What It Would Really Take To Sink a modern Aircraft Carrier

[Penguin]

Look at the way they design the hulls with their bulbous bows and a relatively narrow keel from that bulbous bow just to midship. The area below the waterline is about as minimal as can be for such a massive ship, it's quite impressive. Compare it to the deck's surface area and it's considerably smaller. Add in the overall height and and compare it to the height from the top of the black, water line on down and there is much more above water than below. And because of the ship's deadrise (the angle of the sides from edge of deck or chine if it has one which carriers don't) to keel is quite steep.

Not only are these hulls designed to withstand certain impacts, but look at how little of the hull and keel is actually under the water line. It would take full speed and careless captainship to not follow the state of the art navigation charts and hazard warnings they have at their disposal and make a major mistake and collide with an iceberg. Even if they find themselves in an area with icebergs, they'd proceed with extreme caution at very low speed or avoid that area completely and take the long way around.

With all the miles and miles of cruising that carriers have taken since their inception, I don't recall ever hearing of one being severely impacted by an iceberg. Could be wrong.

Iowa class BB
Length:887 ft 3 in (270.43 m)
Beam: 108 ft 2 in (32.97 m)
Draft: 37 ft 2 in (11.33 m)

Nimitz class CVN
Length:

• Overall: 1,092 feet (332.8 m)
• Waterline: 1,040 feet (317.0 m)

Beam:

• Overall: 252 ft (76.8 m)
• Waterline: 134 ft (40.8 m)

Draft:

• Maximum navigational: 37 feet (11.3 m)
• Limit: 41 feet (12.5 m)

Beam to Length o.a.
Iowa 270/33=8.18
Nimitz 333/41=8.12 (waterline: 317/41=7.73)

Regarding width and draft:

Panama canal > it is the size of the locks, specifically the Pedro Miguel Locks, along with the height of the Bridge of the Americas at Balboa, that determine the metrics and limit the size of ships that may use the canal.

Panana canal has 12.6 m draft restrictions within the canal. Hence, note drafts 11 to 11.3m in both cases.

Initially the locks at Gatun were designed to be 28.5 m (94 ft) wide. In 1908, the United States Navy requested that an increased width of at least 36 m (118 ft) to allow the passage of U.S. Naval ships. Eventually a compromise was made and the locks were built 33.53 m (110.0 ft) wide. The 2006 third set of locks project has created larger locks, allowing bigger ships to transit through deeper and wider channels. The allowed dimensions of ships using these locks increased by 25% in length, 51% in beam, and 26% in draft. The new lock chambers are 427 m (1,400 ft) long, 55 m (180 ft) wide, and 18.3 m (60 ft) deep. This allows the transit of vessels with a beam of up to 49 m (160 ft), an overall length of up to 366 m (1,200 ft) and a draft of up to 15 m (49 ft)

 

[Gomig-21]

Iowa class BB
Length:887 ft 3 in (270.43 m)
Beam: 108 ft 2 in (32.97 m)
Draft: 37 ft 2 in (11.33 m)

Nimitz class CVN
Length:

• Overall: 1,092 feet (332.8 m)
• Waterline: 1,040 feet (317.0 m)

Beam:

• Overall: 252 ft (76.8 m)
• Waterline: 134 ft (40.8 m)

Draft:

• Maximum navigational: 37 feet (11.3 m)
• Limit: 41 feet (12.5 m)

Beam to Length o.a.
Iowa 270/33=8.18
Nimitz 333/41=8.12 (waterline: 317/41=7.73)

Regarding width and draft:

Panama canal > it is the size of the locks, specifically the Pedro Miguel Locks, along with the height of the Bridge of the Americas at Balboa, that determine the metrics and limit the size of ships that may use the canal.

Panana canal has 12.6 m draft restrictions within the canal. Hence, note drafts 11 to 11.3m in both cases.

