they could catch, so were just massacres waiting to happen.

Hi NCC1717,
Agreed. Being coal-fired, the British DDs would have had to be very careful to avoid funnel sparking (or excessive smoke).

One other point I will offer for consideration involves the nature of torpedo carried by the "Beagle" (G Class) DDs. Edgar March ("British Destroyers") indicates that this class carried 2 x single short center-line tubes with 4 x 21-in RGF heater Hardcastle torpedoes with a warhead of only 225 lbs wet guncotton (= only about 75 lbs TNT); I can find no information as to whether these warheads were ever upgraded to TNT or Amatol by 1914.

B

Hi 4c,
I'm guessing from the ranges quoted that you are assuming a daytime engagement. IIRC, Troubridge had 1st Cruiser Sqdn + light cruiser HMS Dublin + destroyers Beagle and Bulldog, while Souchon had (of course) Goeben and light cruiser Breslau.

Some tactical thoughts on my part …

Dublin carried 8 x 6-in [5 gun broadside] + 2 x 21-in torpedo tubes, 2-in max belt and deck protection and could make about 25 kts best speed. By comparison, Breslau carried 12 x 4.1-in (6 gun broadside), 2 broadside 19.7-in torpedo tubes, 60mm max belt and deck protection and could make up to 28 kts on a good day.

Breslau could out-run and out-range Dublin, but had a 1:2 inferiority in weight of broadside, so she had to be careful not to get tangled up in a close-range gun action.

The two British DDs had no realistic margin of speed over Breslau, which could easily crush them with her numerous main battery gun battery, so they needed to be EXTRA careful about getting anywhere near Breslau without support close nearby.

Re Goeben, she could effectively engage two targets simultaneously with her main battery, while her well-protected 5.9-in secondary battery would definitely have kept Dublin at a respectful distance.

- – -

It is pretty clear (at least to me) that Souchon was not interested in a fight if it could be at all avoided. There was simply no profit in it for him. Once he had abandoned his northward feint toward the Strait of Otranto, it would have been obvious to everyone in the stadium that his true goal was the Dardanelles. This, in turn logically implied Souchon shaping a course south down the coast of Greece, past the Ionian Islands, rounding the peninsula of the Peloponnesus, then through the islands of the Aegean Sea to the Dardanelles. Goeben probably had less than 1500 tons of coal aboard for a voyage Messina > Istanbul of about 1,100 sea miles. We know that Souchon was very concerned about his fuel situation, because he had made efforts to arrange for at least three colliers to be strategically positioned at rendezvous points along the route (not, I think, because he believed he needed three colliers worth of coal to make the voyage, but because he did not know how long and dogged a pursuit might be and did not want to get caught while coaling in some confined island anchorage).

With regard to your tactical set-up, I'm assuming that Souchon first encounters Troubridge and 1st Cruiser Squadron to the south, more or less across his intended path. How far apart re the armored cruisers? Where are Dublin and the two destroyers in relation to the scouting line? What is the maximum visibility (funnel smoke over the horizon)?

B

Blutarski,

About the relation between guncotton and TNT in torpedo warheads, you give a ratio of about 0.33 (75/225). Currently I am using these scaling values (normalized to TNT):

Torpedo and mine warhead
Explosive type scaling
Guncotton ------- 0.65
TNT ------------- 1.0
Picric acid ----- 1.04
Hexanite Shimose- 1.1
Amatol ---------- 0.9
SW18 ------------ 1.4

Is there a source you could recommend for the guncotton ratio?

For the short 21" torpedo, Friedman, page 331, has confusing data on the MkI and MkI*. The MkI has much longer range than other sources, and he does not mention the MkI* in the text. Currently I am using the MkI* ranges since they seem more reasonable.

Also, Miller's "Superior Force" does mention sparks from the DD funnels visible at night.

Thanks,
NCC1717

Hi NCC1717,
First off, my apologies for under-rating the value of guncotton versus TNT. Bad memory and failure to double-check my references before typing my post. I suspect I was actually recalling the relationship between prismatic powder and cordite propellants. Chris Carlson, an Annapolis/USN/DoD guy (and fanatical naval wargamer) who did this sort of stuff for a professional living has rated guncotton @ ~0.5 in relative value versus TNT. It seems there were many grades/formulae of guncotton over the decades and the same is probably true of TNT as well.

In the course of research for my (perpetually under development and unfinished) WW1 naval rules, I dug myself a pretty deep research pit on torpedoes and explosives. The more I looked into the relative figures of merit for different high explosives, the more complicated things rapidly became.

The following info comes from a 1945 US weapons data bulletin regarding air/land/sea explosive munitions explosives. I have copied below details of those explosive fillers used for underwater weapons (mines and torpedoes):

"Det Vel" = Velocity of Detonation in meters/second.
"Pk Press" = Relative Peak Pressure versus TNT (TNT = 100)
"Impulse" = Relative Impulse versus TNT (TNT = 100)

Explosive – – – – Det Vel – – Pk Press – – Impulse
TNT – – – – – – – 6800 m/s – – – 100 – – – – 100
AMATOL – – – – – -6300 m/s – – – 104 – – – – 106
TETRYL – – – – – -7300 m/s – – – 100 – – – – 110
COMPOSITION B – – 7500 m/s – – – 110 – – – – 108
TORPEX 2 – – – – -7200 m/s – – – 116 – – – – 127
HBX – – – – – – – 7100 m/s – – – 113 – – – – 125
TRITONAL – – – – -6600 m/s – – – 105 – – – – 118
MINOL 2 – – – – – 5900 m/s – – – 108 – – – – 126
PENTOLITE – – – – 7500 m/s – – – 110 – – – – 125

In the case of guncotton versus TNT, various web sources I have unearthed give an average detonation velocity of ~3,000 m/s.

