Type 42 destroyer - How did the RN get it so wrong?

[FITZ]

It's just a question that has been on my mind lately.

[DesertFox]

It's just a question that has been on my mind lately.

 

What exactly are you concerned with the class?

[Chris Werb]

It's just a question that has been on my mind lately.

 

Being told to build a ship of no larger than a certain displacement.

 

Basing it's design around one scenario (medium/high flying bombers attack convoys with non-sea skimming AShMs in mid Atlantic)

 

An assumption of low rates of engagement.

 

It's interesting to see that our new destroyers likewise seem to be being built with a more limited range of scenarios in mind than those of other navies (no sub threat, no surface threat, no need to strike targets far inland...).

[Tony Williams]

The design of RN warships did get itself in a tangle at that time, and with the benefit of hindsight it is easy enough to suggest more useful alternative choices for similar money (which is exactly what I did HERE).

 

However, it has to be remembered that this was at a time mostly controlled by a Labour government which regarded the RN as a relic of the colonial age whose sole remaining duty was to keep the North Atlantic seaways open. So you got the Type 42s, the anti-sub specialised Type 22s, and various incredibly expensive conversions of the old Leanders. Plus a few Type 21s which were great fun to race around in but weren't notably effective against anything. And of course the "Through-Deck Cruisers" (not politically correct to refer to them as carriers).

 

The Falklands showed up the dangers of making over-specialised ships. The Type 45s will be in a different league from the T42s and at least they are big enough for later mods.

[swerve]

Being told to build a ship of no larger than a certain displacement.

 

Basing it's design around one scenario (medium/high flying bombers attack convoys with non-sea skimming AShMs in mid Atlantic)

 

An assumption of low rates of engagement.

 

It's interesting to see that our new destroyers likewise seem to be being built with a more limited range of scenarios in mind than those of other navies (no sub threat, no surface threat, no need to strike targets far inland...).

 

The land attack can be done by SSNs. Unless we buy a lot more Tomahawks (or Scalp Naval), providing more tubes on more platforms would probablly be pointless, but the Type 45 has room for some strike-length VLS, so we have the option. IIRC the Type 45 is fitted for anti-ship missiles, so again, we have the option. As Tony says, it's big enough (unlike the Type 42) to add everything we might need. Better to have it fully fitted now, but I'd rather have a ship which is initially under-armed but can be re-fitted with more weapons than one which is overloaded from the start.

[FITZ]

Even given the obvious points like the artificial restriction on hull length (intended to keep costs in check) it still seems to me the RN didn't make the most of it. I say this because when you compare the Type 42 Batch 1 to its closest contemporary, the Dutch Tromp, the Type 42 comes off lacking in almost every way.

 

Both types were concieved around the same time and to broadly similar requirements. Both ships are of nearly identical tonnage and similar dimensions with the Dutch ships being somwhat longer and slightly beamier. Both share a virtually identical propulsion plant but endurance is slightly greater in the Dutch ships. Both had similar crew compliments. Both types were originally supposed to use the same Sea Dart missile system and SPS-01 3D multi-function radar. But the RN backed out of the SPS-01 program which left the Type 42's stuck with the antiquated Type 965M volume search radar which lacked MTI, and the Type 992Q 2D target indication set. Type 42 had to use her Type 909 fire control radars to find target elevation which could only have increased target acquisition times compared to the Dutch ship.

 

Type 42 has 2 channels of fire for her Sea Dart missile system arranged at each end. While this provides 360-deg coverage it means that to engage more than one target the Type 42 has to present her bean to the target, making herself more vulnerable. Type 42's Sea Dart magazine holds only 22 missiles compared to 40 Standard SM-1MR missiles of the Tromp in roughly similar volume. Unlike Type 42, Tromp were built with a close-range Sea Sparow missile system to cover the dead zone within Standard's minimum engagement range. This adds another 8 ready to fire missiles with 8 more in the magazine for 56 anti-aircraft missiles to Type 42's 22. Tromp's Sea Sparrow system also has its own separate and independent fire control channel for redundancy and to allow for the engagement of up to 3 air targets simultaneously compared to just 2 targets in Type 42. Tromp's WM25 fire control system also has a separate channel for controlling the Bofors 120mm gun - a system of rather higher performance than the 114mm Mk 8 on a Type 42. Other than her Mk 8 gun and a couple of WWII-vintage Oerlikon's the Type 42 had no weapons to deal with threats inside the 4km minimum effective range of her Sea Dart system. They later got some band-aids in the form of BMARC 20 and 30mm guns with the latter being eventually replaced on some ships by a pair of Phalanx CIWS but the Tromp's were also to recieve the superior Goalkeeper system which tends to balance things out. Having to stock ammo for two different and incompatible types of 20mm gun must have been interesting.

