Shell hits on Yamato

[Disco Duck]

ORIGINAL: derhexer

I have a question about the damage that 6" shells can do to battleships. I'm playing the Japanese player in one of the May 1942 campaign games. The Japanese have launched an invasion of New Caledonia.
The Yamato was sent down to cover the invasion force and bombard Noumea. The Yamato along with several CAs, CLs and DDs engaged in a night action with 3 Omaha class CLs armed with 6" guns. The action was fought between 4,000 and 5,000 yards.
The Yamato took 21 hits and suffered 25 system, 59 floatation and 15 engine hits. The Yamato has 8"-9" armored deck, 16" belt and 26" turret armor.
The amount of damage that Yamato suffered from 6" guns seems unreasonable.
Can somebody explain how WiTP calculates damage?

In ths ship information screen, right under victory value, it states last hit by. What was it last hit by?

[John 3rd]

ORIGINAL: JuanG

ORIGINAL: wdolson

I believe the armor belt on the Yamato only extended around the magazines and left the rest of the ship lightly protected. At 2000 yd range, a US 6" can punch through 13 inches of armor, more than enough to penetrate the lightly armored bow and stern sections.

Everything you ever wanted to know about naval gun penetration:
http://www.navweaps.com/index_nathan/Penetration_index.htm

Just speculating.

Bill

The belt covered around half of the waterline length, including both the 46cm and 15.5cm magazine and the engine and machinery spaces.



With the post-'43 Mk35 Mod 9 shell, the 6in/47 at 2500fps (ie. at muzzle velocity) penetrates 12.9in of Japanese VH, and holes up to 15.2in (without penetration). This is just shy of holing Yamato's 16.1in belt, if it were mounted vertically.

As it is mounted at 20 degrees, these numbers fall by some, and at 2000 yards they fall some more (velocity at this point is ~2250fps). Against a 20 degree inclined plate at 2000 yards total penetration occurs at 9.5in, and holing at 10.9in, well below the actual thicknesses of the plates. Use of the earlier Mk35 rounds (before '43) will shave about an inch off both these values. There is also the matter of the effects of T/D ratio to consider here (6in shell vs 16in plate) which will further reduce effective penetration.

Outside of this belt/citadel area, the 6in will easily penetrate as there is (apart from the steering protection) practically no armour.

Returning to looking at the game, my understanding and experience is that incomplete coverage is unfortunately not accounted for, therefore every 'belt' impact is resolved against the armour value (with possibly some variation) at that location. After reading this, I proceeded to run quite a few tests with the US 6in CLs and some CAs trying to get penetrations at 2,000 yards against Yamato and did not see one, or damage over ~10 points of floatation.

Therefore, I remain skeptical as to the surface action being the source of this damage, though I suppose it is possible that fires caused by superstructure hits and/or critical effects could have caused it. To me it still looks more like a mine or torpedo hit, but clearly it happened before or during the surface action as I presume she was not damaged (shown by smoke on the combat screen) when the action started, and by the end she already has the damage.

Damn Juan. That is great stuff. Love the diagram!

[Buckrock]

Very strange stuff.

The Yamato would only have taken her hits in the first half of the battle as she was never engaged in the second half depite her doing a lot of shooting. If these early hits caused the damage and set her on fire, I would have thought Yamato would be attracting further fire.

Stranger still is the fact the CL Yura is listed in the summary as taking a shell hit but no enemy ship targeted her during the battle according to the report detail.

[Barb]

Every ship being fired upon will also reply similarly ... So every line in Combat report represent such exchange...

[Buckrock]

My bad.

It's been a while since I've read beyond the combat results summary for battles.

[btd64]

Ding ding. School's in session
Cheers. GP

[Gaspote]

From what I see it seems CL Concord run right in the Yamato. In my opinion, except if Yamato was out of ammo. CL Concord should be sunk.
" BB Yamato engages CL Concord at 3,000 yards "

Is it possible to survive a single 460mm shell from 3000 Yard ? (assuming Yamato can't miss at this range)

[witpqs]

ORIGINAL: Gaspote

From what I see it seems CL Concord run right in the Yamato. In my opinion, except if Yamato was out of ammo. CL Concord should be sunk.
" BB Yamato engages CL Concord at 3,000 yards "

Is it possible to survive a single 460mm shell from 3000 Yard ? (assuming Yamato can't miss at this range)

Yes. When so close, it's the speed - and therefore the kinetic energy - of the shell that is greater. Various ships hit by battleship AP shells had those shells pass all the way through without exploding. Obviously even a 14" or 16" hole is serious, but less so than if the shell exploded inside.

I don't know if that would happen with Yamato's shell against Concord or how likely (depends upon what it hit), but in any event surviving an 18" shell hit is certainly possible. It all depends on what it hits, at what angle, etc.

The real problem is that Yamato's main battery shells can sink a CL at any range at which they can hit it. But the CL shells only have chances of doing serious damage in close. So when the two ships run right into each other, as you put it, that gives the CL the best chance possible.

[Alfred]

The Combat Report does not indicate which weapon fired.  The Yamato has other weapons besides 460mm guns.
 