Explosives with high brisance (detonation velocity) are generally held in higher regard across the board. Explosives with a lengthy impulse duration are preferred for underwater weapons. Minol, for example, was developed by the UK early in WW2 as a substitute explosive to make up for TNT shortages (note its modest detonation velocity); but served well in mines, depth charges and torpedoes due to its lengthy impulse duration – as good as Torpex and Hexanite. I have found it difficult to confidently draw up a really meaningful (in game terms) differentiated hierarchy of explosive values, especially when they fell within a common time period or chemical family.

To make a long story short, I chose to rank the explosives on the basis of – [detonation velocity ratio] x [impulse ratio],
which would, for a general example, give a ranking as follows for underwater attack -

TNT = 1.0
0.5 for wet gun cotton (I have no value for impulse).
1.0 for Amatol
1.3 for Torpex
etc.

That provides some sort of rational starting point for the next step, which is a two-parter -

(a) whether or not the effective torpedo explosive value will breach any torpedo side defense system present.

(b) whether the striking point of the torpedo is close enough for its explosive effect to breach any nearby watertight transverse bulkhead. DK Brown wrote some terrific material on this subject before he passed away.

FWIW.

B

Thanks very much Blutarski. I think for now I will lower my guncotton scaling to 0.5 and leave the rest as is. Given the large random variations I apply to damage later on, the others don't matter much.

@ Blutasrski

I have not thought my way that far into it. The only time I've played this was a long time ago using GQ2. In these rules ships are limited to 18 turns' fire. They made it a bit too hard for Goeben to win, because at the longish ranges involved, you won't hit often enough to clobber all Troubridge's ships before you run out of ammo. In fact, you may not hit at all. Worse, if you close to improve your hit rate, you take fire from the cruisers that at their maximum range can penetrate your armour.

I was more coming from the idea that, given the 2 to 3% accuracy of naval gunnery 100 years ago, Troubridge's assumption of certain defeat might have been misplaced. If Goeben's ammunition state meant that she would run out of ammunition before Troubridge ran out of ships, his chances were better than he thought.

It seems he was right about the likely outcome. The discussion above about the probable ineffectiveness anyway of 9.2-inch hits on Goeben, given the type's resilience to 12-, 13.5- and 15-inch, was an angle I hadn't considered.

Hi 4C,
I still have my copy of GQ2 sitting in a file cabinet. We used to play quite a lot of those rules "back in the day". Great "fast-play" game – especially in comparison to Fletcher Pratt; but it was written at a time when good historical research and data on WW1 naval history was very hard to come by in the USA. And, as they say, the devil is always in the details.

What do we know today that might have a bearing on a Troubridge scenario?

1 – At Dogger Bank, Hipper's BC's had averaged hit rates of 2.0-2.5 pct at 16,000-18,000 yards. What would have been the hitting rate at about, say, 8-10,000 yards?

2 – At Jutland, Cordite instability resulted in catastrophic explosions that destroyed two BCs (Indefatigable (@ <14000 yds), Invincible @ ~8,000 yds) and two ACs (Defence @ ~8,000 yds, Black Prince @ ~3,000 yds) within 15 minutes of their having been engaged by heaby German guns.

3 – German heavy AP with delay-action fuzing could reliably penetrate at least a 1/2-caliber of KC @ 30deg obliquity and (usually) burst well inside the target.

4 – British APC Lyddite (until the introduction of the "Greenboys" in 1918) would either break up against KC armor of thickness =/> 1/3-caliber KC at obliquity >/= 20deg. Troubridge's ships would have been better off firing black-powder-filled CPC.

5 – British ships were only trained to conduct two-ship fire concentrations upon a single target (See Defence & Warrior engagement of the crippled Wiesbaden at Jutland – where they failed to hit until reducing range to about 8,000 yds against a stationary target).

6 – All four ACs concentrating upon Goeben would have produced great spotting confusion (see results of the uncoordinated firing of the deploying British battleships upon the crippled Wiesbaden at Jutland).

I do think that Fawcett-Wray (Troubridge's flag-captain board Defence) was right in discouraging Troubridge from seeking a daytime engagement … although I do think that Souchon would have made every effort to use his superior speed to avoid getting embroiled in a pitched dog-fight … considering the ever-present "golden BB" factor being what it is.

OK, enough hyper-ventilating. I'm going to go take a sedative now …..

B

Went into my HM Range Tables 1918 and looked up the 9.2-in Mk XI/XI* firing a 380lb projectile @ MV 2,875 f/s. This document also provided 50% zone dimensions at various ranges. Comment made to the effect that gun not reliably effective beyond 13,200 yards.

Range 16,000 yds
Terminal velocity = 1,051 f/s; angle of fall = 33 deg.
50pct zone: [depth 120 yds] x [breadth 34 yds] x [height 200 ft]
A perfect straddle (salvo MPI placed exactly amidships at waterline of target) = likelihood of 0.50 hits from a four shot salvo.
AP shell likely to break up against any FH vertical armor > 3 inches due to angle of fall > 30 deg; no data (yet) on hit against horizontal armor.

