The nuclear submarine has returned to Devonport for the final time before her decommissioning.

The Royal Navy say that, as is the tradition of a ship sailing into her home port for the last time, the submarine proudly flew her paying off pennant and a number of her crew ‘went up top’ to line the casing.

According to a Royal Navy news article that can be found here:

“HMS Trenchant is a Trafalgar-class nuclear-powered submarine, she was launched in 1986 by war hero Vice Admiral Sir Arthur Hezlet – he was the commander of the original HMS Trenchant submarine during WW2. Together with the Astute class, HMS Trenchant make up the Royal Navy’s hunter-killer submarine force.

During her 35-years on patrol there have been many highlights of her service, two of which have been her ice-patrols. In 2016 the boat punched through the ice and emerged on the surface of the Arctic Ocean. This marked nearly a decade since a British boat had carried out this manoeuvre, re-generating the Submarine Service’s under ice capability.

In 2018 in the harsh environment of the North Pole HMS Trenchant broke through the ice in an exercise with the US Navy, literally sitting on top of the world.”

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HMS Trenchant is the oldest submarine in the Royal Navy fleet.

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Ian M.

Definitely a tad tired looking.

Nigel Collins

Worked very hard over her lifetime no doubt.

On the upside, a couple of GPMG’s going begging for our future armoured strike brigades!

Harry Bulpit

The GPMGs will be owned by the navy not army. So 43 commando might get lucky.

Steve Salt

She does look tired !
Only Talent and Triumph left now.

ChariotRider

According to Navy Lookout she holds the record for the longest patrol of 335 days in the Med., Gilf and Indian Ocean covering 38,000miles. I take it that includes port visits and crew swaps!

Another thing I didn’t know is that the RN used to maintain a TLAM boat East of Suez, just in case. I’m guessing that isn’t the case at the moment.

Well done to the Silent Service and to HMS Trenchant and all who served in her.

Thanks CR

Challenger

Hard to judge as submarine activity is classified but it certainly seems that 1 was almost continuously somewhere East of Suez post September 11th.

I’m sure they do still deploy that far afield nowadays but I doubt it’s continuous with only 6-7 boats in service and the other pressing needs placed on the service (protecting CASD, monitoring Russian activity and now protecting the CSG).

Pacman27

Indeed and one area not covered anywhere near well enough in the recent documents. our submarine service is a real game changer and we need more SSN’s I know they are expensive, but they give us an irreplaceable capability realistically I think we need 10 astutes as a minimum, 7 just won’t cut it anymore as we need 3 active at any given time, 1x CSG, 1 CASD, 1 UK gap, that leaves the south Atlantic and the high Arctic needing a presence. we can assign these at will- they will always be in demand and we get good VFM… Read more »

BB85

Does 7 give us 2 continuously on patrol? The treasury seem to have done the RN out of 1 astute through their shitty accounting and slow build strategy. Pretty sure if the build rate hadn’t been slowed to a snails pace we would have 8 for little more than the cost of 7.

Jonathan

Yes but it’s all about the balanced books in year. Not about the actual cost. Gov dept spending has never been focused on the most efficient way to spend a pound, instead its all about balancing the books in year, even if that costs you 3 pounds down the line.

Levi Goldsteinberg

Does she have an A-boat to directly replace her in the fleet or are we going to have a temporary reduction to as many SSNs as France?

Challenger

7 are in commission but it’ll fluctuate between 6 and 7 actually operational as each Trafalgar leaves service and a new Astute works up.

Levi Goldsteinberg

So I assume we’re going down to 6 then for a short while then whilst a new A-boat is worked up – I assume that Audacious is the replacement for Trenchant

ChariotRider

Hi Levi

HMS Audacious is slated to take over. She was commissioned in April 2020 but appears to still be on trials as her In-service date has been delayed from January this year.

My understanding is that Audacious and the following boats are in effect a batch 2 with some changes from the first 3 boats. All I can say is that the changes must be signiificant given the delays to Audacious!

The SSN force will be 6 strong until the last Astute boat enters service in 2026 when it will increase back to 7…

Way toooo small.

