"WW1 Capital Ship Secondary Armament" Topic

Hi all,

Whilst working on some home brew WW1 Naval rules I have been pondering on the role of secondary armament especially the casemated 6" or similar types as opposed to the deck mouted light QF guns.

Was the traverse quick enough to track a fast moving TB or DD, would the shell smoke from the secondaries effect the observations for the main guns, being mostly low on the belt line could they only be used in light seas ?

I have no doubt that a 6" shell would make short work of a WW1 TB or DD which were by enlarge a lot smaller than their WW2 equivalent, however the prevailing thoughts during the war seem to be that the most effective way to defeat enemy destroyers was with your own destroyer screen. So on that basis they can't be that effective.

So what was the main use of the secondaries, where they "turned off" during main gun engagement or allowed to blast away independently as they seem to be able to in most rule sets.

Discuss

Regards, Ken
yarkshiregamer.blogspot.co.uk

Secondary armament was not fitted at all on the original Dreadnoughts as it was thought that having a single gun type shooting was easier to employ for fall of shot, ranging calculations etc.

As gun control got more sophisticated (but not necessarily better) that belief lapsed and secondaries were added in the belief that they could produce a 'storm of shell' at closer ranges that would disable many of the ships systems.

Evidence from Tushima points to them being right as the Japanese smaller guns seem to have done significant damage and prevented the working of deck guns and blast damage knocked out gunnery control stations.

I doubt 6" guns would be used against destroyers, against cruisers possibly. They would probably have joined in at closer ranges but it is debatable whether the ranges would be short enough for their effects to be felt against the much better protected ships of 1914-18.

Having said that, blast damage was a significant factor in the damage done at the battle of the River Plate, so they may have been effective against those older ships that were less well protected.

Great question.

A WW1 DD or TBD was essentially unarmoured, so a hail of 12-pounder fire from HMS Dreadnought would have laid waste to any such vessel that tried to attack her. But this hail would need to do so in the interval after the TBD came into 12-pounder range and before it got into torpedo range. Otherwise, the enemy gets a chance to sacrifice TBDs for your dreadnoughts.

Between this and the fact (at least, I think it's a fact) that blast made 12-pounder stations mostly inoperable while the main battery was in action, the secondary armament fitment on British dreadnoughts had to get bigger and better sheltered. So 12-pounder became 4-inch in casemates became 6-inch. As this latter clearly wasn't a blast issue any more, presumably the move to 6-inch was about having the hitting power to cope with both destroyer flotillas and the cruisers that typically led them.

It is interesting that German battleships likewise went from 4.1-inch secondaries to 5.9-inch, but retained quite significant tertiary batteries of 3.4-inch (88mm) weapons. All of this suggests to me that secondaries were thought to be only marginally equal to the task of repelling torpedo attackers.

If you look at the design of British versus German smaller craft, is it not the case that German ships had a lot of torpedoes and a handful of guns, whereas British had the opposite – lots of guns and not many torpedoes? Destroyer does after all come from torpedo-boat destroyer. So this says to me that a German torpedo-boat was intended to torpedo a battle line, whereas a British destroyer was intended mainly to thwart this, the mounting of its own torpedo attacks being a subordinate role with capability to match.

Germany's S36, for example, dating from 1913, had three 3.4-inch guns and six torpedo tubes. Her British contemporaries – Acasta for example – typically had only two torpedo tubes, but three or four 4-inch and quite often the odd 2-pounder, 12-pounder etc.

Practically though, if you've got destroyers, you'd deploy them in a screen around your battle line – not only to keep submarines under, but because there's no obviously superior battle station for them.

It is quite difficult to identify from memory examples of combats where the secondary batteries of battleships fought their own battle against torpedo craft while the main batteries duked it out against other capitals. Spee's ships used their secondaries against Sturdee, but this was both batteries firing at the same target, and cruiser doctrine may have been different on this point. At Jutland, secondaries seem to have fired at whatever they could; Massie mentions disappointed secondary crews who never came into range of the German main body.

