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Chris Squire

Why did the Russians surface?


Submarines spend a lot of time on the roof in transit as it is safer.


Slightly off topic, I see 1SL is in discussion with AU’s about the possibility of forward basing an Astute out of Perth.
I wonder if they will use the Gulf T23 model and keep one out there for 2-3 years at a time using two rotating crews. Trying to generate an extra crew for that role might prove some what challenging too!


Submarine manning is a problem. Can Astute operate on 3 for 1 basis as we will only have 7 boats? And so yes your comment is relevant because Russian submarine problem needs to be managed and the best platform for that is another submarine. Submarines may have had the biggest slice of the naval vote but it obvious we don’t have enough of them.


how can we, as much as it maybe desired ?


Basically needs must!
Rightly or wrongly Boza has committed us to the AUKUS pact partly in response to aid AUS with its pivot towards Nuc SMs to counter the PRC military expansion. Both for the UK and US, this is a large commitment which will have huge implications for manning and planning for decades to come, never mind the financial implications involved.
The result has highlighted the inadequate numbers of assets – in this case SMs that we have available. Since the end of the Cold war we have been having to do more with less, sometimes you just can’t!!


Couldn’t 2 crews be split into 3 and the unfilled roles filled with Australian crew who would then gain vast amounts of training and experience of nuke sub operations. Eventually leading to a sub lease to Australia? Could any of our retiring subs be overhauled for Australia to use or are they absolutely knacked?


I think using more AUS personnel will slowly happen. The issue is with the Nuclear watchkeepers back aft. You can’t just put someone into those positions and get them to get on with things.
If not mistaken the Nuclear long course that our Nuc engineers attend is some two years long, then they have to go and qualify on the SM. All takes time, but I have read that some of their engineers are now at HMS Sultan starting down that trg pipeline.
The older SMs we are retiring – T boats, are essentially at the end of their useful lives, completely knackered or we would still be using them.


The problem is it works both ways; if an Astute get’s based in Oz some of ours may end up deciding to stay down under and join the RAN. Not going to help with RN retention!

Last edited 1 year ago by Ben Robins

The issue the RAN has had is mining companies poaching the RAN staff with offers of far better wages and no sea time.
I have no doubt that the same would happen after a return of service if any Nuc watch keepers joined the RAN.

Rob N

Auz personnel are now being trained on UK reactors. I suspect Auz folk will be put on UK boats to learn the ropes. It is likely that RAN with get an Astute with possibly a US reactor as PWR2 has problems…. perhaps the reactor designed for the new US and UK SSBNs.


Sub lease or sublease (pun intended?) ?


Russian machine…don´t work well…


Although it’s a fair way out still, to get into the Baltic they have to transit through the Kattegat Strait (between Denmark and Sweden). It’s a shallow and narrow twisty route. Like @X points out far safer.


To enter the Baltic sea and transit to St. Petersburg through Danish and Swedish waters Russian Subs are obligated to surface (they would be detected anyway).

Bloke down the pub

Correct, the same reason that submarines are required to surface when transiting the English Channel or the Bosphorus.


Not strictly the same but it does seem that surface transit is avoided even when you would think they would be .

The Firth Of Clyde !

Telling porkies is also expected and blame it on the Russians first

Last edited 1 year ago by Duker
Meirion x

Still deepish water in the bay of Firth Of Clyde.
Telling porkies is certainly Russia’s trade mark Ivan,
Ukraine proves it!


Maybe a more cost effective option is the German Type 212 conventional submarine, designed for shallower waters and very quiet.


4 of the coastal variant for training. 8 of the extended variants so 1 for oop north and one for the Med.


I would question who is the most reliable partner before I ordered which SM.

Julian Edmonds

Sweden. They had no lockdown so you can rely on their industry to keep working.


There isnt going to be a new conventional submarine for the RN , before you even decided who is going top build it!


True. But there is little to talk about IRL surely some ‘Fantasy Fleet’ can be forgiven?