Cheers CR

Levi Goldsteinberg

Cheers!

Lusty

Surley Audacious is technically the replacement for Torbay?

Either way, there’s going to be a fluctuation in numbers untill all 7 arrive.

Paul T

I think it was the case that there were ‘issues’ with Audacious coming out of Build ( Batch 2 Improvements ) which held the other Boats up – Anson shouldn’t be too far behind in Joining the Fleet.

ChariotRider

Hi Lusty,

As Paul T says there were delays with Audacious’ build. There is a great bar chart on Navy Lookout showing that back in 2001 we had 12 boats, by 2011 that had dropped to 6 and it will not go back to 7 until 2026 / 27.

Lets hope there are no more delays to the programme and that HMG has learnt the lesson. It takes 15 years to train an engineer and that includes Naval Architects, so no more gapping the build programme…

Cheers CR

Lusty

Yes, I’m well aware of the delays to the build.

JohnG

Gosh, this is a bit concerning. My understanding was that we had 7 boats to ensure 1 was always on patrol protecting nuclear deterrent (requirement of 4 subs) leaving 3 to be used for normal deployments (ensuring 1 is in active use at any time) if numbers go down to 6, and they are still using 4 for our nukes, that will leave 2 for routine deployment.

JohnG

Understanding the build rate constraints, if my post above is correct, the only way I can see to alleviate this slightly would be the purchase of some diesel electric subs. Could be used for training to a certain degree, potential forward deployment and for use around the UK coast and nearby choke points such as Gibraltar.

TrevorH

There is probably a reason, but cannot one of the outgoing subs be used for training?

Martin

The Boats are nearly 35 years old and the design life was 25. Its amazing we got what we did out of it but they are not safe to carry on even for training.

Deep32

Hi Trev, a SM alongside for trg purposes (like Bristol), is not needed, all shore based trg is catered for in simulators pending actually going to sea for pre deployment work up.

TrevorH

Looking at Martin’s response I was then wondering about simulators..
so thank you.

Is there no benefit then is simply familiarizing inside a Hull.
Again I suppose no. Psychologically I suppose trainee submariners do sometimes realise that it is not for them…

Deep32

No mate, SM trg is done slightly differently, basic SM trg is done in a classroom for all trainees. On completion they are sent to various SM SWNs, where they will be assigned to a specific SM for what we term ‘Part 3’ trg. Here they learn all about a specific class of SM and complete their sea trg, qualifying as a Submariner and are then awarded their ‘Dolphins’ to signify they are a qualified submariner.
Hope that helps mate.

Deep32

Sorry Trev, what i should have included is that Pt3 trg is done whilst at sea under real conditions so to speak.

Andy P

You only have a max of 2 boats out usually, the one heading out and the one heading in. One SSN can delouse the outbound one and if required keep an eye on the inbound one. Generally, once the SSBN is out, it does its own thing and doesn’t require a ‘nanny’. Remember the collision between the Brit and French SSBN ??? They’re that quiet they didn’t even detect each other. Fleet boats have a lot of uses, the standard ‘submariney things’ of looking for goddamn commies, assorted ‘snooping’ and they’re also used for SF insertion, training (including Perishers)…. they… Read more »

Sonik

Thanks that’s some interesting insights. Situation not quite as bad as some speculate but still not great. Hopefully the A boats will prove reliable in service. I guess the only possible benefit of a smaller fleet is that it will focus minds on maintaining sufficient resources to maximise availability.

Andy P

From what I gather, things are bad mate. Reduced platforms mean more time away for the guys. All in all its not a happy place from what I’m told, glad I’m done.

Sorry for the negativity.

JohnG

Cheers for the info Andy. Do you know anywhere where I could read a bit more about it? My understanding was that one SSN would be in maintenance, one in training and potentially doing local activities and one being deployed. In the case of the nuclear deterrent, I thought an SSN was used to provide a degree of extra protection for the deterrent, but can’t remember for the life of me where I read that. Also, if this was the case, I thought they used a fourth boat to ensure there was no lack of cover from the astutes. What… Read more »

Andy P

Morning John, sorry mate, no idea where you can read up on this, traditionally submarine ops aren’t shouted from the rooftops, even when they’re mundane. There must be some out there from the recent past (cold war etc) so worth a google maybe.

