How close did the USS North Carolina come to sinking

[Tshipley]

A lot of people know that the USS North Carolina was hit by the I-19s torpedo in the "Luckiest Torpedo shot in WW2". Few realize how close it came to being a catosrophe. The torpedo hit 20 feet below the armor belt. Flames were actually reported by crew member in the Turret One Powder room briefly. Turret One was out of commision until she returned to Pearl Harbor as Ulithi did not have the proper facilities to repair her.

The crew of the USS North Carolina was truly lucky the flames did not set of a catostrophic explosion w/ the flames were flickering in the powder room.

[Guest]

The wreckage suggests that the Scharnhorst suffered a forward turret magazine explosion which may have been caused by a similar torpedo hit as described above.

[Werner]

The constructor said the system performed as expected. Friedman devotes a brief chapter to this damage, and I believe the conclusion was that although the flooding was over a wider area, the ship was never in any real danger.

Compare Boise, which took an underwater hit in a magazine serving three 6-inch magazines. The inrush of water after the hit negated the explosive effect of the torpedo and the ship did not blow up.

The US heavy cruisers which lost bows in the Battles up The Slot had all been designed deliberately to compromise underwater magazine protection in favor of a heavier deck.

[JWintjes]

The wreckage suggests that the Scharnhorst suffered a forward turret magazine explosion which may have been caused by a similar torpedo hit as described above.

Could you go into more detail about that? As far as I know the evidence of the survivor's doesn't suggest a magazine explosion.

Jorit

[Dick J]

Turret One was out of commision until she returned to Pearl Harbor as Ulithi did not have the proper facilities to repair her.

Just a minor point, but Ulithi was not yet in US hands. Forward base repairs were being done at Esprito Santo, and no drydock facilities were available there.

[Filipe Ramires]

Compare Boise, which took an underwater hit in a magazine serving three 6-inch magazines. The inrush of water after the hit negated the explosive effect of the torpedo and the ship did not blow up.

I believe you are speaking of the Battle of Cape Esperance, correct? Boise was not hit by a torpedo but by 8'' shells. 1 of the shells penetrated and went to the magazine or nearby. Immediately after, what is today thought to have been a "diver" 8'' shell struck the cruiser and the consequent rush of water coming from the hole made by the shell allowed the fires to be extinguished immediately.

[MartinJQuinn]

The wreckage suggests that the Scharnhorst suffered a forward turret magazine explosion which may have been caused by a similar torpedo hit as described above.

Could you go into more detail about that? As far as I know the evidence of the survivor's doesn't suggest a magazine explosion.

Jorit

IIRC, the British destroyers reported a very loud rumble once the Scharnhorst had disappeared, which was attributed to a magazine explosion.

[Filipe Ramires]

There were 36 survivors of Scharny if memory serves me well. Regarding the magazine explosion I believe it took place already after he was turning turtle and was in process of sinking. I too have heard of a "large sub-aquatic" explosion shortly after he sink or in process of doing that...perhaps large ammounts of ammo going off their supports and exploding made that happened.

[Dustermaker]

The wreckage suggests that the Scharnhorst suffered a forward turret magazine explosion which may have been caused by a similar torpedo hit as described above.

Could you go into more detail about that? As far as I know the evidence of the survivor's doesn't suggest a magazine explosion.

Jorit

hehe, a torpedo hit was the LEAST of the Scharnhorst's worries....that thing was shelled, torpedoed and still was floating. 1 torp was a drop in the water.

[Tiornu]

NC's turret No 1 was not put out of action. Rather it was to be used only in an emergency. Personally, I find that a somewhat humorous caution.
The amount of flooding caused by the torpedo was surprisingly small, less than 1000 tons. I don't know of any battleship that suffered less flooding from a 21in torpedo hit during WWII--unless it was a dud!
There were reports of flame in a powder room but no signs of it could be found. Flash was reported, not in a powder room, but a handling room. There is a possibility that the crewmen were not seeing flash but instead experiencing an illusion caused by the compression of the eyeballs by the force of the detonation. However, the smell of smoke was strong, and it must have come from somewhere.
Scharnhorst survivors confirm that her big explosion came after she sank. Considering the German magazine arrangement, I suspect she was less susceptible to torpedo-induced magazine explosion and more susceptible to gunfire-induced magazine explosions. During the battle, 14in shells caused fires in two 28cm magazines and one 15cm magazine.
One of the 8in shells that hit Boise was a diving shell that penetrated into the ammo spaces and ignited some of the powder. It is generally held that the watering rushing in through the shell hole prevented a more catastrophic result.

[Werner]

Speaking of turrets not to be used, South Dakota's "B" (I realize that's not US nomenclature) was out of commission during the entire night battle of November 13/14 due to the previous bomb damage.

This is almost never mentioned in the accounts of the battle. I wonder why.

[JWintjes]

Scharnhorst survivors confirm that her big explosion came after she sank. Considering the German magazine arrangement, I suspect she was less susceptible to torpedo-induced magazine explosion and more susceptible to gunfire-induced magazine explosions. During the battle, 14in shells caused fires in two 28cm magazines and one 15cm magazine.

Ah, ok - an explosion after she sank is indeed what I remember from sifting through the survivors' accounts (which admittedly is quite some time ago).

Jorit

[Werner]

Scharnhorst survivors confirm that her big explosion came after she sank. Considering the German magazine arrangement, I suspect she was less susceptible to torpedo-induced magazine explosion and more susceptible to gunfire-induced magazine explosions. During the battle, 14in shells caused fires in two 28cm magazines and one 15cm magazine.

