to point out why WW2 battleships are a bad idea for the modern battlefield, especially pretend battleships that are only different from the Alaskas by 4 gun calibers
to point out why WW2 battleships are a bad idea for the modern battlefield, especially pretend battleships that are only different from the Alaskas by 4 gun calibers
this is what 441 pounds of gun cotton in a contact mine did to USS Minnesota
nearly a hundred years ago.
There's a real reason the new torpedoes are called ' Keel Breakers"
Mk 48 Torpedoes have 650 pounds of PBX, about 6% higher than Guncotton in RE, and no ship, WWI to today, can take a keel shot like that and not be missionkilled, if not sunk outright.
USN has done enough SINKEX on old warships to find this out.
The counter argument being "against whom?" Unless any attack happened within gun range of the Iowas then they could just sit there and get hit (which I suppose is one function if it protected say a Carrier by taking the rounds meant for it, but not the best use for the ships or Crew). I mean when you have "small" frigates like the Singaporean Formidables able to mount up to 24 Harpoon's not to mention the Russia capabilities and the mentioned power of modern torpedoes the idea that the Iowa's is a functioning unit is crazy.
I wonder if we'll ever see a Sin-Ex with a "modern" Carrier, as that would be the closet we'd get to trying to sink one of the Iowa's.
I agree that the Iowa is very vulnerable to shaped charge warheads on AShM's, which no realistic amount of WWII armor can stop. A modern battleship designed from scratch would be much different. I came up with an idea for one a while ago, and I came to the conclusion that a modern battleship can still be worth building, but the Iowa's a WWII design, and it's definitely not effective on a modern battlefield.
That being said, the vulnerability of an Iowa (on any battleship for that matter) to under-the-keel shots designed to snap the ship in half is greatly exaggerated on this thread. In fact, the vulnerability of battleships to torpedo impacts in general is overstated. Take the last post on this page (by navydavesof):
for more information. In particular, note the 2nd post (which I have copied below) and its description of the Tirpitz when she had a 4000 lb mine (during Operation Source) explode under her keel. It tossed her around a lot (and it did indeed mission kill her for several months while the extensive damage was repaired), but it didn't break her in half, as many on this forum would predict.
A ship with a fully developed side protective system is not subject to the type of break-up a lesser vessel is due to under-keel explosions. No capital ship ever in history ever broke in half due to an under-keel explosion even when it was a nuclear explosion. This really only applies to battleships and fleet carriers. Heavy cruisers down did not have the fully developed side protective systems needed for this discussion. When a lesser ship's keel is pushed up it's sides are pushed out and into sheer. You can see this in slow motion film. The bending out of the sides of the ship weaken the steel and then form hinges that the ship will crack on when she sags. So with the breaking of the flat keel the sides are also severely weakened. Once the ship begins to sag only the upper strength deck of the hull is left to support the weight and many times it can not.
In a battleship, the ship has what they call a soft keel. Any longitude bulkhead that makes up over 50% of her length becomes a strength member of the hull girder. In an Iowa as an example, her four bulkhead system on each side gives her eight additional strength members and her third bulkhead is her armor belt which is extremely difficult to place into sheer. The side protection system is so strong it can support the weight of the ship even if the flat keel is destroyed. Each layer of the side protective system acts as an additional keel so in an Iowa she has 8 side keels and her flat keel and she actually has three upper strength decks with the second deck being an armored deck which is also difficult to bend. In the roughly 2 seconds an under-keel explosion has to work on the hull the side hinges that form on lesser ships never form on a battleship or even a fleet aircraft carrier. Therefore, the upper strength deck or decks are never placed in stress. What does occur is the under-bottom is either holed or crushed in and depending on the damage will depend on the amount of flooding just like a side hit by a torpedo.The ship will whip just like Tirpitz did but not break up.