Martin

While numbers are low, I think it’s inaccurate to state that there is an SSN on permanent guard duty for the SSBN. They obviously keep such deployments very quiet but I believe all relevant actions for both FF and SSN’s are keeping the approaches to Faslane clear when an SSBN is deploying and ensuring it’s not followed this will happen four times a year. Once it’s clear no one including friendly SSN’s will know where it is. There may be and hopefully is a UK SSN patrolling the North Atlantic/ home waters but I’m confident it won’t be protecting or… Read more »

JohnG

Cheers for the info Martin,if you could provide any further reading around this I would appreciate it. I too have read about ensuring the subs aren’t followed leaving the base. I wasn’t under the impression that an astute would closely nanny the deterrent, more a nature of the astute being deployed in a certain location to keep an eye out for Russian subs, with a mind to the deterrent, for example providing updates as to where these subs are. I would be surprised if the deterrent was deployed completely unsupported (e.g. deployed to the north Atlantic whilst our astues wee… Read more »

Sjb1968

The T class have been great boats and we have paid a heavy price for having a submarine building holiday with another 2 or 3 being built beyond Triumph saving a fortune in extending the lives of the older boats and eliminating much of the delay and costs associated with the Astute programme.
7 boats is not enough of the most powerful conventionally armed vessels we have.

Harry Bulpit

I do love the look of the twin GPMGS. Interesting that it was never carried over to Astute.

LongTime

Pretty sure it’s still possible to mount a GPMG on the A boats Sail, would be peculiar if they have taken the option away after HMS Astute who definitely had them mounted when we sailed past her returning to port in 2019

Last edited 3 days ago by LongTime
Harry Bulpit

Ah. Never seen an A boat with them before but if you say so.

Lusty

They can be fitted as and when required:

ASTUTEDDS.jpg
Harry Bulpit

Yeah I had a look after LongTime comment. Cant believe I never noticed it before. Although I guess it highlights the size difference between the T and the A. But thanks anyway.

Andy P

They’re not always carried Harry, depends on where you’re going. Not much need when you’re stooging about the Kyle of Lochalsh for example, Malacca straits…different story.

Last edited 3 days ago by Andy P
Harry Bulpit

Makes sense.

Rob

We now have 21 nuclear submarines awaiting disposal sitting alongside. Since we started building nuclear submarines we has safely disposed of exactly zero. Now this has to change. The disposal cost has to be calculated as part of the through life cost of each sub.

geoff

Took the words out of my mouth Rob. They are stacking up in Rosyth and some have been there for 30 years plus I think? It would appear that there is no firm plan on how or when to start the scrapping process proper including of course the tricky job of safely disposing of the reactors. In the USA they are hauled to a desert disposal facility in the western states and buried in concrete bunkers. Can’t do that in Britain so what to do from here?

Andy P

The reactors are removed Geoff, the boats tied up in Rosyth and GUZ are basically shells. I can’t say what happens to the reactors (no knowledge as opposed to a big secret I can’t share) but you can get down the boats (or used to in Rosyth anyway) if you need to, they need to be ‘gas freed’ etc but while they take up space, its down to the half life etc but they’re perfectly safe where they are, if a bit of an eyesore.

geoff

Howrya doin Andy! Thanks for that squire. When you talk of half-life I assume that refers to any residual radioactive pollution on board considering the reactors are gone? Otherwise would they not just ship them of to the breakers?
Cheers

