80mm armor on the upper deck

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alecsandros
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80mm armor on the upper deck

Post by alecsandros »

Hello,

I don't understand this:

- was the upper deck of Bismarck 80mm thick around the main AND secondary turrets, and con tower ? Or only around the secondary turrets ?
- was the upper deck of Tirpitz 80mm thick in the areas mentioned above ?

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Herr Nilsson
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Re: 80mm armor on the upper deck

Post by Herr Nilsson »

According official sources only around the centre and rear secondary turrets.
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Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
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Re: 80mm armor on the upper deck

Post by alecsandros »

But for Tirpitz at least I read accounts of members of the breaking team that mentioned 80mm weather deck around "main barbettes" ?
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Re: 80mm armor on the upper deck

Post by Herr Nilsson »

I don't know such accounts. So what do they say? Where were the 80 mm exactly? What was their purpose?
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Marc

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Re: 80mm armor on the upper deck

Post by alecsandros »

"Around the main barbettes" and "around the secondary barbettes".

Thickness was much bigger than in the rest of the weather deck (8cm vs 5cm), which was why the breaking company observed it - it was much harder to cut the steel from around the barbettes than it was to cut it from the rest of the upper deck.

I don't understand if those accounts mention explicitly a continous thickness of 8cm around the barbettes, or alternating stripes of 5 and 8cm.

I'll try obtaining more first-hand information about this though.

====

P.S.: The 8cm thickness around the main barbettes appears also in Siegried Breyer's analysis. Do you have more thoughts on this ?
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Re: 80mm armor on the upper deck

Post by Dave Saxton »

I don't know how far a thicker section thickness extended in this case, but the use of thicker section thickness at certain points is often used in welded construction. It may not be at the point of the weld joints in some cases, but at particular breaks in continuity or stress points to prevent the formation and then the propagation of cracks or tears. This is because welded construction joins structural pieces into one big piece and a tear or crack can keep progressing unabated through welded joints.
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Re: 80mm armor on the upper deck

Post by tommy303 »

If I recall correctly, William Garzke mentioned in conversation that the increased thickness around the barbettes was for strengthening the weather deck to make up for the inherent weaknesses caused by the very large openings required for the barbettes themselves.

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Re: 80mm armor on the upper deck

Post by Herr Nilsson »

That's why I was asking about the purpose. The strengthening of the deck near the secondary armament was because of the openings and not to increase protection. The specification of the hull is vage regarding the weather deck around the main artillery. I consider it possible that there were thicker plates for strengthening reasons, but I doubt, that one could say that the weather deck over the magazines was 80 mm.
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Re: 80mm armor on the upper deck

Post by alecsandros »

Marc, what was the extent of the 80mm plates around the secondary barbettes ?
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Re: 80mm armor on the upper deck

Post by Herr Nilsson »

I don't know it exactly. I just know for sure that it was plate between the barbette and the hull. Everything else would be speculation. What makes me wonder is that this plate was so small. Normally I would expect a much longer plate.
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Re: 80mm armor on the upper deck

Post by alecsandros »

Well, how small was the plate ?

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Re: 80mm armor on the upper deck

Post by Herr Nilsson »

Well, the plate is not as small as I recalled, but the final welded arrangement differs a lot from the riveted one.
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centre turret, port
centre turret, port
upper deck .jpg (27.14 KiB) Viewed 2382 times
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Marc

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Re: 80mm armor on the upper deck

Post by alecsandros »

And which ones are 80mm thick ? The 4 plates that come in contact with the barbette ?
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Re: 80mm armor on the upper deck

Post by Herr Nilsson »

I don't know. The quality of my copy of the plan is too bad. At least the plate between the barbette and the outer hull should be 80 mm.
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Re: 80mm armor on the upper deck

Post by alecsandros »

Ok...
I tried contacting several Norwegian people who could shed some light on the issue.\
One has a fjord-diving company, which explores the area of Tromso where Tirpitz was destroyed - I thought he may have some aquaintances amongst the men who helped break the ship.
Another is the Tirpitz museum, in Norway, which should have relations to many people who actualy participated in the dismantling of the battleship.
Another is Hovding Shipbreakers, the Norwegian firm who bought the rigths to salvage. (I tried contacting them via the city-halls website)

Until now, no one replied... If I get any luck, I'll let you know...
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