British & French nuke sub collision

[OnYourSix]

Hi, I was hoping someone would be kind enough to help clear up an armchair admiral argument I'm having at the moment.

It started after reports of the 'bump' between the French and UK SSBN's were verified.

My ' friend ' was amazed that this could happen given the size of the operating area.

My counter was that the operating area wasn't as large as some might think, given that both boats are looking to achieve the same thing and would use missile range, geography,currents, thermals, avoidance of shipping lanes and fishing grounds, know Russian routes into the N. Altantic and other considerations when planning a patrol.

He is convinced I'm wrong as the D5 Trident has a range of over 11000km ( it's shorter when all 12 warheads are in place but START 2 reduced this to 4 I think and I've read that the UK only carry 3 warheads.) so these SSBN's could operate within most of the Altantic and be able to hit any target in Russia.

Does anyone know if this is the case or have a rough idea of their effective operating area?

Many thanks.

 

[Grim901]

Hi, I was hoping someone would be kind enough to help clear up an armchair admiral argument I'm having at the moment.

It started after reports of the 'bump' between the French and UK SSBN's were verified.

My ' friend ' was amazed that this could happen given the size of the operating area.

My counter was that the operating area wasn't as large as some might think, given that both boats are looking to achieve the same thing and would use missile range, geography,currents, thermals, avoidance of shipping lanes and fishing grounds, know Russian routes into the N. Altantic and other considerations when planning a patrol.

He is convinced I'm wrong as the D5 Trident has a range of over 11000km ( it's shorter when all 12 warheads are in place but START 2 reduced this to 4 I think and I've read that the UK only carry 3 warheads.) so these SSBN's could operate within most of the Altantic and be able to hit any target in Russia.

Does anyone know if this is the case or have a rough idea of their effective operating area?

Many thanks.

1. While the area used is not the whole Atlantic, actually a relatively small area, it is still pretty big odds against a collision.

2. Trident D5 does have a long range (about least 8000km with 8 warheads fitted), but of course, the further away you fire from, the more chance of detection. (note: the distance between Moscow and the mid Atlantic is between 4 - 5,000 km)

3. Trident D5's only have space for 8 warheads I thought but was limited to 4 by the SORT treaty, which actually doesn't apply to the UK (US/Russia treaty).

4. Side note: START II was about de-MIRVing land based ICBMs and again only applied to the US and Russia.

5. The main target is Moscow, as it is the only current nuclear threat to the UK but it is quite far west so is fairly easy to hit from the Atlantic, and no, Trident could not hit every part of Russia from anywhere in the Atlantic. Russia is over 5,000km wide at least and the Atlantic ocean is a few thousand wide too + Europe in between the 2.

6. I doubt anyone could give you a rough idea of the operating area, too many classified variables.

 

[KGB]

SSBNs don't track each other, they were both on routine patrol and just happened to both be in the same place at the same time.

No one did anything improper and it was all a remarkable coincidence? That's naturally what the governments would say. It's like saying that the dog ate your homework; it's not impossible but no one buys that excuse.

They're not supposed to track each other but what's to stop an aggressive commander from trying? Incentives: practice for the crew, bragging rights, perhaps even career advancement for tracking such an elusive target. Periscope shots of carriers and audio recordings of submarines are like the stuffed buffalo heads of big game hunters. There aren't many Russian boats for sub commanders to track anymore, and I imagine precious few opportunities for a SSBN commander to track anything given their mission profile. But hotdogging and taking risks for career advancement is not unheard of.

 

[Unicorn]

http://pix.motivatedphotos.com/2009/2/17/633704965676927570-hmsvanguard.jpg

 

[OnYourSix]

1. While the area used is not the whole Atlantic, actually a relatively small area, it is still pretty big odds against a collision.

2. Trident D5 does have a long range (about least 8000km with 8 warheads fitted), but of course, the further away you fire from, the more chance of detection. (note: the distance between Moscow and the mid Atlantic is between 4 - 5,000 km)

3. Trident D5's only have space for 8 warheads I thought but was limited to 4 by the SORT treaty, which actually doesn't apply to the UK (US/Russia treaty).

4. Side note: START II was about de-MIRVing land based ICBMs and again only applied to the US and Russia.

5. The main target is Moscow, as it is the only current nuclear threat to the UK but it is quite far west so is fairly easy to hit from the Atlantic, and no, Trident could not hit every part of Russia from anywhere in the Atlantic. Russia is over 5,000km wide at least and the Atlantic ocean is a few thousand wide too + Europe in between the 2.

