Shell hits on Yamato

[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?

[Lokasenna]

How much of that floatation damage is major?

[witpqs]

4,000 to 5,000 yards is really short range. Just what is the penetration of those 6" shells at 4,000 yards?

[JuanG]

ORIGINAL: witpqs

4,000 to 5,000 yards is really short range. Just what is the penetration of those 6" shells at 4,000 yards?

Not enough. Its around 5-6" at those ranges.

From a realism point of view, floatation damage could have been inflicted by hits ahead or behind the area covered by the main belt, which would have been unprotected. Probably not enough to sink her, but still plenty for some yard time.

From a gameplay point of view, I dont know exactly what happened here. The system damage isnt so surprising, as it can easily result from superstructure (armour 0) hits and fire. The floatation is a little more worrying, and my only guess is that perhaps it was also caused by fires?

Sure there wasnt a torpedo or mine involved?

[wdolson]

Is the flotation damage major or minor? Minor float damage could be due to water pumped in to fight fires.

Bill

[witpqs]

ORIGINAL: JuanG

ORIGINAL: witpqs

4,000 to 5,000 yards is really short range. Just what is the penetration of those 6" shells at 4,000 yards?

Not enough. Its around 5-6" at those ranges.

Thanks, Juan!

[Alfred]

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?

Seems like every 2-3 months I have to post the following link to someone who just doesn't provide any data and expects us to mind read what happened.

This is a must read thread for everyone who thinks they know more about ballistics than the devs (plus JuanG a "gun bunny" recognised by the key dev).

tm.asp?m=3343291&mpage=1&key=gun%2Cballistics

Two very important posts in the above thread are absolutely essential reads: post #34 which capture the essence of the issue and post #36 which provides two other highly relevant threads.

Very important to understand that the game algorithm is essentially an abstraction which utilises rolls so that 100% theoretical historical accuracy cannot always be replicated. Of course I will sidestep the point of where the practical demonstration of the Yamato combating Omahas occurred[:-]. Within the game code, in simple terms naval penetration is a function of range, with angle being taken into account.

And before you ask, that algorithm will never be disclosed by the devs.

The following quote made on 11 March 2012 from JWE/Symon, who does happen to know his ballistics, should be borne in mind.

"Any Allied gun, larger than 6", WILL penetrate Yamato's belt armor.
The US 6"Mk-27(sic), base-fuzed shell, WILL penetrate Yamato's belt armor.
Alas, the US 6"Mk-35(sic) is damn close, but no cigar;
And smaller than that won't do the deed."

You see it is all about ballistics (fitted into the game code restraints). Ballistics is something very much discussed between Symon and JuanG in the three threads provided above. The result was some tweaking of the inputs into the algorithm which have found their way into the DaBabes family (and close relatives) of mods.

Alfred

[Lecivius]

And that, as they say, is that.

I lurk here all the time. But Alfred’s ability to conjure up facts from previous post history never ceases to amaze me.
[&o]

[PaxMondo]

ORIGINAL: Lecivius

And that, as they say, is that.

I lurk here all the time. But Alfred’s ability to conjure up facts from previous post history never ceases to amaze me.
[&o]

+1

[&o][&o][&o]

[Disco Duck]

Did anyone during the war realize that some 6" guns were capable of penetrating a BB's armor at close ranges?

[Kull]

ORIGINAL: Disco Duck

Did anyone during the war realize that some 6" guns were capable of penetrating a BB's armor at close ranges?

No one who lived....

[bush]

What really caught my eye was JWE's reference to the sweet spot. I'm wondering if that is true on shore bombardments also. If yes, how can I find the optimum range to engage shore-based targets for my various naval rifles?

[Symon]

ORIGINAL: Disco Duck
Did anyone during the war realize that some 6" guns were capable of penetrating a BB's armor at close ranges?

Obviously they did. It's just like tank guns: At 1000m your basic Sherman 75mm couldn't penetrate a Panther's front; at 200m it could. The 76.2mm M1 was better but it also had issues at 1000m with standard AT shot, but with HVAP it was righteous. It's a function of range, muzzle velocity, and round kinetics .. technically.

As Albert says, it can be done, and everyone knew it.

As Kull says, 99 times out of 100, the Big Boys will wax your brookie before you even get to your "effective" penetration range.

