Cuirassé canons éléctromagnetique et drônes
This is a design study for a modern battleship with electromagnetic main armament and lots of drones, as requested by the Bilge Pumps podcast episode 22. It is a French-Australian collaboration, which is not as unusual as you might think since the Australian Defence Force already uses quite a lot of European naval gear. This particular project should be just as successful as the Attack class submarines.
For people who only speak English and are unsure how to pronounce this French name, "Jon Bar" is close enough.
I'm not any kind of naval professional - which will become evident very quickly - but it was an interesting challenge. I had fun, practised some skills, and learnt a lot. I expect to learn even more as people tell me what I've got wrong.
This is a design study. The purpose is to answer the question can we build this, not should we build this. So please don't bother telling me that battleships are obsolete, you'll just be wasting my time and yours.
It is also a design study, not the design study. A real project would do several different ones for comparison.
Computer drawings look clean, precise, complete. People think that the design is done and are reluctant to criticise. Pencil drawings, still with guide lines and rough spots, look like a work in a progress. People are more comfortable asking for changes.
That doesn't mean these are scribbles or quick sketches. All the drawings are as accurate as I can make them, with measurements from scale plans and manufacturer web sites.
A blank page can be terrifying. If you have the freedom to design whatever you want, where do you start? Many designers and artists believe that constraints encourage creativity, not hinder it.
For a ship, picking an existing hull design immediately sets the size and speed, the power required for the engines to reach that speed, and the internal volume and deck area available for the systems and crew. The designer still has freedom, but now within certain limits. And it's a design study, not a commitment, so even if you pick the wrong hull you can still learn from it.
A good criticism of starting with the hull is that it encourages the designer to "fill the box", fitting systems not because they are necessary but because there is space available. I agree! Another way to design would be to start with the weapons and sensors and speed you want, and then wrap a hull around them. Please try it and let me know what you come up with.
This ship is based on the design for the second French battleship of the Richelieu class, started in 1936 but not completed until 1950. She is named Jean Bart, not Richelieu, because in this timeline the French navy has much more money and so Richelieu is the second of the Charles de Gaulle nuclear powered aircraft carriers.
At around 50,000 tonnes full load Jean Bart is medium sized for post 1930 modern battleships. If I had the time and energy I would do two more, one based on the IJN Yamato with everything turned up to eleven, and one USS Alaska for a smaller design but still considerably larger than any cruiser. (Reactivating the Iowas has already been done so many times, and personally I don't like the shape of the bow.)
The original Jean Bart was given extra bulges when reconstructed after WW2. At the time this made her slightly too wide for the Panama Canal, but since June 2016 the new beam limit for the canal is just over 50 metres so it won't be a problem.
My reference for railgun/coilgun operation and performance, both real and in science fiction, is the excellent Atomic Rockets website. The actual Gauss guns used on Jean Bart will be designed by the French-German Research Institute of Saint-Louis which has been doing research on electromagnetic (and laser) weapons for a couple of decades and revealed their Pegasus railgun demonstrator in 2017. This was part of a technical and operational study into electromagnetic artillery for naval platforms commissioned by the French Ministry of Defence DGA/SCA in July 2015.
There are two primary types of electromagnetic gun or cannon, railguns and coilguns.
In a railgun the projectile is in physical contact with the fixed rails as it is fired, so railguns suffer from "barrel wear" and like the old battleship guns would need replacing after not many shots.
Coilguns have no contact between projectile and the barrel, so don't suffer from this problem. This is ideal for the Jean Bart which expects to fire thousands of shots.
However, railguns are easier to build. All the current prototypes that I know of are railguns, not coilguns. So the Jean Bart might have to be built with railguns and a fast rail replacement system that can be used at sea.
As an example of the current day problems with coilguns, a back of the envelope calculation using the Atomic Rockets formula for the performance of the proposed 64MJ coilgun with (cheap) permanent magnet projectiles and a Tesla 2 magnetic field gives a required barrel length of 1384 metres. Acceptable for a space battleship, but here on Earth we're going to need some kind of clever solution.
Science fiction writers invented the name Gauss gun decades ago to describe futuristic electromagnetic guns without having to specify exactly what kind they were. Instead of writing "railgun or coilgun" everywhere, I'm doing the same.
Performance details of the Jean Bart Gauss guns further down.
The Jean Bart needs a lot of electricity for the main armament of electromagnetic Gauss guns, for the radars, to charge the drones, ... so the ship's drive is now turbo electric rather than steam.
