Bismarck construction flaws

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spicmart
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Re: Bismarck construction flaws

Post by spicmart » Tue Oct 23, 2018 2:32 pm

Yes. Confusion on my part. Thanks.

[/quote]

There may be some confusion here from the DS battle, where one of the three hits by POW did penetrate a boiler room, where five stokers suffered serious scald wounds.
[/quote]

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Re: Bismarck construction flaws

Post by Paul L » Tue Oct 23, 2018 10:07 pm

RF wrote:
Fri Oct 19, 2018 6:22 pm
spicmart wrote:
Thu Oct 18, 2018 12:01 pm
And did Bismarck suffer a hit in her boiler room during her final fight? Some claim so. Her vitals were supposed to be immune against such hits at these ranges.
There may be some confusion here from the DS battle, where one of the three hits by POW did penetrate a boiler room, where five stokers suffered serious scald wounds.
A 14" shell penetration of boiler room only resulted in 5 stokers with serious scald wounds? That does not sound like a complete penetration. Maybe more like a "partial penetration" that could have severed a high pressure line with shrapnel?

Any word on substantive damage to equipment?
"Eine mal is kein mal"

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Re: Bismarck construction flaws

Post by Thorsten Wahl » Wed Oct 24, 2018 1:02 pm

spicmart wrote:
Tue Oct 23, 2018 2:32 pm

There may be some confusion here from the DS battle, where one of the three hits by POW did penetrate a boiler room, where five stokers suffered serious scald wounds.
The shell dived under the belt approximately in this way and detonated in the proximity of the torpedobulkhead

-blue -E-werk out of order immediatlely completely flooded

-green - boilerrom some damage by splinters through transversal bulkhead between E werk and boilerroom;
no or only slight(repairable within few minutes or hours) damage
likely shock damage to the transversal bulkhead;
water entry from E-Werk could be held for a day until a torpedodetonation caused additional shock damage
reduced steam production then caused maximum speed reduced to about 28 knots

-orange -15-cm-shell rooms undamaged

Image
Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!

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Re: Bismarck construction flaws

Post by Dave Saxton » Wed Oct 24, 2018 8:01 pm

Thorsten Wahl wrote:
Wed Oct 24, 2018 1:02 pm
spicmart wrote:
Tue Oct 23, 2018 2:32 pm

There may be some confusion here from the DS battle, where one of the three hits by POW did penetrate a boiler room, where five stokers suffered serious scald wounds.
The shell dived under the belt approximately in this way and detonated in the proximity of the torpedobulkhead

-blue -E-werk out of order immediatlely completely flooded

-green - boilerrom some damage by splinters through transversal bulkhead between E werk and boilerroom;
no or only slight(repairable within few minutes or hours) damage
likely shock damage to the transversal bulkhead;
water entry from E-Werk could be held for a day until a torpedodetonation caused additional shock damage
reduced steam production then caused maximum speed reduced to about 28 knots

-orange -15-cm-shell rooms undamaged

Image
The angle of fall in the diagram is ~19* which corresponds to a range of ~20,100 meters battle range at the time of the hit. Of course, once a shell hits the water the path may alter. Some accounts mention some of the double bottom compartments were ripped up by this hit.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Bismarck construction flaws

Post by Bill Jurens » Thu Oct 25, 2018 10:08 pm

At the risk of being picky, I might point out that the interpretation of the angle of fall in the previous diagram as about 19 degrees is incorrect, and represents an error very commonly made. When one is looking at transverse cross sections (I assume that it is indeed part of a transverse cross section which is shown) the angle of fall is only correct if the trajectory is travelling directly across the beam, i.e. perpendicular to the longitudinal centerline. Projectiles approaching from other angles, due to foreshortening effects, always project a greater-than-real angle of fall on a transverse projection.

In this case, the angle of fall indeed appears to be about 19 degrees, but the projectile is shown in plan (why are the views not aligned?) as approaching from 40 degrees forward of the bow. A bit of mathematical (or geometric) manipulation, which I will not go into in great detail here, indicates that according to the diagrams the actual angle of fall is only a little greater than 15 degrees. Whether or not one considers that sort of error significant or not depends, I suppose on the situation. In this case, the other issues involved, e.g. the probably somewhat erratic nature of the underwater portion of the trajectory, and the fair uncertainty regarding the exact point of explosion, etc., may submerge this sort of nuance in the noise.

As I mentioned before, this sort of thing represents a very commonly encountered error in damage analysis, and I point it out here only to illustrate the principle.

Watch your geometry!