Range 8,000 yds
Terminal velocity = 1,495 f/s; angle of fall = 6.63 deg.
50pct zone: [depth 77 yds] x [breadth 9 yds] x [height 27 ft]
A perfect straddle (salvo MPI placed exactly amidships at waterline of target) = likelihood of 1 hit from a four shot salvo.
Still working on AP penetration capability versus FH vertical armor (AP shell would still tend to break up versus armor > 3 inches if striking obliquity > 20 degrees). Hits on horizontal armor would tend to ricochet on basis of acute 6 degree angle of fall.

Re Times of Flight -
At 8,000 yards, Time of Flight = ~12 seconds. Allowing 15 seconds to spot fall of shot, then compute and transmit
corrections to the guns, makes a total of 27 seconds. Spotted rate of fire then = ~2.2 salvoes per minute.

At 12,000 yards, Time of Flight = ~21 seconds. Allowing 15 seconds to spot fall of shot, then compute and transmit
corrections to the guns, makes a total of 36 seconds. Spotted rate of fire then = ~1.7 salvoes per minute.

At 16,000 yards, Time of Flight = ~33 seconds. Allowing 15 seconds to spot fall of shot, then compute and transmit
corrections to the guns, makes a total of 48 seconds. Spotted rate of fire then = ~1.3 salvoes per minute.

- – -

By comparison, GOEBEN's 28cm main battery had the following times of flight -
8,000 yards = ~11.5 seconds = ~2.6 spotted salvoes per minute.
12,000 yards = ~17 seconds = ~1.9 spotted salvoes per minute.
16,000 yards = ~25.5 seconds = ~1.5 spotted salvoes per minute.

FWIW.

OK. Finally calling it a night.

B

Blutarski,
About 5 years ago we spoke on the phone for a few hours about this.

What did you decide the round trip time is from the spotting top to the plotting room and back?

Wolfhag

@ Blutarski

Sounds like you're about 30 years ahead of me in your thinking on this. Reading back then about Coronel, the Falklands, Dogger Bank, and Jutland, I decided that GQ did not adequately consider the various different versions of each gun, the spotting time issue, overmatch versus thin armour, or the aggregate effects on the rate and effectiveness of fire of all these variables taken together. As you say, good fast-play rules, but many of the gun values appear grossed-up naively from shell size. This works OK among say battleships firing at other battleships, but not so well when a different ship type with a different RoF is involved.

I started to tinker with these rule factors but then decided armour and torpedoes needed to change too, and then you are really saying you need a different set of rules.

An interesting game would be Bluecher rather than Goeben against four CAs. Same speed and gun range dynamic but Troubridge would nonetheless have fancied his chances and sought battle against an 8.2-inch cruiser. At least, he'd certainly have struggled to persuade anybody that Bluecher was a superior force, least of all himself, so I think he'd have gone for it.

I would back Bluecher to blow up a couple of CAs and get away. The interesting what-if is then, what if the RN had thought about this and done something about its causes before, oh, May 31 1916?

Hi Wolfhag,
For deliberate bracketing fire (i.e., disregarding use of initial forking groups, ladders, double-salvoes) I collected and examined data from various sources such as Campbell, which described cases of "n" numbers of salvoes within a given period of time. From there it was a step-by-step process to establish a typical value for processing and acting upon spotting results.

Assume that the account stated that battleship "X" fired 7 salvoes in 4m 30s. Assuming that the stop-watch started with range-taking plus observation and plotting of target motion preparatory to the first salvo, then seven salvoes were discharged over a period of 270 seconds. This implies ~39/40 second cycle per salvo discharge.

Assume that the ranges at which these salvoes were fired averaged 15,000 yds and that the projectile time of flight for that range was 25 seconds.

Subtract the 25 second ToF from the 39/40 second salvo interval, which leaves ~15 seconds for spotting observation to be transmitted down to the T.S. (""Transmitting Station", where the FC computer was located), aim correction to be computed, new elevation and deflection orders to be transmitted to the guns, and turrets to report ready for the next salvo.

It's a convenient but not unreasonable war-game value. In the real world, the time required could vary, depending upon visibility problems, communication interruption, even the nature of the fire control apparatus. (For example, early in WW1 the RN's "Follow-the-Pointer" (FTP) system of communicating elevation/deflection orders to the turrets required only that the operator in the turret manually match dial pointers to cover those remotely controlled by the Transmitting Station in order to apply the new gun orders. In the USN of that era, gun orders were transmitted in degrees/minutes/seconds and required more time and effort on the part of the operator to apply the new orders at the gun. When the USN saw the RN's FTP, they immediately took steps to adopt it).

The more I have gotten into this over the years, the more complication and nuance has emerged.

BTW – Is the "Chattanooga Choo-Choo" still on schedule?

B

Blutarski,
Yes, I figured about 15 seconds. IIRC that's about the timing we discussed. Things like degraded spotting (getting bracketed by near misses), surface glare, poor crews, smoke, and poor environment creating spotting problems, it could take longer. There could always be the chance of the LOS being blocked too. Some factors could also reduce the max spotting range. It would be somewhat random too.

If communications between the two are broken down what method is used to deliver the message and how long would a round trip take?

How do you guys handle determining the amount of time from the first spotting to firing the first ranging salvo? Does more time spent getting the range translates into better accuracy?

Course changes: How many degrees per second could a ship make a course change and still stay on target?

The train is scheduled to leave the stations early as Aug 13. Still, no solid destination to pull into yet but the Chattanooga area is still the main destination.

Wolfhag

Hi 4C,
Sounds like you're about 30 years ahead of me in your thinking on this.

