Yamato + Musahi - Damage taken

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Garyt
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Yamato + Musahi - Damage taken

Post by Garyt » Sat Jan 10, 2015 9:11 pm

I've looked at the Various reports for the Damages taken by the Musahi and Yamato, specifically torpedo damage. The Yamato seems pretty well straight forward, not a lot of disagreement among sources, 10-12 torpedoes seems to be the situation.

The Musahi though seems different, reports of 11 torpedo and 10 bomb hits, 20 torpedo and 17 bomb hits,and 10 torpedo and 16 bomb hits.

Now some of those don't count possibles and probables, for instance the US technical mission gives a range of 10-14 if you factor in possibles and probables.

This (10-14 torpedoes) actually seems to make more sense, given the displacement, anti-torpedo defense, and damage control of the Yamato class.

Looking at other Battleships, we have the Prince of Wales sunk by 4 torpedoes, though 1 may well have done the job, Repulse sunk by 4-5 torpedoes, 1-2 torpedoes for the Fuso though apparently damage from a bomb hit caused a list which would seem to be hull damage, 4-6 Torpedoes + gunfire for the Yamashiro.

I know a missed a handful, but it looks like 4-6 torpedoes were usually sufficient to sink battleship up to about 40k (empty) displacement.

So for a modern battleship the size of the Yamato to take 10-14 torpedoes to sink seems to make sense. I have left out ships sunk in port on purpose, as these were often not at battle stations when hit, which effects damage control in a huge way. I'd also add that while bombs carried by strike aircraft generally did not pose much danger to the sinking of a battleship, they could effect damage control both the parties conducting it and the mechanical issue of damage control.

The torpedoes focusing on one side of the Yamato is often credited for making her easy to sink than the Yamato. My thoughts here - it marginally effected the amount of torpedoes needed, but dramatically effected the time needed to sink, as the Musahi took 4+ hours to sink after the last attack.

Interestingly enough is that the Musahi for whatever reason did not try to pump out excess water in the few hours prior to the last attack - this would have given her more buoyancy for certain, though I think her fate would have been sealed anyway.

One thing that has struck me as odd about the attack on the Musahi - A bomb caused her to lose speed due to boiler room damage. There is no way even a 1760 pound AP bomb should have been able to pierce her deck armor. But the boiler room was not truly damaged, other than steam was pouring out in it. My guess is the concussive effects of a bomb, while not penetrating the deck caused damage to the piping which cause the massive steam leak to occur, rendering the engineering spave uninhabitable.

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Re: Yamato + Musahi - Damage taken

Post by Steve Crandell » Sat Jan 10, 2015 10:12 pm

IJN Kongo was sunk by two torpedoes from USS Sealion.

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Re: Yamato + Musahi - Damage taken

Post by alecsandros » Wed Jan 28, 2015 7:01 am

Garyt wrote:
I know a missed a handful, but it looks like 4-6 torpedoes were usually sufficient to sink battleship up to about 40k (empty) displacement.

So for a modern battleship the size of the Yamato to take 10-14 torpedoes to sink seems to make sense. I have left out ships sunk in port on purpose, as these were often not at battle stations when hit, which effects damage control in a huge way. I'd also add that while bombs carried by strike aircraft generally did not pose much danger to the sinking of a battleship, they could effect damage control both the parties conducting it and the mechanical issue of damage control.
... I also have an urge to label weapons and batleships in terms of "damage" and "hit points" respectively :)

We should add HMS Barham and HMS Royal Sovereign, sunk by 3 torpedoes each.

The German designs seem to have been more resilient (for their size) - Bismarck was doing 12kts after 3 torp hits and 2 heavy underwater hits (and that with 1 boiler room flooded); Scharnhrost was doing 10kts after 4 torp hits (and with severe damage to machinery).

