The UK’s Royal Navy just commissioned a former commercial
offshore support vessel (OSV) into the fleet as HMS Stirling Castle, a mine countermeasures (MCM)
mothership.
The ship – previously named MV Island Crown – was acquired from the commercial market for £39.8 million at the start of 2023 to provide a UK host platform for autonomous MCM payloads … [1]
So, for the sum of around $51M(US), the Royal Navy acquired a mine countermeasures ship. Of course, there had to have been additional expenses in converting it from its commercial role to a naval MCM ship although one cannot imagine the scope of work or the cost would be too significant since the roles are not all that different. Compare that cost to the cost of a new, purpose built MCM ship and the Royal Navy likely saved something on the order of $300M.
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| HMS Stirling Castle |
The salient question, though, is how well suited is the
vessel for its new role? The ship’s
duties are described as:
Stirling Castle…will now take her place on front-line duties, carrying high-tech equipment, including autonomous surface and underwater vehicles, for specialist mine hunting operations, primarily in UK waters.[1]
This is not a terribly demanding role and consists primarily of launching and recovering unmanned MCM assets, not too dissimilar from its previous role of loading and unloading supplies. Is the ship exquisitely optimized for the role? Of course not but is it adequate? Almost certainly … and for a substantial savings.
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This is exactly the kind of pragmatic, responsible action
that the US Navy should be engaged in.
At the moment, we have no viable MCM ships. The LCS remains a joke both in terms of its non-existent
capabilities and inadequate numbers.
Wouldn’t some US Navy $50M MCM motherships look pretty good about now?
https://www.navalnews.com/naval-news/2025/07/uk-royal-navy-commissions-hms-stirling-castle-as-first-mhc-mother-ship/
Performed a google search, & MCM vessels should have low accoustic signature. My take: This would mean quite a bit of modification to accomplish. As I Recall the lCS did not have low accoustic signature, with a mine detection sonar . So a MCM vessel would stand off & let the unmanned UUV do the detection ? One would think the mother ship should be able to detect as well ! Just my opinion ! PB
ReplyDeleteThere's a clear distinction between an active MCM vessel and a mothership. The former is actively involved in detection, classification, and neutralization. The latter merely hosts the assets that do the detection, classification, and neutralization. The mothership simply launches and recovers the assets ... and perhaps hosts some computer analysis of the data. The mothership doesn't need any quieting or other anti-mine features since it is not intended to go anywhere near the minefield.
DeleteYou might also recall this passage from the post: "Is the ship exquisitely optimized for the role? Of course not ..."
No one is stating that the vessel is the ultimate, most perfectly suited vessel ever conceived for MCM work. What we're saying is that, as a mothership that cost a pittance of $50M, it's perfectly adequate.
"One would think the mother ship should be able to detect as well"
Why? Would you think a destroyer tender mothership should be able to launch torpedoes or attack enemy ships? Of course not, so why would you expect a MCM mothership to be/do anything other than host the assets that actually do the work?
So, with all that firmly in mind, what problems, if any, do you have with the concept?
The RFA Proteus is another example of needing a ship
Deleteand adapting a commercial vessel in this case Multi role Ocean Surveillance. After the Nord Stream incident the RN needed something to inspect the ocean floor.
9 month to convert.
"RFA Proteus"
DeleteI'm not familiar with that one but it illustrates the concept that no every naval task/mission requires a dedicated, purpose-built, navy ship to execute. Many times a commercial vessel with some modifications can do the job just fine.
Alternatively, the Navy could be asking commercial builders to build a standard commercial ship with the minimal naval task-specific adaptations built in during construction - a commercial ship with conversion already built in. It's got to be many times cheaper than a purpose-built naval vessel.
Thanks for your explanation ! Now I see the difference ! PB
DeleteHappy to help!
DeleteThese Oil industry vessels are all powered by diesel electric power plants powering multiple thrusters which gives them a reasonable cruise speed (12-14 Knots) and a position keeping capability. They make less noise than you think. If trouble really happens Navies will buy then up for ay number of tasks because there a lot of them available.
