OT: Seven US aircraft carriers have been sunk in the past 30 years.

[RN7]

In 2006 the Chinese Navy Song Class diesel-electric submarine famously reached within striking distance of the USS Kitty Hawk undetected. However in naval exercises a total of seven US Navy aircraft carriers have reportedly been sunk by non-nuclear submarines.

1981: USS Eisenhower was sunk in NATO exercises in the Atlantic Ocean by Royal Canadian Navy Porpoise Class diesel-electric submarine built in Britain in the 1960's, and wasn't even detected by US Navy ASW assets.

1981: During the same exercise the USS Forrestal was also sunk by an unidentified diesel-electric submarine, probably a British Royal Navy submarine.

1989: USS America sunk in the Atlantic Ocean by Dutch Navy Zwaardvis Class diesel-electric submarine.

1996: USS Independence sunk by the Chilean Navy German built Type-209 Class diesel-electric class submarine in the Pacific Ocean.

1999: USS Theodore Roosevelt sunk by the Dutch Navy Walrus Class diesel-electric submarine in the Atlantic Ocean.

2003: Unidentified US Navy aircraft carrier sunk by two Royal Australian Navy Collins Class diesel-electric submarines in the Pacific Ocean.

2005: USS Ronald Reagan sank by Swedish Navy Gotland Class AIP submarine in the Pacific Ocean.

Many other US Navy ships have also been sunk in exercises by non-nuclear submarines. In 1999 the Dutch submarine that sank the USS Theodore Roosevelt also sank the exercise command ship USS Mount Whitney, a cruiser, several destroyers and the Los Angeles Class nuclear attack submarine USS Boise. In 2000 a Royal Australian Navy Collins Class diesel-electric submarine almost sank the USS Abraham Lincoln, and sank two US Navy nuclear attack submarines in the Pacific Ocean. In 2001 another Australian Collins Class HMAS Waller sank two US Navy assault ships in the Pacific, and during the same exercise a Chilean Navy submarine sank the Los Angeles Class nuclear attack submarine USS Montpelier twice. In 2002 another Australian Collins Class HMAS Sheehan hunted down and sank the Los Angeles Class USS Olympia, while in 2003 two Australian Collins Class sank two US Navy nuclear attack submarines and an unidentified aircraft carrier.

Although such losses were only in exercises and its possible that operational restraints were put on US naval forces during such exercises it highlights the fact that US Navy carrier battlegroups could be vulnerable to submarine attack. During the Cold War the principle objective of the Soviet Navy was to eliminate US naval air superiority. The principle means of doing that was through Soviet nuclear submarines which were the Soviet Union's primary naval asset, and followed/shadowed US aircraft carriers and trained to destroy them through conventional or nuclear means in wartime. In the Twilight 2000 timeline this could have led to huge American naval losses.

[raketenjagdpanzer]

Were they on a war footing Were they heavily prosecuting enemy contacts Were they dropping Mk46's on every possible contact Were they using countermeasures and screening forces Were ASW birds constantly dropping sonobuoys

It's easy to cry wolf at scenarios like these but to suggest we don't know what's out there or how to deal with it is...spurious.

[Targan]

No person or war machine is invulnerable.

[headquarters]

simulated naval combat

Were they on a war footing Were they heavily prosecuting enemy contacts Were they dropping Mk46's on every possible contact Were they using countermeasures and screening forces Were ASW birds constantly dropping sonobuoys

It's easy to cry wolf at scenarios like these but to suggest we don't know what's out there or how to deal with it is...spurious.

Excercises - has a starting time and and an endex. Within that time the players act according to orders and scenario. If someone neglected to "stand to"and got hit - thats the way it goes...

[RN7]

Were they on a war footing Were they heavily prosecuting enemy contacts Were they dropping Mk46's on every possible contact Were they using countermeasures and screening forces Were ASW birds constantly dropping sonobuoys

It's easy to cry wolf at scenarios like these but to suggest we don't know what's out there or how to deal with it is...spurious.

Unfortunately during these exercises the US Navy was on a war footing, or as close as they could get to one during an exercise.