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Re: Bismarck construction flaws

Post by dunmunro » Thu Oct 25, 2018 11:11 pm

Paul L wrote:
Tue Oct 23, 2018 10:07 pm
RF wrote:
Fri Oct 19, 2018 6:22 pm
spicmart wrote:
Thu Oct 18, 2018 12:01 pm
And did Bismarck suffer a hit in her boiler room during her final fight? Some claim so. Her vitals were supposed to be immune against such hits at these ranges.
There may be some confusion here from the DS battle, where one of the three hits by POW did penetrate a boiler room, where five stokers suffered serious scald wounds.
A 14" shell penetration of boiler room only resulted in 5 stokers with serious scald wounds? That does not sound like a complete penetration. Maybe more like a "partial penetration" that could have severed a high pressure line with shrapnel?

Any word on substantive damage to equipment?
It was actually a turbo-generator room that was penetrated and shock and splinters damaged the next inboard bulkhead to an auxiliary boiler room and an adjacent bulkhead to a main boiler room.

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Re: Bismarck construction flaws

Post by Dave Saxton » Fri Oct 26, 2018 1:36 pm

Thank you Mr. Jurens. I stand corrected.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Re: Bismarck construction flaws

Post by Paul L » Sat Oct 27, 2018 11:34 pm

dunmunro wrote:
Thu Oct 25, 2018 11:11 pm

It was actually a turbo-generator room that was penetrated and shock and splinters damaged the next inboard bulkhead to an auxiliary boiler room and an adjacent bulkhead to a main boiler room.
It only works with the shell traveling under the main belt that was not deep enough....which I've argued was a big problem.
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Re: Bismarck construction flaws

Post by Thorsten Wahl » Tue Oct 30, 2018 3:14 pm

Bill Jurens wrote:
Thu Oct 25, 2018 10:08 pm

In this case, the angle of fall indeed appears to be about 19 degrees, but the projectile is shown in plan (why are the views not aligned?) as approaching from 40 degrees forward of the bow. A bit of mathematical (or geometric) manipulation, which I will not go into in great detail here, indicates that according to the diagrams the actual angle of fall is only a little greater than 15 degrees. Whether or not one considers that sort of error significant or not depends, I suppose on the situation. In this case, the other issues involved, e.g. the probably somewhat erratic nature of the underwater portion of the trajectory, and the fair uncertainty regarding the exact point of explosion, etc., may submerge this sort of nuance in the noise.

Watch your geometry!

Bill Jurens
the first picture doesnt show the path of the projectile along the trajectory but the projection of the trajectory as seen from a position behind the ship. I made a rough correction of angle of descent of projectile for correcting the line of sight in my estimate.

I used a straight line as estimate, as I could not reliable produce a "real" underwater trajectory, given the uncertainty of the surface of water( entry angle on water, lenght of UW travel...), influence of spin of projectile and development of cavitation on waterentry, velocity loss during traveling in the water - to name some of the uncertainties.
Meine Herren, es kann ein siebenjähriger, es kann ein dreißigjähriger Krieg werden – und wehe dem, der zuerst die Lunte in das Pulverfaß schleudert!

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Re: Bismarck construction flaws

Post by spicmart » Tue Nov 06, 2018 6:11 pm

One major flaw of the Bismarck design were the exposed communication system as is often claimed. But they were beneath the armored deck. So why was it so "easy" to disable them? I wonder if other BBs better would have fared better at that.

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Re: Bismarck construction flaws

Post by lightyear » Mon Jan 14, 2019 12:41 pm

Hi there everyone :D
Brand new guy here. I have read threads in this forum for 100+ hours and I feel information pouring into my head. So I registered and start my 1st post here.
I always wonder the slop portion of bismarck's turrets is weard. Is it too light for 180mm at such an important place? It shouldn't be much trouble to give them extra, like, 50mm to make it safer. :think: So I consider this is a flaw in defence system. At a closer range the projectile maybe glance off while at a longer range the strike angle may not be that favourable. If the designer think BS' conterpart also use flat trajectory gun, maybe we can roughly calculate the distance taht her designer intend to let her engage enemies. Just by calculating at what angles the 180mm work well against Bismarck's gun trajectory. It may greatly different with the German navy's doctorine though, as I know BS is capable of engage foes at a fairly long range with his excellent gun dispersion.
Second, I think the underwater protection is a flaw. I know it is tricky for every warship and a dilemma between torpedo protection and underwater projectile protection. Still, I think it will be much better to have 3-3.5 meters(even tappered) under water to make it safer.