DeleteIt is really interesting to note that in the age of Sails, it was quite natural to convert a captured merchant vessel to naval use. Of course it was not a Ship of the Line but did a host of smaller but essential tasks
ReplyDelete-BM
The Russians have got the largest fleet of MCM ships in the world - 47. I guess they see they’re vulnerable to a mine blockade of the Baltic choke points so planning for that. Looking to build 30 more in the next ten years. Full marks for Good Planning anyway.
ReplyDeleteGoogle search says we have 8 old Avenger Class ships in various states of rust and disrepair and that’s it. Less than third world navies.
A couple mines outside an LNG export hubs would be a disaster and we probably wouldn’t even be sure who laid them or how many there were. Why is nobody worried about this?
I like your idea of getting commercial yards to build an interim replacement class - did I understand that right? Or should we just repurpose civilian ships?
Hard to understand Navy priorities sometimes.
JM
The rest of the Avengers will be gone by 2027 and the existing ones are not seaworthy or, for the few that might be, barely so. The MH-53E MCM helos are long overdue for retirement and, like the Avengers, barely flightworthy, if that. For practical purposes, the Navy has no mine clearance capability.
DeleteWas this something that was ‘thought through’ - ie did someone make a decision that the Avenger Class was approaching the end of its useful life but that a new MCM fleet wasn’t necessary, or was it some sort of oversight - ie we just kinda forgot about it - or maybe not glamorous or something? Thanks.
Delete"Was this something that was ‘thought through'"
DeleteYes, it was thought through. The Navy's plan was for the LCS to take over the MCM role. Of course, we know how that turned out. So, yes, they had a plan but it was a badly flawed one with even worse execution.
Thanks.
Deletefyi - when I tried to drill down a bit and asked AI why the LCSs sucked at MCM It came back with an answer that basically referenced a previous thread on your blog and quoted you pretty much word for word. Congrats!
"asked AI"
DeleteYeah ... ... I'm not a fan of AI. It weakens our abilities just like calculators have left an entire generation or more unable to do simple math unaided. AI makes us dumb and lazy.
Okay thanks.
DeleteSince the LCSs didn’t work out does the Navy have a Plan B?
A couple months ago the Iranians were threatening to mine the Strait of Hormuz and shut off the entire world from Middle East oil.
Surely there must of been a contingency plan for dealing with something like that ?
The Navy doesn’t seem to realize how urgent this is.
"does the Navy have a Plan B?"
DeleteI think crossing their fingers and hoping is Plan B. They are completely delusional about MCM.
If the US would approach the world as a global entity, they could enlist/encourage the lesser military countries to focus on the areas the US is weak, like mine warfare and mine countermeasures. That would be a vital, worthwhile, and COORDINATED international naval cooperation.
That would be sensible - it sounds like MCM is a low capex sort of thing and doesn’t need a lot of big ships to crew. If or when there’s round 2 with Iran the Gulf states should own the MCM since they’re the guys who are gonna have their oil exports shut off.
DeleteWe don’t need Middle East oil but the Europeans sure do so they could focus their efforts on that instead of building a bunch of multi billion dollar frigates that would probably just get in the way of things.
Right now the first thing we’re probably going to know that we’re at war is when a LNG carrier hits a mine or a big merchant ship goes down off Baltimore or something.
Seems to me we got a few MCM motherships already bought and paid for. Since we're out of the amphib assault business, convert some of the older amphibs, they even come with a hanger, flight deck, cranes and well deck. Take some of them 5 ton unmanned vessels the Navy likes so well and turn them into unmanned mine sweepers. Should be able to get at least four of them in a well deck. If they blow up on a mine, big deal, build them cheap and use them like you stole them. It's a mothership, sit back out of harms way and let the unmanned assets do the dirty work,
ReplyDelete"convert some of the older amphibs"
DeleteThose are way too big and costly to operate but as an interim, stopgap measure ... sure.
"5 ton unmanned vessels the Navy likes so well and turn them into unmanned mine sweepers."