I don't recall reading much about the control of secondary fire, but a number of British capitals had tripod masts fore and aft, and the tripod structure was there to support the weight of a fire control position at height. So I sort of thought that was one for the main battery, and the other for the others. The Germans had director control of searchlights so lack of director capacity seems not to be the issue. The point about whether a casemated 6-inch gun could track a destroyer is interesting but the answer must be yes; at combat ranges the deflection doesn't change that fast.

I'm currently reading through Burt's 'British battleships of WW1' and was quite surprised to see that some of the secondary armaments were positoned on the roof of the main battery turrets, for a while anyway.
I would have thought firing both at the same time problematic! Possibly why were repositioned to the superstructure at a later date….

Cheers,
Wilf

Another factor in this is that effective torpedo range was increasing as torpedoes got more sophisticated as well (though actual performance never got close to projected performance the perceived threat was there). So even if your 12 pdr battery could chew up the typical destroyer, there would have been worries that eventually the 12 pdr wouldn't reach far enough to actually deter a torpedo attack. Hence one of the perceived needs for heavier secondaries.

-Will

One of the imponderables for me is why WW1 dreadnoughts were both paranoid about torpedo attack yet also fitted with torpedo tubes.

If your doctrine says that you use secondaries and a destroyer screen to keep the other guy out of torpedo range, what were you expected to do with your own torpedoes?

Meanwhile, if the tubes you had were of the submerged variety, your own torpedo flat was a nice big floodable area under the waterline, should the enemy happen to get lucky with a mine or submarine. Just what's not wanted.

Great work people, nice start to the discussion.

Re the Capital ship torpedo tubes, I think they were merely for a coup de grace (said in broad Yarkshire Accent) against a slow moving or stationary ship, the stats I have (off top of my head) show they only ranged to about 4000 yards.

4th Cuirass and Gildas hit on a main point and that is lack of actual historical data. Tushima is well before the time frame I'm looking at, its the lack of Dreadnought onwards data that's the issue. If Jellicoe hadn't turned away from the torpedo attack at Jutland we would have tons of data. But he did turn away and was clearly (along with other well documented factors) not confident in his ablity to shoot his way out of the situation. Thats 20 plus Battleships covered in 6" or similar not confident !

My feeling is that the larger secondary armament was meant to tackle cruisers whilst the tertiary armament dealt with destroyers. But thats just a feeling.

Cheers for getting involved, discuss on !

Regards, Ken
yarkshiregamer.blogspot.co.uk

I believe the notion with the turret top light guns was that the torpedo and big-gun phases of the battle would be sufficiently distinct that you wouldn't use both sets of guns at once.

The real source you want on this is D.K. Browns' Warrior to Dreadnought, then the follow up-volume The Grand Fleet; this covers a lot of the technical issues and decisions on armament and armor.

-Will

One of the imponderables for me is why WW1 dreadnoughts were both paranoid about torpedo attack yet also fitted with torpedo tubes.

If your doctrine says that you use secondaries and a destroyer screen to keep the other guy out of torpedo range, what were you expected to do with your own torpedoes?

Meanwhile, if the tubes you had were of the submerged variety, your own torpedo flat was a nice big floodable area under the waterline, should the enemy happen to get lucky with a mine or submarine. Just what's not wanted.

As Ken said, mostly for use as coup de grace weapon against an enemy battleship or cruiser. There was also definitely a disconnect going on between the ranges the gunnery schools were expecting to fight at and the ranges the captains were expecting to fight at, and both groups had input into warship design.

-Will

Will – the design of the Royal Navy's ships was as much a 'national' issue as it was a 'service' issue. The press was used to influence the design of ships right from the early ironclads up to the 'Super' Dreadnoughts that fought at Jutland.

Even when the best constructors that the navy could muster disagreed they were forced to incorporate features (such as heavier secondary armament) by political pressure.

We tend to get the idea that the fleets at Jutland were led by and captained by men seeped in a single doctrine and schooled in an agreed tactical system – just like Nelson's fleet at Trafalgar. Sadly this was far from the truth.

So little actual naval combat had been seen since the development of the Ironclad that few lessons were ever 'learned' because there was just too little data to 'learn' it from.

The few large battles each had so many individual features that it was very difficult not to be misled by a few random successes (e.g. the ramming at Lissa) into design decisions which proved wrong. It isn't really surprising that the amateur designers in the press and public could influence the process when professionals could point to very little hard evidence.

