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Bloke down the pub

I haven’t heard anything recently about the RN’s operation of an MSubs Manta LUUV or the possible interest in its big brother , the Moray. If the trials process has been a success, the need for secure communications may well soon become pressing.

stephen ball

This is interesting with NASA with Europa. Mean the moon btw.

Last edited 2 years ago by stephen ball
stephen ball
Supportive Bloke


Thanks for posting that link: it is very interesting listening to the thought processes.

A lot of posters on here would do well to watch it as it does explode a few tropes that come up on here and UKDJ regularly.


It seems to me there are some inherent limitations with underwater communication that will be impossible to overcome, as such AUV will never reach the functionality and utility we see with e.g. UAV.

The solutions with reasonable bandwidth (optical, magnetic) don’t have useful range, might as well just use a cable tether for a few tens of meters, and that distance isn’t very useful anyway.

Acoustic systems can achieve more useful range but bandwidth is inherently limited by the low frequency of the carrier. I suspect that the answer here may be to use a very simple symbol language with standardised word definitions. Almost back to the days of semaphore.

stephen ball

You could learn in cave’s for the system.

stephen ball

Sorry for going off topic, thinking space exploring, Just think if a mar’s rover found a cave.

Supportive Bloke

It needs a different thought process.

So the more pertinent question is “what is the minimum amount of data that I need”.

The “I need everything” approach on a UAV is not possible.

What is “enough to do a really good job”.

Sometimes the key is elegant simplicity.


Yep, that was exactly the kind of thing I was getting at.

Something like a pre-defined list of commands and feedbacks, each represented by a single symbol so you don’t need to transmit the whole thing.

Glass Half Full

AUVs aren’t limited to underwater communications only though.

For example, an AUV might deploy a tethered flat floating AESA antenna to the surface for comms to LEO satellites and/or a mesh network of Poseidon, Protector and any other air based comms node we might deploy. The floating antenna might operate similarly to a SpaceX Starlink satellite, with AESA technology offsetting the sea movement of the antenna and orbiting movement of the satellites or aircraft to retain lock. A flat antenna would probably be more difficult to pick up with radar, assuming one is in the area, versus say a vertical antenna or periscope.

Or a much simpler solution. A persistently patrolling surveillance AUV, such as a sea glider, might have an ability to deploy a disposable comms bouy to the surface, similar to a PLB, that would shout “I’ve found a sub”, enabling surface or air based platforms to deploy to the area to find and prosecute an attack.

In other words underwater comms would be complementary to overwater comms. and used for different purposes.


Or just have a picket line of ‘ocean surveillance’ vessels backed up MPA, UAV, ships, and boats, sorry, submarines.
comment image

Glass Half Full

Certainly an option in some circumstances but the question would be where to put a picket line. Deploying AUVs means instead of just focusing on GIUK gap we might deploy further afield for patrols in the North Sea, Norwegian Sea, or even Barents Sea and Greenland Sea as examples. Having AUVs provide such surveillance in depth (pun intended) enables us to more efficiently direct manned sub-surface, surface and air assets to counter.


Same with an AUV where do you put it?

And then you have issues of command and control, maintenance, and so on.

This is another instance I think where many here think something the size of torpedo will be just launched and do all manner of work. We are decades off that. The task at hand is under estimated in terms of complexity and scale. And the ability of the hardware is over estimated both in terms of resilience and capability.

Glass Half Full

AUVs can be deployed from home waters through to regions where deploying a surface craft would be untenable in conflict, such as the Barents Sea. If instead a surface asset is used then it better be in a safe region or protected from air, surface or sub-surface attack, especially if its actively pinging. Deploying such a system in the Norwegian Sea, let alone the Barents Sea, during a conflict, would be asking for trouble without then requiring escorts for protection, which we won’t have in enough numbers for this role.

Why is command and control such a problem? Why is maintenance on AUVs a special case?

Some may think we just launch something like a torpedo but then perhaps they aren’t paying attention. The article linked above, on the RN evaluating autonomous operation with Manta, shows plans for a high end XLUUV platform. The USN is currently establishing CONOPS for their Orca XLUUV platform. We are going to need these platforms for autonomous range/endurance.

You keep pushing back in general against autonomous unmanned platforms in your comments. I agree that we do have to be realistic about the rate at which we can develop and deploy, along with the level of capabilities we should expect and when from different platforms. However, to state that it will take decades to achieve operational use of such platforms is not accurate. The commercial industry has been developing and implementing autonomous solutions for decades already, we’re not just starting out on this capability. The military world has been following along, typically with MCM operations being the lead application for AUVs. These have been mostly limited range solutions. The development of lithium ion battery technology and its subsequent reduction in cost is enabling far greater range/endurance for larger more capable platforms.