Power is supplied by three General Electric LM6000PG marine gas turbine generator units. The French navy already uses the smaller GE LM2500, so has experience with operation and maintenance.
Each turbine is rated for 70,000 ship horse power or 52 megawatts. Two turbines provide slightly more power than the original steam drive, so the Jean Bart should achieve the full design speed for the Richelieu class of 32 knots. One turbine provides ship power. In combat 32MW of the output would be allocated to the main armament, allowing one Gauss gun shot every 5 seconds.
The turbines also charge the battery pack.
Instead of a second set of gas turbines, the forward boiler room is now stuffed with Tesla Power Packs.
Each pack is, rounded up, 1.5m x 1.1m x 2.2m high.
These are grouped into blocks containing 4 x 4 packs in each of three vertical layers, with 1m separation between layers for cooling. Each block needs an output inverter, replacing one pack so the total is 47. At 232 KWatt hours per pack, each block stores 10.9 MWatt hours.
The power pack room is 18m wide, 16m long, and 9m high so has space to hold six blocks, with 2m to 3m open space for access between each block.
The total power capacity of the battery pack is 64 Megawatt hours, enough to run the engines at half power for an hour and still provide 12 MW of electricity for other ship functions. Which could include firing a single Gauss gun round every 14 seconds.
All these Tesla packs and inverters weigh about 630 tonnes. The original machinery for the Richelieu class was 2865 tonnes. I don't know how to do a proper stability study, but removing the 152mm turrets alone saves 684 tonnes and the battery pack room is right in the centre of the ship. My guess is that it won't be a problem.
Nuclear?
I thought about nuclear power, using the French K15 naval reactor that powers their submarines and carrier Charles de Gaulle. But I think there would be two serious problems.
First is that the French naval reactor needs refuelling more often than British or US reactors. On the Jean Bart, this would mean cutting through the armoured deck.
Second, from a video by Battleship New Jersey discussing the possibility of a nuclear powered Iowa, is that a battleship is meant to go in harms way and is at much more risk of being hit. A gas turbine can burn, but fires go out. A damaged nuclear reactor stays lethal until you take it home for specialist repair.
All the core systems are protected by belt and deck armour.
Armour is not to make a ship invulnerable, armour is to make it difficult and expensive for the enemy to inflict damage. The Jean Bart has 330mm main belt armour and 170mm deck armour, which should protect against RPGs and other infantry carried weapons, the light missiles carried by helicopters and drones, 4" or 5" naval guns, and AA missiles fired in surface to surface mode. The armour cannot defend against larger missiles, but if the point defence guns can destroy the missile fuse or make it tumble, the armour will limit the damage inflicted.
The internal layout is almost identical to the WW2 design but some compartments have been repurposed. From bow to stern:
Electromagnetic gun turret 1 with barbette and magazine. These guns don't have explosive powder charges, but they do have some very high powered capacitors which likewise need protection - or maybe the rest of the ship needs to be protected from them.
Cooling machinery for the turrets, formerly small arms magazine and diesel fuel store. Gauss guns generate a lot of heat, mostly from inefficiencies in converting electrical energy to magnetic field.
Electromagnetic gun turret 2.
The forward data centre (the Jean Bart has two, duplicated) holds the primary computer systems. It replaces the original 100mm magazine, because magazines already have restricted access and good temperature control.
Battery pack. The forward boiler room now contains 288 Tesla battery packs and inverters.
The forward engine room contains electric motors, not steam turbines, that drive the outer propeller shafts. I have assumed these are slightly more compact so shortened the engine rooms. The gas turbine room is longer, so overall length of the machinery space is the same.
The gas turbine room replaces boiler room 2 and contains the three GE LM6000PG turbine/generators.
The funnel is slightly enlarged, and the angled funnel cap is now detachable, because gas turbine replacement is through the funnel. Since there are three turbine units, replacing a wing turbine means first pulling out the central one to make room. Although this does slow down replacement, a single funnel has much better aesthetics.
Aft engine room, again electric, for the inner shafts.
Aft data centre, again computers inside what used to be a 152mm magazine.
The wine or beer store uses up the space allocated for the original turbo generator room. Ever since the old WW1 dreadnought Jean Bart was torpedoed in 1914, French designers have placed this behind armour. The Australian navy is in full agreement on the need for protection of mission critical supplies.
