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Excellent. Thanks.


What are the tiles all over the boat used for? Dampening sound reflection? Insulation?


It’s a shame our Trident and trafalgar class Subs have so many Tiles missing Ut still go to sea,… The Submarine tiles Tech was an amazing advance…


So, Russki wake detection use anechoic tiles detection in wake of the boat (They fall slowly to the bottom) And/or by missing anechoic tiles detection (micro-turbulences and dissimetric noises port starboard sides).

Two new episodes for Tom Clancy…


Its so hard to get a good tiler these days. I’ve been waiting for months for a bloke to turn up and finish the tiling job in my bathroom.


I’m a roof tiler, but my mate dave does bathroom tiles ?


Interesting, I wonder what techniques they are using.


There are also lasers, magnetic detectors and sniffers for combustion detection.

Supportive Bloke

It has been a widening field (sorry for the science joke I’ll get my coat). If you look at the small modules that have been added to laboratory instruments (Hewlett Packard and Varian lead the early manufacturers) to to HPLC-MS etc since the early 90’s it will give a good clue as to what is possible. None of that is even vaguely secret as it is in the manufactures online catalogues.

It is just standard laboratory analytical tech that has been optimised for the job.
The early Russian efforts were very clever but needed quite a lot of space as ‘compact’ was not the operational word.

As ever getting a lab concept to work in the ocean would be interesting.


Thanks for those good hints. I was thinking the other day about MRI technology as used in hospitals, its sensitive enough to detect the small changes in inter molecular bonds in water molecules in the human body ( I hope thats what I think it does) Maybe some adaptation of the tech can find water molecule bonds altered by the nuclear submarines condensors or even the large electric motor magnets ? Im being very speculative here

Supportive Bloke

MRI -> NMR (NMR is the big brother of MRI) tech isn’t sensitive enough unless you are using very high fields and superconducting probes. I can’t really see how you could fit that on a submarine. I still think there would be a few zeros adrift even then.

NMR (MRI) looks at proton nucleus spins. Known as nuclear magnets. So, yes, it is a very sensitive technique for looking looking at magnetism *in very restricted* circumstances.

You could, perhaps, use stop flow HPLC-NMR to concentrate the samples.

Things like HPLC-MS (mass spectrometry) are orders of magnitude more sensitive. Mass Spectrometry can pick up changes in isotopic ratios.

Generally you use hyphenated techniques to enhance complex detection and sometimes to concentrate samples.

That is all in postgrad textbooks from the 2000’s and earlier.

As regards stray field perturbations from motors these have been well screened out, actively for years. Look at Ultra Electronics website. The thing is this stuff is easy to measure so you can engineer it out. You *might* be able to detect artefacts from the cancellation systems if you knew exactly what you were looking for. But I doubt it.

You are not going to reproduce on a submarine something more sensitive than the best university lab instruments which are mounted on massive concrete slabs in controlled environments…..

Last edited 3 years ago by Supportive Bloke


I was wondering if they might be using a development of ISE technology for continuous flow monitoring.

Supportive Bloke

Have a look at

These guys are the very best at the sort of sensor tech we are talking about.


It seems strange that in this day and age with the tech available, the sonar readings look so primitive. Why haven’t we developed “visual sonar” showing a picturial view of the sonar return based upon a HD comparison of returns interpreted by an AI system.

Supportive Bloke

These are reality and have been for some time.

They can be done from multiple sources to produced HD 3D views of air/sea whatever if you have a the sensors available. Input from Sonar/sonar buoys/helicopters with dipping sonar can all be melded together into one view.

Equally for radar/lidar.

The best are composite: bringing loads of systems together. You can’t fool all of the sensors all of the time.


Nice to see an old friend still leading the way. 🙂


It certainly is, she’s getting a tad old now though!?


I remember her when she was new. :0


So do I, are we talking commissioning!


Not far after….


I took her out of build and then did a few years before moving on to bombers would you believe. Got the shock of my life when joing them, totally different way of doing things.


I’m looking at her sisters rotting away in port….

Trevor G

Excellent article. Just mentioned in the final para, but I recall wake homing torpedoes being developed in the latter part of WW2, not sure exactly the technologies involved in that as computer analysis would not have been available?