Of course. But it should be along the merits of the various types and the service that are/will be operating them
Considering who is the better ‘design – build partner for RN’ is beyond fantasy.


You are a spoil sport. 🙁

I hear you. 🙂


How can an AIP SSK follow SSN? SSN can transit underwater in 20 knots, AIP SSK can dash with the speed using its battery, only for several minutes. AIP can only provide several knots of speed.

Last edited 1 year ago by donald_of_tokyo

It’s more about having a unit at a point to observe passing traffic. We had an O-boat off northern Norway for a long while just to observe passing SSN’s etc.


Then, SOSUS or ASW USV/UUV will be the best option, not SSK? They can stay there 24/7/365.


Well that they didn’t put SOSUS up there at the height of the programme tells you perhaps that there are problems with that idea…….

And no just because something is unmanned it doesn’t mean it can be there permanently for a whole variety of reasons from maintenance to command and control and so on. It is front line mission. Not one for clockwork toys.


SSK is very very expensive these days. RN is lacking submarine crew these days. Then, ASW USV/UUV is the ONLY possible answer for me.

If you are happy to BAN a few SSN to get several SSK, that will work. But, if you want something “in addition”, drones are the only hope.

And, ASW with drones is a tactics in near future. RN cannot dismiss it.


So you think that the technology is mature enough to put a USV up there that can manage its own systems, repair itself, react tactically to threats and so on? How big is this robotic boat?

Last edited 1 year ago by X

Never said so.

1: Prepare 3 XLUUVs and station one always at one location.

2: Prepare 6 ARCIMS USVs with LFAPS sonar system (SEASENSE system) and always send tow on station (if it is in the North Sea)

3: Trial iXblue SeaDrix system, if they can provide “a line of compact TASS”.

Yes, these development will need time, say, several years. But, select the design, build, establish training for SSK takes at least several years, and finding their crew in addition to current SSNs ones is, I’m afraid, nearly hopeless.

Item-1 is surely under development. Item-2, if RN decide, can be fielded in 1-2 years (Its sea trial by company has been done, and RN already has several ARCIMS USVs. So, just need to buy, train and operate the SEASENSE option). Item-3 was just a proposal.

I agree it will not be easy. But, making the “FIND” part of ASW to be covered by unmanned systems is the RN view of future. So, it is NOT my personal idea, it is RN’s official vision.


You watch too much sci-fi.


No, it is RN official statement, and AE-UK official announcement. Enjoy it. “Building SSK without losing SSN” is far more “fiction” than these two sources.

Yes, there will be difficulty on obtaining those capabilities. But, in non-military sector, using UUVs for research is now getting more and more common. It is a growing industry. I think the difficulty to “build SSK without losing SSN” is much much higher.


We are decades from these things being intelligent enough to replace men in boats. It is the intelligence of man that allows these things to happen. We are not deploying an array of sensors. I think you grossly underestimate the complexity of the tax and are grossly over estimating the equipment we have today.

Back in 1957 the government through our aviation industry under a bus because of the promise that missiles could do it all. Now 65 years later those missiles are only just about delivering that level of capability. About two aircraft generations on in other terms.

Artificial intelligence in a controlled environment can seem to be very clever. Out in the real world it is not. Underwater in a tactical environment at a distance how do you think it would perform? I asked you above how big would this robot boat be? Because it will have to cope with the ocean. It will have to have an even higher level of redundancy than a manned boat. We are decades away from building such things.


I think you are misunderstanding the aims of these technologies. They are NOT planned to be used to “replace SSKs” in any sense. It is more replacing the capabilities of SOSUS and/or SURTASS in 1990s.

In other words, these drones are planed to cover the task of “FIND”, not “attack”.

Strength of submarine come from stealth. If you can locate the enemy sub, then how to “cook” it becomes the tasks of a P-8A and/or T23/T26-ASW and/or SSN/SSK.

The location information from “ASW drones (or SOSUS and/or SURTASS in 1990s)” need NOT to be precise, because “P-8A and/or T23/T26-ASW and/or SSN/SSK” can do “re-FIND” by themselves.