Initially the locks at Gatun were designed to be 28.5 m (94 ft) wide. In 1908, the United States Navy requested that an increased width of at least 36 m (118 ft) to allow the passage of U.S. Naval ships. Eventually a compromise was made and the locks were built 33.53 m (110.0 ft) wide. The 2006 third set of locks project has created larger locks, allowing bigger ships to transit through deeper and wider channels. The allowed dimensions of ships using these locks increased by 25% in length, 51% in beam, and 26% in draft. The new lock chambers are 427 m (1,400 ft) long, 55 m (180 ft) wide, and 18.3 m (60 ft) deep. This allows the transit of vessels with a beam of up to 49 m (160 ft), an overall length of up to 366 m (1,200 ft) and a draft of up to 15 m (49 ft)

Very cool comparison between the Iowa battleship class and the Nimitz. This is the critical one for the CVN:
Beam: The width of a boat or ship at its widest point, which is almost always at the deck or transom.

• Overall: 252 ft (76.8 m)
• Waterline: 134 ft (40.8 m)

That's almost twice as wide at the deck compared to what's at the waterline. It's quite amazing, that with their uneven, top heavy and cantilevered deck areas, their buoyancy is perfectly level. Then add 150 of the best jet fighters, loaded with weapons, taking off, landing, stored and maintained on it. An engineering marvel.

The only thing that's a bit hazy in those stats and tanker illustrations is how they show the "Draft" of these ships with the arrow pointing down. Someone can mistake that arrow that they describe as the draft to be the total height of the ship. The draft is what any boat or ship "draws", or the boat's hull measurements that it 'displaces" and hence is only the height of the hull that is below the waterline, not overall from deck to keel like what might be perceived in those tanker descriptions.

This makes it a bit clearer as far as what the draft is.

However, the draft numbers sound right, especially on the CVNs:

Draft:

• Maximum navigational: 37 feet (11.3 m)
• Limit: 41 feet (12.5 m)

Back to the picture I posted and if you look at just the draft and if it's around 40'+/-, then imagine how much the overall height is, since from above that black line (which defines the waterline), it's considerably greater than the ship's draft. So what's below the waterline being much less hull area brings back the point that targeting that lower section to make it sink is extremely difficult and close to impossible.

 

[gambit]

The uninvited guest: Chinese sub pops up in middle of U.S. Navy exercise, leaving military chiefs red-faced

Debunked a long time ago...

https://defence.pk/pdf/threads/chinese-submarines-are-they-noisy.369289/#post-4742286

Sweden Has A Sub That's So Deadly The US Navy Hired It To Play Bad Guy

Nothing wrong with that. However, that does not mean the fleet has no defense.

 

[ashok321]

That's almost twice as wide at the deck compared to what's at the waterline. It's quite amazing, that with their uneven, top heavy and cantilevered deck areas, their buoyancy is perfectly level. Then add 150 of the best jet fighters, loaded with weapons, taking off, landing, stored and maintained on it. An engineering marvel.

You forgot that each carrier undergoes what in marine parlance is called a stability/heel test.
Normally below 7 degrees there seems no harm and stability test passed.
Overall its case of fluctuation of center of gravity & center of buoyancy which has to be restrained in extreme cases.

 

[Gomig-21]

You forgot that each carrier undergoes what in marine parlance is called a stability/heel test.
Normally below 7 degrees there seems no harm and stability test passed.
Overall its case of fluctuation of center of gravity & center of buoyancy which has to be restrained in extreme cases.

Absolutely. Makes the design even more impressive. Just like you said, the ship's listing has to be restrained in extreme cases, but really it's somewhat irrelevant IMO and feel free to correct me if you think I'm wrong. Testing for a carrier's listing potential is done for the sake of testing and to make sure it's top speed doesn't cause capsizing. But notice that testing is done with hardly any aircraft or equipment on board and certainly not on deck.

Ronald Reagan

Looks past 7 degrees and this limit, whatever it may be, becomes the tested limit without a fully equipped carrier or aircraft and equipment on deck. I don't believe it would ever put itself in that position while fully loaded for obvious reasons.

Speaking of listing, it seems the larger and heavier the ship is, the more opposite-to-turn it lists during these high speed turns. Majority of boats and even larger ships will list to the same side as the turn; port to port and starboard to starboard. This pic shows the opposite.

Makes me wonder if these larger ships have anything that resembles trim tabs to control listing, not just in turns but in straight cruising from uneven weight distribution or heavy current/waves? It seems like they should.