6. I doubt anyone could give you a rough idea of the operating area, too many classified variables.

Thank you for your reply and putting me straight on a few facts.

 

[nevidimka]

http://www.spacewar.com/reports/Nuclear_subs_didnt_know_theyd_hit_each_other_999.html

http://www.spacewar.com/reports/French_navy_looking_at_damage_from_nuclear_sub_collision_999.html


But the Ouest France newspaper reported Thursday that in addition to the sonar dome, Le Triomphant also suffered damage to its conning tower and sail planes, and that repairs would take some time.

Now I know the French hit the British sub head on towards the belly of the british sub because it damaged its sonar. But how does the French sub damage its Tower ans sail if that is the case? The tower and its sail are behind the nose at the top.

Also if the French sub suffered major damage and the British just scrapes, does it mean the french sub is built less stronger to its British counterpart? they are only 2000 tonnes displacement different.

Also from the report, while the French went back to their port due to the damage, the British sub continued with its patrols! nfloorl:
When the news broke out, I thought both subs came up and then realised they have hit each other, not like this.

Btw I always like the look of the British Vanguard, with its peculiar horn shape for the sail section. Looks menacing out of the water, but has a ugly sonar dome and sail design. The french 1 looks typical though.

 

[FluffyThoughts]

I am surprised no-one has raised this before, so here goes....

Where were the escort SSNs? Surely one of the Trafalgars should have been on sentry with Vanguard...?

One hopeful ray-of-light for Her Majesty's Royal Navy: if no escort was available, then the argument that seven Astute subs are enough flies out-of-the-window. 'Ave-it, as some might say...! :

 

[Grim901]

http://www.spacewar.com/reports/Nuclear_subs_didnt_know_theyd_hit_each_other_999.html

http://www.spacewar.com/reports/French_navy_looking_at_damage_from_nuclear_sub_collision_999.html


But the Ouest France newspaper reported Thursday that in addition to the sonar dome, Le Triomphant also suffered damage to its conning tower and sail planes, and that repairs would take some time.

Now I know the French hit the British sub head on towards the belly of the british sub because it damaged its sonar. But how does the French sub damage its Tower ans sail if that is the case? The tower and its sail are behind the nose at the top.

Also if the French sub suffered major damage and the British just scrapes, does it mean the french sub is built less stronger to its British counterpart? they are only 2000 tonnes displacement different.

Also from the report, while the French went back to their port due to the damage, the British sub continued with its patrols! nfloorl:
When the news broke out, I thought both subs came up and then realised they have hit each other, not like this.

Btw I always like the look of the British Vanguard, with its peculiar horn shape for the sail section. Looks menacing out of the water, but has a ugly sonar dome and sail design. The french 1 looks typical though.

If something 2000 tonnes heavier than you hit you, you'd feel it.

The British sub is slightly newer and possibly more advanced than the French counterpart. Not sre about the French but at least some sections are British subs are hardened like American subs to break ice. It may also have had something to do with the nature of the collision, not an expert but aren't the sonar dome and sail more vulnerable and fragile?

@Fluffy: I hope they do realise 7 isn't enough, but this incident probably won't do it, politicians aren't very good at connecting dots. No mention of the escort though, must have been a little way off and unlikely to have seen the French either. They are on the look out for other Hunter killers, not other SSBN's.

 

[citizen578]

This is in danger of becoming a conspiracy theorists' merry-go-round.

A ~16000 tonne object does not stop in the instance something hits it, it's momentum would have caused damage beyond just the sonar dome. This is common sense.

Will we ever find out the full circumstances behind this? definitely not. I'm surprised the MoD even released a statement about it, very unusual.

Just get over it and stop speculating - it never ends.

 

[Uhu]

Now I know the French hit the British sub head on towards the belly of the british sub because it damaged its sonar. But how does the French sub damage its Tower ans sail if that is the case? The tower and its sail are behind the nose at the top.

This is actually what would happen to any submarine, doesn't matter wether it's a 500t Type 206 or a 45000t Typhoon: The collison forced the Le Triomphant down and the HMS Vanguard up and when the french sub passed below, it's sail struck HMS Vanguard's hull again.

Also if the French sub suffered major damage and the British just scrapes, does it mean the french sub is built less stronger to its British counterpart? they are only 2000 tonnes displacement different.