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Re: Yamato + Musahi - Damage taken

Post by Dave Saxton » Wed Jan 28, 2015 4:01 pm

I have Yoshimura's book on Musashi with a detailed account of its battle. It also includes a diagram of all the hits taken, of what type, and when they were received. It shows 19 torpedo hits, 13 on the port side. 8 of the port side torpedo hits were tken along the citadel or by the TDS. 8 of the total number of torpedo hits were taken forward of the citadel (four on each side) by the long forecastle which had no TDS. After the 6th air strike the entire forecastle was flooded with the bow section submerged as far back as number two turret.

Yoshimura shows 16 direct bomb hits and 17 damaging near misses from bombs.
There is no way even a 1760 pound AP bomb should have been able to pierce her deck armor.
Unlike naval artillery, bombs can strike decks at or very near the normal (a right angle). Given a high enough release point and corresponding high velocity even a much smaller AP bomb striking at or near the normal could defeat such deck protection. A bomb penetration is not unlikely at all. It may have been flash rather than a full intact penetration, however.
we have the Prince of Wales sunk by 4 torpedoes, though 1 may well have done the job,


In the case of the Prince of Wales it was the warping of a drive shaft by the first torpedo hit aft, which destroyed the water tightness of the ship for some 280 feet-all the way to and into the turbine rooms. It was a fatal hit, but kind of fluke result unlikely to very repeatable.

What is of greater concern was the knocking out of most of the ship's electrical power by the first hit.

The torpedos used against POW were not real large having only 330 lbs or 450lb TNT warheads.
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: Yamato + Musahi - Damage taken

Post by Garyt » Wed Jan 28, 2015 8:06 pm

Unlike naval artillery, bombs can strike decks at or very near the normal (a right angle). Given a high enough release point and corresponding high velocity even a much smaller AP bomb striking at or near the normal could defeat such deck protection. A bomb penetration is not unlikely at all. It may have been flash rather than a full intact penetration, however.
First, lets look at the terminal velocity of such a bomb - Per an earlier post of yours on this forum -
I have found original data on the US 1600 lb AP bomb. The terminal velocity was 270m/s. At 270m/s and striking at the normal, the penetration is ~205mm homogenous armour.
The Musahi had 200-230mm deck armor, so at the bombs terminal velocity, penetration is a borderline issue.

Problem is though that to get to a terminal velocity would require a higher drop than dive bombing. I don't have the exact numbers, but we'd be looking more along the lines of fairly high level bombing. Which to my knowledge, the US was using dive bombing against the Musahi. Level bombing from that height would have had almost no chance of hitting a moving battleship. Ask the B-17 bombers at Midway.

based on the above info, I'd argue against a penetrating hit of the armored deck. I would think the decks above the armored deck were penetrated (which would also give any witnesses the appearance that the ship was indeed "penetrated"), and as I said above the concussive damage caused damage to the piping below in the boiler room. Penetration is not required to damage a vessel. Spalling could have been another explanation of the damage caused to the Engine areas.

It's possible it could have hit a joint or seem, but I don't think there is any method to calculate the chances of penetration for every possibility.
Yoshimura shows 16 direct bomb hits and 17 damaging near misses from bombs.
Have to read the US technical mission to Japan and their findings on the damage taken by the Musahi? From what I have read of it, it seems to make pretty good sense. I think sometimes interviews conducted and pieced together after the event can be more credible than what witnesses believe happened during the heat of battle.

I don't know if either is 100% accurate, but I tend to lean towards the US technical mission's findings.

I might add though that 17 damaging near misses add a lot of below waterline damage to the hull. It's amazing that in addition to the severe torpedo damage the Musahi took those near misses, which I think are more damaging to the sea worthiness of a well armored vessel like the Musahi than direct hits.
In the case of the Prince of Wales it was the warping of a drive shaft by the first torpedo hit aft, which destroyed the water tightness of the ship for some 280 feet-all the way to and into the turbine rooms. It was a fatal hit, but kind of fluke result unlikely to very repeatable.

What is of greater concern was the knocking out of most of the ship's electrical power by the first hit.
Yes, I think the POW class was a bit weak in underwater defenses compared to other modern battleships. Not because of that one hit, but because it's voided area was a fair amount thinner than most other vessels of it's class.

