South Dakota´s barbette impact

[marcelo_malara]

In another thread the impact received by South Dakota on the Second Battle of Guadalcanal has been mentioned. I have ever known that the shell was HE, but then Tiornu wrote that in fact it was an AP one. But yesterday revising Campbell´s Naval Weapons of WWII (a most respectfull source) he describes the impact ("the only major-calibre shell hit on US battleship in the Pacific war", Karl will love this phrase) as coming from a nose fuzed, Common Type 0 HE shell.

[Karl Heidenreich]

Hi Marcelo!

Yep, he phrase is quite cool.

And, yep, there is an old thread were the South Dak damage was discussed. In it this intersting info was posted:

http://www.dcfp.navy.mil/cgi-bin/WarGal ... &PgConst=9

Very best regards!

[Tiornu]

Campbell's mistaken. If you read through the SoDak damage report, you'll note some odd things about it. The date, for example. It was written years after the battle--postwar, in fact, and the references inclued the NTM report on Japanese projectiles. The authors had but a single shell splinter to work from, despite there having been 27 hits. The description of the barbette hit is conspicuously silent on the matter of the shell type. But since the Japanese were firing AP ammo only at the time, the shell had to be AP, unless it magically transformed into HE in midair.

[tommy303]

I would tend to agree with tiornu. Had the shell been a nosed fuzed projectile it should have detonated against the hatch combing rather than passing through both sides and into the barbette

[marcelo_malara]

Was the impact above or below deck?

[Tiornu]

The impact was above deck and below the cap of the barbette, which is a very small space. Photos appear to show a second impact point a bit below the deck level--the deck there was blown away from the barbette. It's not possible to be sure of any such details due to the quality of the photos, but a second impact on the same vertical structure could be possible if the shell body deflected downward after the cap was stopped dead by the barbette. The detonation of the shell could have slammed the nose of the shell body into the armor. Who knows? When things happen that fast....

[marcelo_malara]

And there is certainty that the Japanese were shooting AP at that time? Any other ship receive such a shell by then?

[tommy303]

If I am not mistaken, a good many of the lesser rounds which hit the battleship were AP or base fuzed common.

[Tiornu]

The SoDak report is available in full at the link posted by karl. Click the War Damage Home button, and you'll find an amazing collection of reports.
The barbette hit came at the tail end of the fight, and all Japanese reports that I know of agree that the Kirishima had switched to Type 91 AP after a few rounds of Type 3 and Type 0.

[Bill Jurens]

The hit on South Dakota is unlikely to have been from an armor-piercing round. The steel doesn't lie; an impact from an a.p. round would have caused much more damage at the impact point, and the amount of damaged and removed decking is much too large to have been removed by the relatively small charge in an a.p. round. The secondary damage lower on the barbette is likely to have been due to the impact of the base plug or some large piece of dislodged structure.

The possible penetration of an Iowa face plate by a Bismarck bullet represents an interesting topic, but one which I cannot devote very much time to at present. It's worth noting, however, that heavy homogeneous plates were rarely tested at near to normal impacts, so the actual data base is pretty rare. In that regard, I would view other than official (and reproduceable) data with considerable skepticism. GKdos 100 does not cover this type of impact at all, but with considerable extrapolation of lines which are already there, it would appear that the predicted penetration for a 450 m/s impact at 90 degrees would be about 13.5". But this is, admittedly, highly tentative.

Bill Jurens