The sonar dome is the softest spot of any submarine. You might damage it with a strong kick I guess. The dome and sail of todays subs are outside the pressure hull and are pretty weak structures. The pressure hull on the other side is not. So the outcome would be exactly the same if it had happened with switched positions and courses.

I actually expect the interior damage of the HMS Vanguard to be greater than Le Triomphant ones, since subs are stiffer longitudinally than lateral. Maybe the British sub even have lost power (see below).

Also from the report, while the French went back to their port due to the damage, the British sub continued with its patrols!

HMS Vanguard did NOT continue its patrol. While all news agencies agree that Le Triomphant made it back on its own power, some wrote that HMS Vanguard had to be towed.

 

[ASFC]

HMS Vanguard did NOT continue its patrol. While all news agencies agree that Le Triomphant made it back on its own power, some wrote that HMS Vanguard had to be towed.

She wasn't towed home, she was helped up the clyde by her berthing tugs, which, incidently, happens with all Subs moving in and out of Faslane.

 

[Grim901]

She wasn't towed home, she was helped up the clyde by her berthing tugs, which, incidently, happens with all Subs moving in and out of Faslane.

You beat me to it. The rumour of being towed home came from the media and public's ignorance as to RN operating procedures.

I haen't seen a dae for when it arrived back in Faslane? Was it at the same time or later than Triomphant?

 

[Beatmaster]

Its acctually really a lucky thing ill guess, because in the middle of the ocean two sub collide thats has to be a one in a million thing.

Anyway if this is true or not, still think of the damage and risk lets say for a moment they would colide headon at flank speed than you will have 2 subs complete destroyed and probably a huge mushroom.

But one question really pops up, 2 ballistic subs both worth millions of dollars how is this possible that they can collide in the first place?
Because i assume for a moment that the onboard systems will alert the crew of close danger stealth or not there has to be at least a kinda sonar or any radiografic system that tells you that you are in very big trouble. ( Crashing into a sub seems to me a BIG problem)

Still sometimes a sub crashes a ship, a uncle of me is captain at a huge lifting vessel and he did have a crash a few years back with a sub that surfaced when he did run over it.
The damage on both ships was huge.

 

[Grim901]

Its acctually really a lucky thing ill guess, because in the middle of the ocean two sub collide thats has to be a one in a million thing.

Anyway if this is true or not, still think of the damage and risk lets say for a moment they would colide headon at flank speed than you will have 2 subs complete destroyed and probably a huge mushroom.

But one question really pops up, 2 ballistic subs both worth millions of dollars how is this possible that they can collide in the first place?
Because i assume for a moment that the onboard systems will alert the crew of close danger stealth or not there has to be at least a kinda sonar or any radiografic system that tells you that you are in very big trouble. ( Crashing into a sub seems to me a BIG problem)

Still sometimes a sub crashes a ship, a uncle of me is captain at a huge lifting vessel and he did have a crash a few years back with a sub that surfaced when he did run over it.
The damage on both ships was huge.

You need to read up through the posts in this thread and it'll answer how they collided. It's also unlikely for SSBNs to be doing things at flank speed.

I doubt there'd be a mushroom even if it did happen, the chance of the crash causing a nuclear explosion is almost impossible, a radioactive leak though is possible.

Usually when a sub and ship collide it's because someone wasn't paying attention. I read about an American sub a few years ago, the captain was showing off to some civvies, surfaced really quick and killed a bunch of Japanese kids on a tourist boat.

 

[nevidimka]

This is actually what would happen to any submarine, doesn't matter wether it's a 500t Type 206 or a 45000t Typhoon: The collison forced the Le Triomphant down and the HMS Vanguard up and when the french sub passed below, it's sail struck HMS Vanguard's hull again.

That was what I imagine happened when I was trying to make sense of it, but I discounted it because it would have been a massive collision, and the French sailors would have really felt like s**t in their bouncing sub. But again its surprising, that if the tower of the French sub hit the vanguard straight on, it would suggest a huge dent on the Vanguard.

The sonar dome is the softest spot of any submarine. You might damage it with a strong kick I guess. The dome and sail of todays subs are outside the pressure hull and are pretty weak structures. The pressure hull on the other side is not. So the outcome would be exactly the same if it had happened with switched positions and courses.

Is that true? different pressure strength for the Sonar and sail's. How does the sub then dive to crush depth? Wouldn't the Sonar section give way and the Sail's buckle?