In the case of the USS Eisenhower and USS Forrestal in 1981, they were participating in the NATO exercises Ocean Venture/Magic Sword North, the largest exercises in the US Navy's Atlantic Fleet history along with British, Canadian and US Coast Guard ships. The objective was for two carrier battle groups to transit the North Atlantic and enter the Norwegian Sea and simulate air attacks on enemy positions in waves of coordinated air attacks. An old Canadian submarine slipped through the escort screen undetected and conducted a successful simulated torpedo attack on the USS Eisenhower. Another submarine did the same to the USS Forrestal later in the exercise.

The most significant part of the exercise was the transit by the carriers of the GIUK gap. In five previous NATO exercises American carriers had always been attacked trying to transit the gaps, and US tactics were exposed as seriously flawed. In wartime it is believed that neither American carrier would have made it through the GIUK gap unharmed, and that US tactics and levels of training were inferior to their British and Canadian allies.

A US Navy officer who tried to report it to highlight aircraft carrier vulnerability to diesel-electric submarine attacks was censored by navy officials and in fact the officer was ridiculed for reporting it and it harmed his career. In Ocean venture 81 90% of first strikes were by submarines against carriers, a fact that did not sit well with US Navy aviators.

[RN7]

Also in 1983 the Canadian submarine HMCS Okanagan reached within a kilometre of the USS Kitty Hawk and prepped itself for torpedo launch before sneaking away unnoticed through the carriers destroyer escort screen.

In 1996 the Canadian submarine HMCS Onandaga also beat the USS Hartford, a nuclear submarine 30 years younger largely according to its commander because his crew had been together for two years and was well trained while US submarines had a 25% annual crew turnover and 50% over two years. The HMCS Onandaga beat the USS Hartford 6 out of 7 times in exercises according to the Canadian submarine commander, and lost once because he started to get complacent about the American not picking him up during a snorkling procedure.

Closer to current times during NATO exercise 99FEX the Dutch submarine Walrus launched two successful simulated attacks on the USS Theodore Roosevelt, as well sinking its escorts and a nuclear submarine and sneaked away undamaged. The crew of the Walrus even had T-shirts printed with a walrus impaling the Roosevelt.

[Canadian Army]

Royal Canadian Navy Porpoise Class diesel-electric submarine

Got this from Wikipedia:

The Oberon class was a 27-boat class of British-built diesel-electric submarines based on the successful British Porpoise-class submarine.

Thirteen were constructed for the Royal Navy, while another fourteen were built and exported to other countries' navies: six to the Royal Australian Navy, three to the Royal Canadian Navy with an additional two British submarines later transferred, three to the Brazilian Navy, and two to the Chilean Navy.

The Oberon class was arguably the best conventional submarine class of its time, with an astonishing reputation for quietness that allowed it to exist into the 21st century until replaced by newer classes such as the Collins and Victoria classes in Australia and Canada respectively.

The Oberon class was briefly succeeded in RN service by the Upholder-class submarine. The Upholder-class submarines were later upgraded and sold to the Canadian Forces after refit as the Victoria class, again replacing Oberons.

The Australian Oberons were replaced by the six Collins-class submarines.

The two Chilean Oberons were replaced by the Scorpne-class submarines O'Higgins and Carrera.

The Brazilian Oberons were replaced by Type 209 submarines.

[Cdnwolf]

http://www.projectojibwa.ca/

And one of the Canadian ones will be only 50 miles away from me as museum.

[Adm.Lee]

Admiral "Sandy" Woodward's Falklands War memoir relates a story of how an RN DD or FF got within visual range of a US CV shortly before that war, in the Indian Ocean. I cannot recall if he was the skipper or a flag officer at the time. From what I remember:

The exercise rules were that there wasn't supposed to be aerial recon beforehand, but his ship was overflown just before sunset anyway. They had planned for that, however.

After sunset, they rigged every light they could all over the ship, and whenever an American plane flew nearby, they identified themselves as an Indian (or Pakistani) cruise liner, including stereotypical South Asian accent. (I read this in 1991-92, when I had an Indian boss, so the accent written in the book had me chuckling.) Come sunrise, they were on the horizon from the CV, "launching" Exocets.