 

As far as anti-ship capability the Type 42's relied on Sea Dart in anti-surface mode and the Mk 8 gun. Later the Lynx could carry Sea Skua which is arguably a more useful capability anyway, but then the Tromp's also have Lynx. The Tromp's could use Sea Sparrow, SM-1, or the Bofors gun but could also carry up to 8 dedicatd Harpoon anti-ship missiles - a capability never matched by the RN ships. Theoretically at least the Mk 13 launcher on the Tromp's could be used to fire Harpoon as well but I doubt this was practiced.

 

So far as command and control goes ADAWS 4 is presumably comparable to SEWACO I but the Tromp's do provide for a squadron commander and his staff. The Tromp's got Link 11 where I think the Type 42 were stuck with Link 10.

 

In ASW The Type 42's were apparently fitted with a bubble silencing system for their propellers. I do not know if the Tromp's were similarly fitted. Both had a MATCH helicopter (Lynx) and triple tubes for Mk 44/46 torpedo's as ASW weapons. Some Type 42's later lost the tubes as weight compensation for improved radars. Tromp's EDO610 sonar is probably slightly superior to the Type 184 originally fitted to the Type 42.

 

The Tromp's were always regarded as good sea boats and I know of no real complaints about their performance or habitability. The Type's 42's were notoriously cramped and wet forward due to the artificially short hull. They were also structurally weak, a problem which only worsened when they were stretched in the final version. All had to have reinforcements installed. Interesting that the Type 42 Batch 3's crew by 15 meters in length and half a meter in beam yet found no margin for additional armament, major equipment or increased magazine capacity. Possibly it reduced the sidelobe problems between SCOT and the ships ESM system that are frequently blamed for the loss of HMS Sheffield. I don't know.

 

The damage control issues of the Type 42 are already well documented and since I have no specific basis for comparison with the Tromp we will leave that alone except to say the Dutch ships likely at least were not any worse in that regard

 

The other thing I don't know about is costs. It is likely the Dutch ships were more expensive but I have found no cost figures for them with which to compare. Type 42 was certainly designed as the cheapest Sea Dart ship possible so that it could be built in the desired numbers (at one time up to 37 Sea Dart systems were required). This left if deficient in a lot of areas. The Tromps were more well-rounded because the Dutch only needed 2 as flotilla leaders. I suppose that allows one to get more for the money. Question is, could the British had accomplished something closer to Tromp capability at a cost that would not have been prohibitive?

[Chris Werb]

Does the SAM system fitted to the Type 45 have a surface-to-surface mode?

[zakk]

Question is, could the British had accomplished something closer to Tromp capability at a cost that would not have been prohibitive?

Buying the Tromp design?

 

Wouldn't have happened of course. Something like the F-15C instead of the Tornado F3 for RAF...

[Praet]

Does the SAM system fitted to the Type 45 have a surface-to-surface mode?

I haven't heard about any distinctive surface engagement capabilities, neither of ASTER nor of VL MICA (RF), both sharing the same seeker. Even if it was able to discriminate and lock onto surface targets, ASTER has a fairly small warhead being designed as a hit-to-kill missile (or at least highly accurate in terminal phase) not too suitable for engaging surface targets.

 

"The Aster missile system, with which the Type 45s will be equipped, will not have an anti-surface unit capability."

http://www.theyworkforyou.com/wrans/?id=2002-01-10.24022.h

[Tomas Hoting]

AFAIK, the Type 82 was designed as an escort vessel for the CVA-01 aircraft carriers in the 1960s. When the carriers were cancelled, they also decided to stop any further acquisitions of the Type 82 (a total of 4 ships was planned). I would be surprised if they did not design the Type 42 as a cheaper successor. Bristol was already launched in 1969, Type 42 came a few years later.

 

I think the Type 42 greatly benefitted from technological improvements, which made it possible to reduce their size when compared to the Type 82. The COGOG (Combined Gas turbine or Gas turbine) instead of COSAG (Combined Steam and Gas) propulsion system comes to mind. They also removed the bulky Ikara ASW system used on the Type 82, and therefore they were even able to fit enough space for a helicopter landing pad and hangar, something the Type 82 did not have. Funnily enough, the older County class "light cruisers" had a smaller displacement than the Type 82, and still had enough space for a small helicopter.