Dunno about that. But I have been at it a long time. The disease first manifested when I bought the re-issue of Jane's 1914 Fighting Ships back in the late 60's (IIRC). I remember thinking at the time that the Jane's book was the "Cat's a@@" and it contained everything I needed to write the perfect set of rules. LOL.

Reading back then about Coronel, the Falklands, Dogger Bank, and Jutland, I decided that GQ did not adequately consider the various different versions of each gun, the spotting time issue, overmatch versus thin armour, or the aggregate effects on the rate and effectiveness of fire of all these variables taken together. As you say, good fast-play rules, but many of the gun values appear grossed-up naively from shell size. This works OK among say battleships firing at other battleships, but not so well when a different ship type with a different RoF is involved.

What you say is absolutely true, but I will never criticize Lonnie Gill ( author of GQ) for taking the leap. Everyone back then was, figuratively speaking, working from the back of a napkin. Little real data was available to the public and Fletcher Pratt and Seapower were really the only other gaming options. It was only with the later appearance of Alan Zimm's "Action Stations" (which drew heavily upon the 1936 USNWC wargame rules) that real world accurate data began to reach the civilian naval wargaming world – but it was a complicated set of rules. Lonnie's true legacy to the hobby might be his popularization of the "fast-play" concept.

I started to tinker with these rule factors but then decided armour and torpedoes needed to change too, and then you are really saying you need a different set of rules.

I do remember the array of house rule modifications that followed GQ1&2; some of them were IMO very worthy. But you are right in saying that the torpedo rules really needed to change (I think the GQ3 torpedo rules were an improvement). I'm not sure about the armor classification scheme, the principles of which appear to have been borrowed from Fred Jane's old naval war-game rules; I see some merit in the approach. At the end of the day, IMO, the greatest challenge to writing a good set of naval war-game rules is to keep the arithmetic at bay.

An interesting game would be Bluecher rather than Goeben against four CAs. Same speed and gun range dynamic but Troubridge would nonetheless have fancied his chances and sought battle against an 8.2-inch cruiser. At least, he'd certainly have struggled to persuade anybody that Bluecher was a superior force, least of all himself, so I think he'd have gone for it.

I would back Bluecher to blow up a couple of CAs and get away. The interesting what-if is then, what if the RN had thought about this and done something about its causes before, oh, May 31 1916?

It's an interesting scenario idea, 4C – although I wonder if Bluecher alone might be over-matched against four 9.2-in armored cruisers. Bluecher only had max 6-inch vertical armor and I am unsure how powerful her 8.2-in guns might be as "hole-punchers". On the other hand, being the HSF's gunnery research ship, she did hold some interesting cards in her hand –
> she had a "top of the line" fire control system;
> her main battery, with 30deg elevation, had a major range advantage and posed a real threat to deck armor at long ranges.
> she was good for 24/25 knots.

Worth looking into …..

B

Re SMS Blucher versus HMS Defence, I ran across some armor penetration charts I ran more than ten years ago in connection with my WW1 naval project. I'm not claiming that they are surgically accurate. But I verified the ballistics through Brian McCue's ballistics s/ware and then computed the AP performance through an early version of Nathan Okun's FaceHard s/ware.

They may IMO be considered broadly indicative for friendly war-gaming purposes.

AP performance versus KC vertical plate, corrected both for angle of fall and 30deg obliquity of line of fire versus keel line of target. British projectile shatter issue not considered.

British Mk XI 9.2in L/50 (max elevation 15deg)

Vpen:
11in @ </= 2000 yds
9in @ </=4000 yds
7in @ </=7000 yds
5in @ </=11000 yds
3in @ </=16000 yds

Hpen:
1.0in @ 8000 </= 12000 yds
1.5in @ </= 16000 yds

- – -

German 21cm L/45 (max elevation 30deg)

Vpen:
9in @ </= 3000 yds
7in @ </= 5000 yds
5in @ </= 8000 yds
3in @ </= 13000 yds

Hpen
1.0in @ 12000 </= 14000 yds
1.5in @ </= 16000 yds
2.0in @ </= 18000 yds
2.5in @ </= 19000 yds
3.0in @ </= 21000 yds

FWIW.

B

Yes, I figured about 15 seconds. IIRC that's about the timing we discussed.
Things like degraded spotting (getting bracketed by near misses), surface glare, poor crews, smoke, and poor environment creating spotting problems, it could take longer. There could always be the chance of the LOS being blocked too. Some factors could also reduce the max spotting range.

My approach to accounting for issues (whether plus or minus) affecting ranging/spotting efficiency is to address them in the step that determines the outcome of the gunnery effort for the turn ….. the spectrum of outcomes being –

"Ranging" – No clear idea of target range or range rate has been established.
"Bracketed" – Successive salvoes have crossed the target, but not achieved a straddle.
"Straddled" – A salvo has actually straddle the target, which signifies that range has been momentarily found without necessarily having determined that the range rate has been established
"Multiple straddles" – Both range and range rate have been established; firing ship conducts Rapid Fire on the next turn, but returns to Ranging status on the following turn.

It would be somewhat random too.
If communications between the two are broken down what method is used to deliver the message and how long would a round trip take?

I'm speaking from a wargame design efficiency perspective here, but loosely based upon what I have read in the history books
> If the firing order circuit of a turret is severed, the turret will still fire when it hears the gun discharge of its neighboring turret.
> If contact is lost with the Transmitting Station, the turret would technically remain in action under local control, but I would assign a penalty when testing whether a straddle scores a physical hit upon the target.