But occasionally, some smart commander ('Soc' McMorris, fx) will use low visibility conditions to engage at "knife fighting" ranges even though doctrine says don't. Woof !! JWE

[crsutton]

I have yet to see a six inch shell penetrate a BB at any time. Only rarely do they penetrate CA armor but they do. Not saying it does not happen but I played a lot of turns and have yet to notice it even at 2,000 yards. I see no way that 25 hits would do that kind of flotation damage to Yamato. Might do a lot of sys damage though. I suggest you look over the combat reports and OP reports very carefully. You might have a sync bug and Yamato ate a couple of torpedoes that you did not see or look in the notes for mention of a collision.

You should re-watch the replay and see if any of the shots penetrated, and if they did post it here so I can look at it....[;)]

Well, I should say that if heavy fires were burning then flotation damage would happen. Give us some info.

[derhexer]

I have yet to see a six inch shell penetrate a BB at any time. Only rarely do they penetrate CA armor but they do. Not saying it does not happen but I played a lot of turns and have yet to notice it even at 2,000 yards. I see no way that 25 hits would do that kind of flotation damage to Yamato. Might do a lot of sys damage though. I suggest you look over the combat reports and OP reports very carefully. You might have a sync bug and Yamato ate a couple of torpedoes that you did not see or look in the notes for mention of a collision.

You should re-watch the replay and see if any of the shots penetrated, and if they did post it here so I can look at it....

Well, I should say that if heavy fires were burning then flotation damage would happen. Give us some info.

Here's the relevant part of the combat from the Combat Report
"Night Time Surface Combat, near Noumea at 115,160, Range 10,000 Yards

Japanese Ships
BB Yamato, Shell hits 21, on fire, heavy damage
CA Myoko
CA Haguro
CA Suzuya, Shell hits 2
CL Nagara
CL Natori
CL Yura, Shell hits 1
DD Makigumo
DD Arare
DD Shiratsuyu
DD Shigure
DD Yugure
DD Ariake

Allied Ships
CL Raleigh, Shell hits 3
CL Detroit, Shell hits 2
CL Concord, Shell hits 15, on fire, heavy damage
DD Schley, Shell hits 1


