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Sea Dart success?!

JFC Fuller

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Hood,

Whilst the box launcher forward on the 1966 drawing looks very much like the Mk-16 box launcher for Harpoon/ASROC I suspect it is actually meant to represent the Mk.25 Sea Sparrow launcher that was derived from it. For me the giveaway is what appears to be an early representation of the WM25 director mounted just forward of the Broomstick radar above the bridge (just aft of what looks like a surface search radar).

With that said it could well be the case that prior to the decision to integrate a hangar the intention was to install ASROC as the primary ASW weapon (there does appear to be a door in the transom that could be for a towed sonar), but that would leave a stray director.
 

Arjen

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Very pleasing to see a better scan of the 'Alle Hens' sketch.
 

Hood

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JFC Fuller said:
Thanks Arjen, I was just trying to understand your comment about ADA/Sea Dart needing three computers, as built the ADAWS-2 system in Britsol had two Ferranti 1600 computers according to every source I have seen. However, Ed Hampshire in his book 'From East of Suez to the Eastern Atlantic' also mentions that it was realised that two Ferranti 1600s would be insufficient due to the data demands somewhere between 1964 and 1966, that suggests to me that it was the Type 988/Broomstick that was the driver behind the need for a third computer and therefore a major cost driver in the whole programme.
Re-read Ian Sturton's Warship article on CVA-01 last night, he mentions that ADA on CVA-01 would need three, possibly four, Ferranti 1600s.

Re: the 1966 design, I'm open-minded that it could be Sea Sparrow, but it would be a realtively hefty cut in ASW capability given the specification of Ikara and Limbo only two years previously. A VDS does seem plausible given the stern doors and there might be a hint of A/S TT tubes abeam the after directors on the drawing.
 

zen

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SO......

Among the features needed to make this reality possible....

RN needs perhaps to focus on the single arm launcher for Sea Dart. Depending on the mechanism beneath that arm for moving the rounds along and up.
Would they focus on a endless chain type, or a rotary type like the mk13?

An ideal scenario is one were the launcher could accommodate other weapons and being sized to Sea Dart opens up the potential for some variants of say Exocet, Harpoon and Kormorran for example.

The ADAWS system needs to be frigate and destroyer focused rather than carrier focused. Not an unreasonable decision, since such ships would be quicker to design and build and hence getting the AAW capability to sea a lot earlier than any carrier.

I suspect this alters the process by which, what starts as a CF.299 Frigate becomes a Destroyer such as Bristol. In this process do we see the Frigate sized solution go much further and end up being built?
Though these are a bit arbitary terms. But in essence something cheaper than Bristol.
IF they do build a 'Frigate' instead, how many do they build?

Dutch need to stay onboard I would suggest, further driving ADAWS to focus that will make it more attractive to export customers.
I suspect in these circumstances Type 988 will see limited service with the RN.

Invincible will have this single arm launcher, and the Type 988, presumably. Under these circumstances does the ship shrink a little (due to weight savings), or enlarge a little (due to cost savings)?

With such cooperation and exports or licenses. The drive to further develop Sea Dart is far greater. How far would a mk II and possible mk III be developed?
And what would those capabilities look like?
The strongest contender is the autopilot element permitting the TIR to be free of the target save for terminal homing.
Do we see Signaal develop an alternative TIR set?

With the Dutch possibly gaining Ikara as well, do we see any drive to a anti-ship variant of the system, as Abraham Gubler has suggested?
Does this strengthen the case for the Dutch gaining Sea Wolf?

Do the Germans build a copy of a RN or RNLN ship or fit the system into a US based design?

Australia did look at a DDLG and I think for a brief period looked a British systems, though of course they turned to the US in the end and ultimately didn't pursue the design.
 

Hobbes

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Do we see Signaal develop an alternative TIR set?
It's likely, yes. The Tromp class used American directors, but the van Heemskerck used Signaal STIR to guide its Standard missiles. A version of STIR that can guide Sea Dart wouldn't be too far-fetched. STIR 240 uses the same size dish as the Type 909 (8', 2m40).
 

JFC Fuller

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ADAWS was frigate focused, its just the frigate was over-specified for the available funds until the system was scaled back for the frigate sized T42 which also had a lighter but still twin-arm launcher.

T82 was intended as a Leander replacement but the RN designed it seemingly without regard to cost, the result being it was un-affordable in quantity so the specs were scaled back and split between hulls, this was already happening prior to CVA01 cancellation but the end result was the T42 which was originally meant to have an Ikara armed counterpart.