The forward half of the Jean Bart is a lot less cluttered than the aft.
The towers on the current day French Acquitaine and Forbin, like the British Daring, are truncated pyramids and very boring. If it's necessary to reduce the radar signature, how about going back to the tripod mast? All curves like a B-2 bomber. Or, given all the electronic gadgets that need to be carried high up on a modern warship, revive the Japanese 1930s "pagoda" style?
For the Jean Bart I based the tower on the design of the DCNS Belharra class frigate. It is much more visually interesting with lots of facets, reminiscent of an F-117 stealth airplane. Since the Jean Bart is much bigger and taller, it's actually two differently sized copies of the Belharra tower, the smaller stacked on top of the larger.
On either side of the tower are the forward pair of Bofors twin 57mm guns and target trackers / fire controls.
At the top of the tower is the EMPAR C-band radar as used on the French Forbin and Italian Carlos Bergamini air defence destroyers. On the Jean Bart it is the primary radar for the Gauss gun main armament and target identification for the Bofors 57mm point defence.
Below on the tower would be electronic warfare sensors and jammers, long range and satellite communications dishes and antennas, etc, etc, which I could not be bothered drawing. The Jean Bart is big enough for the more important systems to have backup systems on the mast.
On the forward face of the tower is the sixth Bofors 57mm target tracker and fire control.
The foremost Bofors twin 57mm is ahead of the main turrets. I wouldn't recommend standing near the muzzle of a railgun or coilgun when it fires, but they don't generate the massive blast pressure of conventional guns and these 57mm turrets are automatic with no crew.
The Jean Bart carries six Bofors twin 57mm turrets. As with the previous Jean Bart, the gun is the standard Bofors naval Mk3 but the mounting is a custom design by the French navy. The hoists for the Bofors can extend as far as necessary according to the manufacturer, so the ammunition magazines will be below the main deck.
There is one radar/IRST target tracker and fire control associated with each 57mm Bofors turret. Being a modern networked ship, any turret can be controlled by any tracker or radar as required. The fire control infra-red (IRST) component is the wonderfully named vampir.
An alternative point defence gun would be the Thales RapidFire 40mm, but the heavier calibre makes the Bofors better against light surface targets.
Being a battleship, there is plenty of room at the bow and stern for, as Commander Salamander suggested on Bilgepumps, spot-welding light automatic cannon to the deck as required.
The Jean Bart carries four 64MJ Gauss guns in twin turrets. Most concept art for future ships shows single gun turrets, but the Richelieu class has large turrets already internally divided into two duplicated halves. Two guns would also provide redundancy if one railgun needs replacement.
Two turrets are better for all round (OK, 300 degree for a Richelieu) fire. Modern electric motors and higher power should provide faster rotation and elevation, but it would still be useful to have a turret pointing to each side of the ship at once.
The gun calibre is 170mm to fit the CAMM missile dart, and square not round. The barrels are much thicker than conventional guns, and have an octagonal cross section to match the ISL Pegasus railgun demonstrator. Since the barrels are not solid metal, they are protected by armoured covers similar to those used on deck mounted missile launchers.
The Gauss guns are the main armament against surface targets, whether at sea or on land. The solid shot ammunition (details below) has a maximum range of just over 400 kilometres.
The Gauss guns are also the secondary armament against surface targets, replacing the original 152mm and 100mm guns. The hypersonic solid shot are cheap and the Jean Bart carries over three thousand so they can be used against low value targets.
And finally the Gauss guns are also the long range defence against aircraft and missiles, firing guided rounds. These have similar performance to current day SAMs (because they are SAMs without the booster), and again the Jean Bart can comfortably carry over a thousand.
The working chamber below the turret is now for programming Gauss gun rounds, especially the guided AA, before they are loaded and launched.
The magazines below deck are, like the original, divided into two sections. The rear formerly used for charges is now storage for the capacitors. A Gauss gun needs to discharge an enormous amount of energy very very quickly, so it isn't enough just to have a power cable from the gas turbines.
The front of the magazine still holds the shells. The Richelieu class were designed to carry 832 main gun rounds, but the original Jean Bart carried less than that. I'm using 800 for easier maths. The Jean Bart can carry eight solid Gauss gun rounds for every original 380mm shell, or four guided AA rounds. A fifty-fifty split on the original 800 gives the Jean Bart 3200 solid shot and 1600 guided, 800/400 per barrel.