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Re: Bismarck construction flaws

Post by Thorsten Wahl » Thu Jan 17, 2019 3:37 pm

I always wonder the slop portion of bismarck's turrets is weard. Is it too light for 180mm at such an important place?
whats the distance you expect a penetration.

the forward 180 mm slope had a projected hitable area of maybe about 100 m² at 10 km. for Bismarcks guns the 50% zone of impacts at 10 km distance has a surface area of about 2900 m²(out of 8single shots 4 shots are likely to land in this 2900 m² area ).

the ~50m² area of the projected slope area represent represent only about 4% of the size of the 50% zone of impacts. in its ballistic protection the 180 mm sloped part is roughly comparable with the horizontal part of the turret.

But there is a serious problem even a non pentrating hit likely cause concussion damage, its not necessary to produce a hole to put a turret out of action.

but if you hit a faceted portion of the tutrret the projectile is very likely rejected and only a low energy transfer to the turret takes place.
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Re: Bismarck construction flaws

Post by Dave Saxton » Fri Jan 18, 2019 2:53 am

The slopes were angled-back 65 degrees. This presents a very acute striking angle for incoming shells at short and medium ranges. Even against large caliber shells it offers some protection at more likely battle ranges. It reduces the frontal area (14" face plate) that would be vulnerable to large caliber projectiles at those ranges. If the ship is ever involved in a knife fight with cruisers or smaller warships with high rates of fire at close range, it reduces the chances of a turret being knocked out by a non penetrating sub caliber projectile by deflecting it. As the range increases to long ranges and incoming shells develop greater angles of fall, the slope becomes a liability, but as Thorsten points out, how likely is it to be hit. Scoring hits against any part of the ship are unlikely at extreme ranges, much less than on one of the angled plates. It's a trade off for better protection at ranges were it is more likely to receive a hit.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

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Alberto Virtuani
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Re: Bismarck construction flaws

Post by Alberto Virtuani » Fri Jan 18, 2019 9:18 am

Hello everybody and welcome to "lightyear" !

while I do agree with everything Thorsten and Dave have pointed out regarding the sloped part of the turret front and I don't see it as a flaw by itself, I still find a bit strange (a "flaw" ?) that the thickness of these slopes is less than the one of the (very small) sloped part of the armored conning tower (200 mm, if I remember correctly):

the turrets are (usually) pointing directly toward the enemy, thus presenting a normal impact angle as "inclination" and the 65° angle is the only "angle protection" against these shells, becoming a real danger at average-long ranges despite their small size). The conning tower is rounded and does not bear toward the enemy, thus the "normal inclination" is true only for a very limited part of it, while an additional angle is "added" for all incoming shells from any direction different from the perpendicular. I find a bit strange that more armor is put in the conning tower than in the main armament turrets, due to the potential danger represented by a direct penetration of a turret, despite all anti-flash mechanisms.

This is true also for the horizontal part of the main turrets (130mm) vs the horizontal part of the conning tower (200mm). In general, of course, the doubt is revolving around the decision to armor so heavily the conning tower, with its weight so high in the ship, affecting stability much more than the turrets...


Bye, Alberto
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Re: Bismarck construction flaws

Post by lightyear » Fri Jan 18, 2019 10:37 am

To Thorsten, Dave and Alberto
Thank you for your answer about this part. It is really interesting to think about the designer's thought behind the layout. It bring out a long standing question of mine--can the turret be protected vs battleship class caliber projectiles?
This started long ago from Okun's article regarding penetration of bismarck's 380 gun:

HL NL EL
SHIP Yards (Meters) Yards (Meters) Yards (Meters)
KM BISMARCK 35 (32) 29 (26.5) 27.9 (25.5)
HMS KING GEORGE V
-Amidships 28.4 (26) 23.8 (21.6) 22.9 (20.9)
-Magazines 27 (24.7) 21.5 (19.7) 20.8 (19)
RICHELIEU 24.5 (22.4) 20.8 (19) 18.6 (17)


I don't completely agree with the result due to a different result, however, I saw a pattern of in the statistics. The intervals between HL and NL is WAY bigger than that of NL and EL. It means the armor is very easy to be punched a hole even if it is not nearly penetrated or partially penetrated.
When I saw the SD damage report, I further confirm this idea. A 8" shell penetrated 7-8" of the 12.2" belt which is 2/3 of the armor caused the fragments shoot out from the back. And some water got in if I recall correctly. Without any further layer to stop the fragments, the turret is over...
I'm not sure this idea is reasonable or not. But I think the designer might never reckon they will use turret armor to defeat a incoming BB shell completely. They just try to do as good as possible. Back to BS, It looks like the disigner just let go the idea of 14" armor defeating BB projectile from any range and take chance of glancing effet for shorter range.
It is wierd that I didn't see any HL presentation form the Naab software I downloaded form a link of the forum. It has partial penetration immediately adjacent to no whole in the armor. I didn't find HL topic on the forum either. Is my idea about the turret armor a delusion? :shock:
Thanks

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