Total number of shells fired by Bismarck and straddles

[alecsandros]

Hello,

I am trying to picture how many shells Bismarck expended during Rheinubung.

The targets were, to the best of my knowledge:
- Norfolk, 23rd of May
- Hood, 24th of May
- PoW, 24th of May, in the morning
- Norfolk, 24th of May, in the evening
- PoW, 24th of May, evening
- Sheffield, 26th of May, evening, splinter damage.
- VIan's destroyers, 26th of May, night, splitner damage.
- Rodney, 27th of May
- KGV, 27 of May

I know that at DS he fired 93 shells, out of which 6-8 were hits.

Does anyone know about other expenditures and possibly number of straddles attained ?

[lwd]

...I know that at DS he fired 93 shells, out of which 6-8 were hits. ...

That's interesting because on the Myth thread it's been stated she got between 3 and 7 its there and one of them due only to a defective fuse.

[alecsandros]

I don't know where you've seen "3 hits at DS".

Certain hits:
1 - on Hood
4 - on PoW (as described in the British investigation of the damage suffered by PoW)

Probable hit:
1 - on Hood, that passed through the foretop killing several men

Possible hits:
2 - on Hood:
1st - causing the fire that killed 200 men (most arguments favor a hit by PE though)
2nd - in the same salvo that destroyed the ship

[dunmunro]

I don't know where you've seen "3 hits at DS".

Certain hits:
1 - on Hood
4 - on PoW (as described in the British investigation of the damage suffered by PoW)

Probable hit:
1 - on Hood, that passed through the foretop killing several men

Possible hits:
2 - on Hood:
1st - causing the fire that killed 200 men (most arguments favor a hit by PE though)
2nd - in the same salvo that destroyed the ship

There was only 3 38cm hits on PoW and at least one on Hood. Other 38cm hits on Hood are impossible to ascertain with certainty although more are likely.
http://www.hmshood.com/history/denmarks ... amage1.htm
http://www.hmshood.com/history/denmarks ... damage.gif

[tommy303]

I agree with Duncan. It was thought for years that the shell which struck the secondary director tower was a 38cm, but a number of authors have doubts, and have assigned the hit to a 20,3cm shell from Prinz Eugen as it did not appear to have caused as much damage as one would expect of a 38cm. This leaves Bismarck's hits on PoW as being compass platform, hit below the waterline, and hit on boat crane.

[dunmunro]

The other factor is that it is a bit of a stretch to assign the 38cm UW hit equal status to the others, as it is obvious that it must have actually fallen well short of PoW.

[paulcadogan]

The other factor is that it is a bit of a stretch to assign the 38cm UW hit equal status to the others, as it is obvious that it must have actually fallen well short of PoW.

That makes no sense to me. To follow that logic...PE's two hits aft below the waterline on PoW and PoW's hit on Bismarck amidships below the waterline don't really measure up as proper hits, and if Bismarck's fatal shell struck Hood below the waterline it wasn't a genuine hit either!

A hit is a hit whether the shell strikes above or below the waterline. After all, the latter can directly affect watertight integrity!

[dunmunro]

The other factor is that it is a bit of a stretch to assign the 38cm UW hit equal status to the others, as it is obvious that it must have actually fallen well short of PoW.

That makes no sense to me. To follow that logic...PE's two hits aft below the waterline on PoW and PoW's hit on Bismarck amidships below the waterline don't really measure up as proper hits, and if Bismarck's fatal shell struck Hood below the waterline it wasn't a genuine hit either!

A hit is a hit whether the shell strikes above or below the waterline. After all, the latter can directly affect watertight integrity!

No, these other hits were close enough to the ship that the shell could fuze properly upon striking the water and still detonate after entering the ship, which is what the 14" hit from PoW did, as did the UW 20cm hits which also had enough remaining SV to indicate that their fuzes were functioning normally, and that they would have detonated in the water had they fallen shorter than they did.

It is true that a 38cm shell struck PoW UW, but the point is that it gives a false impression of Bismarck's FC accuracy, since it was really equivalent to a very large piece of shrapnel from a miss.

[alecsandros]

I agree with Duncan. It was thought for years that the shell which struck the secondary director tower was a 38cm, but a number of authors have doubts, and have assigned the hit to a 20,3cm shell from Prinz Eugen as it did not appear to have caused as much damage as one would expect of a 38cm.

Maybe the discussion is opened, but a non-exploding shell won't do much damage anyway...

In the words of Garzke&Dulin:
"The shell that destroyed the admiral's charthouse and struck the forward starboard director was first thought to have been a 15-inch, as it could have been part of the same salvo that hit the compass platform; however, there is some conflicting data on the true caliber of this particular shell. It might have been only an 8-inch, because the damage was not comsistent with a 15-inch shell fa heavy caliber shell would not have been so easily deflected by the charthouse structure), and the bearing and angle of descent were not consistent with those of the previous hit. The shell traveled 8.5 feet in the ship, encountering no serious obstacles. As a result of this hit, the port 5.25-inch director was permanently out of action with the starboard director temporarily out of action"

The best argument for assiging the secondary director tower hit to BS is that it apparently came in the same salvo as the one that hit the compass platform.