I really like this idea! They have the size and power to act as true sweepers and, being unmanned, we can afford to lose them. The only thing I might do is reconsider the materials of construction (non-magnetic).
Everyone else is trying to use tiny unmanned boats for sweep pullers and I'm sure they'll turn out to be underpowered with poor endurance and useless in anything other than glass calm seas.
Unmanned boats for MCM are nothing really new. The German Navy has introduced the unmanned Seehund class in 1980. This vessels are used to trigger acoustic mines simulating ship noises via a towed array. These boats have been designed for the Baltic sea and have good seakeeping qualities even in bad weather. Each MCM vessel controls 3 or 4 of these remotely.
ReplyDelete"Unmanned boats for MCM are nothing really new."
DeleteTrue, they're nothing new but no one claimed they were. In a sense, the first unmanned MCM was the streaming paravane. It was an autonomously piloted, unmanned vehicle that deployed a tow/cutter cable. Even better, it required no fuel or power source!!!! No manning, no fuel ... it's the dream weapon system of the modern navy!!!! And we had it a hundred years ago!!!!
Back to 1972, China used unmanned mine sweeper (type 312) to sweep mines laid by US in then North Vietnam water. Post war information showed China swept away 76% mines laid by Pentagon.
Deletehttps://www.globalsecurity.org/military/world/china/ship-mine-vn.htm
One problem of use civilian ship is that they are not constructed study enough thus can be easily sunk once hit.
"Post war information showed China swept away 76% mines laid by Pentagon."
DeleteUtterly false. The passage you cite has a very confusing reference that seems to suggest some creative number crunching. At face value, the statement would mean that less than a hundred mines were ever laid and this is absolutely false. For example, also from Global Security (a questionable site, at best),
"Early on the morning of 8 May 1972, aircraft carrier Coral Sea (CVA 43) launched three Marine A-6 Intruders and six Navy A-7 Corsair attack planes toward the coast of North Vietnam. Shortly afterward, the naval aircraft laid strings of thirty-six 1,000-pound Mark 52 mines in the water approaches to Haiphong, through which most of North Vietnam's imported war material and all of its fuel supply passed. During succeeding months, other carrier aircraft dropped thousands of mines and 500-pound, Mark 36 Destructors in the seaways of North Vietnam's secondary ports and "reseeded" the Haiphong approaches."
Note the reference to "thousands of mines".
I'll leave your comment up for a brief period so that you may see this and then I'll delete your comment as factually inaccurate.
We've touched on the lack of MCM a lot, and obviously it's somthing important that's not getting proper attention. With all the recent focus on individual mine hunting (USN and others), it makes me realize that I really don't understand the modern mine threat. Things have obviously progressed past those spiny spheres... contact mines... but what are we truly facing? With things like CAPTOR, and mines that may be smart enough to wait for certain acoustic signatures, or may ignore certain sounds or a certain number of ships before activating... is mine "sweeping" a dead art?? Are we stuck hunting for mines individually because they're so much more complex? I've decried the Avengers reaching their end without replacement, and the HM squadrons as well... but.. are they actually obsolete in a modern mine environment? Are modern mines, sowed in any quantity, a barrier that is nearly impossible to overcome with any speed at all??
ReplyDelete"is mine "sweeping" a dead art??"
DeleteTHAT'S the key question. There are very few sweep devices out there and, to the best of my knowledge, none have been tested in any remotely realistic scenario. Can sweeping still be effective? As best I can tell, no one knows. As best I can speculate, sweeping will not be very effective.
There has been very little advancement in sweeping technology since WWII. There are one or two units out there that claim to be able to modulate their output frequencies but whether that will be effective is unknown.
"Are we stuck hunting for mines individually"
Yes, but not necessarily because of any technological constraint but because the Western navies have forgotten what true warfare, and true mine warfare is like. They've forgotten that mines are not laid in ones and twos but in tens of thousands. The West has also become enamored of technology for its own sake, hence the obsession with unmanned, autonomous robotic hunters ... which can clear perhaps one mine per hour on a good day and in good weather.
"Avengers ... and the HM squadrons ... are they actually obsolete in a modern mine environment?"
