Washington

Historical what if discussions, hypothetical operations, battleship vs. battleship engagements, design your own warship, etc.
alecsandros
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Re: Washington

Post by alecsandros » Tue Jul 24, 2012 3:26 pm

dunmunro wrote:For those of you who haven't read it, or haven't read the updated version, here is Bill Jurens article on the sinking of the Hood:

http://www.navweaps.com/index_inro/INRO_Hood_p1.htm
Yes, but there are a few things there that need to be revisited...

Wm Jurens

Re: Washington

Post by Wm Jurens » Tue Jul 24, 2012 7:21 pm

Alexandros suggested that there were some portions of my paper that needed revisiting. I visited the wrecks of Hood and Bismarck in 2001, and prepared a complete description of my observations there, at the same time noting that there did not appear to be any significant issues with my previous paper, i.e. that there were really no 'surprises' found on the bottom which would invalidate my previous work.

Barring the rather blatant baloney regarding a forward magazine explosion which has been put forth by 'television experts' on various pseudo documentaries on the subject -- which can be dismissed out of hand as unworthy of serious consideration -- I am unaware of any recent work in this area which might suggest my original paper was in any way substantively inadequate. In that regard, might you be a bit more specific regarding areas where 'revisiting' might be appropriate?

alecsandros
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Re: Washington

Post by alecsandros » Tue Jul 24, 2012 8:07 pm

Hi Bill,
No offense intended there,
Just some bits and bolts that may bring the article more up to date.
For example, the portion where the effects of 38cm shells against heavy armor plate are discussed.
As I undrstand it, German 38cm L4.4 was tested against contemporary German FH armor, meaning the Krupp "new type" cemented armor.

Hood's armor plates were of 1920s vintage, substantialy less resistant to penetration/perforation than the more modern plates [such as KGV class armor plates]

[To put it very short, Hood's FH armor was probably similar in quality to WW1 Krupp FH armors, that was probably ~ 20% less resistant to penetration than WW2 Krupp FH armors...]

----

To be more precise, this part of the article:

"For this angle, corresponding to a shot approaching from 37° forward of the beam, the resolved obliquity would have been approximately 43.85°.53 German armor penetration curves, redrawn below,54 indicate that at the predicted striking velocity of 530 meters per second, the penetration for an intact projectile into face-hardened armor would have been approximately 240mm. An intact penetration of the 305mm main belt would therefore have been improbable, although either of the thinner sections would have been easily perforated."

could be updated:
the 305mm section of the main armor belt was probably similar to 305 x 0.8 = 244mm Krupp KC n/A... pretty close to what the penetration curve says (240mm)...
Another discussion could be done around the probability of the main belt of Hood to successfully decap the AP cap of a German 38cm shell. My intuition is that that kind of armor (1920s vintage) would not always ensure decaping of this kind of shell, meaning that deeper penetrations in a fit state to burst would be possible...

Cheers,
Alex

Bill Jurens
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Re: Update on paper etc.

Post by Bill Jurens » Tue Jul 24, 2012 10:43 pm

Hello Alecsandros:

I see where you are coming from now. My apologies if I came across as a bit defensive; I was fairly severely 'burnt' by the forward magazine explosion fiasco some years ago, and am certainly reluctant to revisit those sorts of speculations (including "Prinz Eugen did it" and "It was all faulty propellant handling/storage") again.

For what it is worth, I did do some additional armor calculations prior to the 2001 expedition to Hood, but didn't find anything too exciting. For what it's worth, even taking the armor and the ballistic limit to be c. 240mm still would yield only 50% useful penetrations, i.e. even at the so-called 'n.b.l.' only 50% of projectiles will successfully penetrate. That being said, it's pretty clear that something big must have penetrated somewhere. The wreckage itself yields no clue, and probably never will, unless one eventually finds a plate with a hole in it.

Now that I am retired, I am hoping to do a rather complete rework of the original Loss of Hood paper. Although I don't expect any dramatic new conclusions, some additional information can indeed be added, e.g. the fact that the rudder position indicates that Hood had already begun her final turn.

Thanks to Jose for his excellent work solving my access problem. The new password you provided works perfectly!

Bill Jurens

alecsandros
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Re: Update on paper etc.

Post by alecsandros » Wed Jul 25, 2012 9:03 pm

Bill Jurens wrote:
Thanks to Jose for his excellent work solving my access problem. The new password you provided works perfectly!

Bill Jurens
Ok Bill,
Looking forward to seeing your new projects!

Cheers,
Alex

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