We do know a lot less hard data from WW1 about the effectiveness of weapons in fleet actions than we would like. While it is still more than we know from earlier eras, it still isn't enough to make more than educated guesses when designing rules.

GildasFacit-

Yes, that was exactly my point; the folks responsible for ship design themselves didn't fully agree on how the ships they were designing were going to fight, though your point about the political influence of the public (or certain members of it) is also spot on. So there is no surprise that the ships sometimes incorporated conflicting features.

All that said, every other nation trended towards a similar solution, and while some of that was 'keeping up with the other guys' reaction, it does indicate that some useful tactical aspect was apparent.

-Will

The growth in secondary armament caliber had perfectly sound reasoning behind it. HMS Dreadnought pioneered a lot of concepts, but one that was quickly invalidated in the new arms race was Fisher's extreme interpretation of the "all big gun" theory. Lighter ships were also getting bigger/faster/better armed, and battleships needed sufficient secondary armament to deal with them. The 12 pdrs included as Dreadnought's "secondary" armament were considered barely sufficient against contemporary 500 ton, 25 knot DDs with 4000 yard torpedoes, but were quickly seen as inadequate, and by WWI they were almost hopeless against 1000 ton 30 knot destroyers with 12000 yard torpedoes. The secondary armaments of BBs grow along with the lighter craft they were expected to deal with at sea, gaining larger shells to damage ever-larger CLs and DDs, and longer range to shoot them from farther away.

Interesting side notes:

BB secondary guns never grew beyond about 6" caliber, even through WWII. Rapid fire was a design requirement for shooting at fast torpedo craft, and 6" caliber was already well-established in the late 19th C. as the maximum size for a "quick firing" gun.

The pre-dreadnoughts serving with HMS Dreadnought in the Channel Fleet were better armed against WWI DDs than she was, with big batteries of 6" secondaries.

- Ix

One of the imponderables for me is why WW1 dreadnoughts were both paranoid about torpedo attack yet also fitted with torpedo tubes.

Dreadnought torpedo tubes are for firing "browning" shots. Long range low probability shots at the opposing battle line.

If you look at the design of British versus German smaller craft, is it not the case that German ships had a lot of torpedoes and a handful of guns, whereas British had the opposite – lots of guns and not many torpedoes?

No.

British destroyers are typically larger than German destroyers. More guns,larger guns, and the same number of torpedoes. They also have better torpedoes, longer ranged and faster.

British destroyers are typically larger than German destroyers. More guns,larger guns, and the same number of torpedoes. They also have better torpedoes, longer ranged and faster.

Yes, a side effect of the RN's global commitments versus the High Seas Fleet's primary mission of fighting in the relative bathtub that was the North Sea. This had a huge impact on ship design for both sides and should never be overlooked.

-Will

Interestingly in WW2 it was the other way round – German destroyers were much larger than British ones.

Yet the Acastas and LaForeys only had two tubes whereas their German contemporaries had six.

GildasFacit wrote:
Even when the best constructors that the navy could muster disagreed they were forced to incorporate features (such as heavier secondary armament) by political pressure.

An interesting parallel to this is aircraft carrier design ahead of WW2. The Japanese had carriers with no island, the island on the wrong side, and the island on the usual side. They had big islands and little islands. They had funnels that leaned out at a 40-degree angle, and they had funnels that led aft along the flight deck like motorbike exhausts. They had carriers with single deck hangars, with double-decker hangars, and with hangars integrated into a hurricane bow.

They look eccentric, even funky today, but all were explorations to find out what worked, which extended to the air group composition as well. If no island had proven to be the superior choice operationally, that would be the default appearance, and it would be the US WW2 design of big-starboard-side-island that looked quaint.

We look back at battleship design now, and we know that the optimal configuration was three turrets fore and aft, dual-purpose secondaries and AA, and no torpedoes. But they didn't know that 100 years ago. Right up until Dreadnought, a battleship was, conceptually, a design that Nelson would have recognised: a range of calibres distributed along the beam of the ship, and the ships fought in line ahead. This sort of configuration in fact persisted into the dreadnought age, in the shape of wing turrets (which were, essentially, guns distributed along the beam of the ship). There was a learning process going on that we tend perhaps to forget, since the ships were, superficially at least, quite similar to the final iteration 40 years later.