Bear in mind that both the Avengers and the helos are not, themselves neutralizers of mines. It's the equipment they carry that find and neutralize the mines. That's semantics and definitions a little bit but it's important to remember that those platforms are, basically, motherships to the equipment that they launch, tow, or otherwise employ. The better question is do we have the effective individual equipment that will make the Avengers/helos or their replacements effective?
"Are modern mines, sowed in any quantity, a barrier that is nearly impossible to overcome with any speed at all??"
Given our modern intolerance for casualties of any kind, yes. In WWII, they swept the best they could and then proceeded forward and accepted a certain level of losses to mines. We have lost that ruthless, hard-hearted acceptance of losses as part of the calculus of war and it cripples us. We can no longer conceive of operations with risk and acceptable losses.
You make great points. But can modern mine hunting sonars detect all of the various modern mines ? Can a UUV sonar do the same? I would like to see a dummy mine field planted ( representing the mines described) and then test ! Perhaps DARPA can experiment.
ReplyDelete"can modern mine hunting sonars detect all of the various modern mines"
DeleteIt all depends on the conditions. If you hang a mine, any mine, in ten feet in front of a sonar with nothing else around it then, yes, it will detect it. If you place that mine on the sea bottom and cover it with dirt and debris, it may well escape detection. A moored mine in acoustically noisy waters with poor sound propagation may or may not be detected.
You also may not understand what 'detection' means. Sonar simply produces echos that the software attempts to present in a form that the operator can look at and make a judgement about what he sees. Is that sound reflection from a rock, a whale, or a mine? Is that indistinct lump on the bottom a mine or just one of the millions of normal bottom rocks and debris. The sonar 'detected' it. The question is whether the operator and software can correctly interpret it.
Most unmanned mine hunting vehicles make their pass, collect the data, and return to their mothership where the data is uploaded for operators and software to analyze to try to pick out the actual mines, if any.
If you've ever seen a medical X-ray, you see mostly indistinct shadows and blurs of light. Two different radiologists can look at the same X-ray and reach different conclusions. There's an art, backed by science and training, to reading an X-ray. Sonar is similar.
Hopefully, that gives you a better understanding of mine detection.
Some years ago, there was experimental work being done into using lasers to create a visual image of the shit underwater (similar concept to using synthetic apeture radar to generate reconnaisance imagery). Unfortunately it seems that it hasn't panned out, which is a pity because that could have conceivably made the process a lot faster.
Delete"Unfortunately it seems that it hasn't panned out"
DeleteThere have been many attempts at mine detection using various methods but, thus far, none have panned out in any real world setting.
fyi
ReplyDeletehttps://www.navylookout.com/in-focus-royal-navy-minesweeping-capability-restored/
I do not encourage links without an accompanying analysis or other value-added contribution. What about the article caught your eye? Assuming you read the article, what did you think of it?
DeleteQuite a good article actually. I read it myself. It details the drone capabilities. As mentioned in other comments, this assets sweeps mine fields simulating (via towed pontoons) larger vessel magnetic and acoustic signatures . It does quite a lot actually.
DeleteIt explains WHY Stirling Castle can stand off so far and doesn't need to be "exquisitely" specified.
Oh, There is also a little bit of details about the difference between MINE HUNTING and MINE SWEEPING which I found quite interesting too.
Delete"Quite a good article actually."
DeleteOnly in the negative sense. It [probably inadvertently] exposes the problems with the modern, Western approach to mine countermeasures.
The number one flaw in modern, Western MCM is that it is slooooow and is suited only for very small areas. As the article states,
"Although slow, mine hunting is well suited to clearing confined or high-risk areas such as harbour entrances or narrow straits"
Without meaning to, this is stating that modern MCM is not capable of clearing large minefields such as area denial fields nor is it capable of clearing approaches to assault sites or even landing craft lanes. Study the Normandy minesweeping operation to see just how lacking modern MCM is.
The article acknowledges this,
"Minesweeping (MS), by contrast, remains the only practical way to rapidly clear or verify larger sea areas."