The Gauss guns are 64MJ, Mega Joules, which is the kinetic energy of the projectiles as they leave the barrel. KE is a useful measurement as it tells you how much energy you have to put into your gun when firing, and how hard the projectile will hit. It isn't perfect, because projectile shape and any explosive charge also matter, but it's a good starting point.
Kinetic energy is mass divided by two, times velocity squared. With a rearrangment you can plug in the power of the Gauss gun and the mass of the projectile and calculate the velocity. Note that increasing the velocity gives more KE than increasing the mass, why bullets are more deadly than arrows despite being usually lighter.
64MJ matches the intended final design of the US Naval Warfare Center EMRG railgun prototype. 64MJ is 64 Megawatts of electrical power for one second, but the Gauss guns need more than that. The conversion efficiency of electromagnetic guns is currently not great, so I've assumed 40%, just under the estimated US EMRG efficiency. The actual power used in each shot is 160MJ, and the excess mostly becomes heat so railguns and coilguns run very hot.
How does 64MJ compare to existing naval guns? It's actually not that high.
The 100mm guns on the original Jean Bart fired 13.3kg shells at 855 metres/sec muzzle velocity, giving 4.75MJ. The 152mm secondary guns, 55kg shells at 870 m/sec, are 20.8MJ, about one third of the Gauss guns. The Richelieu class 380mm main armament are much higher, 884kg shells at 830 m/sec for 305MJ. (The Iowa 16" with super heavy shell is around 355 MJ.)
The advantages of Gauss guns are higher velocity, not needing explosive charges, and being able to carry much more ammunition.
All the guns listed here fire shells at around Mach 2.5, the speed of sound at sea level being 343 m/sec. A 64MJ Gauss gun could fire 100mm shells at 3100 m/sec, or Mach 9; and the 155mm shells at over Mach 4. Higher velocity means less opportunity for the target to dodge, and less variance in flight path due to atmospheric pressure and wind. Smaller shells at higher velocity hit just as hard, and you can carry more of them.
The Gauss guns don't need explosive charges, instead using the ship's electrical supply. This is a lot safer: firing a gun is setting off a large explosion on your own ship in the hope of causing a smaller explosion at the target. With Gauss guns you don't need to worry about magazines exploding. And again no charges means you have more room to store even more ammunition.
Jean Bart will carry two types of Gauss gun round, solid shot and guided.
The solid unguided rounds are 16kg tungsten arrows, 900mm long and 34mm diameter. For technical reasons the barrel of a coilgun needs a larger diameter, (even without the guided rounds discussed below) so I add a 2kg discarding sabot. They are fired at 2660 m/sec, Mach 7.7, with a maximum range of about 400km.
In space you can load up your Gauss guns with old beer cans or spanners in an emergency, but here on Earth aerodynamics matter. The rounds need to be streamlined, and like shells need to be dense or they will slow down too rapidly. High velocity means surface heating from drag, and the intense magnetic field heats up the projectiles even more.
Tungsten is a good choice because it has almost the same density as depleted uranium, is fairly safe and robust to handle, and has a high melting point.
The atmosphere also imposes an upper limit on velocity. In the TV show The Expanse season 4 the Rocinante has a 50MJ railgun which launches 1kg tungsten rounds at 9980 m/sec, or Mach 49. (But in space the speed of sound is zero, so, uh, nevermind.) On Earth these would burn up before leaving the barrel.
Precision machining will make the tungsten arrows expensive, but comparable to shells, not missiles. At 900mm x 170mm (with sabot) the rounds are half the length and half the diameter of a Richelieu 380mm shell, so one-eighth the volume.
As the Atomic Rockets website points out, Gauss gun rounds will punch through armour but it is difficult to predict how much damage they will do. There is a lot of kinetic energy, but no bursting charge. On impact will the rounds disintegrate into high velocity shards, or even plasma? The best guess is something like modern tank APDS rounds, very destructive but within a small volume.
A better alternative against ship sized targets could be flechette rounds, sixteen 1kg arrows fired shotgun style. The smaller rounds would have a lot less range - perhaps "only" a hundred kilometres. (Sorry, I haven't done a proper calculation.)
I don't think Gauss guns firing solid or explosive rounds will be useful for point defence against aircraft and missiles, at least until the guns are a lot more compact. Ultra high velocity rounds are difficult or impossible to dodge, but only if the gun is precisely aimed and the target is relatively close.