The 4,000 lb warheads under Tirpitz were roughly equal to 4 x MK 48 torpedoes or a 1,500 lb warhead detonating 50 feet under her keel. All underwater explosions work the same. So if a MK 48 1,500 lb warhead gives X amount of force at 50 feet this can equal a 4,000 lb warhead at 100 feet and the 28 kiloton nuclear warhead may be the same at 2000 feet and so on. So the distance and the amount of ocean on top of the explosion is important. Even Arkansas did not break up at Bikini. She basically was flipped over and landed upside down on an empty sea bed as all the water had been blown out of the lagoon. Her hull was crushed when all that water came back down. Her sides held her together while she was in mid-air and her armor is cracked in one place near her bow but she is intact.
Depending on the distance the explosion takes place under her keel the soft keel will be crushed in or holed just like HMS Valiant and HMS QE. The closer to the hull the more rupture of the plates and farther more shock damage. Then it will depend on subdivision to contain the amount of flooding. HMS Valiant despite having her keel destroyed directly under one of her forward turrets could have still gone to sea. The sides of the ship were sufficiently strong to support the weight of the turret and barbette despite the keel being completely gone. Triple bottoms are designed to help limit the damage and absorb some of the shock just like a side protection scheme. It was never intended to be immune to all explosions. A lot depends on just how close the explosion takes place. If you look at Tirpitz's hull the physical damage was not that great and the flooding minimal. So the warheads detonated to far away from her hull and shock damage was the main element. HMS QE the explosion was almost directly beneath the hull and very close to the bottom. Here her hull plates were badly ruptured but shock damage minimal. Even lesser ships such as the modern Samuel B. Roberts which took a mine explosion in the 80's survived and did not break in half because of the distance between her hull and the explosion.
The closer the explosion is to the sea bottom the more powerful the shock wave is by a factor of 1.4. Think of the shock wave as a circle. The top half of the circle expands normally but the bottom half hits the mud and then rebounds back upward so the ship is actually hit by two shock waves not just one and this is at different times. This is the main reason Tirpitz whipped so bad. Scharnhorst took a mine under her keel close to her stern in the channel dash. It did break one of her shaft seals and did flood one engine room. Obviously though her other engines remained operational and she made it home. Most capital ships were over designed to deal with shock damage. In Iowa's case this information is still classified but it is an extreme amount based on just how overbuilt the ships are. Don't get me wrong. Under-keel explosions are really bad and no ship even a battleship can absorb that many but they are more likely to sink due to flooding than due to total structural failure.
I agree that the Iowa is very vulnerable to shaped charge warheads on AShM's, which no realistic amount of WWII armor can stop. A modern battleship designed from scratch would be much different. I came up with an idea for one a while ago, and I came to the conclusion that a modern battleship can still be worth building, but the Iowa's a WWII design, and it's definitely not effective on a modern battlefield.
That being said, the vulnerability of an Iowa (on any battleship for that matter) to under-the-keel shots designed to snap the ship in half is greatly exaggerated on this thread. In fact, the vulnerability of battleships to torpedo impacts in general is overstated. Take the last post on this page (by navydavesof):
for more information. In particular, note the 2nd post (which I have copied below) and its description of the Tirpitz when she had a 4000 lb mine (during Operation Source) explode under her keel. It tossed her around a lot (and it did indeed mission kill her for several months while the extensive damage was repaired), but it didn't break her in half, as many on this forum would predict.
A ship with a fully developed side protective system is not subject to the type of break-up a lesser vessel is due to under-keel explosions. No capital ship ever in history ever broke in half due to an under-keel explosion even when it was a nuclear explosion. This really only applies to battleships and fleet carriers. Heavy cruisers down did not have the fully developed side protective systems needed for this discussion. When a lesser ship's keel is pushed up it's sides are pushed out and into sheer. You can see this in slow motion film. The bending out of the sides of the ship weaken the steel and then form hinges that the ship will crack on when she sags. So with the breaking of the flat keel the sides are also severely weakened. Once the ship begins to sag only the upper strength deck of the hull is left to support the weight and many times it can not.
