British & French nuke sub collision

[Grim901]

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?



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.

The British never claimed to have hit a container, the French thought that, and the theory of Vanguard being on the bottom could fit that theory.

Not entirely sure about whether they detected them afterwards, and I doubt the British will say if they did. It is official policy not to talk about stuff regarding the SSBNs.

 

[citizen578]

As mentioned previously, we'll never find out the true circumstances of this event. Like 99.99% of things to do with subs (especially bombers), the details will remain locked in a safe for decades.

However, there is zero chance of Vanguard being sat on the bottom. Sat just above the bottom, stationary - possible but unlikely. Low speed cruising is what these subs are designed for, it is where they are navigationally the most safe (yes, we can all laugh at that given what's just happened), and most importantly it is the condition under which their sensors work best. If the boat is stationary, it will not be able to deploy it's towed-array, it's most sensitive sonar system.

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.

That's a bit of a distortion, a foreign submarine must by law surface in another countries' territorial waters (12nm in most cases - the Yanks are famous for getting caught submerged in the Strait of Hormuz). It has nothing to do with the Isle of Arran. I've navigated up the Firth of Clyde multiple times, and can promise you that under most tidal conditions it's already on the cheeky side to navigate a V or even T boat past the shifting bars and other seabed features.

I can guarantee you that you have not been told 100% of the truth, you never will be. Subs have accidents far more often than you think, Govt's only ever release the information if they have no other option.
Second-guessing the operational procedures of bombers, and trying to visualise an event which only about 200 people will ever know the reality of will get you nowhere.

 

[Sea Toby]

You are correct, we will never know much about the silent service. The truth is the fact that when these ships travel very slowly, they are very quiet. So quiet, they don't hear one another even at close range, even on a collision course.

 

[Lofty_DBF]

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?

The sonar windows on submarines are made from fiberglass you can not kick it and smash it the only thing you will smash it your foot.
After all it has to be able to survive anything the ocean can produce.
Under the casing is all free flood area (when the submarine submerges the area fills up with sea water so it is a exactly the same pressure as diving depth).
The sail or Fin area on a submarine is external to the pressure hull aswel is all free flood area.
It is generally fiberglass construction and is where the submarines periscopes and other masts are located.

 

[Beatmaster]

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.

Yeah i did read up the post buddy about the flank speed thing i said "lets say for a moment they would colide headon at flank speed " so it was pure theoretical/cinical and yeah you are right about the mushroom it is almost impossible still the fact remains that the risks could be huge if 2 subs ram eachother.nfloorl:

 

[Beatmaster]

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.

If my memory serves me correct the vessel of my uncle was called the: Fairmount expedition see link

As far i know the original vessel has been put at the harbor to be turned into scrap metal because the damage was to mutch to repair.

I talked to my uncle he is now captain for 25 years and he said that collisions or near collisions happen even on open water.
It also seems that crashes between naval and commercial vessels happen mutch more often then we all see on the news or read in the news paper.
Most of the times its a near collision or just a small kiss between ships.
He also said that most of the times collisions are handled secret and the problems are solved by "Back door" means specially when it involves warships.

 

[Marc 1]

Yeah i did read up the post buddy about the flank speed thing i said "lets say for a moment they would colide headon at flank speed " so it was pure theoretical/cinical and yeah you are right about the mushroom it is almost impossible still the fact remains that the risks could be huge if 2 subs ram eachother.nfloorl:

I disagree that the risks of a nuclear explosion 'could be huge'. Nuclear warheads have been dropped from aircraft, crashed inside aircraft, survived fires, you name it. They do not go critical unless they are armed and the detonation sequence is initiated. Worst case scenario the reactor core would leak radioactivity for a while. Most likely would be that if the boats are so badly damaged that they could not surface after the collision, reactor would shut down and lie on the sea bed quietly rotting... It's happened before, that nuclear boats have been lost at sea, and unfortunately, it will happen again.

 

[Marc 1]

From my basic knowledge I know you have to be below a certain line ( I forgot the name of the line) for quiter operation but is there a certain depth according to the salinity of the water and other properties that it is perfect for quiet operations?

I think the word you are looking for is 'thermocline'?

 

[Beatmaster]

I disagree that the risks of a nuclear explosion 'could be huge'. Nuclear warheads have been dropped from aircraft, crashed inside aircraft, survived fires, you name it. They do not go critical unless they are armed and the detonation sequence is initiated. Worst case scenario the reactor core would leak radioactivity for a while. Most likely would be that if the boats are so badly damaged that they could not surface after the collision, reactor would shut down and lie on the sea bed quietly rotting... It's happened before, that nuclear boats have been lost at sea, and unfortunately, it will happen again.

Ok got it.....
But theoretic speaking what would be the wors case senario for a sub when they do collide?

Because i know first hand that if a sub get rammed that most of the times the damage will be huge.

 

[nevidimka]

I suspect, the British might have thought that they hit a Russian Submarine. So they left quietly from that place.

 

[Systems Adict]

I suspect, the British might have thought that they hit a Russian Submarine. So they left quietly from that place.

Ruskie sub ?

Pah !

How many ACTIVE vessels are the Russian navy fielding at the moment, including subs ??? (and by ACTIVE, I mean ships / boats that are out "on business", not ready to go (minus a crew), or tied up alongside).

Yes, it's a possibility that the subs (French & British) where in the area to "observe" the movements of the Russian carrier & it's support vessels , although the group was transiting further west, to sail around the Irish / UK coast, before they transited North (& given that i have just the tiniest bit of doubt in my comments, possibly even a single sub??), but that was a group of 4 ships (??).