But, now there is zero chance that numbers of “P-8A and/or T23/T26-ASW and/or SSN/SSK” will be enough to cover the whole north Atlantic area. So, combining them with “FIND” tools is must.

In other words, anyway you need these “FIND” tools.

Last edited 1 year ago by donald_of_tokyo
Meirion x

I agree with you Donald!


One of the reasons subs are used for tracking is to gather the noise signatures of specific types for storage and future use.


You don’t say. Really? Do I suck the egg in from the blunt or pointed end?


The implication in the press release is that Severodvinsk was detected while submerged is interesting, implying that NATO can still find the best boats the Russians can field. ‘


Supportive Bloke

Fundamentally a 1980’s design.

We have seen what happens when Russian Cold War tech comes up against current NATO tech.

Why would this be any different?

Transducers improve, processing software and hardware have come on leaps and bounds in those 40+ years……


if you are talking about Ukraine, it too uses Russian cold war technology.
For submarines , If you read Polmars excellent book on the cold war technology it seems there was a plateau for both sides with cold war technology.
Since then its incremental improvements , Astutes for instance are mostly improved reactor designs, and the computer processing has improved in leaps and bounds , but that can be done by upgrades


It’s obvious the Russians just don’t have the budget to sustain let alone improve their capability, at least in any significant number.

I’d suggest they probably do their CASD patrols under the north pole to save on deep dive cycles, because they know they cannot afford to replace all the hulls they already have.

Last edited 1 year ago by Ben Robins

SSBNs don’t normally conduct there respective patrols at deep depths, normally in the upper 150m of the water column irrespective of the depth of water below the keel. It’s got nothing to do with ‘deep dive cycles’ either, although staying much shallower does impart less stress on the pressure hull. It’s got more to do with staying in constant Comms with home base so to speak.


They explicitly state that they use the ice cap to avoid visual detection, which seems to suggest a planned strategy of staying shallow. It’s also not too far from base which saves reactor life.

Make of it what you will.

captain p wash

Ben, they do stay pretty shallow given the depths below at times.


Average Arctic ocean depth is still around 1000m or 3200 ft

captain p wash

oh here we go, every day is a school day on here ! …… I guess you know the Crush depth as well ? and the deepest parts ? what are they again ?


It was to give an idea of the Arctic ocean , NOT the subs operating depth. Your own assumptions have led to the error .
the map shows the various shelfs are probably much shallower

Captain P Wash

Error ? What error is that then ? you replied by posting a map and then ignored my two questions….. no error on my part just questions you don’t seem to know the answers to. Google is your friend.


I never mentioned operating depth.
Your primadonna approach when you imagine your tutu is crushed does you no credit.
You probably know a lot but spend your energy in other areas


Yes operating under the ice is one of their strategies for their SSBN operations, but they also operate in other areas, whilst staying in what we would call a shallow depth.
FYI, a Nuc SM on say a 10 week patrol will use the same amount of core life regardless of whether it covers 1500 nm or 3000 nm in that time, as long as it stays in the same power state ie Half PS or Full PS. Staying in the FPS burns through core life rather quicker then you would want for only a small gain in extra speed.

Supportive Bloke

Oh no. There have been huge advances in mechanical and electrical systems, control systems…..all have signatures noise and otherwise.

Ukraine’s advantage is NATO training, autonomy of decision making, comms, ISTAR feeds and the NATO weapons tipping the balance.


Well done to the RN and RAF personnel involved. A timely reminder of the need to keep on top of the Russian submarine threat and the astonishing stupidity of moving to two thirds of our escort fleet (T31 and T45) plus the Wildcat helicopter having no ASW detection capability at all

Rob N

Not true T45 can carry Merlin and has a sonar and T31 will be helicopter capable and is likely to have a sonar too. The main UK ASW assets are the T23s, P8 and our SSNs not air defence platforms and T31. Interestingly T31 could be upgraded with sonar 2087 should the RN wish….