In a battleship, the ship has what they call a soft keel. Any longitude bulkhead that makes up over 50% of her length becomes a strength member of the hull girder. In an Iowa as an example, her four bulkhead system on each side gives her eight additional strength members and her third bulkhead is her armor belt which is extremely difficult to place into sheer. The side protection system is so strong it can support the weight of the ship even if the flat keel is destroyed. Each layer of the side protective system acts as an additional keel so in an Iowa she has 8 side keels and her flat keel and she actually has three upper strength decks with the second deck being an armored deck which is also difficult to bend. In the roughly 2 seconds an under-keel explosion has to work on the hull the side hinges that form on lesser ships never form on a battleship or even a fleet aircraft carrier. Therefore, the upper strength deck or decks are never placed in stress. What does occur is the under-bottom is either holed or crushed in and depending on the damage will depend on the amount of flooding just like a side hit by a torpedo.The ship will whip just like Tirpitz did but not break up.
The 4,000 lb warheads under Tirpitz were roughly equal to 4 x MK 48 torpedoes or a 1,500 lb warhead detonating 50 feet under her keel. All underwater explosions work the same. So if a MK 48 1,500 lb warhead gives X amount of force at 50 feet this can equal a 4,000 lb warhead at 100 feet and the 28 kiloton nuclear warhead may be the same at 2000 feet and so on. So the distance and the amount of ocean on top of the explosion is important. Even Arkansas did not break up at Bikini. She basically was flipped over and landed upside down on an empty sea bed as all the water had been blown out of the lagoon. Her hull was crushed when all that water came back down. Her sides held her together while she was in mid-air and her armor is cracked in one place near her bow but she is intact.
Depending on the distance the explosion takes place under her keel the soft keel will be crushed in or holed just like HMS Valiant and HMS QE. The closer to the hull the more rupture of the plates and farther more shock damage. Then it will depend on subdivision to contain the amount of flooding. HMS Valiant despite having her keel destroyed directly under one of her forward turrets could have still gone to sea. The sides of the ship were sufficiently strong to support the weight of the turret and barbette despite the keel being completely gone. Triple bottoms are designed to help limit the damage and absorb some of the shock just like a side protection scheme. It was never intended to be immune to all explosions. A lot depends on just how close the explosion takes place. If you look at Tirpitz's hull the physical damage was not that great and the flooding minimal. So the warheads detonated to far away from her hull and shock damage was the main element. HMS QE the explosion was almost directly beneath the hull and very close to the bottom. Here her hull plates were badly ruptured but shock damage minimal. Even lesser ships such as the modern Samuel B. Roberts which took a mine explosion in the 80's survived and did not break in half because of the distance between her hull and the explosion.
The closer the explosion is to the sea bottom the more powerful the shock wave is by a factor of 1.4. Think of the shock wave as a circle. The top half of the circle expands normally but the bottom half hits the mud and then rebounds back upward so the ship is actually hit by two shock waves not just one and this is at different times. This is the main reason Tirpitz whipped so bad. Scharnhorst took a mine under her keel close to her stern in the channel dash. It did break one of her shaft seals and did flood one engine room. Obviously though her other engines remained operational and she made it home. Most capital ships were over designed to deal with shock damage. In Iowa's case this information is still classified but it is an extreme amount based on just how overbuilt the ships are. Don't get me wrong. Under-keel explosions are really bad and no ship even a battleship can absorb that many but they are more likely to sink due to flooding than due to total structural failure.
