As part of a series covering UK naval infrastructure, here we look at the little-known facilities used to evaluate the acoustic and magnetic signatures of the navy’s ships and submarines.
The RN invests a great deal in ensuring the nose emitted from its submarines and frigates is minimised. When new vessels enter service or have been in a long period of upkeep or maintenance, the effectiveness of these silencing efforts needs to be measured and evaluated. The data gathered from these evaluations allow the operators to understand the particular sound signature the vessel emits into the water and which items of machinery are responsible for creating sounds at particular frequencies. Even ships or submarines of the same class may have subtly variable characteristics as each vessel is unique. Each may received slightly different equipment over time and been subject to different stresses and wear and tear, etc. This knowledge will help inform which machinery may be run and at what speed in different tactical scenarios. The evaluation may also show up deficiencies in equipment that needs further rectification to reduce noise and vibration before the vessel is ready for operations.
It is also necessary to test and calibrate the performance of active and passive sonars in benign and quiet waters before being used operationally. Additionally, torpedoes and underwater decoys need to be trialled in controlled conditions where their performance can be accurately monitored before they can be certified for frontline use.
In order to conduct this testing regime, a series of ranges have been established around the UK. There are small ranges on the South coast off Portsmouth, Portland and Plymouth but the key sites are situated in North West Scotland. These sites were formerly operated by the Defence Evaluation and Research Agency (DERA) and remain MoD-owned but are operated by QinetiQ, DERA’s privatised successor. In 2003 the MoD signed a £1.3Bn Long Term Partnering Agreement (LTPA) with QinetiQ who provide experimentation, test, evaluation and training support to the MoD at 15 land, sea and air ranges. In 2019 QinetiQ agreed to invest a further £190m at various sites including a provision to upgrade the ranges for testing the Dreadnought and Astute class submarines.Scottish-Naval-Range-Facilities-Map
Besides sound signatures, the magnetic signature of warships and submarines are also minimised using internal degaussing coils and external deperming coils. This is primarily to reduce the ship’s magnetic field in order to make them less vulnerable to mines, torpedoes or sensors that rely on magnetic detection. To evaluate the magnetic signature of vessels Qinetiq operates several degaussing ranges in the UK that measure a ship’s magnetic field as it passes over cables on the seabed.
At the naval bases, there are small Harbour Entrance Ranges (HER) that automatically gather the magnetic signatures of vessels as they enter or leave harbour. At Devonport the range is at Eastern Kings and Faslane is served by a range at Rosneath. There are also Open Sea Ranges (OSR) in deeper water at Pier Cellars off Plymouth (20m depth), Portland (9m) and Barons Point on the Clyde (30m).
The OSRs are operated from control buildings ashore and connected by cables to a large coil lying on the seabed. The vessels make passes over the coil and the strength of the electromagnetic field is adjusted to either neutralise or bias the magnetic field of the steel hull and its ferrous components. The vessel’s magnetic signature is continually monitored and the process is repeated until the correct signature is achieved.
The silent lochs
Loch Goil is a tributary of Loch Long, home of RNAD Coulport where Trident missiles are loaded onto the nuclear deterrent submarines. 82 meters deep and sheltered by surrounding hills and distant from underwater noise sources, it is the ideal environment for measuring sound in water. The main facilities buildings are located at the head of the loch and include a control room, workshop, offices, conference room and accommodation for around 30 personnel. The 0.5 km2 range covers the upper half of the loch and is primarily used to evaluate acoustic signatures of ships and submarines (both surfaced and submerged) while moored between four buoys.
Sound data is collected by hydrophones suspended from buoys placed around the vessel under test as well as from a series of fixed hydrophones located on the bottom of the loch. Submarines may also be bombarded with calibrated sound sources, simulating active sonar to measure their Target Echo Strength (TES) so as to determine the effectiveness of their hull shaping and anechoic tiles in absorbing sound waves.
Loch Goil is also used for other static underwater trials and in 2012 HMS Astute conducted an ESCAPEX. Submerged to 28m depth in the loch, volunteer submariners successfully conducted ascents from the Forward Escape Tower (FET) to prove the new escape system on the boat.
The main image above shows HMS Richmond on the Loch Goil range in May 2022. As the only Type 23 frigate so far to have completed the Power Generation Machinery Upgrade (PGMU) with new diesel generators in acoustic enclosures, she will have a significantly different, and hopefully reduced, sound signature compared to her sister ships. Improved stealth was not the main reason for the upgrade but an important benefit that can be assessed using measurements taken on the ranges. As a static range, radiated noise assessment at Loch Goil is focussed on that from sonars, together with auxiliary machinery and generators.