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Re: Yamato + Musahi - Damage taken

Post by Dave Saxton » Thu Jan 29, 2015 3:04 pm

Some how the number 2 turbine room was penetrated. And this was relatively early during the day.

A question remains about the quality of the armour. I'm not one that subscribes to the theory that MNC was of lesser quality than STS or British NCA. According to data in the tech mission it was the same stuff as British NCA.

However, 200mm-230mm is significantly thicker than the 150mm max thickness limit for homogenous armour to retain acceptable quality levels.
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Re: Yamato + Musahi - Damage taken

Post by Dave Saxton » Thu Jan 29, 2015 3:16 pm

Garyt wrote:I might add though that 17 damaging near misses add a lot of below waterline damage to the hull. It's amazing that in addition to the severe torpedo damage the Musahi took those near misses, which I think are more damaging to the sea worthiness of a well armored vessel like the Musahi than direct hits.
Yamato and Musashi still utilized rivetted construction. Near misses loosen rivets and cause flooding.

Another factor is that the armoured citadel, and the TDS, did not protect a large fraction of the ships length. Large areas forward and aft of the citadel were but weakly protected against both projectiles and underwater weapons.
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: Yamato + Musahi - Damage taken

Post by KevinD » Thu Jan 29, 2015 10:04 pm

Garyt wrote:
Yes, I think the POW class was a bit weak in underwater defenses compared to other modern battleships. Not because of that one hit, but because it's voided area was a fair amount thinner than most other vessels of it's class.
Given that only one of PoW's four hits (and a relatively inconsequential one in the grand scheme of things) was in an area that was voided, and the void held up relatively well, what makes you say the above?

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Re: Yamato + Musahi - Damage taken

Post by Garyt » Thu Jan 29, 2015 11:06 pm

Given that only one of PoW's four hits (and a relatively inconsequential one in the grand scheme of things) was in an area that was voided, and the void held up relatively well, what makes you say the above?
Considering the breadth of it's voided area was 13', compared to about 18' for the Iowa, South Dakota and Bismarck classes, and a massive 23.5' or so for the Yamato class, and about 22-23' for the Richelieu and Vittorio Veneto classes.

The top of the POW system was not bounded by deck armor, which was a negative as well.

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Re: Yamato + Musahi - Damage taken

Post by Dave Saxton » Fri Jan 30, 2015 2:50 pm

Garyt wrote:
Given that only one of PoW's four hits (and a relatively inconsequential one in the grand scheme of things) was in an area that was voided, and the void held up relatively well, what makes you say the above?
Considering the breadth of it's voided area was 13', compared to about 18' for the Iowa, South Dakota and Bismarck classes, and a massive 23.5' or so for the Yamato class, and about 22-23' for the Richelieu and Vittorio Veneto classes.

The top of the POW system was not bounded by deck armor, which was a negative as well.

This link originally posted by Kevin might be of interest here:

http://www.rina.org.uk/hres/Death%20of% ... update.pdf

Its true that revisions were made to Vanguard as a result of the sinking of POW, which included higher bulkheads. However, during the war it was mostly based on what they thought might have happened. It wasn't until years later that it was learned that the KGV TDS design had not actually failed out right, concerning the hit it received in the way it was anticipated. It would be interesting to see more research into the possible causes of the electrical failures, however.

A larger TDS doesn't necessarly mean larger capability. Indeed larger voids could mean more flooding and a larger list.

