Naval History Forums

I was reading the technical specs for the Bismarck, and I was somewhat...surprised...to find that on a displacement of 50,000 tons, she only had 17,000 tons of armor, which is around 30% of her total weight.

According to my perceptions of Nathan Okun's very incredible dissertation on her, would it be safe to conclude that Bismarck was lightly armored???

50000 fully loaded with water, fuel, ammo, etc.
Empy weight, without liquids in the TDS would be ~ 39000 tons.
Nominal displacement was ~ 41700 tons.

Bismarck maximum displacement including reserve fuel oil and water was over 53,000 mt. The total weight of the armor (including turret armor) was 19,000 mt. By armor here only KC, Wh and Ww meterials are taken into consideration. Bismarck was anything but lightly armored. Only the Yamatos had more armor weight.

Steffen, one should be very prudent with this kind of statistics. It's difficult to compare the weight of armor of different ships because the navies of WWII didn't use the same methodology to compute the weight of armor. It's like comparing apple and oranges ...

Best,

Francis Marliere

Francis Marliere wrote:Steffen, one should be very prudent with this kind of statistics. It's difficult to compare the weight of armor of different ships because the navies of WWII didn't use the same methodology to compute the weight of armor. It's like comparing apple and oranges ...

Best,

Francis Marliere

Francis,
THis is usualy an excuse to leave out "Bismarck" or to degrade her in relationship with other contemporaries.
IN truth, armor amount CAN be calculated within some error margins.

You can see Thorsten's analysis right here on the forum.

Cheers,

Alecsandros,

I do know that armor CAN be calculated within a reasonnable error margin. What I meant (sorry if I was not clear) is that one may be very prudent when you don't do the math yourself and use secondary sources. You never know how the calculation was done and you are in danger in comparing apples and oranges.

Best,

Francis

Francis Marliere wrote:Steffen, one should be very prudent with this kind of statistics. It's difficult to compare the weight of armor of different ships because the navies of WWII didn't use the same methodology to compute the weight of armor. It's like comparing apple and oranges ...

Best,
Francis Marliere

I understand that. I wasn't trying to compare Bismarck with anything BUT Bismarck. Something about the armor weight seemed wrong to me, so I asked.

Like the title said: Is this a dumb question (on my part)?

So far, the answer seems to be "yes."

Anyways, thanks to all who've weighed their opinions, and more importantly, been patient with my question.

steffen19k wrote: Like the title said: Is this a dumb question (on my part)?

So far, the answer seems to be "yes."

Relax,
It's more complicated than that.
Nobody knows the higher truth :) We\re just trying to understand more...

I'd say it depends on the displacement you use for comparison. For instance, at maximum load, Bismarck would probably go beyond 53000 tons, out of which 19000t armor would represent ~ 36%. However, the construction weight (empty ship) is around 39000 tons, so the armor represents ~ 49% of the total...

In short, the higher the load carried, the smaller the % of armor in the total load. Take Iowa - 46000 tons normal load, and 60000 tons full-load late war. Again, the % would be much more of the normal load...

What is important I guess is to compare ships at similar % loads... (I.e. Vittorio Veneto empty, Bismarck empty, etc)

Cheers,

You also have to be careful as to what is considered armor and what features are included at least if you wish to compare ships especially ships of different nations. For instance I believe I've read on this board that some countries didn't include the turret armor when they listed the ship armor. Or US ships which used armor grade steel extensivly internally. In any case I think one would have a very difficult time makeing the case that Bismarck was lightly armored.

lwd wrote: For instance I believe I've read on this board that some countries didn't include the turret armor when they listed the ship armor. Or US ships which used armor grade steel extensivly internally.

The weight may be calculated by any interested man, having the plans of the ship and measuring the volumes, and knowing the density of steel.
It takes a while, but it works.

That rather depends on how detailed and accurate the plans are and whether or not the steel types are defined or what one chooses to count as armor does in not? If you are taking measurements off the plans you are going to be making errors as well. Then there are case like the KGV's I believe where the armor was actually specfied in weight for a given area but refered to as a nominal thickness.

what is armor?

german methodology is all armor grade materials were counted as armour even if used mainly for structural purpose

armour grade materials were used on (partial list)
cemented Armor (KC(nA)) heavy side armor, citadel armor until spant 186,7m , heavy conning tower, parts of transverse bulkheads Barbettes turret faceplates, main cabeling tube

Wotan weich (Ww) Torpedobulkheads, lashing of main armopred deck/ slope

Wotan hart (Wh) diverse splinter protection all over the ship; conning towers, turret protection heavy and middle artillery- if not KC(na); whether deck, main armored deck/slope, upper platform deck before spant 202,7m, citadel armor before spant 186,7m, hull before spant 202,7 hull after spant 32m - 19,5m, transverse bulkheads at 10,5m, 32 m, 202,7m and 224 m

USN did not consider (as far as i know) torpedo bulkheads as armour; also the waterline skin wich was made from STS was not counted and the splinter deck, not all layers of deck armor grade materials wich were part of the structurals

the british consider D-steel used for splinter protection as armor wich is comparable with the main hull material from Bismarck (St 52 KM)

Thorsten,

Thanks for your clarification, it will really helps out to discrimination of elements.

steffen19k wrote: ... on a displacement of 50,000 tons, she only had 17,000 tons of armor, which is around 30% of her total weight.

According to my perceptions of Nathan Okun's very incredible dissertation on her, would it be safe to conclude that Bismarck was lightly armored???

Within these parameters what tonnage would classify for being heavily armoured?

RF wrote:

steffen19k wrote: ... on a displacement of 50,000 tons, she only had 17,000 tons of armor, which is around 30% of her total weight.

According to my perceptions of Nathan Okun's very incredible dissertation on her, would it be safe to conclude that Bismarck was lightly armored???

Within these parameters what tonnage would classify for being heavily armoured?

Actually, Mr. Rico answered it quite satisfactorily. My information on Bismarck was wrong.

Jose M. Rico wrote: Bismarck maximum displacement including reserve fuel oil and water was over 53,000 mt. The total weight of the armor (including turret armor) was 19,000 mt. By armor here only KC, Wh and Ww meterials are taken into consideration. Bismarck was anything but lightly armored. Only the Yamatos had more armor weight.