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Secundary guns turrets

Posted: Sat Jun 27, 2020 6:56 pm
by marcelo_malara
Hi. In Bower´s AOTS it can be seen that the forward turrets had an under deck structure, just like main guns´ ones, with a lower shell and powder room. The four after ones do not have this. Were the loading arrangements different between both?

Re: Secundary guns turrets

Posted: Sun Jun 28, 2020 1:31 pm
by Herr Nilsson
Yes. The ammunition had to be transported on tweendeck via slides through the splinter bulkhead.
15 Zwischendeck.jpg
15 Zwischendeck.jpg (44.94 KiB) Viewed 14330 times

Re: Secundary guns turrets

Posted: Sun Jun 28, 2020 7:51 pm
by marcelo_malara
Thanks Marc! How was this in other navies?

Re: Secundary guns turrets

Posted: Mon Jun 29, 2020 7:11 pm
by Steve Crandell
In the USN, 5" mounts typically had a handling room directly below them and the magazine below that. That was pretty much true from BBs on down to DDs.

Re: Secundary guns turrets

Posted: Mon Jun 29, 2020 10:13 pm
by marcelo_malara
Marc, in Brower´s book there are two scuttles in the barbette, they do not show up in your plan. Which is correct?

Re: Secundary guns turrets

Posted: Tue Jun 30, 2020 7:51 am
by Herr Nilsson
marcelo_malara wrote: Mon Jun 29, 2020 10:13 pm ...in Brower´s book...
What page?

Re: Secundary guns turrets

Posted: Tue Jun 30, 2020 3:29 pm
by marcelo_malara
Pages 42 and 43, upper plan.

Re: Secundary guns turrets

Posted: Tue Jun 30, 2020 5:10 pm
by Herr Nilsson
Thanks!

Brower is just more detailed. My plan shows the way of the ammuniton from piles on deck into the magazines and from there to each weapons. It shows just doors used for ammunition transport purposes.

Re: Secundary guns turrets

Posted: Wed Jul 01, 2020 1:00 am
by marcelo_malara
The new Bismarck´s book mentions that a secondary turret´s crew became locked in their post because the turret scuttle was deformed and could not be opened. Why couldn´t they escape from below deck?

Re: Secundary guns turrets

Posted: Mon Jul 13, 2020 6:37 pm
by RobertsonN
The ammunition supply arrangements for the midships and aft secondary turrets in Bismarck were criticized in the AVKS-700 report during the ship's commissioning period. This was on grounds of complication and the relatively high manning requirement. By contrast the fore 5.9 in turrets did have a conventional barbette beneath the turret. In Bismarck the outboard locations of these turrets did not allow for a conventional barbette and placing the midships and aft turrets further inboard would have cramped the superstructure and tertiary and light AA armaments badly. The Scharnhorst did have all its secondary turrets supplied by conventional barbettes. This was made possible by the outward slope of the torpedo bulkhead in these ships. As usual, most features in battleships have both advantages and disadvantages.

Ammunition supply for the secondary turrets did seem to be a weak point in most battleships. Either supply was difficult or there was a build-up of ammunition above the armor deck or both. The best protected were those in the Littorios. They did have barbettes but these descended into the space over the Pugliese system and between the two splinter bulkheads inboard of the main belt. From there the ammunition supply went inboard through the inner splinter bulkhead and then down. In US ships the secondary turrets were above handling rooms that seem to have been effectively secondary magazines that were above the armor deck, albeit protected by armor 2.5 in thick. The Hood had a novel system in which men ran with wheel barrows for some distance. A report on the end of Repulse commented that the ammunition supply to the forward triple 4 in mounts was so poor that, once the ready-use ammunition had been fired, these guns were not much use. In Hood and Repulse a problem was that all the secondary ammunition magazines were either forward or aft but that many of the secondary guns were amidships, involving a long and convoluted supply chain,

Neil Robertson

Re: Secundary guns turrets

Posted: Tue Jul 14, 2020 10:56 am
by RobertsonN
Just an addition to my last post. In Yamato the wing secondary turrets were mounted inboard and had proper barbettes. Their magazines were on two levels, the upper one being above the waterline, not the best of locations, but direct. The inboard location of these turrets greatly reduced the extent of the superstructure and limited the size of the AA armament. In the original design of Richelieu with five triple 6 in turrets there were barbettes that ended in a handling room located between the upper and lower armor decks. The magazines were located inboard at lower levels, for the forward turrets, at the lowest two platform levels and, for the aft turrets, on three levels. The ammunition supply had consequently to be moved horizontally inboard of the handling rooms. Overall supply route was rather long and complicated,

Neil Robertson

Re: Secundary guns turrets

Posted: Tue Jul 14, 2020 10:58 am
by Herr Nilsson
marcelo_malara wrote: Wed Jul 01, 2020 1:00 am The new Bismarck´s book mentions that a secondary turret´s crew became locked in their post because the turret scuttle was deformed and could not be opened. Why couldn´t they escape from below deck?
Well....this anecdote is based on Herbert Blum's account. Following his recollection of his way out of the ship it's most likely one of the rearmost turrets. He says he stooped to open the hatch, but it was jammed.

I don't understand his account in several aspects. He had to stoop, that means the hatch was underneath the turret. That's right, but there were two of them, because they were the cartridge ejection openings. I would expect that both hatches were open anyway during the battle. Additionally there was a hatch in the turret roof! ...and yes, furthermore there was the way down.

To be honest I can't make neither head nor tail out of this story

Re: Secundary guns turrets

Posted: Fri Jul 17, 2020 8:49 pm
by Danro
As far as I know, it is the forward turret on the starboard side. That is also why it is the only turret positioned in a non combat position. Facing towards the bow with its guns at 0°

Re: Secundary guns turrets

Posted: Mon Jul 20, 2020 1:22 am
by marcelo_malara
Thanks guys. I have always wondered if in fact barbettes for the secondary battery were not a danger, I mean fire has a clear path to the lower hull and magazines without the same protection of a main turret barbette and gunhouse.

Regards

Re: Secundary guns turrets

Posted: Mon Dec 04, 2023 3:26 pm
by marcelo_malara
Hi guys. Revisiting this. Frontal protection of the secondary battery turrets in Bismarck is 100mm. Foremost turrets had a barbette that go to the armoured deck, the armoured deck has an opening for the turret internal structure. And below that is the magazine. Was not this a risky design? A shell piercing the 100mm plate and exploding within the turret could send flame or hot splinters to the 15cm magazine below and produce a catastrophic explosion.

Would like to hear your opinions.

Thanks