Supportive Bloke

Purely acoustic technology: homed in on the highest sound pressure levels.

Easily spoofed as all you needed was a louder sound.

As they became, relatively, more sophisticated settable notch/band pass filters could be adjusted to the likely frequency range of sound as detected by the passive sonar.

That was before digital lookup tables existed……

Dogs Nads

They weren’t wake himing, they were acoustic (the G7e from Germany and T24 ‘Mine’ from the US). The Wake Homing torps were first deployed by the Soviets late in the Cold War.


Yes. Thats homing on on the noise of the propeller.
The Russians favoured the wake homers because of the large wake of US carriers when at speed and their 65cm torpedoes could be fired a long distance away and travel at 50 kt over more than 50km.
The US now has its small anti-torpedo torpedoes being installed on its carriers to counter this form of attack


Can anyone advise, what is the hump and dome on the rear deck? I dont think the subs originally had them.


It’s a standalone sonar fit.



Mike O

A great really informative article ?

Meirion X

I wonder if both HMS Talent & Triumph, lives could be extended, to be used to patrol the home waters?
She looks larger in a photo on the Clyde.

Last edited 3 years ago by Meirion X

I doubt it. They are worn out. But that isn’t to say there isn’t a need for an SSK to patrol home waters. The 6/7 (eventually) SSN’s could be used in distant seas. Crewing an SSN is an issue too. We need something like 8 of these with a maximum crew of 35 but able to run with a lot less. Just under 2000 tonnes……

In my ideal but realistic (!) world we would be operating 8 A-boats, 8 ocean going SSK’s, and 4 1000 (smaller probably) for training.

Supportive Bloke

Trouble is the number of dive cycles on the pressure hull and the sheer age of the systems. Getting spares is soon going to be an issue.

The North Sea and the Atlantic are not very benign environments so the whole sub would have to be in tip top condition.

Given the small fleet we now have, they will have been worked very hard. Problem is even refurbishing them: who can do it? Barrow is choka, can the refit complex handle a full reworking: don’t know. Then who is the design authority for what is effectively a new class? Do we risk creating an MRA4 submarine?

Don’t get me wrong: I’d love to see a 50% increase in our hunter killer fleet. 11-12 subs would give us the capacity to deal with the unexpected.

There must be a way of speeding up the slug like progress at Barrow so as to create more build capacity. Maybe that involves working on Fridays afternoons and other revolutionary stuff like that? It is pretty unusual in a big setup like that to be effectively working a four day week with little or no weekend working. Almost all big projects like that have some element of weekend working so that the critical path items are expedited.


The long lead time on steel and other high end fitting doesn’t help. New Labour interrupting the SSN drumbeat and then the Tories dithering over Dreadnought did a lot of ‘damage’ too. We most definitely need 8 A-boats.

Last edited 3 years ago by X
Trevor G

Another factor in build times is the rate at which funding is available from HMG. If that is available and there is also some sense of urgency about delivering capability to the RN (seemingly absent in T26 also) then there would be some incentive to address the current almost surreal build times. Some sort of comparison is the average build time for the original RN SSBNs (Polaris) which was approx 4.5 years, icluding first of class. I accept the Dreadnoughts are much larger but based on info in the public domain, build time is going to be nearly 3x that.

Supportive Bloke

Yes, you are right: this was less about delivering the capability needed than about smoothing cash flow curves to the minimum level of spend. This pushes up unit price as all the overheads and contract preliminaries will be charged on calendar days.

It is a new mindset:spend money faster to save money!!!

Trevor G

Yes indeed, and I remember a (rare) admission that slowing the drumbeat of the Astute program for the reasons you quote actually increased the total class spend by £1.6 billion, which would have given us the eighth boat with some left over. My background is in shipbuilding, mostly naval, and I never met a civil servant that understood this reality. The same sort of thinking pervades the thorny issue of cutting ship numbers to save money, so you get the T45 saga repeated ad infinitum.


I say we can afford these things. But HMG decides to spend the money elsewhere.


There’s another reason why the build times extend and it tends to be based on ToBA like arrangements. You can build quicker with more people, but if you have a fixed number of ships / boats to build then you end up with a hiatus when the current class is finished.