I think the basic point is that while there is definitely potential for autonomous underwater systems to add useful additional capability, based on today’s technology it’s clearly not viable as a replacement for manned vessels. That will require significant, and very challenging, technological breakthroughs.

So we need to be careful not to be seduced by the (unproven) potential of what is essentially vapourware, as this can lead to poor decisions and investments as we have seen before elsewhere. Once solutions are proven, then more appropriate decisions can be made.

Just my opinion!

Glass Half full

Perhaps its worth considering what the manned platform is doing? If it is maintaining a slow patrol using passive sonar, and the only action upon detection of a submarine is to report back that it has done so, then why would this need a manned platform?

If on the other hand we expect an AUV to operate as a hunter killer, armed with torpedoes and cruise missiles, then that is an entirely different level of capability. I would agree that we are probably a long way from being comfortable with that level of autonomy.

Classifying what has been achieved so far as vapourware seems a rather negative take. I posted on Kongsberg’s HUGIN Endurance in response to X below, which is leveraging the previous platforms and 3 decades of development.


In response to para 1 above, ‘then why would this need a manned platform’? The answer is to firstly locate the SM, then to track it whilst remaining undetected yourself.
Two important factors come into play when hunting other SMs;
Firstly, it is notoriously difficult to actually go out and find a SM, a lot of assets come together to get your SM into position, then it’s down to a combination of skill and a small dose of luck occasionally. Detection ranges have reduced significantly over the decades, due to lots of reasons, a SM with all its large sophisticated sonar senors can have difficulty in detecting a SM. I wonder how people believe a AUV with less then a 20th of the SMs capability is going to be able to detect one?
Secondly, any AUV is largely a smaller less capable unmanned version of a SSK. A SSK cannot track a transmitting SSN for any length of time, it hasn’t got the capability, a smaller version will have even less capability in this respect.
AUVs will be able to do many things, but detecting and tracking SMs, never mind arming them, is not one of them, nor will it be for the foreseeable.

Glass Half full

Hi Deep. I think that’s why the USN is working on CONOPS with its ORCA program, because using an AUV won’t be the same as using a manned platform for hunting SMs. For example we shouldn’t expect an AUV to track an SM, its role would more probably be to just report a contact for other more capable air, surface and sub-surface assets (that can track) to be vectored in to try to pick up the contact using active sonobouys. The value of AUVs is that we can produce and deploy many more of them for surveillance than we could AIP SSK, let alone SSN, so they can provide a much broader coverage.

Having two SSBNs collide probably tells us that it can be very difficult to detect SMs that don’t want to be found, especially when they travel at very slow speeds.

I’m curious as to why you believe an AUV would necessarily have a 20th of the SMs capability to detect? The AUV is likely to be a 30m class vessel, about half the length of Type 212/214 or Gotland-class SMs. It won’t of course need any space or support systems for personnel and won’t be armed, so it would seem to have plenty of space for sensors and batteries.

I get the scepticism, especially from those with experience, but the major western navies are pursuing this path. Surely we credit some still serving in their respective navies as knowing what you do? They are probably pursuing this precisely because they know how hard it will be to detect Russian and Chinese SMs with the numbers of SSNs and AIP SSKs we have.


I think you are right that AUV have potential as a force multiplier. Essentially as lower cost intel assets, used to make better targeted use, of the much more expensive, and therefore less numerous, manned assets. Like a mobile SOSUS if you like.

And on the submarine gap, between NATO and Russia/China, it’s worth asking the question if it’s wise to get into a new arms race. Not to say we couldn’t use a few more SSN, but the old cold war standoff doesn’t really apply today.

Both Russia and China have a mutual dependence with the west, so they don’t really want to start a war. But we do need to keep tabs just in case. The bigger concern at the moment IMO is the proliferation of submarines in smaller, less stable countries.

So if AUV can be utilised to take on some of the routine surveillance (i.e. keeping tabs on Russia/China) that potentially frees up the more expensive assets to tackle and deter the more immediate threats.

Just some thoughts.

Glass Half Full

IIRC I might have even used the term “mobile SOSUS” in the past, so I do like 😉

I agree an arms race is not smart, particularly because just across European NATO members (i.e. excluding the US) we have air forces and navies comparable, if not superior, in numbers and capabilities to Russia in most respects that matter and are addressing areas where that might not be the case. Across Europe these forces are being modernized too.

I also agree wrt to Russia’s and China’s wish to avoid conflict with the West. What’s important is to have credible deterrence to hopefully prevent any unwise adventures on their part, particularly because we cannot be certain who might succeed Putin or Xi, either of whom is only a terminal illness away from upending any understanding we may have about the respective countries leadership. Hopefully deterrence also works against actions on their weaker neighbours too.