To assess the noise from main propulsion systems, the much larger range at Loch Fyne is used allowing surface ships to be evaluated while steaming at speeds up to 20 knots and submerged submarines up to 14 knots. The instrumented area is about 5km in length, 1km wide and about 140 meters deep. The RN’s large nuclear submarines rarely use this range but it is occasionally used by smaller conventional NATO boats. Placed in the bottom of the loch, there are an extensive array of hydrophones covering various target aspects. Two sets of lights, one located at Leanach and another on Strone Point provide navigational reference points for vessels underway on the range to keep them on the correct course relative to the hydrophones. Target vessels can be accurately tracked using a Differential Global Positioning System (DGPS) and coordinated from the range control building on the eastern shore of the loch.
The third noise range in Scottish waters is the Rona Noise Range is situated between the Isle of Skye and the mainland. It is primarily used by submarines as the only UK range that has the space to allow submerged boats to reach full speed. The test area is around 12km long by 4km wide and has an average depth of 235m. The Hebridean Islands and the Scottish mainland provide shelter on three sides which helps isolate the range from the ambient noise of the ocean.
The range is equipped with sensors comprising 8 noise measurement hydrophones and 9 underwater tracking hydrophones. These are connected by cables to the terminal buildings at the northern end of the island of Rona, where data is recorded and analysed. The underwater signatures of submarines are especially sensitive information and is highly classified.
To the South of the Rona Range and is the most sophisticated naval range in the UK. The British Underwater Test and Evaluation Centre (BUTEC) provides real-time tracking in three dimensions above and below the water and is used in the trials, testing, calibration and development of submarines, UUVs, torpedoes, underwater weapons, decoys, sonars and above-water systems. BUTEC was established in the 1970s and has seen significant investment since, including further modernisation as part of the Qinetiq-MoD LTPA contract amendment announced in 2019.
Local bye-laws prevent public access, limit fishing in the area and the airspace up to 1,500 feet over the range can be restricted when required. The deep water, soft sea bed, shelter from wind and swells together with low levels of ambient ocean noise make the site ideal. The instrumented inner sea area is about 10km long and 6km wide, having a depth of up to 200m.BUTEC-and-Rona-Ranges-3
Sophisticated sensor arrays are installed in the inner sound and monitored from the Applecross range terminal buildings. BUTEC is supported by the logistics and administrative depot at Kyle of Lochalsh which has a harbour used by the range vessels operated by Serco.
Royal Navy submarines regularly visit BUTEC to certify crews and equipment in weapon and operational skills. Inert weapons clearance (Spearfish torpedo and TLAM) trials for the Astute class boats were conducted at BUTEC. For more sophisticated submarine tactical trials and development including test-firing Trident missiles, the RN makes use of the US Atlantic Undersea Test and Evaluation Center (AUTEC). Located in the Tounge of the Ocean basin in the Bahamas, this vast facility is 90 km long by 28km wide and 1,800m deep in places.
Development of sonars is facilitated at BUTEC with a floating laboratory and includes towed array calibrations, mine warfare development, hydrophone calibration and measurements of target echo strength and beam pattern trials on submarines and ships. There is a sonobuoy test facility (STF) at BUTEC which was recently upgraded in partnership with Ultra Electronics. The STF certifies that production samples meet their specifications, and supports the development of new sonobuoy types. Qinetiq also maintains underwater acoustic targets, torpedo-sized vehicles that simulate the noise and echo strength of a submarine for ASW training purposes.
The geography of Scotland provides the optimal environment for these ranges with deep, sheltered sea lochs, conveniently located for the Faslane submarine base and main submarine operating areas of the North Atlantic. In the event of independence, besides the enormous expense, it would be difficult to relocate these facilities as there are no equivalent sites in the rest of the UK that can match the geography of Scotland. There is a small noise range at Grove Point off Portland but located in relatively shallow water of 22 metres with just 3 hydrophones and exposed to ambient sounds of the busy English Channel.
The facilities described above are another example of low-profile but critical infrastructure needed to maintain an effective navy, especially through acoustic hygiene that can provide a battle-winning advantage in underwater warfare.
That is all…..
Nice places around there.
Used to spend a lot of time in that area in my younger days.
Trouble is the roads are so bad it takes an age to get anywhere.
QinetQ also has a deployable range facility for the MCMV force in the Gulf. It can be set up and conduct noise and magnetic signature ranging locally for the UKNSF based ships.
