AHQ: Could a US 'Los Angeles' class SSN trail a British Vanguard class SSBN?

[Finbarr the Fair]

Simple question prompted by one of the numerous sub plots in a recent British TV drama. ( Vigil ) The overall plot has more holes in it than a colander but this is an intriguing side issue.

HMS Vigil is unable to detect the USN submarine even when the latter has fouled the net of a trawler and sunk it. The why of the stalking is still not fully explained, the how may revolve around a mix of crew incompetence or subtle sabotage of the passive sonar filtering software.

But, is it feasible in real life? Assuming competent crews and well maintained systems on both boats.

I suppose that anyone who really knows the answer cannot reveal it. But, what's the consensus of those interested in modern submarine warfare?

 

[Father Maryland]

Even if they couldn't its still possible that in the vastness of the ocean they could accidentally ram each other.

 

[Finbarr the Fair]

Even if they couldn't its still possible that in the vastness of the ocean they could accidentally ram each other.

Yes,

The drama has the US submarine trailing the British boat from shortly after it left Faslane. On orders from the Pentagon, or at least the navy CinC.

Or so we are led to believe.

 

[sparky42]

Even if they couldn't its still possible that in the vastness of the ocean they could accidentally ram each other.

As happened to the French and British SSBNs a few years back.

 

[gatordad699]

A 688 class is certainly capable of trailing a Vanguard class SSBN. They would probably have the frequency specs on file. NATO practices against itself all the time. That would make it much easier. (All boats/targets make noise. If you know the frequency range to look in, it makes it much easier to find and trail them.) Knowing their operating patterns would also be a big help. Crew skill and training is another item that factors in. Does the CO of the SSBN clear his baffles randomly or on a set schedule, does he go to PD or shoot trash at the same time each day? A Crazy Ivan (yes they’re real and really performed) is a great way to find a boat trailing you.
A side note. The net thing happened quite a bit to the 41 for Freedoms back when the US had boomers up north.

 

[Father Maryland]

As happened to the French and British SSBNs a few years back.

Hence the reference. Gotta be astounded at the odds that in all the vastness of the underwater world they actually managed to literally run into each other.

 

[McPherson]

Hence the reference. Gotta be astounded at the odds that in all the vastness of the underwater world they actually managed to literally run into each other.

Depends in context. Underwater topology channels submarine traffic into lanes. If two subs are in the same underwater canyon, the chances of collision are "very" good.

 

[steamboy]

There was several collisions and scrapes in the cold war where NATO subs door dinged with soviet subs they were trailing, they would get VERY close to them.

 

[Riain]

It might be possible if the LA class was waiting for the Vanguard just off the base, however just off SSBN bases are so wired for sound and covered with ASW forces so tightly and the SSBN sonar itself is so good that it's more likely the SSN gets detected, tracked and harassed. The LA class would be pinged with active sonar from ASW Helicopters, aircraft and surface ships so hard that the Vanguard would slip by in the commotion.

IIUC the British Government have nominated sonar as a national strategic capability, to be nurtured at any cost, so it's safe to say they're world class and not at any disadvantage with a USN SSN.

 

[gatordad699]

Depends in context. Underwater topology channels submarine traffic into lanes. If two subs are in the same underwater canyon, the chances of collision are "very" good.

The ocean is so deep that even at max depth boats don’t come close to the bottom. They also stay the heck away because they can’t use active sonar to “see” where they’re going and bottom charts are notorious for being wrong (San Francisco). A US boat would never ever try and move down an underwater canyon.
NATO boats are given “boxes” to operate in. There are not supposed to be any other boats in that “box” at one time.

It might be possible if the LA class was waiting for the Vanguard just off the base, however just off SSBN bases are so wired for sound and covered with ASW forces so tightly and the SSBN sonar itself is so good that it's more likely the SSN gets detected, tracked and harassed. The LA class would be pinged with active sonar from ASW Helicopters, aircraft and surface ships so hard that the Vanguard would slip by in the commotion.