Hi GHF, AUV development will continue at a pace over the next decades, and they will undoubtedly become more effective in what they can do. However, the incident with the 2 SSBNs should tell us all we need to know about potential detection ranges of SMs. Given that both units have large sensor suites, indeed the bow array on a UK SM weighs north of 20 tonnes, and the flank array not far behind. Together they contain thousands of hydrophones and have a very capable TA system. Any AUV will have a considerably smaller sensor suite, including a smaller slimline TA, and in this game, size matters.
Most of the space in the AUV will be taken up be the propulsion system. Lithium batteries are a must, but any system will probably also include a combination of either a small DE engine and/or an AIP system, or you won’t get the endurance out of a battery only system.
C&C and Comms are all well known issues that will impact on the capabilities of any AUV in this environment.
We are pushing this technology hard, but are light years behind what we can do in the air domain. What we would like them to do and what they can currently deliver are polar opposites despite what is being advertised.
If two SMs with state of the art sensor systems can’t detect each other until literally the last few seconds, then what chance a smaller less capable system? A transmitting SM typically 10-15 kts will emit more noise, so, the probability of detecting it will increase, however, the range is still not great, even less for a AUV.


That should say transitting and not transmitting!!

Glass Half Full

Good points Deep, I appreciate your detailed response.

Your observations regarding the two SSBNs and the low transit noise even at 10-15 kts, seem to support a view that we could double our SSNs, but still have a problem being in the right place at the right time to use them to passively detect other SMs, even when working in concert with allies? The exception being if we are using our SSN to defend an asset or area, where the adversary has to come to us, or where there is a choke point.

If we are patrolling large regions of seas then it seems that it becomes a numbers game, in combination with an AUV having different CONOPS to manned platforms.

A basic AUV for the role already exists in the form of Boeing’s Echo Voyager evaluation platform that as you suggest uses hybrid propulsion, albeit with relatively short range battery only ops. Boeing’s Orca is leveraging this platform to improve performance, endurance, reliability and reduce risk. It is interesting that Japan has removed the Stirling AIP from its last two Sōryū-class SMs and replaced with additional Li-ion, so we may see a battery-only platform with only emergency diesel backup evolve for AUV. The Orca costs ~$55M on an order for five, but probably excludes the necessary sensor suite for ASW. It is however an order of cost lower than a modern AIP SM and doesn’t have the personnel or operational cost issues of a manned platform. So the trends in XLUUV costs would seem to enable the higher numbers we need.

The key to AUVs though is how we use them. We might for example use them to deploy expendable and/or attritable drones to create a multi-static sonar system, either wholly passive or including active sonar on the drones. Using active sonar from expendable or attritable platforms might reduce the cost, size, weight and power requirements for state of the art passive sonar arrays on the XLUUV.

NATO appear to have been evaluating using AUVs for multi-static ASW sonar solutions for over a decade now, per paper linked below which may be of interest if you’re not already familiar with it.


Evening @GHF, tavm for the link. Yes, am familiar with multi-static sonar, it was the next ‘big thing’ in ASW ops back in the late 90’s early 00’s, especially with the US and Canadian navies. Not sure why, but by the mid/late 00’s seemed to fizzle out and tbh that was the last we heard of it. The link you sent was new to me, perhaps the next step after what the US/CAN achieved?

Yes the detection ranges of a modern SM are an issue, but, certainly in the NA, the issue of a OOA deployer is handled differently. We track a unit from when it leaves port, and the aim being to follow it, utilising a great many assets (SM, MPA, WS, Helos and Sosus) as required to keep tabs on it(this is how we ensure CASD remains safe – not by sending a SSN to ride shotgun as many would believe!!)
It gets interesting when/if we lose contact with the unit, or if more then one unit comes out and turns left at the top of Norway. We’re pretty good at this, having had some 50 yrs practising it. The Pacific, now that’s a different ball game entirely, vast distances, few assets to utilise.
In the cold war the US had several T-Agos ships working in both oceans doing a lot of the sanitising/hunting and queing in Nato assets. It is a capability that we need, as we are very short of SSN numbers across NATO. A working solution with AUV’s would be highly desirable and probably couldn’t come soon enough, as a combination of what is currently available is very expensive as you know.

I’ve seen the information regarding what the Japanese are doing with switching from AIP to greater battery capacity on their SSK’s using Li-ion technology. They seem to believe there is more to be gained from going this route despite the extra expense – believe the difference in SM build cost between AIP and Li-ion only Soryu is some $150 million per hull. Obviously don’t know how much of that was for the extra battery capacity(believe they have doubled the number of battery cells)? Of course, the advantage they have is that the SM has several large Diesel engines capable of rapidly charging the batteries, and people to monitor the results.

I don’t doubt that AUV’s/XLUUV’s will become more essential to the way we operate at sea, eventually. The sceptic in me has to agree with @X on this, it will be a while yet until they have the technology to replicate what drones are doing in the air domain.