It's anybody's guess what the consequences of a gunnery communication failure might be. At Jutland, Princess Royal's Argo FC tower was disabled by hits at approx. 3:56pm during the Run to the South. Her gunnery log shows one salvo fired at 4:06pm, but she did not resume normal fire until 4:15pm. So, apart from that single salvo, her gunnery log suggests that her main battery was silent for about 20 minutes.

How do you guys handle determining the amount of time from the first spotting to firing the first ranging salvo?

When action is first commenced, the OITC of the formation (say, Beatty and 1st BCS) must first formally signal the enemy target to the ships under his command and also the fire distribution to be used. Beatty specified Hipper's 1st Aufklarungsgruppe as the target and, since there were 6 British ships to 5 German ships, he ordered the Lion and Princess Royal effect a pair concentration upon Hipper's flagship Lutzow and the other four British ships to engage the other four German ships on a one-on-one basis.. At that point everyone industriously starts ranging and plotting to the best of their abilities; but no one is permitted to open fire until the flagship first opens fire.

A slightly different deal was in play with 1AG. Since Hipper had one ship less than Beatty, the first four ships fired one-on-one against the first four British ships; Von der Tann, as the last ship in line was expected to split his main battery to engaged the last two British ships (New Zealand and Indefatigable), presumably on the basis that it was considered tactically important to leave no opponent unfired upon. However, Von der Tann's gunnery officer (Mahrholz) opted to engage the last ship in the British line (Indefatigable) with his entire battery and ignore her next ahead (New Zealand). His gamble paid off, as he sank Indefatigable within about 15 minutes while New Zealand had a terrible day gunnery-wise – barely hitting anything during the entire battle. After sinking Indefatigable, Mahrholz then shifted his fire to New Zealand.

A slightly different situation applied at Dogger Bank. Lion was well ahead of her consorts and the only British ship in range of the fleeing Blucher. He ordered Lion's gunnery officer to open fire upon Blucher, but when the next British ship astern of Lion came into range of Blucher, Beatty had Lion shift her fire to the next German ship ahead. The same process continued as other British ships came into range, until Lion succeeded in getting into range of the lead German ship – Hipper's flagship Seydlitz.

Of interest to note is that, in both battles, errors occurred in the distribution of fire by the British battle-cruisers. At Dogger Bank, Tiger chose the wrong target and Moltke spent the entire battle never having been fired upon. At Jutland, Tiger (having apparently missed or misunderstood Beatty's fire distribution signal) again chose the wrong target, leaving Derfflinger (number two ship in Hipper's line) unfired upon for a considerable period.

Does more time spent getting the range translates into better accuracy?

In my opinion, no., unless the range is closed greatly or the visibility improved greatly. Normally, a range-taker will know whether conditions are amenable to decent ranging. If he believes "yes", he will start taking ranges and reporting them; if "no", I think he would have so informed the gunnery officer and the gun would then be employed as its own range-finder (as was done by Lion at Dogger Bank).

Course changes: How many degrees per second could a ship make a course change and still stay on target?

Based upon my reading, no ships in WW1 would fire while physically in the act of turning (this had to await the development (by some navies, but not all) of RPC (remote power control) for heavy main batteries in WW2. Only when the ship had settled down on her new heading would fire resume. However, the adaptation of gyros to FC systems in WW1 would (it was claimed) permit ships so fitted to continue target plotting during minor alterations of own ship course – described in one source as up to two points at normal speed and up to one point at high speed.

The train is scheduled to leave the stations early as Aug 13. Still, no solid destination to pull into yet but the Chattanooga area is still the main destination.

Cool. Looking forward.

B

Regarding turning:
Didn't the German Navy in WWII have BB's in the battle line slightly zig-zagging snakelike to throw off the rangefinders but maintain an overall course?

So while a ship is making a course change the guns cannot fire?

If contact is lost with the Transmitting Station, and the remained in action under local control, how would it know which shots were theirs if other turrets are firing too?

Wolfhag

Regarding turning:
Didn't the German Navy in WWII have BB's in the battle line slightly zig-zagging snakelike to throw off the rangefinders but maintain an overall course?

This subtle weaving technique appears to have been standard operating procedure of the German Navy right from the start of WW1. It was first commented upon by Rudolf Verner (gunnery officer of HMS Inflexible at the Falklands), and was also mentioned in British reports after both Dogger Bank and Jutland. IIRC, the RN itself adopted the method after Dogger Bank. AIUI, the degree (amplitude?) of weaving was kept low in order not to interfere with own ship fire control. I think the ultimate result was really only a slight degradation of the spotting accuracy of the opponent, but it was effectively a freeby.

Blutarski comment – For all the fascination with the elaborate mechanical fire control computing systems that emerged upon the scene in WW1 (Pollen, Dreyer, Siemens), at the end of the day all were reliant upon accurate data inputs – target range, speed, inclination – in order to make useful predictions. But the instruments necessary to measure such data were in many cases unable to do so with sufficient accuracy – especially so with respect to target inclination. As a result, spotting was arguably still the most important factor in achieving good gunnery results.

So while a ship is making a course change the guns cannot fire?

It appears that they did not fire (as opposed to being physically unable to fire). That is my belief, based upon two things:
1 – The FC computers of the era were capable of solving straight-line trigonometric problems in real time, but were unable to accommodate/resolve pronounced curvilinear movements
2 – When I compared the Jutland gunnery logs of the surviving ships of 1st BCS, lapses in fire tend to coincide in time with pronounced course alterations.