 

[ashok321]

Absolutely. Makes the design even more impressive. Just like you said, the ship's listing has to be restrained in extreme cases, but really it's somewhat irrelevant IMO and feel free to correct me if you think I'm wrong. Testing for a carrier's listing potential is done for the sake of testing and to make sure it's top speed doesn't cause capsizing. But notice that testing is done with hardly any aircraft or equipment on board and certainly not on deck.

Ronald Reagan

Looks past 7 degrees and this limit, whatever it may be, becomes the tested limit without a fully equipped carrier or aircraft and equipment on deck. I don't believe it would ever put itself in that position while fully loaded for obvious reasons.

Speaking of listing, it seems the larger and heavier the ship is, the more opposite-to-turn it lists during these high speed turns. Majority of boats and even larger ships will list to the same side as the turn; port to port and starboard to starboard. This pic shows the opposite.

Makes me wonder if these larger ships have anything that resembles trim tabs to control listing, not just in turns but if straight cruising from uneven weight distribution or heavy current/waves? It seems like they should.

This is a general yet mandatory (survey) procedure after the new ship is out from dry dock and ready to roll.
Stability test is a MUST.

Here is something on inclining test:

 

[Penguin]

That's almost twice as wide at the deck compared to what's at the waterline. It's quite amazing, that with their uneven, top heavy and cantilevered deck areas, their buoyancy is perfectly level. Then add 150 of the best jet fighters, loaded with weapons, taking off, landing, stored and maintained on it. An engineering marvel.

Why assume top heavy? Just because they are tall structures? Remember those tend to be hollow. Down below are tons and tons of aviation fuel, ordnance, etc to counterbalance .....

Back to the picture I posted and if you look at just the draft and if it's around 40'+/-, then imagine how much the overall height is, since from above that black line (which defines the waterline), it's considerably greater than the ship's draft. So what's below the waterline being much less hull area brings back the point that targeting that lower section to make it sink is extremely difficult and close to impossible.

You seen to be assuming a submarine attack with a torpedo, in which the torpedo actually hits the hull. But this is not how torpedoes break a ship's back!

This series of images show the destruction of an Australian warship HMAS Torrens by a MK48 Mod 4 heavyweight torpedo with 292.5 kg PBXN-103, which is equivalent to about 544 kg of TNT. This torpedo is designed to detonate under the keel of a surface ship, breaking the keel and destroying its structural integrity. In the event of a miss, it can circle back for another attempt. The plume rising above the ship’s superstructure is caused by the collapse of a large gas bubble sucking sea water upward in a powerful jet.

 

[Gomig-21]

Why assume top heavy? Just because they are tall structures? Remember those tend to be hollow. Down below are tons and tons of aviation fuel, ordnance, etc to counterbalance .....

There's definitely counterbalances, but those are not done with ordnance or aviation fuel. Counterbalancing is mostly done with ballast compartments. The aviation fuel is filled in tanks that are already spread out to even the weight distribution. Although it has no bearing on the actual ballast of the ship because it's filled in a predesignated tank system that is already structurally engineered and specifically located to spread the weight evenly, the fuel mostly affects the overall weight. Then you have a design like this...

and like this...

...and you have a base that is half the square footage of the top, and you have extreme cantilevering of the deck on both sides, including one side that has an offset and rather large, heavy control tower placed on one of the cantilevered sides, add in the weight of the deck (which is not exactly hollow but rather quite thick and strong since not only does it have to withstand the cumulative weight of 30+ working aircraft at a time, but their tremendous pressure exerted on that fight deck during takeoffs and especially landings). The framing structure that supports the deck is quite extensive as well. Then add in the 4 catapult systems that are just beneath the deck with their massive, steam tanks that operate them. Then you have the 4 arresting gear cables that also use 4 independent hydro-pneumatic tank systems. Each one of those filled with oil weighs 45 tons and are not far below the deck. Add all the other systems that are on or near the deck and especially when its active with all gear and personnel, I think it's safe to say it's -- not necessarily "top heavy" as in the true definition of top heavy like an overloaded cargo ship with too many containers stacked up too high -- but more along the lines that the structure is heavy at the top because of all the aforementioned items.

