The Royal Navy Discussions and Updates

[Systems Adict]

30mm is just not likely to have the hitting power to bring down a missile at that rate of fire. This is why the USN moved to heavier 76mm with VT fuses in the late 40s. Just because it's a 70 year old lesson does not make it any less valid, in fact with fast missiles it is more relevant and why the Italian and US Navies have using 76mm & 57mm for anti missile defence

Mmmm....

With the 30mm Gun we're discussing having a 600 rpm fire rate, that's 10 per second at a target.

With the right hardware (i.e. a gun-fire predictor), fitted with software that can take the data input from another sensor, eg. radar / tracker, calculate how fast the target is travelling, then calculate were it will be in the near future, then pass this info to the command system, which in turn dictates were the gun will point in time & space, it means that a 3 metre long, 30cm diametre tube (e.g. a missile), travelling at a rather large rate of knots, can still be hit about 4 times from that burst of 10 rounds in that 1 second !

It only takes 1 hit of either the guidance system, the fuel tank, or the warhead for that missile to be toast !

While I agree that the 57mm / 76mm would have a greater impact, due to the ability to fit these rounds with proximity fuses & their larger NEQ (qty of explosives they carry), don't discount the 30mm round...

SA

 

[1805]

I still dont get you. Type 42 is/was a high end air defence vessel. When HMS Sheffield and HMS Coventry were hit they were carrying out their designed function, providing high end (with budgetary compromise) air defence. in the case of Sheffield, as one of 3 ships in the outer screen, in the case of Coventry as part of the "Type 64"making a royal nuisance , giving early warning, drawing attacking aircraft away and trying to attrit the enemy.

You cant guard your carriers and amphibs with anything other than your top assets, and your top assets have to be put in harms way at the risk of loses. If you had surrounded the task force with "expendable" less capable smaller ships they would have either been bypassed by the argentinian airforce or sunk in greater numbers.

Type 21 was a private venture, bought to beef up numbers during the intense cold war, as a ship it served a role but was compromised by budget and the current crop pf sensors and weapons available at that time.The Type 21s and Leanders again did a job, taking immense punishment, splitting air attacks and taking bombs that othewise would have hit far more valuable assets, but to a 450knot skyhawk pilot at ultra low level, through cloud, spray, gunfire and smoke they would have appeared as something worth bombing. Its only with an immense application of hindsight that you could suggest that in the 1970's and 1980;s the Navy should have purchased some cheap "flak" ships that we could have used in the advent of an amphibious landing, to some way stop us having to sacrifice more expensive ships. We didnt have the luxury of affording specialised canon fodder in the cold war.

I didn't say they should only be there as target and expendable. I meant they should be expendable if necessary. The ships described had better air defences than the T21 & T12 (1 76mm & Sea Sparrow). Yes some is with hindsight agreed but then other Navies did build such ships. One point though the T42 where not budgetary compromise in the AA department they carried the same kit as the T82. Agreed the hull was poor. It was probably the worst decision pulling out of the joint Dutch 3D radar, it might have transformed the Falklands

 

[1805]

Mmmm....

With the 30mm Gun we're discussing having a 600 rpm fire rate, that's 10 per second at a target.

With the right hardware (i.e. a gun-fire predictor), fitted with software that can take the data input from another sensor, eg. radar / tracker, calculate how fast the target is travelling, then calculate were it will be in the near future, then pass this info to the command system, which in turn dictates were the gun will point in time & space, it means that a 3 metre long, 30cm diametre tube (e.g. a missile), travelling at a rather large rate of knots, can still be hit about 4 times from that burst of 10 rounds in that 1 second !

It only takes 1 hit of either the guidance system, the fuel tank, or the warhead for that missile to be toast !

While I agree that the 57mm / 76mm would have a greater impact, due to the ability to fit these rounds with proximity fuses & their larger NEQ (qty of explosives they carry), don't discount the 30mm round...

