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

[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]

Originally Posted by 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.

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]

Originally Posted by 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.

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 Scorpène-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]

Originally Posted by Canadian Army

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