Commentators on here who know more than me have posted that the T45’s (low quality) sonar is no longer manned to save operating costs. The T31 is in build without a sonar despite the GP T23’s that they are being built to replace having a good quality hull sonar.

T45, GP23 GP (and hence the T31 that will replace them), normally deploy with Wildcat. Although Wildcat is a next to useless job creation scheme, we don’t have enough Merlin’s for the carrier’s and all escorts (particularly now that we are using Merlin for carrier bourne AEW as well as ASW).


44 Merlin ASW helicopters were delivered, 2 lost, so that leaves 40 or so.
I understand 30 were converted to HM2.
Still seems plenty of airframes , if the will is there


You’re right at 30 airframes. I don’t know what typical availability is but they are ageing and I’m told that they were always complex to maintain. If I remember right, HMS QE deployed with nine on board for her Asian deployment which I’d guess probably only leaves half a dozen for the rest of the fleet.

I’d love to know the real numbers rather than my guesses but I suspect that’s classified. I do know that T45 and T26 GP have carried the largely useless Wildcat on every operational deployment I’m aware of (I stand to be corrected of course).


If T45 is destined to be always somewhere with something else I would suggest it doesn’t need to carry a helicopter.

Last edited 1 year ago by X
captain p wash

They are mostly in Portsmouth normally.


Of the 12 that were not converted, four are off the MAR (so essentially defunct), one is at the AES at Sultan and the remaining seven are stored at MoD Boscombe Down. However, some of them were also Christmas-treed, in some cases to donate folding rotorheads and tailrotors for the first batch of Merlin HC that were marinised. Details here :

Demobbed – Out of Service British Military Aircraft

Of the 30 HM2, you generally plan on around 2/3 being in the forward fleet (ie issued to squadrons) and the remainder being either in MDMF (Depth) or as trials cabs (AW or QinetiQ).

That leaves basically around 20 cabs to provide aircraft for 814 (T23 ships flights), 820 (carrier flights) and 824 (training). It doesn’t take a genius to figure out that six cabs for 824 and (say) another 3 for active T23/26 (814) isn’t going to leave too many for 820.

I’d say the best solution would be a follow-on buy of new airframes (12-18) – preferably with some of the more egregious problems (gearbox and ILS) sorted out. There really isn’t an equivalent helicopter (not SH/MH 60 or NFH) out there. Supports UK helicopter capability, makes airframe management and availability a bit easier.

Trouble is – like all these things – money’s got to come from somewhere.


Great post in terms of the availability of helicopters.
I totally agree with you on the need for a follow on buy of new airframes. The money could come from cancellation of the national ship and curtailment of Ajax


Wildcat is just a torpedo delivery system on ASW.

But, on patrol and anti-surface tasks, Wildcat is useful, FAR FROM useless.

By the way, UK is planning a 3t-class rotary UAV to deploy Sonobuoys. I do not know why not Wildcat can do the same?


I think we’ve severely compromised the anti-swarm capability of Wildcat by not having Martlet as a fire and forget missile. Sea Venom looks fit for purpose. We might finally be installing a data link in Wildcat which is essential but it’s astonishing that such an expensive helicopter didn’t have that equipment or any ASW detection gear in the first place.

The Army seems to have very little in the way of missions for Wildcat.

I just think that Wildcat is desperately poor capability for what it cost (which is why it’s been an export flop). We could have had far more capability for our money but (as with much of our equipment), the objective was not to give the military the capabilities that it needs but was to create or sustain jobs.


Not sure. I think lack of investment resulted in the Wildcat’s situation. Its “system” is complex = high-end, but its airframe is not. Wildcat has good radar, good EO sensor, and good self-defence kits. But, as these high-end systems weight to some extent, Wildcat lacked endurance.

Wildcat can carry sonobuoy, its transducer, and even a dipping sonar, but it will severely reduce its endurance.

Lynx, SH-2G and Dorphan were/are ~5t-class. Wildcat was designed to be similar in size. Among them, Wildcat is surely the best equipped helicopter. But, all of them now is not a good seller.