Hobbes,

I concur about loss of ASW capability within the hull but the Tromp class were intended to operate as part of a task group, the Van Speijk class could provide long range ASW strike with their helicopters. We won't really know until we can get a good history of the design of the Tromp class but that radar housing forward of the Broomstick is awfully reminiscent of the WM25 Sea Sparrow Director that was ultimately installed on the class.

With regard to ADAWS/Type 988, it certainly seems that it became a major driving factor, by far not the only one though, in the cost increases associated with the fleet modernisation as schemed in the first half of the 1960s. What I find ironic (given the petty and ill-informed squabbling by supporters of both services) about the computer issue is something very similar occurred in the TSR-2 programme, the chosen Verdan computer basically wasn't up to the task it had been chosen for.
 
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zen

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I seem to recall reading of a "lightweight" TIR for Sea Dart of about 6ft diameter as well. I think from the 80's.....?

In computer terms my guess is each is handling an individual FICMW set and the third is being passed the data for display. Really it boils down to the limits of the processors and memory. But it could also relate to word length.
 

zen

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So what next.....mk II.....process seems to connect with the Type 43 and the idea of a wide variety of improvements.
Discussed the autopilot.

But there is VLS, and 1976, the year of the beginning of the Type 43 is also the year of the beginning of the mk41 VLS. Certainly that is one of the options, though it seems the RN favoured the continuation of the twin arm launcher, perhaps for cost reasons?
An 'odd' saving but a typical one. Whatever it 'saved' certainly should be weighed against the potential savings of a VLS silo's packaging the missiles is a neutral atmosphere. Or to put it another way the initial saving likely was wiped out by the costs of maintenance of both missiles and launchers over the decades to follow.

Under this alternative scenario, would this follow the same pattern? Would for instance the Dutch be in favour of VLS this early?

VLS would also have potential for the landbased system replacing Bloodhound.
 

zen

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Certainly post-Bristol, but pre-1966, there were a number studies of limited Sea Dart equipped ships. DS336 for instance adds reduced installation with 20 missiles and one Type 909, but only a short range air search radar Type 992P.

In the scenario of a single arm system using a mk13 style drum (scaled up to Sea Dart), it should be possible to have achieved the larger missile loadout DOR considered necessary for Fleet air defence. Projected cost being 9 million, compared to Bristol's 11.25 million.
 

JFC Fuller

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The RN built a cheaper Sea Dart ship- it was the Type 42.

The Sea Dart Magazine arrangement was very flexible in terms of ship design and it was actually pretty dense, it could be scaled to a new ship design very easily by simply changing the number of lanes and rows which is what was done between the T82 and the T42 (4 lanes in the former 3 in the latter).
 

JohnR

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Just as a matter of interest, what was the intended missile capacity of the T43s? I've always assumed it would have been two T82 sized magazines, so a total of 76 missiles. Can anyone confirm that?

Regards.
 

Abraham Gubler

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JFC Fuller said:
The RN built a cheaper Sea Dart ship- it was the Type 42.

The Sea Dart Magazine arrangement was very flexible in terms of ship design and it was actually pretty dense, it could be scaled to a new ship design very easily by simply changing the number of lanes and rows which is what was done between the T82 and the T42 (4 lanes in the former 3 in the latter).
The problem with the Sea Dart magazine compared to the similar American Mk 26 was that the missile bay was located an extra deck beneath the main deck. Which pushed this large and very wide room low into the hull where it conflicts with the hydrodynamic shaping of the hull (forward) and propulsion shafting (aft). Which is why the Australian DDL EV2* and Dutch Tromp class could be similar in hull size with identical propulsion yet accommodate much more stuff with lower costs (even without the extreme, and unbattleworthy cost cutting of the T42) and still be better sea boats.
 

JFC Fuller

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T42 Batch I/II came in a bit smaller than either a Tromp or an OHP but still managed two directors, a helo hangar, 4.5" gun and torpedo tubes in addition to the 22 round Sea Dart system. The batch III boats got to roughly the same size as those two classes and in doing so took the theoretical (though apparently never utilised) Sea Dart load to 37.

The sad thing about the T42 Batch I/II class is that if the design had been given another 500 tons, or been allowed to come out at about the same size/displacement as the T22 from the outset it would have been a much, much better ship. There is some evidence that the hull was shortened for cost saving reasons during the design process.
 
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Abraham Gubler

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There is some good data about T42 costs and its comparative potential with the Tromp to be modified with the RAN's spec combat systems in the DDL options paper. Which is i think uploaded here but if not i will provide a summary.
 

zen

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The RN built a cheaper Sea Dart ship- it was the Type 42.
And very tightly packaged they are, and the I's and II's are so tight there's no scope for anything else on them.

