Triple and quatruple turrets

[paul.mercer]

Gentlemen,
I have read in these forums about the problems experienced with the quadruple 14" on the KGV's and the triple 16" on the Nelsons, also the dispersion problems with the 15" on Italian ships and I would be grateful if you could explain what the trouble was, after all the twin 15" was the most reliable of all so was it trying to cram three or four guns in one turret or problems caused by the shell rooms/cordite rooms and their hoists, did the US triple gunned ships have the same troubles?
If this has been answered elseware please point me ot the posts.

[tommy303]

Each had its own set of unique problems plus some problems shared with the others. In the case of the 14-in quads of the KGV class, the main problem was sheer complexity; instead of dealing with the safety interlocks for two guns and their hoists, one had twice as many components. The quads were rushed into service and there were comparatively few men experienced with them and able to deal with breakdowns and correct them as they occurred. Had there been more time, most of the problems would have been corrected through modifications and the mountings would have turned out to be quite reliable in much the same way as the 16-inch triples of the Nelsons. The 16-inch triples also began service with a litany of problems which took the better part of a decade to finally put right so that when WW2 came along, the turrets were comparatively reliable. However, while the 14-inch guns themselves were reliable and accurate, one cannot say quite the same thing for the 16-inchers of the Nelsons. As designed, the guns had a tendency to wear out quickly and the problem was quickly traced to a poorly matched APC shell length for the rifling pitch and velocity, causing the shell to be unstable in the barrel and to batter the rifling unduly. The obvious answer was to redesign the APC and that was done, but budgetary constraints prohibited the new shell from going into production as numerous complete outfits of the suspect shells had already been produced at great cost. The next best solution, which was put into place, was to reduce the powder charges slightly to reduce the muzzle velocity and this helped prevent the shell from battering the rifling, although the cost was a bit of velocity and a resulting loss of power and range. New liners were also produced with different rifling twists and gradually replaced the older ones as they wore out. By WW2 the guns were fairly accurate and the mountings were reliable, but it took a long time to get them that way.

In the case of the Italian 15-inch, the major complaint seems to have been poor quality control in the final machining of the shells intended for service. This, together with the very large powder charges, caused the bores to erode quite rapidly and dispersion patterns to be unacceptably large. When the guns were test fired and range tables developed, the manufacturers provided very carefully machined shells that insured excellent results and tight patterns, as opposed to the practice of other nations where shells for testing were randomly selected from production batches. In foreign ships, what you got in testing was what you would get in service; in Italian ships, you would get excellent results during testing but disappointing results in service.

[tommy303]

The wonderfully reliable British 15-inch owed much of its success to the older, equally reliable 13.5-inch guns upon which it was based. The original mountings for the 15-in also resembled those for the 13.5-inch, making the transition from 13.5-in to 15-in comparatively easy for personnel. The 15-inch mounting was refined and modified throughout its service, becoming both more effective and safer due to increased elevation and more effective flash protection. Perhaps most importantly of all, by 1939, when the 15-inch gunned battleships were once again called upon to defend the Great Britain and its empire, there was a large pool of experienced personnel and reservists who were intimately acquainted with the guns and their mounts. This was something only marginally available to the 16-inch triples of the Nelsons by 1939, and not available at all for the 14-inch of the KGV's whose personnel were quite literally having to learn everything from the ground up in wartime (one has to bear in mind that the 14-inch mountings were brand new designs having little in common with older guns and mountings).

[RNfanDan]

This was something ... not available at all for the 14-inch of the KGV's whose personnel were quite literally having to learn everything from the ground up in wartime...

Let's not forget however, that the Royal Navy's 15-inch / 42 cal. gun, one of the best in history, was itself a "rushed" weapon, never put through the "usual" process of development (as defined by the standards of the day). In its case however, the "recipe" turned out to be right, with an excellent balance of m.v., barrel length, rifling, charge, shell weight, and other critical "ingredients". It was a good mix.

Although the 13.5" features that were carried over may have helped a great deal, the refinements to the actual weapon were not as extensive as might have been feared, under the political and military pressures of the early 20th-century naval arms race. A happy result, in this case. By WW2, there was also a substantial stockpile of spare guns available for the battleships, battlecruisers, and monitors which all used the same weapon. It was fairly easy to swap-out worn 15-inch barrels, thanks to such standardization.

Is it any wonder then, that the world's last true battleship (HMS Vanguard) carried the 15"/42 cal (albeit with a bevy of improvements in the turrets and supporting mechanisms)?

[paul.mercer]

Gentlemen,
hOnce again, many thanks fopr your replies, if i stay on this forum for the next 20years or so I might begin to get somewhere close to your vast knowledge.
I hope you all have a great Christmas, I'm sure I will have more questions in 2013!

[RF]

Each had its own set of unique problems plus some problems shared with the others. In the case of the 14-in quads of the KGV class, the main problem was sheer complexity; instead of dealing with the safety interlocks for two guns and their hoists, one had twice as many components. The quads were rushed into service and there were comparatively few men experienced with them and able to deal with breakdowns and correct them as they occurred. .

The evidence from Rheinubung is that both POW and KGV itself encountered problems with the ''B'' double gun turret as well as with the two quad turrets which perhaps would suggest that these problems outlined in the quote weren't really just with the number of guns per turret.

One aspect not so far discussed here is whether the Germans had any problems with the triple ii inch turrets in the panzersciffe and the twins, I don't recall any significant problems being recorded by them at all.

[dunmunro]

One aspect not so far discussed here is whether the Germans had any problems with the triple ii inch turrets in the panzersciffe and the twins, I don't recall any significant problems being recorded by them at all.