1 more thing I'm curious of. They say they did not detect anything as they were going silent and both boats were stealthy, and that fine. But the moment they have that hugh impact, wouldn't the situation on both boats go haywire? Alarm ringing, people moving activity increasing? How come the sonar of both boats did not detect this heightened activity and realise another sub is there?

 

[Grim901]

That was what I imagine happened when I was trying to make sense of it, but I discounted it because it would have been a massive collision, and the French sailors would have really felt like s**t in their bouncing sub. But again its surprising, that if the tower of the French sub hit the vanguard straight on, it would suggest a huge dent on the Vanguard.



Is that true? different pressure strength for the Sonar and sail's. How does the sub then dive to crush depth? Wouldn't the Sonar section give way and the Sail's buckle?


1 more thing I'm curious of. They say they did not detect anything as they were going silent and both boats were stealthy, and that fine. But the moment they have that hugh impact, wouldn't the situation on both boats go haywire? Alarm ringing, people moving activity increasing? How come the sonar of both boats did not detect this heightened activity and realise another sub is there?

Remember the collision was very slow. To use an anology, think of two cars both reversing out of a parking space at the same time and scraping against each other, lots of superficial damage to soft areas and paintwork, but the drivers hardly get thrown out of their seats.

I'd also heard that the Sonar dome and sail were outside the main pressure hull and were weaker areas (mentioned in my above post). But I think that their pressure can be increased but it reduces sonar efficiency *not sure on that one though so don't take my word for it*.

If an SSBN becomes easy to detect when it goes "haywire" as you say, how the hell are they supposed to prepare to launch a nuke without being detected. Anyway to answer the question, the stuff that makes the sub quiet to sonar works for things inside the sub too, so sonar won't pick up much from inside either, you'd only get a bigger return if they decided to increase speed or fire missiles just in case - which as you will agree, is a completely ridiculous idea after a crash.

 

[localhost127]

That was what I imagine happened when I was
Is that true? different pressure strength for the Sonar and sail's. How does the sub then dive to crush depth? Wouldn't the Sonar section give way and the Sail's buckle?


1 more thing I'm curious of. They say they did not detect anything as they were going silent and both boats were stealthy, and that fine. But the moment they have that hugh impact, wouldn't the situation on both boats go haywire? Alarm ringing, people moving activity increasing? How come the sonar of both boats did not detect this heightened activity and realise another sub is there?

also interested in both of these questions if anyone can answer.

now, after things settle down and this matter appears to have actually happened, i have to ask ... why/how is it that the sun and the daily mail were the first to report of such an incident?

 

[Systems Adict]

Is that true? different pressure strength for the Sonar and sail's. How does the sub then dive to crush depth? Wouldn't the Sonar section give way and the Sail's buckle?

Yes...

The Sonar dome is outside the pressure hull of a sub. It's filled with sea water which is at the same pressure as that outside. It's usually made of a thinner material to allow sound waves to move through it, (as are the diving planes). If a sub went to crush depth & was crushed, the dome would be okay, but the pressure hull would buckle like an empty coke can being squished in your hand.

1 more thing I'm curious of. They say they did not detect anything as they were going silent and both boats were stealthy, and that fine. But the moment they have that hugh impact, wouldn't the situation on both boats go haywire? Alarm ringing, people moving activity increasing? How come the sonar of both boats did not detect this heightened activity and realise another sub is there?

After a bit of trawling the web & a few blogs we can confirm that the accident took place between the 3rd & 5th of Feb, in the Bay of Biscay...

http://www.dailymail.co.uk/news/wor...es-packed-nuclear-missiles-come-disaster.html

From the info I've picked up, it would appear that the British sub was sat on the bottom, silent. The French boat was in the process of submerging when it hit what it initially though was "a submerged shipping container". Having been more badly damaged it surfaced to check out all systems & as a precautionary measure. During this time, both boats would have went to damage control stations, but being silent on the bottom, it would have been easier for the British sub to identify the French boat.

The news only broke on Monday the 16th of Feb, & at that time the local Scottish TV news crew shot film at the boats' home base of Faslane, with HMS Vanguard in the background. As it's possible that they would have changed out the crew, it would have been more beneficial for the Govt to break the story to the media, prior to it being passed by word of mouth from the crew.

Finally...

To clarify some comments in earlier posts...