[alecsandros]

No, these other hits were close enough to the ship that the shell could fuze properly upon striking the water and still detonate after entering the ship, which is what the 14" hit from PoW did, as did the UW 20cm hits which also had enough remaining SV to indicate that their fuzes were functioning normally, and that they would have detonated in the water had they fallen shorter than they did.

It is true that a 38cm shell struck PoW UW, but the point is that it gives a false impression of Bismarck's FC accuracy, since it was really equivalent to a very large piece of shrapnel from a miss.

I don't think it's a good idea to leave that hit "out". Even non-exploding shells can cause a great deal of damage (like the hit on the compass platform), and PoW got betweeen 400-600 tons of water inside her because of the bwl hits. So leaving this one out is just wrong.

And Dunca, for the last time, Bismarck fired MUCH better than PoW at DS.

[dunmunro]

I don't think it's a good idea to leave that hit "out". Even non-exploding shells can cause a great deal of damage (like the hit on the compass platform), and PoW got betweeen 400-600 tons of water inside her because of the bwl hits. So leaving this one out is just wrong.

The 20cm hits caused the vast majority of the flooding, mainly because they were effective hits that detonated with high SVs while the 38cm dud hit probably caused less than a 100 tons of the total. As I stated earlier, the 38cm UW hit was basically a large piece of shrapnel from a near miss.

[alecsandros]

If you want to take it this way, then you should also leave out 2 out of the 3 hits PoW obtained in the same battle.
The reason: neither the fw hit on the bow, nor the hit that went through the aircraft crane did not explode, and it is probable they did not fuze. Thus you can not know for sure if they worked properly, and anyway they did not cause damage in the way they were "supposed to".

[dunmunro]

If you want to take it this way, then you should also leave out 2 out of the 3 hits PoW obtained in the same battle.
The reason: neither the fw hit on the bow, nor the hit that went through the aircraft crane did not explode, and it is probable they did not fuze. Thus you can not know for sure if they worked properly, and anyway they did not cause damage in the way they were "supposed to".

The 3 hits on Bismarck were obtained from shells that either struck Bismarck directly with enough SV to have caused damage even if the shell didn't detonate, or struck the water, plunged and detonated within the hull after the shell fused from striking the water - these hits were all in the 14" danger space - this is the critical point to consider. The 38cm UW hit had very little SV and a dud fuse, which is why it hit. If the shell had fallen close to the hull, within the fuze delay range, it would have done a lot of damage (assuming it could dive under PoW's deep main belt) even if it had a dud fuze because it would have had sufficient remaining SV to have passed through the armoured SPS bulkhead. However the 38cm UW hit resulted from a shell that struck the water outside the 38cm danger space, which is why it did so little damage; it was basically just shrapnel, and if PoW's 14" hit on Bismarck's bow had the same low SV, it wouldn't have even penetrated the 6cm splinter belt.

Danger Space - That distance in front of the target, measured parallel to the line of fire, that the target could be moved toward the firing point, so that a shot striking the base (waterline) of the target in its original position would strike the top of the target in its new position. The flatter the trajectory, the greater the danger space. See "Hitting Space," below.

Hitting Space - The distance behind the target, measured parallel to the line of fire, that a projectile striking the top of the target will strike the horizontal plane through the base (waterline) of the target. It may also include a distance in front of the target within which impacts are likely to produce underwater or ricochet hits upon the target. In other words, the hitting space is the distance between the point where a shell falling short of a target will start to inflict damage and the point at which a shell falling long of a target will stop inflicting damage. The greater the angle of fall, the smaller the hitting space. At long ranges, danger space and hitting space are about the same size, but at short distances the danger space is larger than the hitting space. See "Danger Space" above.

http://www.navweaps.com/Weapons/Gun_Data_p3.htm

[alecsandros]

Yes, but it functioned nonetheless, at the "outer edge" of the danger space.

The behavior of that particular shell is quite curious, as it traveled a considerable distance underwater, allthough it wasn't designed at all to do so. In fact, German gun and armor designers believed little about uw hits before the war, one of the consequences being Bismarck's somewhat shallow main belt.

Another peculiar aspect is the shell's trajectory. If I understand correctly Nathan's and Jurens's papers regarding BB caliber uw shell behavior, the uw trajectory for a "perfect" shell is shaped like a bell, with the shell diving a certain depth, after which it starts to re-emerge and potentialy go outside of the water.
The curiosity lies in the 8.5m (estimated) depth at which the 38cm shell dove. This implies either an atypical, linear trajectory, or a very-very long uw trajectory.
Of course, this is just an imaginary curiosity, as the fuze timer wouldn't provide the necessary delay for such trajectories to occur. It's odd nevertheless...

[lwd]

Shell trajectories in particular underwater ones are subject to random fluctuations in their trajectories. There is some evidence that a similar outlier in Japanese test which ended up penetrating into the magazine of the target resulted in the Japanese obsession with underwater trajectories. In spite of extensive shell design for that purpose it seems to have been of little benefit. On average a shell apparently tends to dive after hitting the water but some few take shallower trajectories. I personally would still consider it a hit but an extremely lucky one as not only did the shell have to follow a low proability path but the fuse had to fail as well. There's a line from a play that goes something like:

It's smarter to be lucky than it's lucky to be smart

As far as Bismarck shooting went at Denmark straits she was defintily lucky.