 

It would be interesting to know why the Argentinians also bought the Type 42 and what they thought of them.

[Chris Werb]

"The Aster missile system, with which the Type 45s will be equipped, will not have an anti-surface unit capability."

http://www.theyworkforyou.com/wrans/?id=2002-01-10.24022.h

 

That sucks! Offhand I can't think of an RN or USN shipboard SAM (other than Stinger or the earliest RAM) that didn't have an anti-surface capability.

[Chris Werb]

I think the Type 42 greatly benefitted from technological improvements, which made it possible to reduce their size when compared to the Type 82. The COGOG (Combined Gas turbine or Gas turbine) instead of COSAG (Combined Steam and Gas) propulsion system comes to mind. They also removed the bulky Ikara ASW system used on the Type 82, and therefore they were even able to fit enough space for a helicopter landing pad and hangar, something the Type 82 did not have. Funnily enough, the older County class "light cruisers" had a smaller displacement than the Type 82, and still had enough space for a small helicopter..

 

I wouldn't exactly call a Wessex 'small'

[Tomas Hoting]

I wouldn't exactly call a Wessex 'small'

 

Whoops, it seems I mixed it up with the Wasp!

[DesertFox]

That sucks! Offhand I can't think of an RN or USN shipboard SAM (other than Stinger or the earliest RAM) that didn't have an anti-surface capability.

 

Does "Sea Wolf" really have an anti-surface capacity?\

It only has a 14 Kg warhead, not much bigger than the RAM warhead

[Lambda]

Does "Sea Wolf" really have an anti-surface capacity?\

It only has a 14 Kg warhead, not much bigger than the RAM warhead

Well anyway, the ASTER is significantly heavier stuff than the Sea Wolf, more in the league of the Standard (e.g.). So I can see the objection.

Now just a thought: most US/UK naval SAMs are quite aged stuff, right? I mean, there has been a number of upgrades, but are there among this lot weapon systems which, conceptually, date back to sooner than the 60s? If I'm right (correct me otherwise), they date back to a time when there were few anti-ship missiles available, efficient and cheap, and these SAMs could easily do with the additional surface attack ability, to balance the capabilities of the ships.

And as Praet says, they had significantly lager warheads than an ASTER, being significantly less accurate.

Now don't get me wrong, I'm not saying that the Standards and Sea Darts and such are hopelessly outdated, but in this context, I could understand why they had a built-in anti-ship capability and the ASTER wasn't developed with one, since any ship carrying it would have its complement of light SSMs (Harpoon, Exocet, Sea Eagle, Rb.15, you name them) to take on adverse ships with better results.

[Josh]

Well anyway, the ASTER is significantly heavier stuff than the Sea Wolf, more in the league of the Standard (e.g.). So I can see the objection.

Now just a thought: most US/UK naval SAMs are quite aged stuff, right? I mean, there has been a number of upgrades, but are there among this lot weapon systems which, conceptually, date back to sooner than the 60s? If I'm right (correct me otherwise), they date back to a time when there were few anti-ship missiles available, efficient and cheap, and these SAMs could easily do with the additional surface attack ability, to balance the capabilities of the ships.

And as Praet says, they had significantly lager warheads than an ASTER, being significantly less accurate.

Now don't get me wrong, I'm not saying that the Standards and Sea Darts and such are hopelessly outdated, but in this context, I could understand why they had a built-in anti-ship capability and the ASTER wasn't developed with one, since any ship carrying it would have its complement of light SSMs (Harpoon, Exocet, Sea Eagle, Rb.15, you name them) to take on adverse ships with better results.

 

 

I suspect it was more along the lines of how easy it is to make SARH missiles anti surface and also that they were developed before active homing AShMs really were popular, at least in the west. Basically you just generate a target solution that is at an altitude of 0 feet and direct the emitter onto the target ship, from what I understand. It probably took almost no technical work to make it have a secondary anti surface role, where as I suspect the Aster seeker might have to be made to be a little clever.

 

Nominally anti-surface attacks would be made from the air via bombs and rockets and such. NATO navies generally had land based or embarked air; Soviet naval units could be expected to be ringed by unfriendly bases along with mobile CV groups able to pop out of no where (particularly before real time sat recon).

[Chris Werb]

Does "Sea Wolf" really have an anti-surface capacity?\

It only has a 14 Kg warhead, not much bigger than the RAM warhead

 

I've not read of it explicitely but the missile does have a secondary TV/IR tracker mode if the radar goes TU. It wouldn't take much to aim in at (or slightly above, as the missile is proximity fused) an incoming Boghammer. I'm sure this could be done with Seacat. OTOH I'm pretty sure you couldn't engage a surface target with either Stinger or the original RAM.