So considering we are discussing an alternative in which Sea Dart is more successful, exports more, is developed more. Either we are looking at bigger Type 42's OR we are looking at things being less tight on the cost and displacement limited ships.
In this context the 'as is' launcher system isn't going to get the Dutch onboard and isn't going to give us any wiggle room.
Ergo there needs to be an alternative launcher pursued, ideally from the start of the CF.299 Frigate studies and definately by the time the Dutch consider dropping Sea Dart for Tartar.
A single arm system, with a rotary magazine, or even the lane system but not taking up three decks is the way forward.

In this the magazine being built to take Sea Dart opens up other weapons as applicable to the launcher.

Three decks is more justified if we're going down the VLS route, which I think is more a product of the 70's mkII process, than the mkI.
 

JFC Fuller

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The floor of the Sea Dart magazine may have been three decks down but the magazine itself was still only two decks deep- it was only the base of the launcher and the transfer mechanism that occupied any space on the deck directly below the launcher.

The Type 42 had an alternative launcher, the much lighter Mk.30 Mod.2. Larger Type 42s from the outset are far from ludicrous either as the type may very well have been bigger for a good period prior to being laid down, and a bigger version basically gets you to the same size as the successful (in terms of export sales) Oliver Hazard Perry class and the Tromp class.
 

zen

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A 14ft long missile magazine should in theory be possible to be contained within two 8ft high decks of 16ft in total.
Granted in the ceiling of the deck below there might need be some structural reinforcement needed, depending on weight distribution.
But otherwise it should be do-able.

Does rather raise a question about why......is this really down to the launcher? or......was there something else....?

Equally, if continuing with locating the system three decks down, a system of three 'lanes' is a curious beast, likely a product of being a derivative of the four lane setup. Two lanes would impose less requirements on the huillform's beam, at the potential cost of greater length.

Whereas if we look at a different launcher, such a single arm system, perhaps we can fit this into two decks, or use two lanes?
 

zen

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Resurrected for the following development and general musings.

Anti-ship Sea Dart was a real if brief proposal.

Land Dart option would open up with lighter guidance system. Dutch STIR might be that opening. Potential rival to HAWK, lighter and more compact than Thunderbird. Jones Report favoured this.

ARM Dart
Anti-Radiation option during Mk II studies.

Fast Dart
....both a hypothetical option during the Mk I process.
And a real option during Mk II process.
In both cases the option of optimising the ramjet for higher speeds is entirely possible and research into such systems was extent.
Reasonable to assume a maximum speed of Mach 4.5 though Mach 5 is not impossible. Possibly a means to pursue limited ABM capability.

Long Dart
Extension to provide more volume for fuel and avionics. Earlier INS and Datalink coupled with more range makes a more viable successor for Bloodhound. Ideally with a change in guidance elements to answer criticism of the basic system.

Sky Dart
Lighter guidance system permits possible AAM, ARM and AShM options pursued for aircraft. Of these the AShM ought to be the strongest case.
 

Zootycoon

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Missing is Sea Dart Box Fire;- One of the drawbacks with Sea Dart was the polyrod guidance antennae which needed a fair bit of RF to be squirted at the target to get a usable reflection. Although this was good from a jamming perspective it meant the transmitter was somewhat weighty requiring a big ship. So the idea of Box Fire was to distribute missiles in boxes onto small surface assets (without illumination capability) and slave them to a central capital asset with illumination and fire control. This was used to increase the size and threat density of the defended airspace.

As for Fast Dart, I was told that in the early/mid 70’s a small number of trial rounds (4?;- gee it was a long time ago) were modified to explore just how fast it was possible to get a Sea Dart to go within the basic architecture. Ground test in the Patchway High Altitude ramjet facilitates got the Odin hot end to well over Mach 4, but these had a slave intake to represent the missile front end. I’m unsure as to how much the intake was modified in these high speed trials. I’m also remember that the fastest ground test achieved was around Mach 4.6 but I can’t remember if that was Odin or a technology demonstrator.

I’m also pretty sure high energy density fuels (Boron enhanced) were explored with flight tests;- a range enhancement but their pyrophoro’s properties were most unwelcome in the ship’s magazine.
 
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zen

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I like the idea of distribution. Would work with ideas of cheap TAS ships etc..

But I think boxed SD might best apply to the AShM variant if this could've gained an ARH seeker.

Actually giving a Mk II or III an ARH seeker is not impossible and could transform the system. A stepping stone to FAMS capability.

And of course in line with other threads I've developed ideas on....had this whole system centered around the ASWRE 3d C-band set and this had proved successful. Then with cheaper lighter IR (not proper tracking needed so no TIR just IR), then I suspect Sea Dart might actually have more affordable for the Dutch (yes I'm saying Broomstick is part of the reason for Desertcar) as well as landbased applications.
 
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