Unless you watched the actual combat animation you would not know what actually fired.
 
Alfred

[crsutton]

ORIGINAL: Alfred

The Combat Report does not indicate which weapon fired.  The Yamato has other weapons besides 460mm guns.

Unless you watched the actual combat animation you would not know what actually fired.

Alfred

In the game at close range, rarely does a BB land a MA hit on any ship. I personally really do not fear old BBs at night. Almost always the hits come from secondary armament. Could even be AA guns. There is a historical basis for this as older BBs and CAs has slow turrets, dated fire control systems and slow rate of fire. The frequent course changes in a close night action limited the usefulness of the main armament.

Once again. Watching the combat replay again would be the only solution-unless it was a sync bug. I doubt very seriously if you would see any six inch projectiles penetrate the Yamato. I just don't think it is possible in game terms.

[FDRLincoln]

I'm not saying this is what happened in the actual game engine, but I can imagine a real life scenario where a "lucky hit" from a US 6-inch penetrates something like an ammunition magazine for Yamato's 6-inch or AA guns, causing an explosion which does substantial damage to the ship.

[wdolson]

A small ship with a good captain can close to within knife fighting range on a BB without getting hit. The USS Johnston did at the Battle Off Samar. The Johnston got so close to the Kongo that the Kongo couldn't depress her main guns down far enough. The Johnston pretty much emptied her magazines against the Kongo, hitting her many times with practice rounds when everything else ran out.

The game engine does allow for critical hits. I don't think they show up in the combat report. I believe they do show up in the status screen which is also recorded in a file on disk. Accidents can happen too. It's possible the Yamato had a premature explosion while loading the main guns, or a fire broke out from an accident during the fight.

Bill

[Disco Duck]

ORIGINAL: crsutton

ORIGINAL: Alfred

The Combat Report does not indicate which weapon fired.  The Yamato has other weapons besides 460mm guns.

Unless you watched the actual combat animation you would not know what actually fired.

Alfred

In the game at close range, rarely does a BB land a MA hit on any ship. I personally really do not fear old BBs at night. Almost always the hits come from secondary armament. Could even be AA guns. There is a historical basis for this as older BBs and CAs has slow turrets, dated fire control systems and slow rate of fire. The frequent course changes in a close night action limited the usefulness of the main armament.

Once again. Watching the combat replay again would be the only solution-unless it was a sync bug. I doubt very seriously if you would see any six inch projectiles penetrate the Yamato. I just don't think it is possible in game terms.

Is there any way to replay the combat animation? I know replaying the turn doesn't work because it is always a little different. Many time I have wanted to re-watch it.

[Alfred]

Replaying the turn does work.
 
Change absolutely nothing in the orders phase and the same seed number is used, resulting in the same replay.
 
Alfred

[spence]

Quite some time ago I read "A Glorious Way to Die" which concerned itself with the last sortie of Yamato. IIRC it was written by a Ltjg who was an Assistant Damage Control Officer. I remember him mentioning a couple of defects in the design of Yamato which came into play during her last sortie: the longitudinal bulkhead in the middle of the iron box (belt protected) which hampered or prevented counterflooding within that area and the over-concentration of the ship's AAA defenses.

I didn't see anything in the text of the replay that suggests a secondary explosion (of AAA ammo) but the game system seems to protect the entire hull of Yamato with the belt armor so the flotation damage does seem a mystery.

Perhaps it is just best to remember that "unsinkable" is also a very unlucky adjective for a ship.

[tigercub]

yes "unsinkable" ships tended to "sink" a lot

[Disco Duck]

After the war the Navy found some armor plate that had been destined for the Shinano. The first link is a picture of the armor after being hit with a 16 shell and the second link is a summary of the ballistic tests on the same armor.
http://www.practicalmachinist.com/vb/an ... rd-113898/

http://www.navweaps.com/index_tech/tech-040.htm

[pontiouspilot]

Fascinating discussion.

Was this the right TF composition for Yamato? I should think that this composition is more likely to bring her in to these short ranges.

[crsutton]

I believe it was Helena that made a close range run past the BB Hiei during the first Naval Battle of Guadalcanal wrecking Hiei's superstructure with five and six inch shells while suffering little or nothing from return fire. The crippled Hiei went down the next day.

[Disco Duck]

ORIGINAL: crsutton

I believe it was Helena that made a close range run past the BB Hiei during the first Naval Battle of Guadalcanal wrecking Hiei's superstructure with five and six inch shells while suffering little or nothing from return fire. The crippled Hiei went down the next day.

According to this it was the DD Laffey which suffered heavily from return fire.
The enemy battleship continued on her course and bore down on our second destroyer, the Laffey. Only by speeding up did the Laffey manage to cross the enemy's bows with a few feet to spare. Two torpedoes were fired, but the range was so short that there was not time enough for them to arm. The Laffey then shelled the battleship's bridge with all guns that would bear, damaging it severely before she was silenced by a heavy caliber salvo which smashed her own bridge, as well as No. 2 turret, the after fireroom, and the electrical workshop.

From http://www.history.navy.mil/library/onl ... al1942.htm