Andy P

Hi Geoff, yeah its the ‘background’ radioactivity, I’m not an expert so anecdotal but apparently parts of the boats have a ‘normal’ background level of radioactivity and some is a bit higher than ‘normal’. Nuclear safety is thankfully a big thing so everything is extra careful before the hulls are turned into razor blades. Like I say, if you booked it, you could go down them for bits and bobs, sure I posted it recently but I even went down Swiftsure looking for a plug for the sink in the mess so they’re not exactly ‘glowing in the dark’. I’m… Read more »

geoff

Haha-no glowing in the dark or not exactly Chernobyl 🙂
As a kid I had a metal model of the Cruiser HMS Swiftsure painted in an unusual light blue grey. I thoroughly agree with the protocols that forbid the recycling until levels are safe but when you think of Chernobyl and how wildlife around the region has returned to almost pre-modern man levels plus the fact that there remain a few stubborn human residents, all seemingly unaffected by radiation, it makes one wonder..!

geoff

ps I know of course you were referring to the Swiftsure sub in your post. Also did the RN ever paint warships in a light blue grey for duty perhaps in tropical waters or was it always just shades of grey?

Martin

Don’t be silly, off course the reactors have not been removed. They are all just sitting there fuelled up waiting for the MOD to find £7.5 billion down the back of the couch to scrap them. Rosyth is starting to look like the Russian White Sea in the 1990’s. There has also been reported instances in the past of power failures on the dock potentially leading to meltdowns.

https://www.sgr.org.uk/resources/devonport-and-nuclear-submarines-what-are-risks

Deep32

It’s normally the fuel rods that have been removed with the Reactor s still in place until the half life residual levels drop to a safe level. If the fuel rods remain in place then you need all the shoreside safety systems in place, including a full duty watch including nuclear engineers 24/7.
The places they are berthed does not support those requirements despite said article I’m afraid.

Andy P

Seems to make sense mate, sorry I didn’t see your response until I’d replied to Marin. I’ve heard some cracking stories about nuclear submarines, more the missiles and how the Americans can override them through GPS… but you would think any old Jolly Jack just gets a shot at playing with the reactor. Or the missiles. I can understand why people aren’t keen on nuclear, either power or missiles but they don’t do themselves any favours with either guesswork or falsehoods although in fairness, that’s what passes as ‘fact’ on a range of subject now so I suppose they shouldn’t… Read more »

Deep32

No worries mate, I was just trying to expand on your previous post about the decommissioning of old nice, and read that article as well!!! Give it due diligence then ignored it, seems to me it was written to suit said author, omitting lots of actual detail which was probably ban inconvenience for him!!!!!

Andy P

Yes, pretty much everything that gets published/posted/passed as news seems to come from one angle or another and its getting harder to separate the wheat from the chaff on pretty much everything. I guess its easier than ever just to pick a side than sift through it. That applies to all of us.

Andy P

I skimmed the article you linked, I wasn’t aware of the defueling stopping in 2002 but in my defence, I’m more familiar with Rosyth (which really doesn’t look like a post Cold War USSR base) and all the vessels up here are ’empty’.. Being picky you say “all” which suggests an agenda, they’re not ‘”all” fuelled as the article admits. While there will always be some who aren’t keen on having nuclear reactors (even ones with the rods dropped and the ignition key removed) its safe to say that corners really aren’t cut when it comes to nuclear safety. Again,… Read more »

Robert1

Decent amounts of info around about the overarching plan for dismantling (lots of public consultation between 2012-2015). All boats (Rosyth & Guz) all still have reactors onboard. Rosyth as you say all defuelled and some of Guz. Chopping bits out has started at Rosyth (think public accounts committee have a good report on the status of it all).

ChariotRider

Hi Rob,

The cost was included in the costs of at least some classes of SSN / SSBN (can’t say about the earliest boats), but I think the disposal costs were taken as savings during the last 30 or 40 years!

Cheers CR

Rob

Hi CR,
Thant about figures, short term gains, long term costs…

Billythefish

The fuel will be removed and reused in the next generation atomic power generation in the 2030s. Until then – they then sit there. No harm done.

Captain P Wash

Rob, I’ve been saying this for Years and Years, not just on sites like this but in the right places. All I gather from the responses given are that it’s a future generations problem, that includes the horrendous Costs too.

Daniele Mandelli

Alongside the QEC the jewels of the RN fleet and which set the RN apart from most navies.

6 or 7 way too few as others have noted and I place the blame for that with the politicians who were in charge at the time the last T boats were being ordered and the yawning gap allowed to appear afterwards disrupting our drumbeat and skills.