SA

I think you might hit it, but it may not be destroyed. In the 70s a US technican was killed when a Phalanx (ok 20mm) hit a target but it carried on in a balistic trajectory

 

[Hambo]

I didn't say they should only be there as target and expendable. I meant they should be expendable if necessary. The ships described had better air defences than the T21 & T12 (1 76mm & Sea Sparrow). Yes some is with hindsight agreed but then other Navies did build such ships. One point though the T42 where not budgetary compromise in the AA department they carried the same kit as the T82. Agreed the hull was poor. It was probably the worst decision pulling out of the joint Dutch 3D radar, it might have transformed the Falklands

The Type 82 didnt get the "broomstick", it was cut for budgetary reasons. The Type 42 therefore inherited an older 965 radar for budgetary reasons
, the cost per ship on design was capped, its hull was shortened in original form for budgetary reasons resulting in lack of space for guns or planned lightweight seawolf, I understand they were first commissioned without a full ECM suite and corvus launchers..for budgetary reasons.

Other navies never fought a high intensity war for weeks 8000 miles from home so it is pure speculation if 76mm guns or sea sparrow would have fared any better in San Carlos Water or in the heavy seas off the islands than the RN vessels.

 

[1805]

The Type 82 didnt get the "broomstick", it was cut for budgetary reasons. The Type 42 therefore inherited an older 965 radar for budgetary reasons
, the cost per ship on design was capped, its hull was shortened in original form for budgetary reasons resulting in lack of space for guns or planned lightweight seawolf, I understand they were first commissioned without a full ECM suite and corvus launchers..for budgetary reasons.

Other navies never fought a high intensity war for weeks 8000 miles from home so it is pure speculation if 76mm guns or sea sparrow would have fared any better in San Carlos Water or in the heavy seas off the islands than the RN vessels.

That is true I doubt anyone could have predicted the Falklands but they should have planned for an intense air war off Norway and a harsher opponent than old Skyhawks. I don't really think Sea Wolf was the answer there was nothing much wrong with Sea Dart as it became (even with valve technology!) , it was always an issue with the poor radar to put more missiles on a ship with poor radar seems to just compound the problems. I hear you say Sea Wolf had better Radar.....well better just to fix 965 (remove). Trouble was the RN was in transition as it is now, same issue the RN thinks it is acceptable to have such huge gaps in capability for quite long periods, a recipe for disaster.

 

[ASFC]

I didn't say they should only be there as target and expendable. I meant they should be expendable if necessary.

That is quite an interesting thing to say given that, in any war, everything is expendable if necessary. The two T42s were lost because they were put into positions where they could act as AAW Pickets, and take the brunt of any attack, rather than say lose an aircraft carrier or STUFT ship carrying supplies, because the T42s were more expendable than the Carriers or supply ships.

I don't really want to write a small essay on this, but I think the RN of today is fundamentally different from the RN of, say, the Falklands. We sent a large task force to the Falklands, and I suspect the Admirals knew some of the ships it sent would not be coming back, they were expendable, because many where verging on being obsolete, it is the problem of maintaining a large navy (look at the PLAN for example nowadays). In the modern RN, if the Falklands happened again, we would most probably send another Task Force, and it would be smaller, because the modern navy is smaller. Difference today (and in the immediate future) is that the modern navy is full of ships more than capable of defending themselves, because instead of having a large fleet of frigates where only some are up-to-date, we now have a smaller fleet, but which all are kept relatively up-to-date. I don't think the Admirals would expect to lose 2 Darings, for example.

Therefore I don't really think building 'expendable' warships is cost effective in the long term.

Now if you want to discuss building cheaper ships to do jobs that using a fully blown frigate isn't really cost effective for (like patrolling the Carribean).........

(And FGS why are we still discussing trying to sell 2 Bay Class, probably some of the most versatile ships available to navy!)

 

[Hambo]

I think you might hit it, but it may not be destroyed. In the 70s a US technican was killed when a Phalanx (ok 20mm) hit a target but it carried on in a balistic trajectory

So one example? Did the US then ditch Phalanx? No.

The fact is if you detonate a missile that is heading directly at the ship from close enough those fragments of missile will still plough forward and hit the ship regardless if you use 20mm,30mm or 76mm guns. That is why most navies will actually favour missiles, eg ESSM, Ram, Sea Wolf, Aster, Mica etc because the target should be hit a safe distance from the ship avoiding the debris.Guns are there for the leakers, and in the split second gap between minimum range of a ships air defence missile and the ship, then the quicker reacting smaller calibre guns may be of greater value. It s a question of what you would trust, 2 rounds per second of a Super Rapid with an 80 round magazine or 70 rounds per second from Goalkeeper with 1190 rounds?
If a 76mm has a max AA range of 8000 metres from the ship, a sunburn for instance will cover that in 12 seconds, are you going to let the gun crew have a pop first? because if they miss its then too late to engage your missile system, it has to be missile above gun all the time IMO.