Thats interesting, I agree on modern battleships with a real mission. The under keel thing would probably mission kill by hitting the screws or jets if that is chosen if powerful enough. However it is food for thought and something I suspect a few major navies are looking at (British Dreadnought proposal)
Thus, all of today's anti-ship missiles (example: Kh-35/31, RGM-84, Exocet, C-803, YJ-18, LRASM, P-270/700/800/1000, NSM, TLAM Block IV, Brahmos.....) can not do anything with the armor of Iowa, unless they attack in large numbers (100 or more)
Fritz X was an early ASM - arguably the first and it has a decent track record
Fritz X vs Roma 2 hits 1 near miss - Ship sunk
Fritz X vs Italia 1 hit - Ship badly damaged
Fritz X vs Warspite 1 hit 1 near miss - Ship mission killed
Fritz X has a warhead of 320 KGs - in context a modern Harpoon has 221 kg warhead using what I would imagine is a more modern and therefore powerful explosive
SSN-12 Sandbox has a 1000 KG warhead!
Granted Iowa is well armoured but I don't think she would resist multiple hits from modern ASMs
FX-1400 was not actually a missile, but an early form of radio guided free fall bomb with high penetration duties, especially against heavily armored ships.
The Fritz X was a further development of the PC 1400 (Panzersprengbombe, Cylindrisch 1400 kg[Note 1]) armour-piercing high-explosive bomb, itself bearing the nickname Fritz. It was a penetration weapon intended to be used against heavily protected targets such as heavy cruisers and battleships. It was given a more aerodynamic nose, four stub wings, and a box shaped tail unit, consisting of a roughly 12-sided annular set of fixed surfaces, and a cruciform tail with thick surfaces within the annulus, which themselves contained the Fritz X's aerodynamic controls. The Luftwaffe recognized the difficulty of hitting moving ships during the Spanish Civil War.[2]Dipl. engineerMax Kramer, who worked at the DVL, had been experimenting since 1938 with remote-controlled free-falling 250 kg bombs, and in 1939 fitted radio-controlledspoilers.[3] In 1940, Ruhrstahlwas invited to join the development, since they already had experience in the development and production of unguided bombs.[4]
I don't know if anyone has bought it up yet but the BROACH multi-stage warhead might be a good chance, the shaped charge making a hole for the SAP warhead to travel through, particularly if used in top attack profiles which wouldn't be too hard to arrange.
I agree that the Iowa is very vulnerable to shaped charge warheads on AShM's, which no realistic amount of WWII armor can stop. A modern battleship designed from scratch would be much different. I came up with an idea for one a while ago, and I came to the conclusion that a modern battleship can still be worth building, but the Iowa's a WWII design, and it's definitely not effective on a modern battlefield.
That being said, the vulnerability of an Iowa (on any battleship for that matter) to under-the-keel shots designed to snap the ship in half is greatly exaggerated on this thread. In fact, the vulnerability of battleships to torpedo impacts in general is overstated. Take the last post on this page (by navydavesof):
for more information. In particular, note the 2nd post (which I have copied below) and its description of the Tirpitz when she had a 4000 lb mine (during Operation Source) explode under her keel. It tossed her around a lot (and it did indeed mission kill her for several months while the extensive damage was repaired), but it didn't break her in half, as many on this forum would predict.
A ship with a fully developed side protective system is not subject to the type of break-up a lesser vessel is due to under-keel explosions. No capital ship ever in history ever broke in half due to an under-keel explosion even when it was a nuclear explosion. This really only applies to battleships and fleet carriers. Heavy cruisers down did not have the fully developed side protective systems needed for this discussion. When a lesser ship's keel is pushed up it's sides are pushed out and into sheer. You can see this in slow motion film. The bending out of the sides of the ship weaken the steel and then form hinges that the ship will crack on when she sags. So with the breaking of the flat keel the sides are also severely weakened. Once the ship begins to sag only the upper strength deck of the hull is left to support the weight and many times it can not.