ALL submarines (no matter their nationality), must by law, surface & remain that way, once they leave the exercise areas South of the Isle of Arran, prior to entering the Firth of Clyde, for thier transit to Faslane / Coulport. They are then accompanied by a Police launch & an RN tender / support ship (NOT TOWED !).

This follows an incident in the 1980's when an RN sub dragged a fishing trawler to the bottom, when it snagged its nets.

 

[Padfoot]

Yes...

The Sonar dome is outside the pressure hull of a sub. It's filled with sea water which is at the same pressure as that outside. It's usually made of a thinner material to allow sound waves to move through it, (as are the diving planes). If a sub went to crush depth & was crushed, the dome would be okay, but the pressure hull would buckle like an empty coke can being squished in your hand.




After a bit of trawling the web & a few blogs we can confirm that the accident took place between the 3rd & 5th of Feb, in the Bay of Biscay...

http://www.dailymail.co.uk/news/wor...es-packed-nuclear-missiles-come-disaster.html

From the info I've picked up, it would appear that the British sub was sat on the bottom, silent. The French boat was in the process of submerging when it hit what it initially though was "a submerged shipping container". Having been more badly damaged it surfaced to check out all systems & as a precautionary measure. During this time, both boats would have went to damage control stations, but being silent on the bottom, it would have been easier for the British sub to identify the French boat.

The news only broke on Monday the 16th of Feb, & at that time the local Scottish TV news crew shot film at the boats' home base of Faslane, with HMS Vanguard in the background. As it's possible that they would have changed out the crew, it would have been more beneficial for the Govt to break the story to the media, prior to it being passed by word of mouth from the crew.

Finally...

To clarify some comments in earlier posts...

ALL submarines (no matter their nationality), must by law, surface & remain that way, once they leave the exercise areas South of the Isle of Arran, prior to entering the Firth of Clyde, for thier transit to Faslane / Coulport. They are then accompanied by a Police launch & an RN tender / support ship (NOT TOWED !).

This follows an incident in the 1980's when an RN sub dragged a fishing trawler to the bottom, when it snagged its nets.

It's possible that Vanguard did see the French boat, just never had time to get out of the way? Indeed, how could they avoid such a collision if they were just sitting there?

 

[nevidimka]

Yes...

The Sonar dome is outside the pressure hull of a sub. It's filled with sea water which is at the same pressure as that outside. It's usually made of a thinner material to allow sound waves to move through it, (as are the diving planes). If a sub went to crush depth & was crushed, the dome would be okay, but the pressure hull would buckle like an empty coke can being squished in your hand.

OK, based from what you say the sonar being designed to be in the same pressure as the outside, and the sail I believe doesn't have enough volume inside for it to be crushed. Can anyone else confirm this?

After a bit of trawling the web & a few blogs we can confirm that the accident took place between the 3rd & 5th of Feb, in the Bay of Biscay...

http://www.dailymail.co.uk/news/wor...es-packed-nuclear-missiles-come-disaster.html

From the info I've picked up, it would appear that the British sub was sat on the bottom, silent. The French boat was in the process of submerging when it hit what it initially though was "a submerged shipping container". Having been more badly damaged it surfaced to check out all systems & as a precautionary measure. During this time, both boats would have went to damage control stations, but being silent on the bottom, it would have been easier for the British sub to identify the French boat.

The news only broke on Monday the 16th of Feb, & at that time the local Scottish TV news crew shot film at the boats' home base of Faslane, with HMS Vanguard in the background. As it's possible that they would have changed out the crew, it would have been more beneficial for the Govt to break the story to the media, prior to it being passed by word of mouth from the crew.

Again that doesn't make sense. How does the French sub damage its Sail and Tower which is on top of the sub if the Vanguard is below it? I wouldn't expect that it did a somersault or role maneuver?


And IF the Vanguard was indeed static and below the french sub, they would certainly know that something that just hit them from above must be another sub, not a container. Plus once the French sub sonar dome,tower and sail are damaged, I doubt that it could even move away from that spot in its stealthy mode as its smooth outer surface design just went away. For sure the Brits with their claims of having some of the best sonar in the world would be able to detect a sub in that condition.

I suspect at least 1 party in the accident is letting us know less than what they really know.
Perhaps the Brits or even the french kept quiet about their discovery on the spot because they thought they might have hit a Russian submarine? The brits only decided to come out in public when the French came out with their story. Had the French never revealed anything, the Brits wouldn't have said a word too.