 

[1805]

So one example? Did the US then ditch Phalanx? No.

The fact is if you detonate a missile that is heading directly at the ship from close enough those fragments of missile will still plough forward and hit the ship regardless if you use 20mm,30mm or 76mm guns. That is why most navies will actually favour missiles, eg ESSM, Ram, Sea Wolf, Aster, Mica etc because the target should be hit a safe distance from the ship avoiding the debris.Guns are there for the leakers, and in the split second gap between minimum range of a ships air defence missile and the ship, then the quicker reacting smaller calibre guns may be of greater value. It s a question of what you would trust, 2 rounds per second of a Super Rapid with an 80 round magazine or 70 rounds per second from Goalkeeper with 1190 rounds?
If a 76mm has a max AA range of 8000 metres from the ship, a sunburn for instance will cover that in 12 seconds, are you going to let the gun crew have a pop first? because if they miss its then too late to engage your missile system, it has to be missile above gun all the time IMO.

I agree, I think the day of the gun as major weapon in air defence is over. but as a last ditch I think worth a try, that is why I like that Kashtan thing. I think the USN kept with Phalanx because it is just so handy, but why they didn't move to 30mm is odd. Also the RN has not been consistent on the subject which does make you think they really only have faith in missiles. Personally I would like to fit out a ship with armour/and equiped with 76/57mm, Goalkeeper & Sea Wolf/RAM moor it off a range and just fire any stocks of old MM38s at it and see what works in an intensive trial.

 

[tphuang]

So one example? Did the US then ditch Phalanx? No.

The fact is if you detonate a missile that is heading directly at the ship from close enough those fragments of missile will still plough forward and hit the ship regardless if you use 20mm,30mm or 76mm guns. That is why most navies will actually favour missiles, eg ESSM, Ram, Sea Wolf, Aster, Mica etc because the target should be hit a safe distance from the ship avoiding the debris.Guns are there for the leakers, and in the split second gap between minimum range of a ships air defence missile and the ship, then the quicker reacting smaller calibre guns may be of greater value. It s a question of what you would trust, 2 rounds per second of a Super Rapid with an 80 round magazine or 70 rounds per second from Goalkeeper with 1190 rounds?
If a 76mm has a max AA range of 8000 metres from the ship, a sunburn for instance will cover that in 12 seconds, are you going to let the gun crew have a pop first? because if they miss its then too late to engage your missile system, it has to be missile above gun all the time IMO.

actually, there is a general movement back to guns for CIWS. Otobreda 76 mm is used as the close in defense system for a lot of ships. 57 mm was selected as the CIWS for DDX and LCS. Goalkeeper is still used everywhere. And PLAN is now strictly going with guns for CIWS over missiles.

 

[1805]

Now if you want to discuss building cheaper ships to do jobs that using a fully blown frigate isn't really cost effective for (like patrolling the Carribean).........

With the cheap small ship idea, I don't see theta small/cheap should be seen as low threat war only, like a global OPV, I think it could have a have a role as: a CIWS close escort for important asets (as the T22 were treated in the latter stages of the Falklands and as a ship to control local waters from FAC etc. As well was peacetime police work

(And FGS why are we still discussing trying to sell 2 Bay Class, probably some of the most versatile ships available to navy!)[/QUOTE]

With the Bays I was talking about having a significant logisic capability in 12 effectively crusier type ships a combined Absalon/T45 so you would need less Bays

 

[1805]

actually, there is a general movement back to guns for CIWS. Otobreda 76 mm is used as the close in defense system for a lot of ships. 57 mm was selected as the CIWS for DDX and LCS. Goalkeeper is still used everywhere. And PLAN is now strictly going with guns for CIWS over missiles.