In a battleship, the ship has what they call a soft keel. Any longitude bulkhead that makes up over 50% of her length becomes a strength member of the hull girder. In an Iowa as an example, her four bulkhead system on each side gives her eight additional strength members and her third bulkhead is her armor belt which is extremely difficult to place into sheer. The side protection system is so strong it can support the weight of the ship even if the flat keel is destroyed. Each layer of the side protective system acts as an additional keel so in an Iowa she has 8 side keels and her flat keel and she actually has three upper strength decks with the second deck being an armored deck which is also difficult to bend. In the roughly 2 seconds an under-keel explosion has to work on the hull the side hinges that form on lesser ships never form on a battleship or even a fleet aircraft carrier. Therefore, the upper strength deck or decks are never placed in stress. What does occur is the under-bottom is either holed or crushed in and depending on the damage will depend on the amount of flooding just like a side hit by a torpedo.The ship will whip just like Tirpitz did but not break up.
The 4,000 lb warheads under Tirpitz were roughly equal to 4 x MK 48 torpedoes or a 1,500 lb warhead detonating 50 feet under her keel. All underwater explosions work the same. So if a MK 48 1,500 lb warhead gives X amount of force at 50 feet this can equal a 4,000 lb warhead at 100 feet and the 28 kiloton nuclear warhead may be the same at 2000 feet and so on. So the distance and the amount of ocean on top of the explosion is important. Even Arkansas did not break up at Bikini. She basically was flipped over and landed upside down on an empty sea bed as all the water had been blown out of the lagoon. Her hull was crushed when all that water came back down. Her sides held her together while she was in mid-air and her armor is cracked in one place near her bow but she is intact.
Depending on the distance the explosion takes place under her keel the soft keel will be crushed in or holed just like HMS Valiant and HMS QE. The closer to the hull the more rupture of the plates and farther more shock damage. Then it will depend on subdivision to contain the amount of flooding. HMS Valiant despite having her keel destroyed directly under one of her forward turrets could have still gone to sea. The sides of the ship were sufficiently strong to support the weight of the turret and barbette despite the keel being completely gone. Triple bottoms are designed to help limit the damage and absorb some of the shock just like a side protection scheme. It was never intended to be immune to all explosions. A lot depends on just how close the explosion takes place. If you look at Tirpitz's hull the physical damage was not that great and the flooding minimal. So the warheads detonated to far away from her hull and shock damage was the main element. HMS QE the explosion was almost directly beneath the hull and very close to the bottom. Here her hull plates were badly ruptured but shock damage minimal. Even lesser ships such as the modern Samuel B. Roberts which took a mine explosion in the 80's survived and did not break in half because of the distance between her hull and the explosion.
The closer the explosion is to the sea bottom the more powerful the shock wave is by a factor of 1.4. Think of the shock wave as a circle. The top half of the circle expands normally but the bottom half hits the mud and then rebounds back upward so the ship is actually hit by two shock waves not just one and this is at different times. This is the main reason Tirpitz whipped so bad. Scharnhorst took a mine under her keel close to her stern in the channel dash. It did break one of her shaft seals and did flood one engine room. Obviously though her other engines remained operational and she made it home. Most capital ships were over designed to deal with shock damage. In Iowa's case this information is still classified but it is an extreme amount based on just how overbuilt the ships are. Don't get me wrong. Under-keel explosions are really bad and no ship even a battleship can absorb that many but they are more likely to sink due to flooding than due to total structural failure.
That is only half the story. Tirpitz was attacked by X-craft, putting four large 4000 lbs charges under her keel, at a depth of around 60 feet, rather than directly under her keel at aproximately 36 feet. The difference in the colum of water between hull and explosive device makes a lot of difference, about what the energy of the explosion does to a ship. More space means more diverted energy to the surroudings. Less space, as a warhead near the hull under a ship, means catastrophic amounts of explosive energy diverted into the hull, such as with USS Houston near Formosa 1945. Here the warhead was much smaller, around the 500 lbs, typical ofr a 1945 period Type 91 aircraft dropped torpedo, not the larger heavy weight warhead of a shiplaunched torpedo.