Now – normal shipyards are quite happy with that, because its an opportunity (build slot) to get more contracts in. Trouble is – if your only client has a fixed number of ships / boats in mind and you are too expensive to get export work, then you end up laying people off. That is precisely what happened in Barrow post V-boat and is the reason behind the comically long build time for T26.

The T31 programme seems to have been set up to try the alternate approach (rapid build time), but it then leaves Babcock looking for something afterwards.

Long build times are significantly more expensive in total (you tend to be paying the whole yard workforce for the duration) and you end up with equipment that has been in the yard store for years before being flashed up. The flip side is that short-term cash outflow is higher and if there’s a gap in orders you risk losing your workforce.

Not simple.

Supportive Bloke

The curse of ToBA coupled with too small a fleet.

Let’s see how the T31 builds go: worth trying.

Hopefully they read the bit in the Parker report about keep building them (T31/T32) and selling them off without expensive refits.


Let’s hope they didn’t. It’s a bonkers idea and will never get past the Treasury.

For the sake of argument, the economics would go something like :

  1. Build cost (highly optimistic) £250M over three years (or £83M pa)
  2. Refit cost ~ £20M per refit
  3. Resale recovery optimistic (poss inc refit) ~ £50M

So what you’re saying to HMT is something like :

For a drumbeat of one ship added / retired every three years, we’d like you to give us £83M pa. Every three years we’ll give you back £70M saved / recouped – or ~£23M pa.

Or, for a drumbeat of one ship added / retired every year you give us £250M (three ships in build at a time) and we’ll give you £70M.

I can’t possibly imagine the response, even after “tax receipts, VAT, powerhouse, wibble”.

Supportive Bloke

The £20M midlife refit after 12 years seems a tad optimistic.


You need a recertification docking every six years anyway.

Your refit costs will obviously rise with age. But won’t be a.million miles away on average.

Either way, lots of money asked for, not so much returned.


Another factor in build times is the rate at which funding is available from HMG.

Yes. As I said,

New Labour interrupting the SSN drumbeat and then the Tories dithering over Dreadnought did a lot of ‘damage’ too.

Yes I do wonder too if there was a sense of urgency about the build of Dreadnought if the build time would fall. New technology doesn’t seem to ease build times only increase them.


‘Drumbeat’ was interrupted before Blair came to power in May 97 (and likely continued previous spending plans till 98.)

The last 2 Trafalgar class was laid down in 86 and 87 which over lapped slightly to 4 Vanguard class in 86, 87, 91 , 93

Astute of course was laid down in 2001. If the ‘drumbeat’ had continued with the conservatives the next SSN class would have laid down by say 95 or 96….which didnt happen so there was a gap from 94 to 98 with no new boats laid down , which was significant in that era.
The real reason was likely the end of the cold war by 1990 and the downsizing of the RN

Last edited 3 years ago by Duker

Yes you are right! 🙂

Peter Hulme

I is difficult to see how a submarine campaign would wok with a handful of nuclear submarines . Is there any relationship to the submarine campaigns of WW2 where the U- boats grew to near a 1000 and the USN ended the war in surplus at 250 . The RN ran a campaign in the confined Med’ with a significant fleet then in the Far East (as opposed to the Pacific) . There are lot of ships out there to sink and each one needs at least one torpedo or missile . The Russians have a significant number of diesel boats and scattered through out the world countries are maintaining perhaps three modern diesel boats — To move from Perth to Brisbane still takes significant time , matched by a surfaced diesel boat >This is rough and ready , but surely there will never be enough nuclear submarines to sink all the ships as in WW2 — is there a policy I have missed completely Peter


Trouble is the number of dive cycles on the pressure hull”
Nuclear boats dont really surface and dive on a regular cycle like an air breathing SSK might and the missile boats go down and stay down.
As for major refits , those arent done at Barrow – I dont think that place is chokka either – they are done at the Devonport dock yard


Any depth change – irrespective of surfacing or not – incurs pressure change, which incurs stress in pressure hull and any internal fluid system exposed to dive pressures.

Barry Larking

Very interesting article. I have wondered how a wake detector works.

I was more taken with the (exceptionally fine) photograph of Talent displaying two GP machine guns going into Gibraltar. Makes one think.