Yes agreed, really missiles are the greatest threat faced by ships, as aircraft are unlikely get past the layers of defence. The risk of current and future generation missiles is so great that just for close in protection I think you need to have all three: 57 or 76mm guns, then a combined Kashtan type weapon missile/gatlin arrangement. The Russians probably have the best air defence systems as I suspect they expected to face tougher air attack not having CV based planes.

 

[1805]

Yes agreed, really missiles are the greatest threat faced by ships, as aircraft are unlikely get past the layers of defence. The risk from current and future generation missiles are so great that just for close in protection, I think it makes sense to have all three: 57 or 76mm guns, then a combined Kashtan type weapon missile/gatlin arrangement, this lot would probably weigh no more than a 4.5" mount. The Russians probably have the best air defence systems, as I suspect they expected to face tougher air attack not having CV based planes.

 

[Palnatoke]

Concerning CIWSs and missiles


Scenario
A ship with advanced radars will probably detect an incoming LO surface skimmer at around 10km. This means that, in the case of a missile travelling near mach1, the time from detection to impact is around 30s. Likely there will be multiple missiles performing complex evasive manouverings.

Upon detection, the defensive system of the ship will have to analyse the threath, identify it (you don't want to shoot your own assets) and track it before a missile can be fired.

I don't know how long this response time is for a modern systems, but it's probably not insignificant. Let's for the sake of fun say that this response time is 3 secs.

When the AD missile is fired it will have to travel to it's target. Let's say that the AD missile travels at an average speed of Mach3 (some 900-1000 m/s, I know modern missiles are faster, though they have to accelerate and they don't follow a straight path).

Then, from the top of my head, engagement happens after 7-8secs after the AD missile is fired, at a distance of some 7km from the ship.

Let's assume that we have a miss, The ship will have to spend some time detecting the miss and that a missile is still inbound, before it can shoot again. Let's assume that this delay is 3 secs.
Then the 2nd missile is fired while the anti ship missile is some 6km away. What then happens depends on the missiles initial flight charracteristics of the AD missile - which I don't know, at best maybe the missile could be able to engage it's target at some 4km distance from the ship or some 13 secs before impact. Though I don't think that's realistic. a vertical launched missile will follow a far from straight path, also is the illuminater agile enough to track a fast moving target that close?

In any case, the second shoot, won't leave much room for error/delays or unfavorable corrections to my amature assumptions on speed and response time of the defense system.

Likely, in any case the point of engagement of the second shoot will happen within or near the engagement range of a modern 30-40mm gun-CIWS. Though it should be so, that you will have one clean shoot with a missile on a horison detection of an inbound missile, it appears to me as likely that the second shoot can might as well be done with a gun.

Some CIWS systems can fire AHEAD ammounitions (Like the Orlikon contraves CIWS gun on the absalon class). As far as I remember this weapon fires some 800 30mm shells a minute. And during the (very short) time that a given shell is in the barrel, the weapon can actually "time" (set the fuse?) the shell, so that it will explode at a predetermined optimal distance. Each shell explodes in 150 tungsten fragments each at some 3-4g and the relative speed of impact on it's target will likely be some 3-4mach or the same as a high powered rifle.
So in a 10 sec burst of fire (about the time it will take the anti ship missile to close the distance to the ship, after being in range of the gun) this weapon will fire some 140 shells laying out a dense "cloud" of some 20000 high speed metal fragments, in a shotgun like effect.

As far as I know the 76mm OTO Melara Super Rapid, can also be equipped with this type of ammunition. this gun will be able to initiate engagement at horison. And eventhough it has a slower rate of fire, it's shells are larger, carring many more fragments, As far as I know the ready to fire magazine is around 80 rounds, the gun should be able to fire 60 rounds in 30 secs (the time between detection and "game over").

 

[1805]

Concerning CIWSs and missiles


Scenario
A ship with advanced radars will probably detect an incoming LO surface skimmer at around 10km. This means that, in the case of a missile travelling near mach1, the time from detection to impact is around 30s. Likely there will be multiple missiles performing complex evasive manouverings.

Upon detection, the defensive system of the ship will have to analyse the threath, identify it (you don't want to shoot your own assets) and track it before a missile can be fired.

I don't know how long this response time is for a modern systems, but it's probably not insignificant. Let's for the sake of fun say that this response time is 3 secs.