Glass Half Full

Evening Deep. Thanks for your thoughts. BTW I didn’t mean to suggest that multi-static sonar might be new to you, it was its combination with AUVs in experimentation a decade ago that I thought was interesting. Mostly because I agree its likely to take decades to develop such capabilities as X had suggested, but that NATO have already been working on this for well over a decade already, so we’re not just starting the clock now.

Perhaps part of the RN drive behind AUVs is a working assumption that detecting and tracking from when a SM leaves port is unlikely to be viable with modern SMs for the reasons we’ve discussed. Not just due to our/NATO SSN numbers but also because we may not be able to passively detect them with the level of confidence/success we need.

Perhaps our planned cable surveillance ship will have a tail.


I don’t think we are fundamentally in disagreement here. Just for clarification, I wasn’t talking about any existing systems being vapourware, just the fact we need to be realistic, about what’s reasonably possible, in the foreseeable future. Hope that makes sense.


I push back in my comments because I know how these systems plug together and how reliable defence systems are in general.

Do you think a crew of submarine does nothing? Yet you think a robot can just do the same now? It will take decades. How far are we along the path of say F35 as an instance. How many decades there?

Unmanned doesn’t no manning. Unmanned doesn’t mean smaller. Unmanned doesn’t cheaper. Are these systems getting cheaper or easier to maintain or less complex? No, no, and no.


IMO the bigger issue (besides cost) is in regard to RoE – there is the very fundamental ethical question of man-in-the-loop i.e. the human(s) making the final decision to engage. This is the true value of crewed platforms.

No mater how advanced it becomes, AI can never solve this problem, because it’s an ethical issue, not a technical one. And without effective, real time coms, there can be no man-in-the-loop, for remote weapons systems.

So IMO, autonomous underwater capability, will necessarily be limited, to non offensive capability (i.e. sensors and detection) for the foreseeable future.

Which doesn’t replace SSN, and other maned platforms, which (when RoE permits, and circumstances dictate) are able to engage near instantaneously. And just as importantly, are able to choose not to engage.

Last edited 2 years ago by Ben Robins
Glass Half full

Where did I write anything about replacing all the functions of a manned submarine? I didn’t. The primary role of large AUVs is going to be surveillance, listening for submarines and probably other AUVs in due course.

By all means push back, but companies like Kongsberg (along with the Norwegian Navy) have been developing and deploying AUVs for decades. We are now at the point where the HUGIN Endurance, a 10m AUV, has a 1200nm mission range, capable of uninterrupted shore-to-shore operations, deployable from pier side, for up to 15 days mission duration. While impressive, the sensor package and associated power required for anti-submarine use would probably reduce this range/endurance. Which is probably why the RN is defining a requirement for a 30m class vessel with a 3000nm range and up to 3 months on patrol once there.

While HUGIN Endurance is undoubtedly targeting the commercial market, it is also for defence – “For defence applications, HUGIN Endurance makes persistence a reality. Whether it is long range military survey; wide area mine detection, classification and identification; or even patrolling a choke point listening for submarines, this new extended range capability offers new solutions to existing and future challenges.”


I know you are underestimating the difficulty of the problem. And if you think anything in the next 2 decades we can put in the sea can replace a manned platform you are talking about replacing all functions. Submarines spend 99.99999999999999999999% of their time doing ‘surveillance’. Have we or have we not been promised all sorts from defence companies over the decades? Go look at the endurance of 20m submarine, the minimum hull size for you want, and then think about all the tasks a crew does at sea, they are not there for a ride, think about all the redundancy you would need, never mind a leap in AI and automation in other systems and get back to me. Or play defence Top Trumps and fantasy fleets.

Glass Half Full

Ahhh the all knowing X 😉 I seem to recall you were totally dismissive of the RN’s MCM solution too. You seem to think its all about me and what I think. Its not. Perhaps … just perhaps there are people in the world, maybe even in the RN and MOD, that know a bit more than you do. You seem to be ignoring the Kongsberg solution I posted. Presumably they don’t know anything either.

And then in typical X form, throw in a disparaging and/or patronising remark at the end, as with so many of your comments. A number of knowledgeable ex-RN people post here and manage to do so without that, you might learn from them. I thought you might be worth exchanging comments with, apparently not.


So frustrating that we can’t use quantum entanglement for communication, there’d be no range problems there.


Ask Dynamo the slight of hand guy. Id like to think you offered that that concept from a position of knowledge, but I fear the worst


If we could harness spooky physics, then yes you could have instant communication over any distance as that’s what entangled particles do. we can’t now, but never say never as in the last 20 years we have really started to use communication systems based around quantum mechanics.

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James Charles Thomas

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