You seen to be assuming a submarine attack with a torpedo, in which the torpedo actually hits the hull. But this is not how torpedoes break a ship's back!

This series of images show the destruction of an Australian warship HMAS Torrens by a MK48 Mod 4 heavyweight torpedo with 292.5 kg PBXN-103, which is equivalent to about 544 kg of TNT. This torpedo is designed to detonate under the keel of a surface ship, breaking the keel and destroying its structural integrity. In the event of a miss, it can circle back for another attempt. The plume rising above the ship’s superstructure is caused by the collapse of a large gas bubble sucking sea water upward in a powerful jet.

Fair point. That's why I previously mentioned in my first post on this thread IIRC that in IMO, the biggest threat to an aircraft carrier is still the submarine and not airborne threats or even sea skimming, cruise missiles. It's still the very dangerous and elusive threat from below. However, I don't think that a comparison of a destroyer, that is, maybe, if we're generous, 1/4 the length and 1/6th the width of a modern aircraft carrier (and one that is built with much less heavier framing and hull thickness in its structure and engineered design) is a fair one. Protection against torpedoes is much more inferior just by default alone in something like the Torrens which was built in the mid 60's and went in service in the early 1970's and could only have so much hull protection against torpedoes. Modern aircraft carriers have extensive, hull designs limiting the amount of the ship that is actually below the water as I previously mentioned and extensive engineering designs strictly for the protection against incoming threats. There is protection around the engine compartment which is strategically located in the center away from the sides and of course, think of the walls around the nuclear reactors that power those engines. Then you have specifically engineered bulkhead systems that are precisely designed to isolate and seal off any compromised areas. All that needs to be factored in. Just an educated guess on my part, if a torpedo manages to penetrate the hull, I don't believe you will see that much vertical, blast energy and damage as you see in the Torrens.

 

[ashok321]

There's definitely counterbalances, but those are not done with ordnance or aviation fuel. Counterbalancing is mostly done with ballast compartments. The aviation fuel is filled in tanks that are already spread out to even the weight distribution. Although it has no bearing on the actual ballast of the ship because it's filled in a predesignated tank system that is already structurally engineered and specifically located to spread the weight evenly, the fuel mostly affects the overall weight. Then you have a design like this...

and like this...

...and you have a base that is half the square footage of the top, and you have extreme cantilevering of the deck on both sides, including one side that has an offset and rather large, heavy control tower placed on one of the cantilevered sides, add in the weight of the deck (which is not exactly hollow but rather quite thick and strong since not only does it have to withstand the cumulative weight of 30+ working aircraft at a time, but their tremendous pressure exerted on that fight deck during takeoffs and especially landings). The framing structure that supports the deck is quite extensive as well. Then add in the 4 catapult systems that are just beneath the deck with their massive, steam tanks that operate them. Then you have the 4 arresting gear cables that also use 4 independent hydro-pneumatic tank systems. Each one of those filled with oil weighs 45 tons and are not far below the deck. Add all the other systems that are on or near the deck and especially when its active with all gear and personnel, I think it's safe to say it's -- not necessarily "top heavy" as in the true definition of top heavy like an overloaded cargo ship with too many containers stacked up too high -- but more along the lines that the structure is heavy at the top because of all the aforementioned items.




Fair point. That's why I previously mentioned in my first post on this thread IIRC that in IMO, the biggest threat to an aircraft carrier is still the submarine and not airborne threats or even sea skimming, cruise missiles. It's still the very dangerous and elusive threat from below. However, I don't think that a comparison of a destroyer, that is, maybe, if we're generous, 1/4 the length and 1/6th the width of a modern aircraft carrier (and one that is built with much less heavier framing and hull thickness in its structure and engineered design) is a fair one. Protection against torpedoes is much more inferior just by default alone in something like the Torrens which was built in the mid 60's and went in service in the early 1970's and could only have so much hull protection against torpedoes. Modern aircraft carriers have extensive, hull designs limiting the amount of the ship that is actually below the water as I previously mentioned and extensive engineering designs strictly for the protection against incoming threats. There is protection around the engine compartment which is strategically located in the center away from the sides and of course, think of the walls around the nuclear reactors that power those engines. Then you have specifically engineered bulkhead systems that are precisely designed to isolate and seal off any compromised areas. All that needs to be factored in. Just an educated guess on my part, if a torpedo manages to penetrate the hull, I don't believe you will see that much vertical, blast energy and damage as you see in the Torrens.