Andy P

The gap was an issue, Barrow had to let a lot of guys go after the V boats were built and it bit them on the arse with the A’s. You’d like to think all concerned have learned something from it but as everything seems to come down to short term thinking, and finance, I doubt it.

geoff

Hi Daniele. Hope all well in the Home Counties my friend.Seven is indeed too few. They are allegedly the finest of their kind in the world but to coin the overworked phrase they can only be in one spot at a time!
Cooling down in Durban now and the humidity has dissipated.24 degrees in the day but dropping to chilly teens in the evening

All the Best Geoff

Daniele Mandelli

Hi Geoff

Yes, thank you my friend. Scorcher today, off work, in the garden. Bliss.

Order of the Ditch

We need for submarines. The Swedes new submarine class the A26 is working out at about £320 million per unit. Us acquiring a class of 5 of these conventional subs to ease the load off the SSN fleet would therefore cost £1.6bn or about the same as a single Astute. What is better 5 extra subs or a single extra SSN?

AndyCee

A shame the last Astutes are in build, but the maths works out otherwise. And even the crewing – roughly 100 for an Astute and 17-26 (so Wikipedia says) for the A26s

Deep32

@OotD @AC We are in need of more SM assets, with Barrow at capacity there will be no more SSNs until SSN(R) is built-somewhere after Dreadnought hull 2 is completed. The only way to increase numbers is to build SSKs, UAVs are not currently mature enough to substitute them for the more demanding roles undertaking by Submarines, ie sub hunting. As a broad brush when comparing costs/crew you get roughly 3 SSKs for 1 SSN.. A26 or indeed a Soryu type would more then fit the bill in this case, they are able to conduct everything a SSN can do,… Read more »

Martin

I can’t see any useful roles that an SSK can fulfill for the RN to take pressure off of the SSN fleet. We did get rid of the Upholders for valid reasons. SSK’s will likely begin to be phased out soon as large USV’s can take over many of their taskings for a fraction of the cost.

Andy P

Sneakies, I suppose you could go unmanned but you’re potentially putting a lot of very sensitive equipment in a place where they’re more likely to get harvested. Small SSK’s could still be useful in places like the Gulf or even the Med.

Can’t see it but there is a role for smaller, shallower draft submarines leaving the A boat ‘big boys’ to do the high seas stuff.

Martin

True but we do this all this time with items like sonar buoys and SOSUS equipment. Depends how sensitive the onboard equipment is. If Manta is designed to be large and cheap then it’s not carrying anything like 2076. Could very well be using off the shelf sensors. It’s trickier If it’s armed with something like stingray but arming such platforms would probably be something done only in a time of war and if we can put Bimestone and Paveway IV on a Reaper over Afghanistan no reason why we can’t have stingray on a Manta. Also if Manta is… Read more »

Andy P

Its not just the sensor Martin, how does this information get passed back ?? There would need to be a some comms in there and there is a lot of stuff that would be of interest to ‘the baddies’ involved with that.

Its all a long way off so maybe not an issue in 20 years but for now there might be too many pitfalls. Just my take of course.

Sonik

That’s a very good point – subs main defence is stealth, on a manned sub that’s maintained by first line of decision-making being on the boat itself, avoiding uplink that can be detected. AI is a possiblity but that’s a whole new can of worms legally and morally. Sonarbouys and such are are expendable. Afghan is different too, due to low-tech adversary, any enemy of a sub is by definition much more technically capable. I imagine coms solution for unmanned will be directional links like MADL on F35, but that’s hard enough to get working in the air, and a… Read more »

Last edited 2 days ago by Sonik
Martin

AI is the only way for UUV as electronic communication with anything deeper than a few feet becomes nearly impossible. I don’t see it opening up any moral concerns for a sensor platform which is probably the most valuable use and if we do get in to ww3 then their will be much bigger moral concerns than AI subs.