The KM were rather dismayed at the poor reliability of their 28cm triple turrets on the Scharnhorst class, as Koop makes clear in Battleships of the Scharnhorst class. S&Gs gunnery officers were rather impressed with Renown's shooting during their April 1940 engagement.

[Thorsten Wahl]

Zwilling-Drilling-Vierling B.Nr. A IV a 4835-34 G.Kdos
german study
https://docs.google.com/open?id=0B12aaM ... nRhZGY0Mnc

[dunmunro]

Each had its own set of unique problems plus some problems shared with the others. In the case of the 14-in quads of the KGV class, the main problem was sheer complexity; instead of dealing with the safety interlocks for two guns and their hoists, one had twice as many components.

It seems to me that the major fault of the 14in quads was the possibility of 14in shells surging past their stops in rough seas/tight turns and fouling the loading trays that transferred shells from the fixed to moving parts of the turrets. This problem was largely fixed in the summer of 1941.

[alecsandros]

Each had its own set of unique problems plus some problems shared with the others. In the case of the 14-in quads of the KGV class, the main problem was sheer complexity; instead of dealing with the safety interlocks for two guns and their hoists, one had twice as many components.

It seems to me that the major fault of the 14in quads was the possibility of 14in shells surging past their stops in rough seas/tight turns and fouling the loading trays that transferred shells from the fixed to moving parts of the turrets. This problem was largely fixed in the summer of 1941.

I would also expect so.
The shooting during NOrth Cape wasn't that bad, considering the circumstances; it wasn't to good either, though. [pretty much the same output as KGV against Bismarck, 2 years earlier, allthough in better circumstances]

A better test would come in more normal conditions.
I know KGV was transferred in the Pacific in 1944, and participated in several attacks on Japanese islands.
It would be nice to know some performance indicators there...

[Dave Saxton]

One aspect not so far discussed here is whether the Germans had any problems with the triple ii inch turrets in the panzersciffe and the twins, I don't recall any significant problems being recorded by them at all.

The KM were rather dismayed at the poor reliability of their 28cm triple turrets on the Scharnhorst class, as Koop makes clear in Battleships of the Scharnhorst class. S&Gs gunnery officers were rather impressed with Renown's shooting during their April 1940 engagement.

Prager reports that the Germans we not satisfied with the safety of the triples on Deutschland, and Deutschland did suffer a blow back incident pre-war.

The problems encountered by S&G's forward turrets during the April 9th 1940 squirmishs were due to water coming though the ejection ports with the turrets trained around with their backs facing the spray coming over the bows. The problems were mostly electrical, rather than mechanical, through the short circuits caused thereby. SH had to go over to back up systems instead of using the primary RPC.

The Germans didn't know that Renown was having similar problems. Bewteen 0419 and 0456 hours (British time) Renown was forced to reduce its speed more than once, because of the water coming over the bows made her forward turrets unworkable. At 0544 Renown had worked up to 29 knots, but had to keep the forward turrets trained around facing away from the water coming over the forcastle while doing so. Such was the sea state that day.

[alecsandros]

Prager reports that the Germans we not satisfied with the safety of the triples on Deutschland, and Deutschland did suffer a blow back incident pre-war.

Dave,
any leeds on the performances of German 2-gun 15" turrets and it's integration with radar?

My best source so far is the AVKS-700 report of Bismarck's March 1941 tests, yet I don;t know if the RPC system was completely functional by mid- May 1941, as some problems were noted during the tests.
Tirpitz appaerently encountered similar problems during tests, and it is possible, yet I don;t know exactly if, they were corrected by Sep-1941 re-run of tests...

[Thorsten Wahl]

according war diary Tirpitz, the Kaliberschießen S.A. against Hessen were conductedt on Oktober, 11th 1941 in between 0215 and 0300 p.m and Oktober, 12th 0530-0625 p.m. .

According the Többicke Study on behalf of the Soviet Army " Die Panzerung der deutschen Kriegschiffe 1920-1945"; published in Marine Arsenal Special Band 6, Tirpitz achieved 9 hits at a range around 25 km. There is a photo of a near miss salvo (double impact MPI ca 30 m off target, spread approx 50 m) in a book about Tirpitz, but i dont know wich it is.

According "DENKSCHRIFT über die Kriegsbrauchbarkeit der Seeziel- und Flakartillerie" B.Nr. Skl. Qu A I 2983/41 gKds
"The 38 cm twin turret is assessed from all sides as ballistically fully succeeded, a view, which is confirmed in practice by the excellent shooting results of Bismarck and Tirpitz"

[paul.mercer]

Gentlemen,
A further question I'm afraid, did the US or Italian battleships have the same problems with their triple turrets (apart from dispersion on the italian ships)?

[Dave Saxton]

Dave,
any leeds on the performances of German 2-gun 15" turrets and it's integration with radar? ...

I don't understand why this keeps coming up as if there's any question about it. It was in fact intergrated directly to the firecontrol system, no question about it. And of course the firecontrol system controlled the 15" gun turrets. The following quotes are in relation to the new 1940 series of radars:

....The data wheels (of the fine ranging system) were so arranged as to allow selsyns for data transmission. With this improvement GEMA offered the Navy, (and the Luftwaffe -both Flum and Flak), electrical transmission of data either directly or through adapters. This design proved itself and was feature of all subsequent equipment....the lateral-motion drive was altered to have special selsyn for transmitting bearing data. The whole drive and its control consisted of AEG componants and construction. AEG used this drive aboard ship as well.... (Harry von Kroge)