What is the biggest warship of WW2 that an M1 Abrams MBT can reasonably damage with it's main gun?

[Free-Stater 101]

Keep in mind this isn't a strictly serious question over an academic one MBT aren't meant to fight warships, but I still find this interesting. For the sake of this scenario, we are going to assume that the Abrams is standing still on a beach and any ship you chose is unmanned and anchored with no chance of resisting.

 

[PsihoKekec]

All of them? Basic M829 round is rated for penetration of 520 mm of RHA at 2000 meters, Yamato main belt thickness is 410 mm, so apart from turrets pretty much every part of the ship can be penetrated as long as the round is hitting the armor at 90° degree angle. The trick however would be hitting points where rounds could do significant damage though, so the crew would have to know the areas where pyrophoric effect of the DU rounds would give the best effect.

 

[Bear Ribs]

Does it have to punch through the Warship's armor belt or is, like, breaking a bridge window still damage?

More seriously, this is probably easy to get a good calc on. Rolled Homogenous Steel was what they predominantly used on ships in those days and also what an Abram's main gun is measured in penetrating power.

Assuming it's got the typical 120mm smoothbore firing tungsten penetrators it's rated for 470mm, 19in of steel armor at 2,000 yards. The higher-end Sabot rounds are rated for 800mm, 31in of steel armor. Those are the official figures, anyway.

The Iowa class had about 12.5 inches of armor and Yamato had 16.5, and those were about as tough as it got. So at point-blank range, it looks to me like an Abrams could expect to penetrate their armor with a direct hit. This is primarily because of the absurdly short range, however, those ships expected to engage at ten to twenty times the distance we're putting our tank at here.

That's sufficient to do damage, however the tank would need to fire for days, maybe even weeks to actually sink one, the amount of damage is also going to be really, really paltry.

 

[Simonbob]

Having looked into this a bit? All of them, to some degree.

Depending on ammo type, it'll either make small holes anywhere above the waterline, to more widespread damage on external mounts and lighter armored bits, on battleships.

 

[bintananth]

If the ship is anchored 1.6nmi offshore an Abrams tank crew can't even hit with it the 120mm/L44 unless they get really lucky.

If the WWII-era warship was crewed and manned 1.6mni would be considered "close range" along with "Are you joking?" and "We're actually doing this?".

A Brooklyn-class CL could send about 135 "to whom it may concern" 6" projectiles to an address 14nmi away in ... roughly 1 minute.

 

[Bear Ribs]

If the ship is anchored 1.6nmi offshore an Abrams tank crew can't even hit with it the 120mm/L44 unless they get really lucky.

An Abrams could most certainly hit a ship at 1.6 nautical miles, that's 3,240 yards, within the range they expect to land hits on other tanks, much less something as large as a ship. They may not get good penetration with it, because the L44 is a much smaller gun than modern Abrams use, and was obsolete over 30 years ago. Using the up-to-date version the "Silver Bullet" rounds are rated for 3,300 yards and the LAHAT is good out to 8,700.

 

[Husky_Khan]

The main thing is as referenced earlier is damage. Putting tiny holes in the belt won't do much. If the main gun could cause enough damage to take out turrets or cause major flooding etc to reduce it's combat effectiveness significantly.

Kinda reminds me of cruise ships hit by Somali Pirate RPGs. Big black burn marks but very tiny holes of penetration to the point of almost being negligible.

 

[Simonbob]

The main thing is as referenced earlier is damage. Putting tiny holes in the belt won't do much. If the main gun could cause enough damage to take out turrets or cause major flooding etc to reduce it's combat effectiveness significantly.

Kinda reminds me of cruise ships hit by Somali Pirate RPGs. Big black burn marks but very tiny holes of penetration to the point of almost being negligible.

Heh.

I was reading about Taffy 3, and the battle off Samar, and one of the big reasons it lasted so long is the Japanese thought they were crusers, so used armor piercing rounds for much of the battle.

They were unarmored destroyers, so it went right through without causing much damage.

 

[Bear Ribs]

Yeah, tanks are extremely compact, punch through their armor and the shell is almost certainly going to hit something vital, like the engine, the crew, or the ammo bin.

Ships contain vast volumes of relatively empty space, punch through one's armor and you're as likely to hit a crew quarters, a kitchen, or a cargo hold as you are anything important to staying afloat and doing its own hole-punching back.

 

[ShadowArxxy]

Ships contain vast volumes of relatively empty space, punch through one's armor and you're as likely to hit a crew quarters, a kitchen, or a cargo hold as you are anything important to staying afloat and doing its own hole-punching back.

That's true of most of the ship. If you're specifically targeting the gun turrets and/or the bridge, those have a lot less empty space in them. All in all, large armored warships are relatively easy to cripple using modern weapons, but very difficult to outright sink unless using purpose-made weapons.

The main reason they're obsolete remains twofold: one, nuclear weapons. Two, while efficient "heavy shipkiller" missiles do not exist, they can be created in vastly less time and for vastly less budget than it would take to actually develop any modern armored warship.

 

[Knowledgeispower]

That's true of most of the ship. If you're specifically targeting the gun turrets and/or the bridge, those have a lot less empty space in them. All in all, large armored warships are relatively easy to cripple using modern weapons, but very difficult to outright sink unless using purpose-made weapons.

The main reason they're obsolete remains twofold: one, nuclear weapons. Two, while efficient "heavy shipkiller" missiles do not exist, they can be created in vastly less time and for vastly less budget than it would take to actually develop any modern armored warship.

You forgot heavy weight torpedoes from subs as a major potential predator of vessels like that

 

[ShadowArxxy]

You forgot heavy weight torpedoes from subs as a major potential predator of vessels like that

True, but not necessarily optimal. While they do have surface target modes, modern heavy torpedoes are focused on high-performance submarine-to-submarine combat.

 

[VictortheMonarch]

All of them really. most didn't have the armor nessessary to fight off a modern gun. The problem however, would be sinking it. You would have to be able to hit the Ammunition, which would be rather hard. Not only that, but you would need to be in range for it, which would be rather... difficult for MBT.