"The RN has now restored a minesweeping capability"
No, it has restored an unproven fantasy that is, in all likelihood, incapable of the intended sweep function.
Now, here's the absolute key statement that proves just how fantasy-based sweeping currently is:
"While the system has not yet detonated live mines in trials, it has been evaluated against operational mine algorithms"
No live exercise, yet. Simulation only. Well, guess what? Simulations always work - it's just a matter of programming them the way you want. Reality exposes the flaws. A real life mine explosion will hugely roil the water and obscure all signals, incoming and outgoing for a period of time. How will that affect the sweep effectiveness and efficiency? No one knows. Themoclines will impact signals. How will that affect the sweep effectiveness and efficiency? No one knows. Wave action will affect the sweeps. How will that affect the sweep effectiveness and efficiency? No one knows. And so on.
Instead of being the puff piece that the author intended, the article was actually a vivid condemnation of the modern, Western MCM approach if you know how to read and interpret it properly.
To me the greatest failure of the LCS program wasn't the anemic vessels, it was the failure of the module programs. Had the money wasted on pathetic hulls instead be used to create useful, functioning, container-based MCM, ASW, and light Surface warfare systems. These wouldn't have needed a purpose-built ship. We could have built more merchant vessels (which we still sorely need) and converted anything from an oil rig crew supply vessel to a full on containership to do some of the work. Larger commercial vessels already have a helo spot.
ReplyDeleteAs you stated, not ideal but useful in the right circumstance. Once we started doing that, the commercial industry would see that they could make a lot profitable GRP hulled light container vessels for MCM, and acoustically isolated small vessels for ASW because there is no need for tight integration or going through the insanely complicated route of trying for a military contract in a field dominated by the big Navy contractors. This kind of economic competition against the current big contractors would force them to lower their costs, or at the very least improve quality control. That's the power of free enterprise.
Currently we are basically a capitalist country who tries to build a Navy like socialists.
"create useful, functioning, container-based MCM, ASW, and light Surface warfare systems."
DeleteCareful, here. ASW, for example, MUST be exquisitely integrated with the ship's hull from the first rivet. Quieting MUST be built into the ship and no module or container can do that. Anything less than a fully integrated ASW function is just a sunken ship waiting to happen.
Similarly, unless you're contemplating a suicide vessel, anti-surface warfare MUST be tightly integrated with the hull. A slow, lumbering, non-stealthy, commercial vessel with a container of missiles is going to lose to a purpose built surface warship every time. You need top level stealth, extensive passive detection sensors, stealthy UAVs, etc. in order to have a chance to find the enemy first and strike first.
MCM is the one area where a container approach might be possible, depending on the specific MCM equipment. This would, essentially, be the mothership approach for sweeps and searches.
"the greatest failure of the LCS program"
DeleteThe greatest failure of the LCS program was that it began with an absurd concept (the entire littoral thing) and that was compounded by being entirely dependent on non-existent technology (the modules).
Here's a couple ideasfor future posts that you could sink your claws into: 'Why is fleet maintenance such a challenge for the Navy when the cruise boat industry seems to have it down (mostly) pat?' And...closely related ...'What's up with this "right to repair" thing? How's that gonna work out when the shooting starts?'
ReplyDeleteI would love to hear opinions (and maybe a few facts) about these topics.
I suspect a post is not needed. The maintenance issue is too simple. Maintenance problems are driven by two main factors:
Delete1. Environmental laws that make maintenance difficult or impossible such as those that result in lower quality coatings or forbid scraping of rust/paint in port due to possible water contamination.
2. The Navy's conscious decision to reduce manpower and focus the available manhours on issues other than maintenance such as diversity, gender equity, climate, etc.
A contributing factor, compared to the cruise industry, is that cruise ships do not spend many months at sea on useless, interminable deployments, away from port maintenance facilities. And, of course, ship appearance is a high priority for the cruise industry as opposed to the Navy where it is not a priority at all.
I'm vaguely familiar with the idiotic right to repair movement but I've never heard it discussed in conjunction with naval ships or aircraft.