Ships are not stable platforms. Against surface targets the Gauss gun can wait a few seconds before firing for the right pitch and roll, but that would be too slow against missiles. We can build axially stabilised light AA guns, but all current Gauss guns have barrels as long or longer than the old battleship guns, even if they don't weigh quite as much. They won't move quickly.
For long range fire against aircraft and missiles the Jean Bart need guided rounds. These are SAM missiles, but without a rocket booster because the Gauss gun launches them at supersonic speed. As with shells, this allows many more to be carried for the same volume, and launching one doesn't spray the ship with superheated toxic rocket exhaust.
The Jean Bart fires the terminal dart stage of the Common Anti-air Modular Missile (Sea Ceptor). At 1.95m long and 32kg mass these are launched at 2000 m/sec, Mach 5.8; twice the advertised maximum velocity of the current CAMM ER. The missile itself has a diameter of 166mm, hence the 170mm Gauss gun calibre.
I don't have figures for the various components of the CAMM missile, only the overall size and mass, so 1.9m and 32kg are estimates assuming similar proportions as the larger ASTER-15 SAM, which has a 2.6m 110kg terminal dart within an overall 4.2m and 310kg missile. A more conservative estimated mass of 48kg for the CAMM would give launch velocity 1630 m/sec, Mach 4.5.
The CAMM darts are the same length as a Richelieu 380mm battleship shell and half the diameter, so four can be carried for each original shell.
The guided rounds won't have the fantastic range of solid shot, because SAMs are not that good as unpowered projectiles. They need a much larger diameter to fit a seeker head, whether radar or IR, which means more drag. And they are not as dense as solid tungsten or even regular shells, so lose speed more rapidly once the rocket booster has burnt out. And at sea level the air is denser, so missiles perform worse than they do for high altitude jets.
As a non-specialist I had trouble finding more information about missile flight performance that I could understand. I'm basing this on the AIM-120-C5 Performance Assessment which I found through the Restless Technophile website. (Since we're in the 21st C, the authors hunted through non-classified sources and did extensive computer modelling, because they wanted to make a computer video game more realistic. I also found some great technical detail about the Mistral missiles on a forum thread by gamers complaining that the designers of War Thunder had nerfed the Tiger attack helicopter.) The AIM-120 is big, but my back of the envelope calculations give similar density to other missiles so I assume the CAMM won't be too different.
At 500 m altitude the AIM-120C loses just over 40 m/sec of velocity every second when flying straight at high Mach numbers. Making a 5 - 10 G turn, the kind a modern fighter jet can do, increases the loss to 60 or so m/sec, and a maximum 30 G turn, which might be needed for an anti-missile missile, loses 100 m/sec.
How would this affect our Gauss gun rounds? I assume that once the velocity drops below 1000 m/sec (Mach 3) the missile can't cope with an evading high velocity target. In mostly straight flight, losing 50 m/sec per second, the CAMM dart has a flight time of 20 seconds and a range of 30km. In the absolute worst case of pulling 30 G turns from the moment of launch, this drops to 10 second flight time and 15km range.
This is actually good! Mach 3 at 30km is better than the original CAMM missile, even the extended range version, and comparable to the much bigger ASTER-15. It just isn't as amazing as the range and velocity of Gauss gun solid shot.
It is tempting to add a sustainer motor to the guided rounds to give a longer flight time. A ramjet like that on the Meteor air to air missile would be possible, and easier and simpler to design because the Gauss gun launches the dart immediately into supersonic speed. The disadvantage of adding motors to the guided rounds is that they're big and bulky (and not heavy enough to improve the density) so the launch velocity goes down and volume required goes up. The more the missiles rely on their own powered flight, the less efficiency there is in using a large, energy intensive, single point of failure Gauss gun for the boost phase.
The rear hull has the high box shape of most hybrid aviation ships. It's more volume than mass, so after removing the original 152mm turrets which were nearly 700 tonnes I would worry more about the rear not being heavy enough to balance the turrets at the front.
The superstructure above the main deck is now angled inwards. This is mostly because that is the fashion for current warships, not an attempt to make a 50,000 tonne stealth battleship. It presumably does help a little to reduce the radar signature.
Midships between the funnel / mast and forward tower is used for antisubmarine defences. There is much debate over whether battleships would survive missile attack or not, but submarines are also a serious threat. On each side the Jean Bart carries two EuroSLAT torpedo countermeasure launchers and two MU90 anti-submarine torpedo launchers.