Ah, ok - an explosion after she sank is indeed what I remember from sifting through the survivors' accounts (which admittedly is quite some time ago).

Jorit

Considering the physical properties would make an explosion underwater seem more powerful, we have to remember that a sunk ship will experience several loud "explosions" as the remaining watertight bulkheads collapse and let out any large remaining air pockets. I would expect this to be more true of a large warship than a commercial vessel.

[Guest]

The wreckage suggests that the Scharnhorst suffered a forward turret magazine explosion which may have been caused by a similar torpedo hit as described above.

Could you go into more detail about that? As far as I know the evidence of the survivor's doesn't suggest a magazine explosion.

Jorit

The Norwegian survey of Scharhorst's wreckage shows the hull around A and B barbettes has apparently been completely demolished in a manner strongly suggestive of magazine detonation. The hull was intact from behind B barbette to just behind the rudder post. But the tip of the stern has also been violently destroyed or torn away in a manner much more brutal than the loss of Bismark's stern.

[Guest]

The notion that the magazine explosion may have come immediately before, and was the proximal cause of, Scharnhorst's sinking was advanced in the documentary covering the Norwegian underwater survey of the hull. The reasons, if I recall, advanced for this suggestion were the following:

1. The ship was clearing going to sink as result of battle damage but the actual foundering was surprising abrupt. Evidence of impending loss of stability was not clearly observed minutes prior to the capsizing.

2. The ship was observed minutes prior to capsizing and minutes after capsizing, but was obscured at the time of capsizing. However large flashes, rather more sustained than can be accounted for by a torpedo detonation, was seen at approximately the time of the capsizing.

Based on this the documentary suggested that a torpedo impact penetrated the TDS near forward magazine and detonated it while the ship was still on the surface.

My own suggestion is that, if this had happened, it could have come about as result of one several factors:

1. The TDS on Scharnhorst noticeable narrows towards the fore and aft turrets. Thus is effectiveness there are reduced from the what is assessed at the mid-ship section.

2. The hit near A turret may represent the second torpedo strike on the same section of TDS around the turret. A TDS section that has absorbed a torpedo losses almost its entire protective value to any second hit.

3. The ship might have listed sufficiently, or the rough sea might have effect torpedo depth control, such that the hit struck against the bottom rather than TDS.

I am not saying Scharnhorst was blowup on the surface by magazine detonation. But I see not reason why such a scenario would be intrinsically difficult to accommodate within the ship's design and her state just prior to sinking.

[chuck]

There were reports of flame in a powder room but no signs of it could be found. Flash was reported, not in a powder room, but a handling room. There is a possibility that the crewmen were not seeing flash but instead experiencing an illusion caused by the compression of the eyeballs by the force of the detonation. However, the smell of smoke was strong, and it must have come from somewhere.

Was there flooding in the powder room? If the flash of the explosion indeed penetrated the powder room, then surely it must have done so through an aperture punctured from the site of the explosion through the torpedo bulkhead. Since the USN did not use water exclusion barriers in the French manner, any such aperture would cause flooding in the powder room once the explosion gases have vented. So if there were no flooding in the powder room after the hit, then there were no real flame or flash from the explosion. Perhaps a electric spark from shock response.

BTW, I believe that after the torpedo hit, the guns of A turret can still be fired, but the turret itself can not longer train. So its availability in an emergency was completely theoretical and unlikely to have any practical effect.

[Werner]

The effects Chuck refers to are called "phosphenes" and is a well-understood phenomena. It is reasonable to assume this is the case in any number of reported explosions, especially those reporting "blue" or "greenish blue" light.

You can safely duplicate the effect by gently pressing in on the white of your eye while in the dark.

[Tiornu]

There was flooding in the magazines. One would think that smoke from the explosion (there was no other smoke and no fires at all) would indicate compartments that would also be subject to flooding, but that turned out not to be the case; smoke was detected in all compartments near the point of impact
The crew made some minor repairs to turret 1, after which the turret "trained without difficulty." Use of the turret was restricted out of structural concerns.

[Werner]

There was flooding in the magazines. One would think that smoke from the explosion (there was no other smoke and no fires at all) would indicate compartments that would also be subject to flooding, but that turned out not to be the case; smoke was detected in all compartments near the point of impact
The crew made some minor repairs to turret 1, after which the turret "trained without difficulty." Use of the turret was restricted out of structural concerns.

I wonder if the "smoke" was not indeed dust and paint flakes dislodged by the compression waves that would have proceeded across the width of the ship and for some odd distances fore and aft....

[Guest]

NC's torpedo bulkhead is situated inboard of the lower edge of the armor belt. Consequently there is a relatively unprotected passage leading over the top of the TDS into the upper decks inside the citadel. It is seem possible that after rupturing the outer shell, some of the explosive gases vented themselves upwards along one of the unruptured bulkheads of the TDS into the space above the torpedo bulkhead, but behind the belt armor and below the armor deck. From there they can then propagate into the ship's citadel. This may account for the smell in the ship after the torpedo explosion.

Since the decks behind the armored deck is at or above waterline, it would be possible for gas emanate from there into the ship without subsequent flooding of the same passage. However, the powder magazine is underwater, and any passage allowing the penetration of flame or smoke, unless by an extremely circuitous route, would manifest itself in subsequent flooding.

- Chuck