This scene was later reprised, more or less, in the almost-classic naval movie "Down periscope."

[RN7]

Got this from Wikipedia:
The Oberon class was arguably the best conventional submarine class of its time, with an astonishing reputation for quietness that allowed it to exist into the 21st century until replaced by newer classes such as the Collins and Victoria classes in Australia and Canada respectively.

They were excellent submarines and based on a German design of WW2, and only surpassed in quietness by current generation diesel-electric/AIP submarines.

The Canadian submarine service is like its Australian and British cousins a very professional and well trained service, and the Australian and Canadian submarines have caused the US Navy huge problems in exercises. But other navies have also frequently got the better of the US Navy ASW forces and nuclear submarines; Chileans, Dutch, Japanese and Swedish. Even a Pakistani Navy submarine approached a US Navy amphibious group in the Arabian Sea in 2001. It was detected by one of the amphibious groups escorts; a Canadian frigate, and escorted away from the area.

There seems to be a bit of a hubris problem within the US Navy that stems from the fact that the US Navy is the most powerful and the most advanced and that no one else can challenge it, when in fact the reality is that they can and frequently do. In naval aviation, the strategic use of nuclear submarines and possibly anti-air warfare the US Navy is the unquestioned leader, but in ASW and mine detection capabilities the Americans are by no means the leader of the pack, and this fact has frequently been commentated on by US naval commanders since the First Gulf War.

The all nuclear submarine fleet has many advantages in range, speed and firepower, but its superiority can be countered in shallow waters or even in the open ocean by a willy diesel submarine commander with a well trained crew. During NATO exercises European submarine commanders were frequently more worried about colliding under water with big US Navy nuclear submarines than being detected, because the US submarines seemed to be blind to their presence until they hit one of them.

Even the notion that US Navy nuclear submarines are the quietest nuclear submarines in the world would be seriously questioned by current generation Russian nuclear submarines, who have enjoyed at least a parity in noise levels with American submarines since the Victor III Class was introduced in the mid-1980's. Russian under-water detection technology is also very advanced.

Part of the problem with the American's is that their navy is so big and covers so many roles that a smaller professional navy can specialise more. Even the US Navy submarine service is huge by any standard. However US submarines have got the better of quieter diesel submarines when a commander operates outside the box.

[stormlion1]

I notice all of those sunk CV's have been killed by Diesel Subs. I guess it is true that Diesel boats are quieter than nuclear subs.

[dragoon500ly]

The diesel subs have an advantage when they are cruising on their batteries, one thats is counter-balanced by the noise of their diesels when they are recharging the same batteries. Due to the capacity of their batteries, the diesel subs have to creep up on their targets. If the can get into position in front of the carriers, then they can creep, maintaining steerage way and let the carrier come to them. Faster speeds, eats rapidly into battery endurance.

As for the nukes, their reactors are, for the most part, rely on pressurized water for cooling. The noise of these pumps are the most noticable part of their signature.

Towards the latter days of the Cold War, subs started covering their propellers with shrouds (to reduce the prop noise) or even replacing the props with pump jets in an effort to reduce their signature even more.

The diesel-eletric subs have more than proved their worth, in certain situations they have a superior advantage to a nuke. On the other hand, sooner or later, they have to approach the surface and recharge their batteries, and they are quite vulnerable during those times

[RN7]

The main advantages of a modern AIP and diesel-electric sub over nuclear subs is that they are quieter and cheaper.

Nuclear subs still dominate in submerged endurance, deep-ocean performance, speed and weapons load, but modern non-nuclear subs are stealthier and with the right equipment and tactics are more suited for operations in littoral waters with choke points, islands and shallow coastlines such as the North Sea, the Mediterranean and the Western Pacific.

A nuclear subs reactor must constantly pump coolant, generating some amount of detectable noise. Non-nuclear subs running on battery power or AIP can be virtually silent. New small, high-tech non-nuclear attack subs are highly effective in coastal operations and pose a significant threat to less-stealthy and less-maneuverable nuclear subs. Measures can and have been taken to reduce sound and magnetic signatures of nuclear subs, but the steam turbine still makes them naturally far more noisy than AIP subs. Nuclear subs are also generally larger making them more detectable through either acoustic, infrared or magnetic sensors. Nuclear subs also have to cool down nuclear reactors with hot water being dumped into ocean, leaving long trails behind the submarine which is detectable by IR sensors.