IIUC the British Government have nominated sonar as a national strategic capability, to be nurtured at any cost, so it's safe to say they're world class and not at any disadvantage with a USN SSN.

In peacetime nobody has assets just waiting around. You try and schedule the timing so another SSBN or SSN can cover you, but if not available, there is no one else. Sub and target bases might not even be the same base. US SSBNs operate out of their own bases. A 688i would have to screw up to get detected by a Vanguard SSBN.
It is very possible to find a boomer in its operating area. You just have to know where that is.
Nobody has sonar as good as the US 688 with WAA, Seawolf, or Virginia. They all have WAA and amazing processing power to filter out background and biological.

There was several collisions and scrapes in the cold war where NATO subs door dinged with soviet subs they were trailing, they would get VERY close to them.

It’s not that the trailing boat was close to the other boat. When a boat turns, or slows, it takes time to figure that out on passive sonar. By the time it is figured out, it might be too late. Boats don’t slow very fast and using an astern bell would cause cavitation and give you away.

 

[steamboy]

I recall reading that in some cases NATO subs would sail along at close range under a Soviet sub, using camera/video's to get very detailed views of their hull form etc.

 

[gatordad699]

I recall reading that in some cases NATO subs would sail along at close range under a Soviet sub, using camera/video's to get very detailed views of their hull form etc.

Not touching that comment with a 10 foot periscope. Recommend “Blind Mans Bluff.”

Amazon.com

Great book.

 

[McPherson]

The ocean is so deep that even at max depth boats don’t come close to the bottom. They also stay the heck away because they can’t use active sonar to “see” where they’re going and bottom charts are notorious for being wrong (San Francisco). A US boat would never ever try and move down an underwater canyon.
NATO boats are given “boxes” to operate in. There are not supposed to be any other boats in that “box” at one time.

Not going to speculate. Hypotherical thought experiment. Suppose we look at the eastern Atlantic undersea topology?

Old Maps, Expeditions and Explorations: RUSSIAN SCIENTIST ...

Interesting topology there...

 

[Father Maryland]

The ocean is so deep that even at max depth boats don’t come close to the bottom. They also stay the heck away because they can’t use active sonar to “see” where they’re going and bottom charts are notorious for being wrong (San Francisco). A US boat would never ever try and move down an underwater canyon.
NATO boats are given “boxes” to operate in. There are not supposed to be any other boats in that “box” at one time.



In peacetime nobody has assets just waiting around. You try and schedule the timing so another SSBN or SSN can cover you, but if not available, there is no one else. Sub and target bases might not even be the same base. US SSBNs operate out of their own bases. A 688i would have to screw up to get detected by a Vanguard SSBN.
It is very possible to find a boomer in its operating area. You just have to know where that is.
Nobody has sonar as good as the US 688 with WAA, Seawolf, or Virginia. They all have WAA and amazing processing power to filter out background and biological.

It’s not that the trailing boat was close to the other boat. When a boat turns, or slows, it takes time to figure that out on passive sonar. By the time it is figured out, it might be too late. Boats don’t slow very fast and using an astern bell would cause cavitation and give you away.

My favorite has always been the Seawolf. Even today arguably the single most lethal attack sub in any fleet in the world ( And the Jimmy Carter has some very interesting capabilities none of us will ever really know about). Of course that came at the cost of being super expensive especially in the 90s Post Cold War world. I suppose its what attack subs are to what Typhoon class SSBNs. Fucking awesome but too expensive for its own good.

Of course I dream of a Seawolf that was intended to be a little more multi mission and a little larger to accommodate say 12 VLS tubes sames as the later LA class boats. 8 660mm torpedo tubes packing a mix of 50 torpedos, harpoons, tomahawks, mines, or more exotic toys and 12 VLS tubes for Tomahawks and maybe that Subroc replacement that never made it. All in a beautiful atomic powered work of art capable of 35 knots flat out.