When the AD missile is fired it will have to travel to it's target. Let's say that the AD missile travels at an average speed of Mach3 (some 900-1000 m/s, I know modern missiles are faster, though they have to accelerate and they don't follow a straight path).

Then, from the top of my head, engagement happens after 7-8secs after the AD missile is fired, at a distance of some 7km from the ship.

Let's assume that we have a miss, The ship will have to spend some time detecting the miss and that a missile is still inbound, before it can shoot again. Let's assume that this delay is 3 secs.
Then the 2nd missile is fired while the anti ship missile is some 6km away. What then happens depends on the missiles initial flight charracteristics of the AD missile - which I don't know, at best maybe the missile could be able to engage it's target at some 4km distance from the ship or some 13 secs before impact. Though I don't think that's realistic. a vertical launched missile will follow a far from straight path, also is the illuminater agile enough to track a fast moving target that close?

In any case, the second shoot, won't leave much room for error/delays or unfavorable corrections to my amature assumptions on speed and response time of the defense system.

Likely, in any case the point of engagement of the second shoot will happen within or near the engagement range of a modern 30-40mm gun-CIWS. Though it should be so, that you will have one clean shoot with a missile on a horison detection of an inbound missile, it appears to me as likely that the second shoot can might as well be done with a gun.

Some CIWS systems can fire AHEAD ammounitions (Like the Orlikon contraves CIWS gun on the absalon class). As far as I remember this weapon fires some 800 30mm shells a minute. And during the (very short) time that a given shell is in the barrel, the weapon can actually "time" (set the fuse?) the shell, so that it will explode at a predetermined optimal distance. Each shell explodes in 150 tungsten fragments each at some 3-4g and the relative speed of impact on it's target will likely be some 3-4mach or the same as a high powered rifle.
So in a 10 sec burst of fire (about the time it will take the anti ship missile to close the distance to the ship, after being in range of the gun) this weapon will fire some 140 shells laying out a dense "cloud" of some 20000 high speed metal fragments, in a shotgun like effect.

As far as I know the 76mm OTO Melara Super Rapid, can also be equipped with this type of ammunition. this gun will be able to initiate engagement at horison. And eventhough it has a slower rate of fire, it's shells are larger, carring many more fragments, As far as I know the ready to fire magazine is around 80 rounds, the gun should be able to fire 60 rounds in 30 secs (the time between detection and "game over").

I think the radar might pick up earlier and could they fire two missiles in succession. Also the 76/57mm could up up at the same time, but then it might shoot down the SAMs?? But I agree you make a good case for having all three layers. I thinkt he gun on the Absalons is 35mm so more hitting power. Questions might be, how robust are these guns for long/repeat engagements, and radar detection when close to shore if multiple missiles are fired from a lurking FAC or lorry based shore battery, when a ship is distracted (INS Hanit) looking for mines/subs or shore bombardment? But for me time to start replacing (SOME) of the 4.5" guns for a fit as you describe above.

 

[swerve]

I would go for a larger ship using the flex deck as adding size to the ship making an even better helicopter/Radar platform and a vast space for VLS (probably not all fitted) of say c9,000t with 500 crew (150-200 sailors 300 marines) . Yes the logistics is not up to a LSD/LPD but would be much greater than needed for most relief work as unlike the LSD can be in 12 places without an escort bacause the escort themselves.

I would sell some LSD to friendly navies Canada, RAN, or NZ. Then you have say 2 LSD and 2 LPD for serious operations which are rare.

I really think there is a Dreadnought moment and it is only a matter of time before a Navy merges a AWD with an Absalon type. I know it would require the RN being a bit brave and doing a first but surely it is time?

One problem with this proposal is that your super-Absalons won't have docks. They'll therefore be incapable of performing many of the tasks an LSD does. They won't even have the big stern ramp of a Point-class ro-ro, unless you're going to compromise them even more for all their other roles. They'll therefore be effectively limited to alongside loading & offloading in a port. This is a severe limitation.

They'll also be very expensive to operate in the logistics role. You'll need to send a few of them to do the job of one Bay, burning far more fuel, & tying up a large multiple of the number of sailors. What'll be doing all the other stuff while they're doing that? The Bays are very busy ships now, not just in a hypothetical major operation. Replacing two of them with the flex decks of super-Absalons implies that those super-Absalons won't be doing much else. To me, that's an extraordinarily expensive way to get some logistics capability, & a waste of destroyers.