If contact is lost with the Transmitting Station, and the remained in action under local control, how would it know which shots were theirs if other turrets are firing too?

If the data transmission cabling from Transmitting Station to turret is severed, I am fairl confident that alternate means of communication remained available to verbally transmit gun orders (telephone, voice tube). This would likely be slower, clumsier and more liable to mistakes. I confess that I have not explored this particular point in detail (although I do know that, in the RN, range cut data from turret range-finders (when available) were passed verbally to the transmitting station; only the single aloft range-finder (thanks to the single Argo range-finder mounting mounted to each GF dreadnought) could send range-cut readings (and bearings) automatically to the Transmitting Station below.

One other thing that afflicted RN fire control was its choice of DC electrical power. Unlike AC power, DC required use of "stepper motors" to electrically transmit gun orders and these stepper motors had to be properly aligned (so that a movement of X clicks by the transmitting motor produced X clicks on the receiving motor. These motors could occasionally get out of step through shock, etc. At Jutland, Tiger apparently had one of her turret stepper motors go "out of step" as a result of a hit.

Quoting from Campbell –
Hit number 13 – Hit ‘X' barbette at about 13500yds on 9in armour near junction with 3in armour and 1in upper deck. A piece of 9in armour 27in x 16in was broken off, and the shell entered the turret through the revolving structure about 3ft below the turret shield, but did not explode properly though the filling ignited. The centre training shaft ws smashed, one of the flash doors jammed, the left gun depression control valve casting fractured and director laying and firing circuits cut. After 7 minutes the turret began firing again with both guns in director training, individual laying and percussion firing. A total of 75 rounds was fired by ‘X' in the battle but some probably went very wide as 2 hours 17 minutes after the hit it was discovered that the turret was 19deg off its correct bearing in director training.

Hope this helps.

B

Blutarski,
Thanks, that's what I was looking for.

Are there any rules that simulate or handle the fire control method of "walking" salvos back and forth across a target?

Wolfhag

Are there any rules that simulate or handle the fire control method of "walking" salvos back and forth across a target?
Wolfhag

Hi Wolfhag,
When you refer to "walking salvoes back and forth across a target". are you referring to "rocking ladders" as was practiced by the USN in WW2?

B

It is my thought that, from the perspective of wargame rules, there is nothing special about "walking salvoes back and forth across a target". At least some navies (maybe all navies) had the equivalent, would appear to just be an organized means to ensure that at least some shells fell on both sides of the target so you could continuously spot them.

These are my thoughts on it.

At longer ranges normally only shorts can be observed and a successful straddle may not be detected. So if you observe shorts and do not detect a straddle or hit the only thing you can do is to increase the range for the next shot. If you fired a salvo and could not detect shorts or longs your only choice would be to drop the range. I'm not sure how most games handle that regarding accuracy.

One way I look at the gunnery problem is range keeping and there is always going to be a +/- range error no matter how accurate your equipment may be. So a range keeping error of 5% at 12,000 yards is +/-600 yards. As the gunnery officer, you are going to attempt to drop a salvo of a certain length into an area 1200 yards long and hope for a straddle. If the salvo length is 400m you have a 33% chance of a straddle and a straddle may have 1 or at most 2 rounds hit. There are various ways to determine where the center of the salvo lands.

If a straddle or hit is detected you'd fire again at the same range (subject to the other plotting table results)or go into rapid-fire mode. If a straddle is detected the range keeping error would then be +/- the salvo length wouldn't it? So if a straddle was achieved with a 400-yard length would the new range keeping error would be +/-400 yards no matter what the plotting table showed?

After observing a straddle or hit, the gunnery officer would have the choice of firing another 400-yard salvo with about a 50% chance of a straddle or a 200-yard salvo with about a 25% chance to straddle but get twice as many hits as a straddle with a 400-yard length. I know there are many other factors, I'm trying to keep the concept simple.

In a game, each ship would record its range-keeping error on its target. There are various factors that could increase the error at the time of shooting (crew, damage, ranging/plotting equipment, maneuvering, smoke, etc) making the target harder to straddle and achieve a hit.

I'd expect that if a salvo did not straddle the range keeping error would be reduced by the amount of the salvo length for the next shot reflecting the adjustment. So if it started out at +/-1200 yards a miss with a 400-yard length salvo would make the next salvo +/-800 yards error with a 25% chance for a 400 yards salvo to hit. Each salvo gets closer reflecting bracketing adjustments but is never better than the salvo length. The player (as the gunnery officer) can choose to shorten his salvo length to achieve more hits but with a lesser chance of a straddle.

I've tried out different versions of this and while I can't vouch for the historical accuracy of the mechanics it works pretty well by eliminating many of the accuracy modifiers some games like Seekreig have, especially when laying the salvo over a ship model.

Since you'd be determining results on each salvo using a structured game turn of a certain amount of time (like 1+ minutes) would require the need for additional rules to parse the shooting between all of the ships within a turn depending on their ROF. My method has been basically what Blutarski has been discussing regarding the timing of observations, corrections, and time of flight. Each ship operates within its own OODA Loop timing with a manually player-operated game clock to track the game time. This would give a better interaction between ships firing salvos.

So if salvo was fired when the game clock showed 11:21:18 a ToF of 25 seconds means it lands at 11:21:33. If spotting and transmit time takes 20 seconds the next salvo goes of at 11:21:53 if the gun is already loaded or later when the gun is reloaded. The clock is always "ticking" until a salvo is scheduled to land. When a salvo is fired a marker can be put next to the firing ship to let everyone know the rounds are on the way. The player "stops the clock" to determine the results and schedule his next salvo to be fired.