[Guest pfcem]

Type 42 destroyer - How did the RN get it so wrong?

Tried to (or were forced to) get by with AAW destroyers that were too small & too cheap.

[Tony Williams]

Considering that modern SAMs like Aster are designed to knock down sea-skimming missiles, and must therefore be able to home in on, and detonate by, targets very close to the sea's surface, I can't see why they wouldn't be able to hit surface targets.

[GregShaw]

Considering that modern SAMs like Aster are designed to knock down sea-skimming missiles, and must therefore be able to home in on, and detonate by, targets very close to the sea's surface, I can't see why they wouldn't be able to hit surface targets.

Surface ships don't have 600+ knots doppler.

 

Greg Shaw

[Tony Williams]

Surface ships don't have 600+ knots doppler.

You mean the system would be incapable of engaging a slow-moving helicopter? If so, a serious oversight given the ASMs they can deploy.

[Lambda]

Considering that modern SAMs like Aster are designed to knock down sea-skimming missiles, and must therefore be able to home in on, and detonate by, targets very close to the sea's surface, I can't see why they wouldn't be able to hit surface targets.

They are also meant to home in on sometimes really small radar signatures, so how would they react to a SER 100m wide? It's not as if the Aster had a man-in-the-loop-with-a-joystick feature, or has it?

Granted, if it is smart enough to home in on a ship, it is certainly fast enough not too miss is, should ignore any kind of anti-SSM chaff and jamming without too much bother, and well... 15-kg warhead or not, if it can be set to delayed-impact fusing, I'd bet the 3.5+Mach and missile mass (and remaining fuel at short ranges...) won't be a sweet perfumed kiss to even a destroyer-class ship.

I'd tend to believe it would be mostly a software issue of targeting or no targeting, after all.

[Risto Järnström]

You mean the system would be incapable of engaging a slow-moving helicopter? If so, a serious oversight given the ASMs they can deploy.

 

The fast rotating rotor blades of the helicopter generate quite a lot of Doppler effect themselves. A ship would not generate any similar effects as it doesn't have any fast moving parts visible and it would be moving slowly.

[Tony Williams]

What it seems to come down to is basically the programming of the software: there's no way that the radar can fail to detect a ship (extreme stealth excluded).

[FITZ]

AFAIK, the Type 82 was designed as an escort vessel for the CVA-01 aircraft carriers in the 1960s. When the carriers were cancelled, they also decided to stop any further acquisitions of the Type 82 (a total of 4 ships was planned). I would be surprised if they did not design the Type 42 as a cheaper successor. Bristol was already launched in 1969, Type 42 came a few years later.

 

I think the Type 42 greatly benefitted from technological improvements, which made it possible to reduce their size when compared to the Type 82. The COGOG (Combined Gas turbine or Gas turbine) instead of COSAG (Combined Steam and Gas) propulsion system comes to mind. They also removed the bulky Ikara ASW system used on the Type 82, and therefore they were even able to fit enough space for a helicopter landing pad and hangar, something the Type 82 did not have. Funnily enough, the older County class "light cruisers" had a smaller displacement than the Type 82, and still had enough space for a small helicopter.

 

It would be interesting to know why the Argentinians also bought the Type 42 and what they thought of them.

 

 

Actually a firm program for at least 8 Type 82's existed for some time after the cancellation of CVA-01 as the best way to quickly get both of the new high-priority weapon systems - Sea Dart and Ikaka - to sea. Type 42 would have been built anyway because Type 82 was too expensive to build in sufficient quantity to meet the number of Sea Dart systems required at sea. I look at Type 42 as more of a follow-on to the Air Direction and Air Defense frigates of the 1950's.

 

Type 82 had no requirement for a permanent helicopter facility (not even one as goofy as the County's) which is why they did not carry one. A CVA-01 battle group would most likely have consisted of CVA-01 which herself would have carried Sea Dart and probably Ikara, 3 Type 82's, a County and the "Escort Cruiser" armed with Sea Dart and carrying the battlegroups ASW helicopters so that CVA-01 could concentrate on carrying fixed-wing aircraft. The Escort Cruiser emerged as the Invincible.

 

Argentina I suspect bought Type 42 because there was no other SAM system in the class of Sea Dart available to them - the U.S. would not have exported Tartar D to South America at the time. Argentina was offered a variety of different weapon configurations but in the end opted for standard Type 42's.