The hefty (per square meter) price commanded in the US is not that of iconic Empire state building but USS Gerald R Ford, which has 13 billion dollar price tag on it = GDP of Jamaica.

The island alone weighs 550 tons:

 

[Penguin]

Fair point. That's why I previously mentioned in my first post on this thread IIRC that in IMO, the biggest threat to an aircraft carrier is still the submarine and not airborne threats or even sea skimming, cruise missiles. It's still the very dangerous and elusive threat from below. However, I don't think that a comparison of a destroyer, that is, maybe, if we're generous, 1/4 the length and 1/6th the width of a modern aircraft carrier (and one that is built with much less heavier framing and hull thickness in its structure and engineered design) is a fair one. ... Just an educated guess on my part, if a torpedo manages to penetrate the hull, I don't believe you will see that much vertical, blast energy and damage as you see in the Torrens.

Not every torpedo sinking looks like HMAS Torrance's ....

Perry class frigate USS Thach (FFG-43)

T-AE-26 USNA Kiauea ammunition ship (at 28 sec) : 20k ton fld

T-AFS-5 USNS Concord Mars-class combat stores ship : 19k ton fld

Belleau Wood (40k ton fld) rolls over and sinks following her use as a live fire target in the 2006 RIMPAC exercises

 

[S.Y.A]

Perry class frigate USS Thach (FFG-43)

It stays afloat in the video, just shows that if an old frigate is so durable, then a modern aircraft carrier will be able to or can survive multiple hit by torpedoes

 

[Green_Patriot]

Definitely not a Missile. ACC is too big and compartmentalized to sink by any strike above the waterline. Moreover the carrier screen has a ton of AAW PDMS CIWS, they wont let 5 simultaneous missiles come close even.
Best bet is a Nuclear tipped Torpedo or Torpedoes

 

[Asian.Century]

5 Ways Russia and China Could Sink America's Aircraft Carriers

Aircraft carriers have been the primary capital ship of naval combat since the 1940s, and remain the currency of modern naval power. But for nearly as long as carriers have existed, navies have developed plans to defeat them. The details of these plans have changed over time, but the principles remain the same. And some have argued that the balance of military technology is shifting irrevocably away from the carrier, driven primarily by Chinese and Russian innovation.

So let’s say you want to kill an aircraft carrier. How would you go about it?.

Torpedo

On September 17, 1939, the German submarine U-29 torpedoed and sank HMS Courageous. Courageous was the first aircraft carrier lost to submarine attack, but would not be the last. Over the course of World War II, the United States, the UK and Japan lost numerous carriers to submarines, culminating in the destruction of the gigantic HIJMS Shinano in 1944.

Submarine-fired torpedoes remain a critical threat to modern carriers. Russian and Chinese submarines regularly practice attacks on U.S. carrier groups, as do those of allied navies. Modern torpedoes cause damage by exploding beneath a ship, an impact that can break the ship’s back with dramatic effects. Fortunately, no such torpedo has ever hit a ship the size of a U.S. supercarrier, although the U.S. Navy did conduct a variety of tests on the hulked USS America in 2005. Those tests, which may have involved underwater charges (of the sort that damaged USS Cole) did not result in America’s sinking; she was scuttled in the wake of the process. The short answer is that no one knows how many modern torpedoes a U.S. carrier could take before sinking, but we can estimate with little doubt that even a single torpedo would cause extensive damage, and severely impede operations.

Cruise Missile

In 1943, the Germans used a precision-guided bomb to destroy the Italian battleship Roma. Such bombs soon gave way to self-propelled cruise missiles, which could launch from aircraft, ships, submarines, or surface installations. During the Cold War, the Soviets developed a dizzying array of platforms for launching cruise missiles at carrier strike groups, ranging from small patrol boats to massive formations of strategic bombers.