This works for smaller engagements as you'd need more abstractions for larger engagements.

Wolfhag

Hi hinds TMP –

It is my thought that, from the perspective of wargame rules, there is nothing special about "walking salvoes back and forth across a target". At least some navies (maybe all navies) had the equivalent, would appear to just be an organized means to ensure that at least some shells fell on both sides of the target so you could continuously spot them.

If you are referring to WW1 naval gunnery, kindly clarify what you mean by the phrase "walking salvoes back and forth across a target". Do you mean to imply it being done in a random sense?

- – -

If you are referring to WW2 naval gunnery, the USN's use of "rocking ladders" appears at first glance to be a bit like what you describe, but it was not initiated until target range and range rate (hence "a firing solution") had already been established by radar. The utility of the method was (IMO) twofold – first, to take advantage of radar to deliver a high rate of fire at greater ranges, while also countering the problem of the target being obscured in the forest of shell splash returns showing up on the radar range scope. Firing rate was so fast that it would sometimes evolve from salvo fire into continuous fire. A USN destroyer with a 4 x 5in/38 main battery was expected as a matter of course to be able to deliver 15 rpmpg (60 rounds per minute); USN light cruisers with 6in/47 main batteries (12 to 15 guns pre ship, depending upon class) were capable of delivering 80-100 round in one minute. USS Washington (shooting at ~8,000 yds, to be sure) was using a +/- 200 yard rocking ladder and averaging close to four 3-gun turret salvoes per minute in her engagement with Kirishima.

FWIW.

B

Here is a graphic example of what I'm talking about.

Wolfhag

My browser crashed when I was trying to replace the image with the one below:

Wolfhag

Apologies to the OP for continuing thread drift, but to respond to Blutarski above:

Wolfhag and I were referring to phraseology used in a number of accounts of the Solomons night battle of 14-15 November 1942, as in Friedman, "Naval Firepower", page 220, where Washington's salvoes were "rocked back and forth over the target". So WW2.

Looks like I was mistaken in considering this to be the wargame equivalent to using a ladder, as Friedman continues "This was not a ladder as the practice had been understood pre-war; the area through which the salvoes were rocked was probably about the size of a salvo pattern. There was no attempt to bracket, because initial radar range was considered accurate.". So you were at least partly correct on the connection with radar fire control.

However, your second idea, that "… countering the problem of the target being obscured in the forest of shell splash returns showing up on the radar range scope." is perhaps questionable. This, because at least one later battle (e.g. Tassafaronga), that very problem plagued U.S. radar controlled gunfire, causing the shell splashes to be confused with the target ship within the range gate, thus pulling the director off the target, "chasing the shell splashes". From Crenshaw, "The Battle of Tassafaronga", chapter X.

MH

Hi Wolfhag,
Your attached excerpts are excellent. From where do they come? I'd be interested. I thought at first that they were from one of John Brooks's books, but could not find them in either of his books.

Bracketing Fire was the standard RN gunnery methodology at the start of WW1. After the unexpectedly poor results experienced by the British battle-cruisers at Dogger Bank, Beatty and Chatfield carried on a correspondence about what measures might be taken to improve matters. A significant complaint was that bracketing simply took too long to fix the range, especially at long distances. Beatty also proposed that size of salvo patterns be scientifically assessed to determine the largest spread ("some figure between 10 feet and 10 cables") that would promise at least one hit from a straddle.

Chatfield (Beatty's gunnery chief) went a step further – arguing that, in view of the great ranges encountered at Dogger Bank (16,000-20,000 yds for most of the battle) the conventional bracketing method should be abandoned and replaced by a more rapid method of fire. Chatfield described his idea as follows ("Beatty Papers", pg. 232) –

Recommendations for Control – The chief lessons to be learnt are -
(a) That rapidity of fire is essential. The difficulties in controlling it are nothing compred to the disadvantages that ensue once the enemy's volume of shorts is greater than your own.

(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 then 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 correction in the former case in order to get short, hence the reason for 1,000 yards, even after straddling.

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

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

(e) Directors must fire rapid double salvos as soon as range is found.

Derfflinger 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.

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

(g) Sights of 13.5-inch guns and all corresponding instruments, time of flight watches, &c, to be graduated up to 25,000 yards.

- – -

Chatfield, in his book "The Navy and Defence", stated that after Dogger Bank he established a committee within the BCF to further study the gunnery issue and refine it. It is my belief that some evolved gunnery method, rooted in the above-mentioned Chatfield memo, was employed by the BCF at Jutland. I unfortunately cannot prove it; as no BCF archival documentation from the period appears to have survived. All we really have is Hipper's commentary in his post-Jutland report to Scheer of July 1916 – "The fire of the English battle-cruisers has not caused to our battle-cruisers damage of considerable gravity. Since the fall of shot was rarely in proximity to our own ships it is not possible to judge very accurately as to the ‘spread' of the shot" ("Beatty Papers", page 451)

- – -

The best evidence points to the Grand Fleet having retained conventional bracketing fire methods. On the other hand, Frederic Dreyer commented ("The Sea Heritage") that at the time of Jutland, every gunnery officer of every ship in the GF had his own way of doing things.