Maximum visibility in Partly Cloudy Conditions and 42% moonlight: 11,000 yards
Range closes to 22,000 yards...
Range closes to 16,000 yards...
Range closes to 10,000 yards...
CONTACT: Japanese lookouts spot Allied task force at 10,000 yards
CONTACT: Allied lookouts spot Japanese task force at 10,000 yards
Tanaka, Raizo crosses the 'T'
BB Yamato engages CL Concord at 10,000 yards
CL Detroit engages BB Yamato at 10,000 yards
BB Yamato engages CL Raleigh at 10,000 yards
CA Myoko engages DD Schley at 10,000 yards
CL Yura engages CL Concord at 10,000 yards
Range closes to 4,000 yards
CL Concord engages BB Yamato at 4,000 yards
CA Suzuya engages CL Concord at 4,000 yards
BB Yamato engages CL Raleigh at 4,000 yards
CA Myoko engages CL Concord at 4,000 yards
CL Natori engages CL Detroit at 4,000 yards
Range closes to 3,000 yards
BB Yamato engages CL Concord at 3,000 yards
CA Suzuya engages CL Concord at 3,000 yards
BB Yamato engages CL Raleigh at 3,000 yards
BB Yamato engages DD Schley at 3,000 yards
CL Natori engages CL Concord at 3,000 yards
DD Ariake engages DD Schley at 3,000 yards
CL Concord engages DD Yugure at 3,000 yards
Range increases to 5,000 yards
BB Yamato engages CL Concord at 5,000 yards
CA Suzuya engages CL Concord at 5,000 yards
CL Raleigh engages BB Yamato at 5,000 yards
BB Yamato engages DD Schley at 5,000 yards
CL Yura engages CL Concord at 5,000 yards
CL Concord engages CL Natori at 5,000 yards
DD Arare engages DD Schley at 5,000 yards
DD Makigumo engages DD Schley at 5,000 yards
Range increases to 7,000 yards
BB Yamato engages CL Concord at 7,000 yards
CA Suzuya engages CL Concord at 7,000 yards
CA Haguro engages CL Concord at 7,000 yards
CA Myoko engages CL Concord at 7,000 yards
DD Schley engages DD Yugure at 7,000 yards
Range increases to 8,000 yards
BB Yamato engages CL Concord at 8,000 yards
CL Detroit engages BB Yamato at 8,000 yards
CA Haguro engages CL Concord at 8,000 yards
CA Myoko engages CL Concord at 8,000 yards
CL Concord engages CL Natori at 8,000 yards
DD Arare engages DD Schley at 8,000 yards
DD Makigumo engages DD Schley at 8,000 yards
Range increases to 10,000 yards
BB Yamato engages CL Concord at 10,000 yards
CL Concord engages CA Suzuya at 10,000 yards
CL Raleigh engages BB Yamato at 10,000 yards
CL Concord engages CA Myoko at 10,000 yards
DD Yugure engages DD Schley at 10,000 yards
DD Shigure engages DD Schley at 10,000 yards
Range increases to 12,000 yards
BB Yamato engages CL Concord at 12,000 yards
CL Concord engages CA Suzuya at 12,000 yards
BB Yamato engages CL Raleigh at 12,000 yards
DD Arare engages DD Schley at 12,000 yards
CL Yura engages CL Concord at 12,000 yards
CL Concord engages CL Natori at 12,000 yards
DD Arare engages DD Schley at 12,000 yards
Range closes to 11,000 yards
BB Yamato engages CL Concord at 11,000 yards
CA Suzuya engages CL Concord at 11,000 yards
CL Concord engages CA Haguro at 11,000 yards
CA Myoko engages CL Concord at 11,000 yards
DD Shigure engages CL Concord at 11,000 yards
DD Shiratsuyu engages DD Schley at 11,000 yards
BB Yamato engages CL Concord at 11,000 yards
BB Yamato engages CL Detroit at 11,000 yards
CL Concord engages CA Haguro at 11,000 yards
CA Myoko engages CL Concord at 11,000 yards
CL Yura engages CL Concord at 11,000 yards
CL Concord engages CL Natori at 11,000 yards
DD Ariake engages CL Concord at 11,000 yards
DD Schley engages DD Arare at 11,000 yards
DD Schley engages DD Makigumo at 11,000 yards
Range closes to 9,000 yards
BB Yamato engages CL Concord at 9,000 yards
BB Yamato engages CL Detroit at 9,000 yards
BB Yamato engages CL Raleigh at 9,000 yards
CA Myoko engages CL Concord at 9,000 yards
Range closes to 8,000 yards
BB Yamato engages CL Concord at 8,000 yards
CA Suzuya engages CL Concord at 8,000 yards
CA Haguro engages CL Detroit at 8,000 yards
DD Schley engages DD Arare at 8,000 yards
DD Yugure engages DD Schley at 8,000 yards
DD Makigumo engages DD Schley at 8,000 yards
Range closes to 6,000 yards
BB Yamato engages CL Concord at 6,000 yards
BB Yamato engages CL Detroit at 6,000 yards
BB Yamato engages CL Raleigh at 6,000 yards
DD Schley engages DD Arare at 6,000 yards
DD Yugure engages DD Schley at 6,000 yards
DD Schley engages DD Shigure at 6,000 yards
DD Arare engages DD Schley at 6,000 yards
BB Yamato engages CL Concord at 6,000 yards
BB Yamato engages CL Detroit at 6,000 yards
CA Haguro engages CL Raleigh at 6,000 yards
DD Arare engages DD Schley at 6,000 yards
DD Schley engages DD Ariake at 6,000 yards
Range closes to 4,000 yards
CL Concord engages CA Suzuya at 4,000 yards
CA Haguro engages CL Concord at 4,000 yards
CL Concord engages CA Myoko at 4,000 yards
CL Yura engages CL Concord at 4,000 yards
CL Concord engages CL Nagara at 4,000 yards
DD Shigure engages DD Schley at 4,000 yards
DD Shiratsuyu engages DD Schley at 4,000 yards
Range increases to 11,000 yards
BB Yamato engages CL Concord at 11,000 yards
BB Yamato engages CL Raleigh at 11,000 yards
CL Detroit engages CA Myoko at 11,000 yards
CL Yura engages CL Concord at 11,000 yards
CL Concord engages CL Natori at 11,000 yards
CL Concord engages CL Nagara at 11,000 yards
DD Shigure engages DD Schley at 11,000 yards
Task forces break off...

[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

[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.

[Sardaukar]

Could it be a collision? That should be in Ops report, I think?

[wdolson]

Or a critical hit.

Bill

[Lokasenna]

Guys, this is fascinating stuff.