 

[DougM]

The problem with this question is that the correct truthful answer is very few people on Earth know the answer. And those few (assuming the exist at all) can’t tell you.
688s are still extremely classified. When I was young and considering entering the navy the recruiter wanted my to try for subs (even though I was frankly to tall) because my tests were good but just the basic info packet on the background checks and restrictions and whatnot was enough to be scary. And I know a few ex Silent Service types both Fast Attack and Boomers and they were the The most vague pepole you could image. It was funny with the trying to one up each other but actually being able to say anything. They were obviously talking between the lines…

You also have the issues that Fast Attack vs Boomer with each side supporting the home team and then the US vs GB bit on top of that and getting an unbiased opinion from anyone that has a chance of truly knowing…. well if you get a correct answer he (other then by accident) then you should have used that lucky roll to buy a lotto ticket.

That being said… In THEROY based on what so called reliable sources say. A 688 should be able to trail her as long as the 688 doesn’t screw up and make the approach correctly. But this is no sure thing. But you could easily make the argument the other way.
To complicate things you have the “i Know you know”. But you don’t know that I know that you know that I know.. but I know that you know that I know that you know that I know. Argument. Because even if someone has been in a boot that did this the argument could be made that the Boomer let the Attack boat think it was not detected or that the Attack boat intentionally let the boomer detect it because it wanted to make folks think it is noisier then it really is.

There used to be a story (that I truly don’t believe) about a class of subs that had a strange gear system in its drive line that could be switched out. The gears in question supposedly had a bit of a noise to them (but not much) the concept (as the story goes) was that the gear was there to make the other side think that A) the class was noisier then it really was and B) to make the others think they had the correct acoustic signal on the class. Then in theory when it truly truly mattered the gear could be pulled or switched out or whatever and suddenly the sub would be a lot quieter and with a drastic ly different signature. And while I TRULLY doubt this story as I have heard it as being a US class a Russian boat and an English class. So I doubt it but… this is the kind of thing that a navy might do with its subs. So you cant tell if the other side is playing its A game or not. After all durring peace time does it really matter? But if just before all he’ll breaks lose you subs suddenly vanish the other side is going yo be in a world of hurt.

So good luck with this post.

 

[gatordad699]

The problem with this question is that the correct truthful answer is very few people on Earth know the answer. And those few (assuming the exist at all) can’t tell you.
688s are still extremely classified. When I was young and considering entering the navy the recruiter wanted my to try for subs (even though I was frankly to tall) because my tests were good but just the basic info packet on the background checks and restrictions and whatnot was enough to be scary. And I know a few ex Silent Service types both Fast Attack and Boomers and they were the The most vague pepole you could image. It was funny with the trying to one up each other but actually being able to say anything. They were obviously talking between the lines…

You also have the issues that Fast Attack vs Boomer with each side supporting the home team and then the US vs GB bit on top of that and getting an unbiased opinion from anyone that has a chance of truly knowing…. well if you get a correct answer he (other then by accident) then you should have used that lucky roll to buy a lotto ticket.

That being said… In THEROY based on what so called reliable sources say. A 688 should be able to trail her as long as the 688 doesn’t screw up and make the approach correctly. But this is no sure thing. But you could easily make the argument the other way.
To complicate things you have the “i Know you know”. But you don’t know that I know that you know that I know.. but I know that you know that I know that you know that I know. Argument. Because even if someone has been in a boot that did this the argument could be made that the Boomer let the Attack boat think it was not detected or that the Attack boat intentionally let the boomer detect it because it wanted to make folks think it is noisier then it really is.