Important point. In peacetime RN ships never enter a harbour (except for those named above) with DG on. If they did you could get fingerprinted and give an enemy important ship signature data.
“give an enemy important ship signature data.’
Would that be the ‘all knowing, all capable’ enemy ?
You never know who may have dropped a hydrophone or magnetometer at a harbour entrance. The nation in question may not even know something has been left there by a third party. Its the same policy as EMCOM. Don’t make it easy to fingerprint your assets so that the information could be used against you in the future.
Are the Chinese balloons overhead yet? From that not interesting part of Asia?
Nose emitting? Causing a stink?
The largest European navy by tonnage is RN by miles.
When T26 and T31 come in it will have a low average age per ship.
Compare that to the Russian scrap heap approach or the other theoretically large navies padded out with Cold War relics.
You know the only other truly global navy apart from the USN…that one.
You doubt the French have a blue-water navy when Operation Jeanne d’Arc is literally a round the world trip this year?
The French do have a blue water navy. But there are different grades of blue water navy, proffessor D Todd’s hierarchy Is a good one, as blue water navy describes any navy that can really operate from around 1500NMs from base and has ASW and AAW assets as well as the ability to sustain deployment through RAS there are around 13 of those in the world. The more sensitive hierarchies split blue water navies into around 4 groupings from global power projection to regional power projection. Generally the RN skips between global power projection and limited global power projection, with La Royal Sitting just below the RN usually, due in the main to the RNs better support structures ( the RN is still able to support multiple global deployments, just about).
Plus the French actually have considerable territories in the South pacific still- UK has Pitcairn!
Plus theres an island well off Mexico ( Clipperton Is) which they have long claimed even though its 1000s of km from the Tahitian islands.
US also has some island territories in odd places , which they dont mention when China says distant islands like Paracels are theirs
Remember the Astute grounding in 2010
‘The inquiry found poor planning and communications, combined with a failure to adhere to correct procedures, had been to blame for the £1.2 billion vessel being left marooned near the Kyle of Lochalsh.’
It seems that was the real reason it was in the immediate area was the Butec Range, but another cover story put out
Not sure why a new submarine undertaking trials on a test range would need a cover story. Doesn’t excuse the actions that led to the grounding but the reason it was in the area was pretty well known, you can see the range from the road.
The story alludes to the ‘trials’ but completely avoids mentioning Butec, which isn’t exactly a secret.
The board of enquiry report refers to Astute having been on the “noise range” and includes detailed charts. There is no attempt to cover anything up https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/27118/astute_grounding_si_report.pdf
The media stories seem to refer to some ‘transfer from sub to helicopter’. They could have only have got that story from the MoD media spin doctors.
It seems later enquiry gave the full story, as it wasnt really a secret but media interest had moved on.
Media spin 101
Sounds a lot like the grounding of the good old 16 inch-gunned battleship HMS Nelson in earlier times, groundings happen fairly often IMHO
With the Carriers getting in and out of Rosyth for maintenance we can exppect more of them in the future til the RN finds or renovates another dockyard, they exist in British waters but are mostly abandoned.
China has surpassed the United States in the number of land-based intercontinental ballistic missile (ICBM) launchers it possesses.
The Pentagon estimates that China currently has approximately 300 total ICBMs in its rocket force, including those used by both fixed and mobile launchers.
Four main ballistic missile types are currently known to be in Chinese inventory. DF-4 entered service in 1980 and is a transportable, liquid-fueled missile with a single nuclear warhead and a range of up to 3,417 miles. DF-5 is a silo-based liquid-fueled ICBM that entered service in 1981 and has a range of around 8,077 miles. A DF-5A variant carries a single warhead while DF-5B carries multiple independently targeted warheads, and the Pentagon believes a DF-5C is now in development as well.
Third on the list is DF-31, a solid-fueled missile that entered service in 2006, carries a single warhead, and has a range of up to 7,270 miles. Finally is DF-41, a road-mobile ICBM that was first tested in 2012 but has yet to officially enter operational service despite the country having already explored a train-based launch system for the missile. DF-41 is solid-fueled, can carry up to 10 warheads, and has a range of about 9,320 miles.
Well the us has 400 minutemen 3 ICBMs that can take 3 warheads each although only carry 1 at present.. In total at present the US has around 1300+ warheads on strategic ballistic missiles and around 300 for air launched platforms and 100 air launched tactical weapons in Europe. For a total of 1700+ deployed warheads…it has about the same again in storage and another same again in retired warheads that are stored intact for a total of 5000+ warheads…China has around 400 warheads in total….