HESH I believe would also suffer from the same effects as HEAT on a battleships. Again, the extensive compartmentalization would save the battleship. HESH is not really designed to penetrate armor but rather transmit a shock wave through the solid metal. Where it reaches the "end" of the armor on the interior of the ship, it projects pieces of armor at high speed throughout the interior, starting fires, killing crew. I cant help but think it would just cause localized damage and nothing else. Also, HESH can be mitigated by spall liners on the interior.
The spalling from a large-calibre HESH round would, I suspect, be very significant - it's not often appreciated that the main purpose of the bursting charge on an AP shell (and in fact the warhead on an anti-ship missile) is to create fragments, so the damage mechanism would be similar. The sorts of fragments we're talking about here can penetrate thinner armour plating and middling-sized machine tools.
My main concern is that the structural backing to the armour plate would act as a spall liner. I'd still go for conventional AP shells given the choice, but if forced to choose between HESH and HEAT against a ship, I'd bet on HESH.
That is only half the story. Tirpitz was attacked by X-craft, putting four large 4000 lbs charges under her keel, at a depth of around 60 feet, rather than directly under her keel at aproximately 36 feet. The difference in the colum of water between hull and explosive device makes a lot of difference, about what the energy of the explosion does to a ship. More space means more diverted energy to the surroudings. Less space, as a warhead near the hull under a ship, means catastrophic amounts of explosive energy diverted into the hull, such as with USS Houston near Formosa 1945. Here the warhead was much smaller, around the 500 lbs, typical ofr a 1945 period Type 91 aircraft dropped torpedo, not the larger heavy weight warhead of a shiplaunched torpedo.
Maybe, but the difference in explosive power is largely irrelevant relative to the structural strength of the hull. I don't disagree that it will cause serious damage and possibly flooding in the bottom of the ship, but it still won't snap the ship in half even if it's much closer to the hull. The USS Arkansas was literally thrown out of the water by the Baker test (23 kt at 90 feet depth and 510 feet distance), and still didn't snap in half due to the force of the explosion. The fact that a well-constructed battleship can be lifted entirely out of the water and still remain intact despite the stresses on the hull is a good indication that even a large torpedo detonated under the keel properly would not break the ship in half. For that reason, the experience of the HMS Queen Elizabeth at the Raid on Alexandria (she suffered almost no shock damage, only direct explosive damage on the bottom of the hull, albeit a lot of it), and the moderate amount of structural stress the Tirpitz received from the mines, I suspect that the Tirpitz still wouldn't have her back broken even if the mines had been detonated directly under her keel at 36 feet. The hull would have been devastated from the blast and flooding, but it wouldn't have snapped in two.
The USS Arkansas was literally thrown out of the water by the Baker test (23 kt at 90 feet depth and 510 feet distance), and still didn't snap in half due to the force of the explosion.
The fact that a well-constructed battleship can be lifted entirely out of the water and still remain intact despite the stresses on the hull is a good indication that even a large torpedo detonated under the keel properly would not break the ship in half. For that reason, the experience of the HMS Queen Elizabeth at the Raid on Alexandria (she suffered almost no shock damage, only direct explosive damage on the bottom of the hull, albeit a lot of it), and the moderate amount of structural stress the Tirpitz received from the mines, I suspect that the Tirpitz still wouldn't have her back broken even if the mines had been detonated directly under her keel at 36 feet. The hull would have been devastated from the blast and flooding, but it wouldn't have snapped in two.
I would expect the forces on Arkansas to be have been relatively evenly distributed across her hull, whereas a mine under the keel applies extreme forces to a small area of hull and much weaker forces to the rest, favouring hull deformation and stress in the target area, so the example of Arkansas may not be particularly useful. But I agree with the point about capital ships having much stronger structures. The low armour deck of Tirpitz, being more central within the ship, might also have helped limit deformation.
Those are easy to do, some are fired every year. But "These explosions were designed to simulate underwater attacks."? On something this big? It was one in a lifetime chance.