The older Los Angeles Class boats cost US $1 billion. The newer Virginia Class cost between US $1.8 to $2.5 billion, and Britain's Astute Class costs US$1.8 billion. A Swedish T-96 Class costs $100 million, while at the upper end a German Dolphin Class would cost US$ 500-870 million. American nuclear submarines also cost US $21 million a year to operate and US $200 million to refuel and modernise at their half-life cycle.

[Raellus]

Thanks for the info, RN7. I could have used this in my In Defense of the Red Army arguments.

http://forum.juhlin.com/showthread.phpt=897&highlight=Defense+Red+Army

At the height of the Cold War, the USN was no doubt the most powerful navy in the world, but it clearly wasn't the invincible juggernaut that we'd like to imagine. As these exercises clearly demonstrate, the USN was pretty conclusively not invincible and, at the very least, the Soviet Navy in its prime could have given it a seriously bloody nose or two. This is especially so if you add in the X-factor of command.

[RN7]

Thanks for the info, RN7. I could have used this in my In Defense of the Red Army arguments.

http://forum.juhlin.com/showthread.phpt=897&highlight=Defense+Red+Army

At the height of the Cold War, the USN was no doubt the most powerful navy in the world, but it clearly wasn't the invincible juggernaut that we'd like to imagine. As these exercises clearly demonstrate, the USN was pretty conclusively not invincible and, at the very least, the Soviet Navy in its prime could have given it a seriously bloody nose or two. This is especially so if you add in the X-factor of command.

I think it's difficult to judge how the Soviet Navy would have fared against the US Navy in wartime has it never happened. Unlike the US Navy the Soviets used a large number of conscripts in their navy, although maybe not so many in their submarine service which was likely to have been the elite of their navy.

Known and covered up fatal accidents aboard Soviet submarines points to reliability problems and sub-standard levels of training, but Soviet nuclear submarine technology was advanced enough to cause NATO some headaches. From the late 1970's the Soviets incorporated light and strong titanium hulls on their nuclear submarines, which enabled smaller size, greater diving depths, reduction in radiated noise and increase resistance to torpedo attacks. Victor III, Sierra and Alpha Class nuclear submarines were faster, more maneuverable and deeper diving than any American submarine up to the Los Angeles Class. The Alpha Class with a lead cooled fast reactor had a top speed of well over 40 knots and a claimed dive depth of 800 meters, which alarmed the US Navy enough to develop the ADCAP torpedo program and the Sea Lance missile programs projects, and the British to develop the high-speed Spearfish torpedo.

However the Soviet were clearly intimidated by US Navy air power and had a very healthy respect for NATO submarines. Their two main assets for eliminating US naval air power were nuclear submarines and bombers with long ranged anti-ship missiles as they knew they couldn't match the US Navy carrier fleet in numbers or capabilities. Their first proper carriers; the Kiev's, were basically hybrid-missile cruisers with an air arm heavily biased towards ASW operations. In fact all major Soviet surface warships seemed to be defensively orientated and almost top heavy with either air defence or ASW weapons. When the Soviet started reaching parity with America across a number of military areas in the 1970's a more offensive mind set seems to have taken hold in Soviet naval doctrine. The Kuznetsov Class emerged from the drawing board in this period as did the Kirov class battlecruiser anomaly, which seems to have been designed to bludgeon its way out into the north Atlantic and eliminate the NATO threat to its emerging carrier arm and nuclear missile submarines.

Results from exercises with NATO and Western aligned navies may be a bit unfair on the US Navy. Smaller NATO navies are very professional and they can specialise more and their smaller subs are better suited for littoral operations, while their equipment and tactics are very different to the Soviets. In regards to US nuclear subs versus AIP diesel subs, generally once the US sub commanders learns the tactics of opposing AIP subs the results are more in favour of the US submarines.