However, only about six months after Jutland (IIRC), Jellicoe imposed the brand new "1916 Spotting Rules" (the product of a newly convened gunnery committee (involving Chatfield and gunnery expert Captain Sidney Bailey) as a mandatory gunnery method to be employed by all ships throughout the fleet. This new approach departed from previous practice by being based upon fire by double-salvos (triple salvos for rapid-firing batteries) in all cases including ranging fire. These new rules remained in RN service right through WW2.

Hope this is of some use/interest.

B

Hi hinds TMP

Wolfhag and I were referring to phraseology used in a number of accounts of the Solomons night battle of 14-15 November 1942, as in Friedman, "Naval Firepower", page 220, where Washington's salvoes were "rocked back and forth over the target". So WW2.

Looks like I was mistaken in considering this to be the wargame equivalent to using a ladder, as Friedman continues "This was not a ladder as the practice had been understood pre-war; the area through which the salvoes were rocked was probably about the size of a salvo pattern. There was no attempt to bracket, because initial radar range was considered accurate.". So you were at least partly correct on the connection with radar fire control.

USS Washington's gunnery report mentioned (in reference to its main battery shoot against Kirishima) – "Salvos were walked back and forth across the target". At the same time, the 4-gun 5in/38 division which was also targeting Kirishima was said to be employing fire by "rocking ladder". No mention of the term "rocking ladder" was explicitly used to describe the 16in fire on that occasion, but the function is effectively similar – walking salvoes back and forth across a target in range is what "rocking ladders" typically do.. I did find use of the term "rocking ladder" in relation to main battery gunfire in a 1944 US battleship gunnery memorandum, but, to be fair, it related to use of a "rocking ladder" in deflection rather than range. Either way, I agree that neither related to a conventional pre-war interpretation of the term "ladder"
.

However, your second idea, that "… countering the problem of the target being obscured in the forest of shell splash returns showing up on the radar range scope." is perhaps questionable. This, because at least one later battle (e.g. Tassafaronga), that very problem plagued U.S. radar controlled gunfire, causing the shell splashes to be confused with the target ship within the range gate, thus pulling the director off the target, "chasing the shell splashes". From Crenshaw, "The Battle of Tassafaronga", chapter X.

I have Crenshaw's book on Tassafaronga. He is a terrific "I was there" source on the Solomons campaign. Two other works of his that I would recommend (in the unlikely case that you do not already have them) are "Destroyer Squadron 23" and "South Pacific Destroyer" (which has a very nicely presented description of the range-gate problem)..

I'm not trying to claim that rocking ladders were a cure-all for the pyramiding shell splash problem. What it (a 200 yard rocking ladder for DDs at any rate) did provide was about a 600 yard danger zone in range, which arguably doubled or tripled the chance of getting a hit on a target seeking to evade out of what was typically a small (1,000-2,000 yds?) range gate. Once out of the range gate, the enemy ship would not be easy to rapidly relocate in a chaotic night action. That is one of the major reasons why so many of those early war USN after-action reports erroneously claimed to have sunk great numbers of Japanese ships simply because they had disappeared from the FC screen while under fire.

B

FWIW:
From NavWeaps: Definitions and Information about Naval Guns
link

Bracket – A succession of two salvos, one over and one short or one left and one right, with no straddles.

Bracket Salvo – A method used to determine the range to a target. This procedure was extensively used by the German Navy in both World Wars. As used by the Germans, three half salvos were fired. The first half salvo was fired at the range determined by the rangefinder, the second at a range 400 meters too long and the third at a range 400 meters too short. By seeing which half salvo lands closest to the target, the actual range and bearing can be determined.

Ladder Salvo – Also called "Ranging Salvo." When a ship is firing at a target and isn't quite sure of the range, what the gunnery officer will often do is elevate each gun or group of guns slightly differently. This makes each shell land a little farther along than the last one. By watching to see which shell hit or landed closest to the target, the range can be determined more accurately. During the early part of World War II, the procedure used by the new US battleships was to fire all nine guns as a ranging salvo, a typical pattern being one group (three guns from one turret) at 200 yards (180 m) up from the initial range estimate, one group at 200 yards (180 m) down and one group at 400 yards (370 m) down. There was also a timing difference between groups to avoid confusion between the shell splashes. Once a bracket had been obtained, thus indicating the correct range, the ship would then switch over to rapid fire, with the guns firing as they were ready.

Rocking Ladder – "Walking" the point of aim back and forth across the target, thus allowing for small errors in the firing solution. Often used for rapid-fire and automatic weapons.

From reading the radar GFCS manual WWII fire control radars could lose the splashes when a target is bracketed and hit as they merge into one blip. I'd imagine rapid-fire would increase the chance of it happening too.

I'm not sure of those sources, I'll have to check.

Wolfhag

Bracket – A succession of two salvos, one over and one short or one left and one right, with no straddles.

Also referred to (in British parlance at least) as "crossing the target". Sometimes I see the word "straddle" used in British accounts when "bracket" would seem to have been a more accurate term. Very frustrating to understand the correct progress of events when this occurs.

- – -

Bracket Salvo – A method used to determine the range to a target. This procedure was extensively used by the German Navy in both World Wars. As used by the Germans, three half salvos were fired. The first half salvo was fired at the range determined by the rangefinder, the second at a range 400 meters too long and the third at a range 400 meters too short. By seeing which half salvo lands closest to the target, the actual range and bearing can be determined.

I realized last night that I had failed to mention anything about German fire control methods in WW1. I am posting in a separate message thread a translation of Mahrholz's experience as gunnery officer of Von der Tann in her engagement with HMS Indefatigable at Jutland It provides good detail on how the fire control process was managed aboard VdT.

B