Add that to the two other (x2) groups from Russia that are sailing (??), then maybe 12 vessels in total (including subs) are out of Russian national waters.

Another million to 1 chance that they would have hit each other, just like the 2 vessels this thread is discussing ??

Then again, if the Brits had hit a Russian sub & kept quiet about it, I think the Russian's would have sung out about it !

SA

 

[Marc 1]

Ok got it.....
But theoretic speaking what would be the wors case senario for a sub when they do collide?

Because i know first hand that if a sub get rammed that most of the times the damage will be huge.

You've been inside a sub that had been rammed?

I agree that the worst case scenario which would be for the reactor to go critical at the exact same time as all the MIRV warheads went off would make a bit of a dent in the ocean for a second or two...But as has been pointed out the odds of that are pretty damn slim.

There are plenty of worst case scenario's we could play - one of these bulk LNG tankers going up in the harbour of a major city would cause a blevi (spelling - don't know the acronym) that would be like a tac nuclear weapon going off, and tens or hundreds of thousands killed or injured but people don't run around panicking over that.

 

[localhost127]

I agree that the worst case scenario which would be for the reactor to go critical at the exact same time as all the MIRV warheads went off run around panicking over that.

pardon my lack of experience wrt fission reactors, but isn't the fuel in nuclear power-plants quite low yield (enrichment?); enough to be critical for continuous fission reaction, but not high-enough yield to sustain an explosion?

...or can someone inform me if LEU in a fission reactor (sustained reaction) could somehow create a nuclear explosion? i don't believe so, but open to the information.


edit: sorry about the tangent, but i know information on naval vessel reactors is quite non-existant, but could anyone provide any useful links on the subject, or whether land-based fission reactors (fuel-type, etc) are the same type/materials (enrichment grades) being used in naval based?

 

[Grim901]

pardon my lack of experience wrt fission reactors, but isn't the fuel in nuclear power-plants quite low yield (enrichment?); enough to be critical for continuous fission reaction, but not high-enough yield to sustain an explosion?

...or can someone inform me if LEU in a fission reactor (sustained reaction) could somehow create a nuclear explosion? i don't believe so, but open to the information.


edit: sorry about the tangent, but i know information on naval vessel reactors is quite non-existant, but could anyone provide any useful links on the subject, or whether land-based fission reactors (fuel-type, etc) are the same type/materials (enrichment grades) being used in naval based?

The Uranium used in Nuclear reactors is much less reactive. By that I mean that it is only about 5-7% Uranium-235 and the rest is mostly Uranium-238, which is useless in most reactors. However the main control mechanism to stop meltdown in the reactor is the control rods (boron). If they were entirely removed i'm unsure exactly what'd happen, it's never actually been done as far as i'm aware, but the chances are a meltdown would occur where the reactor, moderator and casing melt (happened at Chernobyl for a different reason) creating a kind of lava, and releasing the irradiated substances contained within the reactor. In the case of a nuclear subs reactor, e.g the PWR2, water is used as a coolant and moderator, and becomes highly irradiated, this would mix with the sea water if released and cause massive damage.

As to whether the reactor would explode is a different story, that'd depend on the amount and enrichment of uranium present and how the damage actually occurs, but I think it is highly unlikely for a modern design to do so in terms of a nuclear explosion.

 

[localhost127]

The Uranium used in Nuclear reactors is much less reactive. By that I mean that it is only about 5-7% Uranium-235 and the rest is mostly Uranium-238, which is useless in most reactors. However the main control mechanism to stop meltdown in the reactor is the control rods (boron). If they were entirely removed i'm unsure exactly what'd happen, it's never actually been done as far as i'm aware, but the chances are a meltdown would occur where the reactor, moderator and casing melt (happened at Chernobyl for a different reason) creating a kind of lava, and releasing the irradiated substances contained within the reactor. In the case of a nuclear subs reactor, e.g the PWR2, water is used as a coolant and moderator, and becomes highly irradiated, this would mix with the sea water if released and cause massive damage.

As to whether the reactor would explode is a different story, that'd depend on the amount and enrichment of uranium present and how the damage actually occurs, but I think it is highly unlikely for a modern design to do so in terms of a nuclear explosion.

those were my same thoughts, but was just looking for confirmation.

thanks,

 

[Beatmaster]

You've been inside a sub that had been rammed?

I agree that the worst case scenario which would be for the reactor to go critical at the exact same time as all the MIRV warheads went off would make a bit of a dent in the ocean for a second or two...But as has been pointed out the odds of that are pretty damn slim.

There are plenty of worst case scenario's we could play - one of these bulk LNG tankers going up in the harbour of a major city would cause a blevi (spelling - don't know the acronym) that would be like a tac nuclear weapon going off, and tens or hundreds of thousands killed or injured but people don't run around panicking over that.

No No No not in a sub but i have seen photo's from my uncle and have seen the damage my uncles ship is/was really huge on of the biggest lifting vessels ever build and the hull and left side of the bow got almost complete destroyed.
The huge impact and damage on both ships did cost no human lifes but the Fairmount expedition was to damaged, and they did sell it to a scrap metal company and the sub, did also sustain to mutch damage to repair but my uncle never found out what they did with it he only knows that the sub did have a really big crack and was making water because the hull of the Fairmount expedition did penetrate very deep into the sub before he actually did run over the sub.

Thats all i know about it, i could ask my uncle for photos's but i cannot promise that he will allow it.


Yeah lets hope a wors case senario never happens