But, a modern utility helicopter must have had a 9t-to-10t class size (like BlackHawk and NH90). And, AW-UK Yeovil factory lacked that size of product. In short, Lynx-successor shall better be much larger design, say, 8t-class at least. It will not resemble Lynx, but that is what was needed.

Just me personal thought.


Proteus isn’t just to deliver sonobuoys. It’s to do surface and subsurface find and track, and optionally MITL. Fire Scout MQ-8C, the US equivalent, comes in at about £10m, much cheaper than Wildcat. Not to mention the fact that we don’t have enough rotaries, so using Wildcat would take numbers away from their main attack function. The US are talking about developing the next generation of Fire Scout, and that’s exactly what Proteus will be for the UK.

If Leonardo get the timing right, they might even be able to sell the design to the US. The model-C Fire Scout’s engine is Rolls Royce, its radar is Leonardo (UK) and the sonobuoys are Ultra, so there’s more than a whiff of British about it already.

Last edited 1 year ago by Jon
captain p wash

The new Belgorod is about 185 metres and it looks like It’ll be carying the Posiedon torpedo which is 2 meters diameter and 20 meters long…. that’s going to cause a headache !

Rob N

The Type 23 active/passive sonar has an active low frequency capability that can detect subs that are even quieter then the ambient ocean noise. This sonar will also be fitted to Type 26 and the US Constellation class frigates.

Supportive Bloke

That doesn’t make a lot of sense.

You are saying it can detect quieter than ambient?

Then you state it is an active system which isn’t that relevant to ambient except at extended range……..?


Isn’t he simply saying, by active pinging, CAPTAS4 can detect subs with good sensitivity? In this case, even if the sub is very quiet, it doesn’t matter because it has a pressure vessel which will surely reflect the ping.

captain p wash

“One Ping”…..

Scott Elaurant

A submarine may make less noise than the background ocean but it is still noise. The comparatively low noise level would mean the signal/noise ratio would be low and it would be hard to distinguish from the background ocean noise. So possible but I assume a bit slow.

Supportive Bloke

That is a matter of signal processing.

Machinery, generally, has a pattern of noise.

Ambient noise tends to be more random.

This is where more processing power is really useful as clever things can be done to discriminate and yes, as you say, more signal averaging so more time.


I understand passive ASW is now almost useless against modern SSK/SSN with good silence mode capability. I understand it is really noiseless in that mode. This is why low frequency ASW tactics came out = why CAPTAS4 was introduced. Also, now it is evolving into multi-static active ASW.

Still passive ASW is used to catch the SSK/SSNs in transit. As they steam at speed, they make noise. So, P-8A widely distributes sonobuoys on choke points to detect such noise. ASW USV/UUVs main tasks are the same.

When hunting “silent mode” SSK/SSNs, Merlin pings, CAPTAS4 pings, and passive sonobuoys are coupled with active-pinging buoys. Actually, all these sonars/sonobuoys’ data will be combined to look for multi-static echo.

This is my understanding.


You track by listening for noise but also listening for the absence of noise. An example would be the T23 tracking a Russian sub hiding underneath a commercial vessel, due to the anomalous sound signature.

Scott Elaurant

Rob N
I take it the Type 23 sonar that will go into the Type 26 will be fitted to the Australian Type 26/Hunter frigates as well? How would it compare to the Astute Sonar? I assume the Astute Sonar is still the best available.


One is a surface ship sonar, designed to provide LF active pinging over considerable distances. The other is a submarine sonar designed to conduct primarily passive operations.

Apples and undercrackers.


I was looking up further information on the Astutes’ sonar fit. Reports from 2013 say the final 2 of the class had the names Agamemnon and Ajax

For some reason the last of the class is now named Agincourt. Why was this changed- apart from the cover story of being temp name , which is refuted by this:

Gavin Gordon

Would you fancy going underwater in something called Ajax? Obviously not the reason, but a good second place non the less.


Lost me on that one

Nigel Collins

A first-class opportunity to collect more data which will be useful in the future.