Why not just keep the two Bays & buy one fewer escort, without the flex decks? You spend less money & get more capability. If you worry about not having logistics capability in as many places, buy a few more Point-class. You should be able to do that for less capital cost than one super-Absalon, & a similar operating cost. More logistics - much, much more! - and more deployable escorts than in your proposal. Or buy more Bays - still doable cheaper than your idea, while providing more capability..

Fighting ships cost a lot more than pure transports, even when built as cheaply as Absalon & Esbern Snare. LSDs come in between, but an austere LSD is still a small fraction of the cost per ton of a destroyer, & with small manning needs.

The Absalon class is designed for a small navy which lacks the resources for a range of specialist ships, & is an interesting solution which I think could also be appropriate for some other small navies. But even that navy leases ro-ros for most of its transport needs. It's neither meant for, nor suitable for, replacing real destroyers & frigates, except in low-intensity conflicts.

 

[Palnatoke]

I think the radar might pick up earlier and could they fire two missiles in succession. Also the 76/57mm could up up at the same time, but then it might shoot down the SAMs?? But I agree you make a good case for having all three layers. I thinkt he gun on the Absalons is 35mm so more hitting power. Questions might be, how robust are these guns for long/repeat engagements, and radar detection when close to shore if multiple missiles are fired from a lurking FAC or lorry based shore battery, when a ship is distracted (INS Hanit) looking for mines/subs or shore bombardment? But for me time to start replacing (SOME) of the 4.5" guns for a fit as you describe above.

I think the 10km is a good quess. I also believe that thales advertize that their APAR radar will detect LO surface skimmers at that range.

The actual horizon line for a standard sized frigate's mast is probably 12-14 km out, though the missile will apear to be extreamly low flying at that range and it will be very hard to make it out from the surface of the sea, not mentioning the scatter field near the waves,

 

[Palnatoke]

Swerve

While I agree with much of what you say, the ability of the ABS class to change roles, is undeniably a cost saver. F.ex. a navy can expect to utilize such a ship much more than a more specialized ship, simply because it can solve more tasks/different roles. That being in boring everyday peacetime stuff that navies allso has to do, relief efforts, low intensity warfare as well as high intensity warfare. That should translate into fewer ships, fewer designs and a less complex infrastructure.

Also the ABS class do bring a formidable arsenal to the table, which is, at least on paper, much more powerfull than many large frigates currently in service.

 

[AndrewMI]

I fear you have them the wrong way round. In the published RN material, C1 is the specialist ASW ship.

Yeah - but i think some or most of that material is reasonable old? (2-3 years?)

The understanding is that they heve merged together somewhat, the key distinguishing feature being their fit out.

The obvious thing is that the C2 has to be a jack of (most) trades at low cost, capable of operating on its own, and that the C1 needs to pack a punch either in a battle group or as a centrepiece of a surface action group or on its own.

This means they need some capability (I would assume).

 

[Grim901]

Yeah - but i think some or most of that material is reasonable old? (2-3 years?)

The understanding is that they heve merged together somewhat, the key distinguishing feature being their fit out.

The obvious thing is that the C2 has to be a jack of (most) trades at low cost, capable of operating on its own, and that the C1 needs to pack a punch either in a battle group or as a centrepiece of a surface action group or on its own.

This means they need some capability (I would assume).

Sort of, but only 1 or them is going to be getting TAS, which will be C1, making it the high end ASW frigate.

C2 is going to have to be cheaper somehow in order to justify it, so simply saying that we'll whack everything on except the TAS won't really work.

 

[radar07]

I think the 10km is a good quess. I also believe that thales advertize that their APAR radar will detect LO surface skimmers at that range.

The actual horizon line for a standard sized frigate's mast is probably 12-14 km out, though the missile will apear to be extreamly low flying at that range and it will be very hard to make it out from the surface of the sea, not mentioning the scatter field near the waves,

the radar horizon for the apar ships (f-124/de zeven) is little more than 20 km if the target high is 0 m. so i think that your numbers are wrong.