There used to be a story (that I truly don’t believe) about a class of subs that had a strange gear system in its drive line that could be switched out. The gears in question supposedly had a bit of a noise to them (but not much) the concept (as the story goes) was that the gear was there to make the other side think that A) the class was noisier then it really was and B) to make the others think they had the correct acoustic signal on the class. Then in theory when it truly truly mattered the gear could be pulled or switched out or whatever and suddenly the sub would be a lot quieter and with a drastic ly different signature. And while I TRULLY doubt this story as I have heard it as being a US class a Russian boat and an English class. So I doubt it but… this is the kind of thing that a navy might do with its subs. So you cant tell if the other side is playing its A game or not. After all durring peace time does it really matter? But if just before all he’ll breaks lose you subs suddenly vanish the other side is going yo be in a world of hurt.

So good luck with this post.

What I tried to say in my first post on this thread. It is very possible, it is also not possible. Depends on many different factors.
It is also true that when me and my friends talk about being on fast boats, we can’t/don’t talk about what other boats did.
UK submariners are great highly trained professionals. Just don’t ever try to out drink them.
You probably weren’t too tall. You would have developed a permanent stoop, learned to sleep on your side with your knees sticking out of your rack, and had a red mark in your forehead from banging your head into crap. Other then that it would have been great.
All your friends did was conduct oceanographic research and the ability to stay deployed for long periods of time.

 

[DougM]

I am 6-5 it would not have been fun. I walked/crawled through a WW2 boat once. That was interesting.
Also frankly there was no way I was going into sub service. Just not happening…. Then they changed recruiters and the new guy was an ass and I decided it wasn’t for me. at all. At the time the Navy had started to allow certain privlages when entering based on scores if you scored high enough you could select certain paths and depending on the specialty you could chose different number of years and a bunch of stuff and the new recruiter was some fossil that still believed in the you get one choice to enter or not and would only accept you as a gern Eric enlistment as if you had all but flunked your tests. I probably should have gone to a different center and bitched but I figured this idiot was an example of the crap I would run into so I said no thanks…. And walked away. Never understand how that idiot became a recruiter with his attitude, That was definitely the biggest potential POD for my life.
As for my co workers it was really funny listening to them try and one up each other but not being able to actually say anything. Very strange conversations.
They we’re both computer geeks by profession. And I never did figure out what they did on the subs other then be on them.

 

[Sanderford]

I expect it could happen, but more and more these days the question should be could a Virginia-class do the same thing? Because they are slowly but surely replacing the old 688 boats as the backbone of the fleet, as well as likely soon replacing the Seawolf trio which was originally intended to replace the 688 boats. Already there are nineteen SSN-774 units active, and more under construction or planned for future work.

Having said that and speaking as a layman nerd, I do believe a Los Angeles-class submarine could successfully track a Royal Navy missile submarine. Now, if the U.S. boat fowled a fishing trawler's net and sank it, and then a Royal Navy attack boat could not find her? That would likely be cause for the Admiralty to review that SSN's skipper and officers.

 

[PMN1]

Simple question prompted by one of the numerous sub plots in a recent British TV drama. ( Vigil ) The overall plot has more holes in it than a colander but this is an intriguing side issue.

HMS Vigil is unable to detect the USN submarine even when the latter has fouled the net of a trawler and sunk it. The why of the stalking is still not fully explained, the how may revolve around a mix of crew incompetence or subtle sabotage of the passive sonar filtering software.

But, is it feasible in real life? Assuming competent crews and well maintained systems on both boats.

I suppose that anyone who really knows the answer cannot reveal it. But, what's the consensus of those interested in modern submarine warfare?

Well if Vigil couldn't hear that bloody great tanker that nearly ran it down in Ep2 and didn't pick up whatever snagged the comms cable in Ep4 it does suggest something wrong with the sonar......of course, it could just be plot.

 

[sparky42]

Well if Vigil couldn't hear that bloody great tanker that nearly ran it down in Ep2 it does suggest something wrong with the sonar......of course, it could just be plot.

From the show that accidentally promoted someone in the middle of a scene from what I’ve seen online…