(The Jean Bart is not designed for hunting submarines and should never do so. As a battleship she is big enough to carry ASW weapons in case of emergencies. Better to have and not need than to need and not have.)
Since the ASW stuff is within the superstructure, the space on the midships deck is used for more 57mm Bofors guns and fire controls, and launchers for antimissile chaff and decoys.
The mast supports a Herakles S-band radar, as used on the French Acquitaine class frigates. On Jean Bart this radar is for controlling air operations, but could also be used for long range target tracking and fire control if the main tower EMPAR radar is out of action. (The two radars operate on different bands, so should not interfere with each other.)
The mast also has the usual crop of antennas and dishes for short range drone radio links, long range links, satellite communications, ... One nice thing about a battleship is that it can handle more topweight due to sheer size.
Behind the funnel is the drone hangar. Internally it is divided by a longitudinal bulkhead for damage limitation, and each half is in turn two decks high.
There are eight 4m x 2m launch and recovery bays on each side. I thought about launching drones vertically, but that would be more exposed to rain or snow and the drones would be flying closer to the funnel exhaust stream.
The drones themselves are quadcopters with aprox 3m wingspan unfolded. Since they are small and light, the Jean Bart carries as many as can be loaded. Computer systems like powers of two, so I'll say one hundred and twenty eight.
Most of the drone hangar will resemble a model aircraft workshop, but the inner area is devoted to sixteen drone controllers per deck. It would be cool to have the remote piloting stations from the movie version of Enders Game, but in reality this will look like a computer gaming cafe, rows of desks with dual monitors and joysticks and headsets. (We can at least have some VR headmounts.)
On the roof of the drone hangar is the aft Bofors 57mm turret and a fire control.
At the rear is the hangar for two NFH-90 Caimain marine helicopters. Usually one would be configured for ASW, one as a drone herder for controlling a swarm away from the ship. The hangar is large enough for Eurocopter Tigre attack helicopters if needed.
The design philosophy for the Jean Bart drones is quantity over quality.
These are not advanced UCAVs such as the nEUROn demonstrator. A ship that isn't an aircraft carrier could carry only a few of such large high performance, drones; not enough to be really useful. Nor do they need to be autonomous UCAVs with onboard AI systems making all the decisions. (Although given the advances in computer technology, that will most likely be economical in the future.)
Instead Jean Bart carries over a hundred quadcopters, with 32 under control at a time. The quadcopters are based on the Griff Aviation 135, which is able to carry a 25kg payload for at least 30 minutes, or 50kg for less time. The major disadvantage of most small drones is a short radius of operation, here just 15km (30km for a one-way mission). The Jean Bart will carry slightly enlarged models with the extra capacity used for endurance, not payload.
Payloads can be swapped between various high resolution cameras and LIDAR for reconnaissance and target identification, ground mapping radar for surveillance over land during littoral operations, and light missiles. Drones will operate in squadrons for combined effect.
The drones can also provide a Combat Air Patrol flock.
Yes, the drones are completely outmatched by jet fighters, but the jets will run out of million dollar AMRAAMs or Meteors before Jean Bart runs out of drones at one tenth the price. And if the jets try to close, the drones are large enough to carry a Mistral air to air missile. Any jet pilot even dinged by a drone, let alone shot down, would have to resign from the service in shame.
My early drafts had Sylver A-70 8 cell VLS modules distributed midships, but I deleted them as unnecessary. This ship has a lot of Bofors short range guns, and the main Gauss gun turrets can carry 1600 missiles, a stupendous number by current day standards.
There are two possible benefits to fitting VLS modules.
One would be the ability to launch large missiles, such as the SCALP Naval long range cruise missile. But if you want to fire missiles at a target more than four hundred kilometres away, you don't need a battleship. If it's within 400km, you can hit it with the solid shot.
Another would be defence against a saturation missile attack in overwhelming numbers. Jean Bart can only fire four guided rounds at a time, backed by the six twin Bofors 57mm turrets. If that isn't enough in some scenarios, Sylver A-35 VLS modules with quad packed Sea Ceptor missiles would be insurance.
Feedback to laranzu @ ozemail . com . au
Changes 27 Jan: added the perspective sketch at the start, some minor edits for clarity.
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All text and drawings on this web page created by Hugh Fisher. The spelling of my name makes no sense to most of the world's population, so I don't mind being called Hugo Fisher.
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