Sonik

Yep AI is no issue for sensors I meant with regard to engagement. Moraly I take your point WRT to an existential situation like WW3, but in normal daily defence it’s not so simple. I would say you can’t defend our values of freedom and fair rule of law if you throw all that out the window in doing so, so it’s not so simple. We like to think we are morally superior to China, Russia, Terrorists etc so we have to live up to that. Hence I predict role of AI will become a bit of a minefield in… Read more »

Last edited 2 days ago by Sonik
Martin

Yes I agree but I see “unmanned armed” AI platforms being an easy precursor to armed AI platforms and very much finding out that they are fitted for but not with. NATO naval superiority is so overwhelming than I can envisage a situation where would we need such a thing other than operating close to the Chinese coast in an all out shooting war where friendly civilian traffic will be clear and the Chinese would probably be operating similar AI platforms. The real challenge for the AI is locating targets and operating in general. If it can do that then… Read more »

Martin

Depends again on what your using. We just bought a world wide Low earth orbit commercial satellite array offering global broad band coverage. So we don’t need super secret communications necessarily and the platforms are suppose to be autonomous. In an all out shooting match where you might tell it to stay off the kola peninsular or Hainan island then it basically becomes a type of reloadable and reprogrammable mine that can be deployed at long range. If it’s just floating in the Atlantic augmenting SOSUS coverage then it’s simply a moving SOSUS buoy and we have been dropping them… Read more »

Deep32

Can I ask what do you think Manta will be able to do exactly? For one it won’t be carrying any weapons-MOD have already stated as much, for obvious reasons. Sinking the wrong ship is not good PR!!!! For it to be of use to detect a SM it will require a Tower Array, or will literally have to run into one to detect it. That will be the start of the issues with UAV detecting , classifying and tracking SMs. If they ever get the AI to this stage, what then are they going to do with said information?… Read more »

Martin

Given there is virtually zero naval threat to the UK at present outside of a few choke points then there is no need for an armed XLUUV much the same as their is no need for SSK’s in UK service. So Manta will focus on sensors providing wide area surveillance in the Atlantic and possibly on sensor deployment in sensitive areas like South China Sea. However I have no doubt the platform will be fitted with Mission bays able to eventually accept weapons such as stingray or even up to spearfish. With the exclusion of launching TLAM and Conqueror in… Read more »

Deep32

Hi Martin, sorry, but I have to disagree with your comments above. We are in need of more SMs, whether SSNs or SSKs is a mute point, ideally more SSNs, but we are at build capacity in nuclear SMs , so realistically the only way of increasing numbers is via SSKs. It won’t happen though as HMG has no ambition in this direction so won’t pay for it. You greatly underestimate the threat potential of Russian SMs, even their older Akulas are still pretty good units, they are building new units and their activity in the North Atlantic is steadily… Read more »

Order of the Ditch

The SSKs used to be used for Perisher courses, but SSKs would be good for protecting the CASD until it reach the Atlantic. Med and UK coastal patrols could be covered by SSKs as well.

Martin

I just don’t see the UK having any real need of costal defence beyond CASD protection but I think that’s probably better covered by aircraft and frigates and deep Atlantic is probably a bit too much for such a platform on a regular basis.

If we were in a position such as in the Cold War facing off against the Red Banner Fleet I would agree. However for the price of one SSK you can get dozens of XLUUV like Manta better able to carry out missions like costal monitoring and holding choke points.

dan

Machines guns. They expecting trouble in their home port? lol

Daniele Mandelli

Were you expecting trouble on 9/11?
Were we expecting trouble In July 2005?

They’re not in HMNB yet while running in.

You never know and plan for all contingencies.

dan

I wonder if this is just something the Captain ordered or whether it’s SOP for all RN subs no matter which port they are entering?

Jonathan

It’s not so much being decommissioned as tied up with all the rest waiting for:

A) Some other government finally dealing with it (in say 30 years).
B) a major radiological incident that means everyone has to be evacuated from Devonport and the Plymouth surrounds for the next 50 years….which is money saving when you think about it ( we would all feel a bit sorry for Saltash, but having Mutley evacuated would worth it).

Last edited 2 days ago by Jonathan
Nate m

salute to the her crew. keep it up boys.