Buts it’s all academic because if the USA launched its 1300 warheads on strategic ballistic missiles, the human race is probably done for even if no one fired back…. as crop production and black soot modelling has evidenced that around 100 nuclear warhead dropped would remove around 10% of the worlds crop production. For a decade…1300 warheads =no crop production for a decade which = no more people.
I have a vague memory of a British firm, 15-25 years ago?, came up with a cheap way of building icebreakers. The hull would have been two thin sheets of steel, with a layer of plastic inbetween. I think they partnered with BASF, on construction & recycling techniques. Might be a cheap way of armouring up & quietening a frigate or Destroyer hull?
It would have to be carbon fibre . Thats expensive and since an icebreaker needs about 1.75 in max thickness at the front they will continue with that. Scantlings increased as well
No, it was BASF plastic of some sort.
This is all really good and very impressive and it definitely demonstrates that the “bones” of the Royal Navy (and in fact, of the entire UK defence establishment) are still very strong. Again, however, the military in general and the Navy in particular are too small. They just are. You know it’s bad when a blog dedicated to UK land forces is advocating for a bigger Royal Navy. If even the landlubbers are worried, you’ve got big problems.
The answer is screamingly obvious and not expensive as such things go. What is wrong with Parliament and the MOD that this doesn’t get done yesterday?
Not happening because of this fanciful notion of ‘corvettes’ based on history. Also when a long ago time subs were far slower and AS warfare was dropping a pattern of 12 depth charges directly on top of the target. The main warship builders in 1939 were already full and to enable the smaller yards – which dont exist anymore- build ships to fit the slipways and to mostly commercial standards and in less than 9 months.
The Russians just dont have that many submarines – apart from those mostly dockside- plus they face the combined naval forces of Nato not just Britain
I would think it is quite obvious that the warships proposed in that article bear virtually no resemblance to WWII Flower class vessels. A present day “corvette” would be a multirole vessel (albeit with an emphasis on ASW) that would certainly be considered a “frigate” in most navies until the past 20 years or so. The obvious solution for the shortfall in RN hulls is a new class of general purpose, smaller warships in the 2500 – 4000 ton range. You could call them “corvettes” or “sloops” (as in the proposed Black Swan class), but whatever the name, the RN cannot fulfill its mission with a small boutique battle line made up of fewer than 20 major surface warships in the escort fleet.
Why call it Flower class and cover these whaler based ships in some detail – if theres no comparison.
You and I know this , but does the general public or even Mps grasp the difference.
They are better off saying a ‘improved Leander type’, as they were by todays standards light frigates.
That’s quite an old article. I think the Navy’s mind has gone to cheap larger frigates rather than corvettes for good reason. The days of the Flower class are gone, because everything these days is quieter. A cheap and cheerful corvette can’t hunt subs alone.
A top class ASW ship needs a purpose-designed hull, quiet mode of travel, a top of the line set of ship-mounted sonars, a means of creating a distributed sonar mesh, protection torpedoes, decoys, a hangar and an ASW-capable helicopter with all the onboard maintenance and safe munitions carrying/arming to support it. That’s expensive so you will want extra protections, such as anti-ship, local anti-air and CIWS. Oh look, it’s a Type 26.
If we go for a lower tier ASW, it still needs a lot of these capabilities, and given steel is cheap and air is free, why wouldn’t you go for a Type 31 rather than a corvette that would barely have room for all the kit required? Could multiple Type 31s working together rival the quieter Type 26?
A third solution is to go for a hetrogenous swarm-type capability, where a complex mesh of cheap ships, boats and planes hunt the subs. I think the mothership-drones-P8 combination is the way the Navy is heading in this regard. The mothership would still need a helicopter unless Project Proteus (currently advertised as sub-hunting but not sub-killing) can also deliver lightweight torpedoes. Stingray is over a quarter ton, so a 3-ton MTOW rotary drone might just be able to deliver one, as might a Malloy T-650 if we ever get around to ordering it, albeit for a very limited range.
I don’t think any single route is obvious, and if the Navy is trying to play all lines despite a lack of cash (or perhaps because of it), I can’t blame them.
I could definitely live with more T31s, though I think they are somewhat larger vessels than are really needed. But yes, the design is established, the production lines are set up, and the RN and UK would definitely benefit from economies of scale if additional units were to be built.
The actual smaller light frigates, if you notice the buyers, are for countries that use them for limited reach ( Qatar, Algeria, Mexico, Indonesia) and dont have to face North Atlantic type weather – for longer periods.
Can I just say HMS Richmond looks very freshly painted in that picture.