From what I've read secondary guns were mainly used against enemy torpedo boats. They normally had their own fire control / range finders. Since there was no way each gun could spot and correct on their own shots with 4-8 guns firing at the same time they fired as a battery. The fire control gave all guns an elevation and azimuth to aim and fire when the "gong" went off. The spotter made adjustments and sent the next salvo firing data to the guns and they fired again.

Even though the guns may have a higher rate of fire I think they were limited to 4-5 rounds per minute when salvo firing.

They were probably limited to firing at one target at a time because of having only one range finder. If firing with local control at max ROF they could probably get off twice as many rounds.

Secondary guns could cause a big problem because they stocked ammo on the gun deck without much protection. They needed to have a lot of ready rounds available as the ammo lifts from the magazine were fairly slow. These could catch fire just from hot shrapnel.

Wolfhag

Secondary armament was not fitted at all on the original Dreadnoughts as it was thought that having a single gun type shooting was easier to employ for fall of shot, ranging calculations etc.

Secondary armament was never fitted to any British dreadnought. What we call "secondary" was eliminated for the reasons you state. On the other hand they still had 12pdr (3") and then 4" guns strictly for anti-torpedo-boat use. When the RN finally convinced their superiors to let them mount 6" guns they were still considered "anti-torpedo-boat" guns, and they were only allowed common shell to insure that they would not be used against other capital ships. Whether they actually obeyed that restriction, I'm still not sure.

The Germans, on the other hand, kept their secondary armament right through, and usually had a tertiary battery for anti-TB work.

I doubt 6" guns would be used against destroyers, against cruisers possibly. They would probably have joined in at closer ranges but it is debatable whether the ranges would be short enough for their effects to be felt against the much better protected ships of 1914-18.

The 6" guns mounted on the Iron Duke class and later British dreadnoughts were specifically for use against destroyers, and at long range. This was because of the increasing range and power of the torpedo and the need to knock those ships out before they got too close.

Yet the Acastas and LaForeys only had two tubes whereas their German contemporaries had six.

British doctrine at the time was that destroyers were there to protect the fleet and sink enemy torpedo boats. German doctrine was that they were ocean-going torpedo boats (hence the name 'Hochsee Torpedoboot'). This led to British tactical doctrine leaning toward the gun and not the torpedo.

Interesting discussion.

In order to appreciate the steady increase in anti-torpedo boat gun caliber, it is necessary to understand the very rapid growth in the size of torpedo carrying light craft (torpedo-boats and later torpedo-boat destroyers). In the span of little better than a decade, these vessels grew in tonnage from 200t to 1000t. That trend, coupled with the equally dynamic increase in effective torpedo range from perhaps 1000 yds to 10,000 yds, drove a demand for an anti-torpedo boat weapon of ever increasing power and reach.

British dreadnoughts had only a main battery and an anti-torpedo boat battery. German dreadnought types carried in addition an intermediate (150mm) secondary battery intended for general use – arguably a hold-over from pre-dreadnought design practice. The British displayed a steady increase in anti-torpedo boat gun power, from 12-pdr to 4in to 6in; the Germans discovered their 88m guns to be inadequate to their assigned task and dismounted them in favor of AA weapons, but their existing 150mm secondary batteries (found to be of very limited use against capital ships) serendipitously provided a very good substitute against modern torpedo craft. The RN did a considerable bit of testing with regard to anti-torpedo weapons (BZ to the poster who mentioned DK Brown's book; see also DKB's multi-part series "Attack and Defence" published in "Warship"). By 1914, even the 4in gun caliber was found to be of marginal utility; hence the move to 6in in the QE and R Class designs.

As an aside – in both British and German services, the gun crews of their unarmored anti-torpedo boat batteries (4in and 88mm respectively) were customarily kept under shelter during day actions until an approaching torpedo attack was identified. These men were far too exposed to be kept at their open battery positions during a gun action.

Happy holidays to all.

B