Today, China, Russia and several other countries field a wide variety of cruise missiles capable of striking U.S. carrier battle groups. These missiles vary widely in range, speed and means of approach, but the most advanced can fly at high (often supersonic) speeds while offering a very low radar profile. As with torpedoes, the available evidence on the effectiveness of cruise missiles against a modern supercarrier is virtually nil. Much smaller ships have survived such hits, as have civilian tankers similar in size to CVN-78. Nevertheless, even a nonfatal cruise missile hit would probably result in severe damage to the flight deck, impeding or completely stopping flight operations.

Ballistic Missile

The most important development in carrier-killing technology over the last decade has been the antiship ballistic missile (ASBM). The Chinese Df-21 has the potential to strike American carriers from heretofore unrealizable ranges, and threatens to penetrate existing defense systems. The missile can maneuver in its terminal phase, targeting a moving carrier on a high-velocity final approach. The kinetic energy alone of the weapon could inflict devastating damage on a flight deck, putting a carrier out of action if not sinking it entirely.

The development of the Df-21 has forced the U.S. Navy to significantly step up its ballistic-missile defense efforts. However, the ability of a U.S. task force to manage a large barrage of ASBMs is in great question; more than anything else, the development of the ASBM has forced the U.S. Navy to reconsider the role of the carrier in high-intensity warfare.

Cost Overrun

The new Ford class (CVN-78) carriers cost somewhere around $13 billion, a price that does not include the air wing. With a contingent of F-35Cs, F/A-18E/Fs and various support aircraft, the price of an individual carrier is simply staggering, and the numbers go higher when accounting for the escort group that a carrier requires. Although the per-unit cost will go down as more ships are acquired, the Fords take so long to build that each new ship will need to incorporate a host of new technologies, just as with the Nimitz class.

The tolerance for large defense expenditure in the United States has varied considerably over the past three decades. The Trump administration has combined a fondness for increased spending with a grand strategy of retrenchment, an odd pairing. If retrenchment takes hold, then generating enthusiasm for defense spending may become increasingly difficult. And at some point, the military utility of an aircraft carrier may become literally irrelevant, relative to the cost of building, maintaining and effectively deploying the ship and its air wing.

Excess of Caution

Maybe China and Russia don’t need to kill a carrier to drive the species to extinction. All of the factors above—the weapon systems that can kill carriers, and the costs associated with the ships themselves—come together to create caution about how to use the ships. In the event of a conflict, U.S. Navy admirals and the U.S. president may grow so concerned about the vulnerability of carriers that they don’t use them assertively and effectively. The extraordinary value of the carriers may become their greatest weakness; too valuable to lose, the carriers could remain effectively on the sidelines in case of high-intensity, peer-competitor conflict.

And if aircraft carriers can’t contribute in the most critical conflicts that face the United States, it will become impossible to justify to the resources necessary to their construction and protection. That, more than anything else, will lead to obsolescence, and the end of the aircraft carrier as the currency of national power.

Do these factors mean that the aircraft carrier has become obsolete as a platform? No. China and Russia have worked relentlessly on ways to kill aircraft carriers because they perceive those ships as critical security threats. Moreover, China and Russia have developed the array of systems they now deploy because aircraft carriers have good answers to many of these weapons. Finally, China has embarked on its own carrier program; the PLAN will soon operate the second-largest carrier force in the world.

Nevertheless, aircraft carriers face real dangers from advanced military technology. The greatest threat, though, probably comes from the procurement process; unless the United States can restrain cost growth in the carrier and its air wing, the ships will struggle to retain their place in the overall architecture of U.S. defense policy.

 

[Gomig-21]

Who ever bumped this thread, that was a good thing because it reminded me of how there was at one point in time some excellent, technical discussions happening and that @Penguin has been missing for a while, now. Hope he's ok.

 

[Army research]

Who ever bumped this thread, that was a good thing because it reminded me of how there was at one point in time some excellent, technical discussions happening and that @Penguin has been missing for a while, now. Hope he's ok.

I was thinking the same , it was great to read his insights