The Yamato class TDS was unique in that it had no liquid loading.The Japanese did some interesting research in this area. Interestingly the system they used for Yamato with no liquid loading was not the best system according to their own research. They went with no liquid loading to give them more options in terms of pumping and counter flooding, however.
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Re: Yamato + Musahi - Damage taken

Post by Rick Rather » Fri Jan 30, 2015 6:42 pm

Garyt wrote: One thing that has struck me as odd about the attack on the Musahi - A bomb caused her to lose speed due to boiler room damage. There is no way even a 1760 pound AP bomb should have been able to pierce her deck armor. But the boiler room was not truly damaged, other than steam was pouring out in it. My guess is the concussive effects of a bomb, while not penetrating the deck caused damage to the piping which cause the massive steam leak to occur, rendering the engineering spave uninhabitable.
The bomb may have gone-off in the air flues that either take air to or exhaust from the boilers. This type of hit snuffed the boilers on the Yorktown at Midway. Only some of them could be relighted.
Garyt wrote: Problem is though that to get to a terminal velocity would require a higher drop than dive bombing. I don't have the exact numbers, but we'd be looking more along the lines of fairly high level bombing. Which to my knowledge, the US was using dive bombing against the Musahi. Level bombing from that height would have had almost no chance of hitting a moving battleship. Ask the B-17 bombers at Midway.
If we asked them, they'd tell you they hit! :dance:
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Re: Yamato + Musahi - Damage taken

Post by Dave Saxton » Fri Jan 30, 2015 7:10 pm

It was a turbine room, not a boiler room.
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Re: Yamato + Musahi - Damage taken

Post by Garyt » Fri Jan 30, 2015 9:33 pm

The Yamato class TDS was unique in that it had no liquid loading.The Japanese did some interesting research in this area. Interestingly the system they used for Yamato with no liquid loading was not the best system according to their own research. They went with no liquid loading to give them more options in terms of pumping and counter flooding, however.
Looking back on this, it's hard to argue with the results when Musahi and Yamato were hit by topedoes. They took far more to sin than any other ww2 battleship.

Even if you go with the 12-14 to sink the Musahi from the US technical mission (I'm inclined to agree with their estimates), it again is a fair amount more than other battleships took to sink. Yamato took 12, concentrated on one side from lesson learned from the attack on the Musahi. If the other estimates of about 20 torpedoes for the Musahi are accurate, that's even further out of the box than any other battleship. And we can't count Shinano - that had far more to do with it's being not ready to go to sea.

So apparently they got it right to a point.
A larger TDS doesn't necessarly mean larger capability. Indeed larger voids could mean more flooding and a larger list.
What it does mean is that a thicker area of the vessel will have to be compromised by the concussive effects of a torpedo in order for the area inside the void to begin taking water. No we can discuss a more gray area is to what was better, flooded or not, oil or water, whether v/f/v or f/v/f or even v/v/v is a more effective layout, even if crushing tubes have any positive effect. But the thickness of the void and the ability to cause the concussive effects to dissipate over distance before striking the true interior of the ship is a given as being a factor. To my knowledge, ships were still see worthy if their entire voids were flooded.

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Re: Yamato + Musahi - Damage taken

Post by Dave Saxton » Sat Jan 31, 2015 3:13 pm

Its not really a gray area. The Japanese had collected hard data. Their findings indicated that a V/L/V layered system like that of the North Carolina (KGV was similar) or like the German design* worked equally the best. The Italian Pugliese cylinder design was the largest per hull volume although the Japanese didn't test it.

The reported larger volume of the South Dakato/Iowa arraingment vs KGV didn't translate into superior performance in tests, especially in terms of absorbing shock, although fortunately it was not battle damage tested. John Jordan wrote:
This system was not tested before the ships were laid down, and the results from later testing of purpose built caisson gave cause for concern.
The main problem was the rigid lower belt could not deform to help absorb shock. And South Dakota did demonstrate a vulnerability to the shock of its own guns firing to knock out its electrical power.

* Scharnhorst suffered 11 torpedo hits of the larger ship launched variety.
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: Yamato + Musahi - Damage taken

Post by Steve Crandell » Sat Jan 31, 2015 4:05 pm

Dave Saxton wrote: The main problem was the rigid lower belt could not deform to help absorb shock. And South Dakota did demonstrate a vulnerability to the shock of its own guns firing to knock out its electrical power.
Are you saying that somehow a rigid lower belt caused South Dakota's breakers to trip when firing her main guns? Yamato also had a rigid lower belt. That sounds extraordinary. Were all ships with rigid lower belts like this?

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