Vertical launch Sea Dart

Practica
I think the article quoted is referring to the system as opposed to the missile and in this respect the article is correct. The system (or GWS30 as it was known) consisted of a target acquisition radar Type 965 (WW 2 vintage and full of valves), 2 off Type 909 illumination radars (solid state I think?), an FM1600 computer (solid state using an F1000 integrated circuit CPU), the missile itself (solid state) and the associated launcher/magazine. The Type 965 radar was imposed as a stop gap/cost cutting measure and was gradually replaced by the more modern Type 1024 which is largely solid state I understand. But according to college of mine and a fromer Sea Dart development Engineer, the missile itself was definitely solid state electronics and totally maintenance free whilst at sea. Consider that the Bloodhound Mk2 missile, which pre-dated the Sea Dart design by about 10 years, also had a solid state seeker head, but the earlier Bloodhound Mk 1 used only valves. Apparently the Bloodhound Mk1 needed to be switched on for several minutes prior to launch so as to warm up the electronics! (you can see these seeker heads sectioned at the Bristol Aero collection – Kemble)

Interestingly the Missile itself is stored in the magazine dry, it was only filled with Kerosene in the second or so prior to blast off.

Sea Dart was once launched from a box by way of a demonstration, and vertical launching using TVC was explored in study form. I think this would have been problematic because in the boost phase you have to get the ramjet lit and this was tricky enough with the missile going in a straight line. As a missile, Sea Dart Mk 2 was only studied and never flown.

To Vega ECM

I admit that my proposition regarding the fuel system for the missile is my opinion based on spending a lot of time on ships over a ten year period, and seeing the damaged that could be caused in heavy weather.

However, regarding the electronics, from Naval Institutes World Naval Weapons Systems; page 237, I Quote:

“Because it employs vacuum-tube technology, this system is reportedly not entirely reliable”

“However , Mark 2 would also have had thrust-vector control, new wings and fins to allow the missile to engage higher altitude targets, more fuel, and a higher proportion of solid-state circuits”

Regards

Quite a lot might have been possible: http://www.quarry.nildram.co.uk/Alternative%20RN.htm

🙂

Tony Williams: Military gun and ammunition website and discussion forum

Yes your article did get me wodering when I first read it.

The ultimate limiting factor in producing a vertical launch Sea Dart was chronology.

It was developed with early to mid 1960’s technology, which needed to be maintained. The electronics were valve/vacuum tube not solid state electronics, also the missile itself was liquid fueled. These factors mean that Sea Dart could not be treated as a round of amunition in the same way as more modern missiles. The missile had to be accessible for maintenance.

I’m sorry but the Sea Dart missile itself was from its very first flight fully solid state electronics and certainly from the Odin engine perspective it required no maintenance whilst on the ship (I believe the rest of the missile was the same, but I don’t know for sure).

I agree Kerosene is a relatively benign fuel as against HTP or LOX, however, in my view the thing to remember is that liquids leek. I would imagine that the any missiles would be subject to a very high degree of slamming if the ship was caught in heavy weather.

I do not know what protocols that the RN uses when maintaining the missiles on board, but I would certainly want to know that non of my missiles had fuel leeks, however unlikely. Otherwise a very spectacular fireworks display could result when the booster ignited when being launched.

Once again I make the point regarding the electronics. I remember as a child watching over the shoulder of the TV repair man on his twice yearly call out replacing the valves in the telly – which was the item that always needed to be replaced. So what chance for these delicate items on a 3500ton destroyer in a force 10 gale. This reliability problem would have been address in the Sea Dart Mk2, and was only resolved after the Falkands in 82 when a back door Mk2 program was undertaken and the missiles and radars where upgraded in stages.

As regards aquiring the targets, surely the German SAMs where designed to take on high level bombers flying at 30,000ft, therefore there would have been time for the missile to gain sufficient velocity to become aerodynamically manouverable. However, for the missile to “tipped over” immediately upon launch; as would be required with a VLS, thrust vector control would be necessary, a technology which I understand only matured in the 1970’s – Taildog/SRAAM as an example.

Also if vertical launching was so easy why then was SM1, SM2, SAN3, 4 & 7, Crotale, Sea Sparrow and Aspide all launched on mechanical launchers when all of these came after Sea Dart, and why did it take until the early eighties to come up with an effective verticle launcher.

I absolutely agree that VLS launching is desirable, but believe it would have come with a “Sea Dart Mk3”.

The ultimate limiting factor in producing a vertical launch Sea Dart was chronology.

It was developed with early to mid 1960’s technology, which needed to be maintained. The electronics were valve/vacuum tube not solid state electronics, also the missile itself was liquid fueled. These factors mean that Sea Dart could not be treated as a round of amunition in the same way as more modern missiles. The missile had to be accessible for maintenance.

True, but as a ramjet it just burned jet fuel (or something like it) – quite easy to handle, and can be left in the missiles for long periods. It didn’t suffer from the serious problems of the liquid-fuelled ballistic missiles, which used all sorts of exotic and dangerous chemicals, some of which had to be kept extremely cold.

Also there is the technical problem of how to gather the missile onto the target after launch. Far easier to point the missile in the general direction of the target, especially if the target was approaching at a low level. On NavWeapons, someone has just posted that the most difficult aspect of the development of VLS Seawolf was tipping the missile onto the target and that was with two decades worth of development in electronics.

I don’t see why – it’s just command guidance, which is what some of the earliest missiles used (like the German SAMs in WW2). The system tells them via radio control which way to steer to aim at the target. A bigger headache (especially for short-range missiles) is the need to turn them to point at the target quickly, before their aerodynamic control surfaces are effective. So you have to have some sort of steering vanes in the rocket or jet efflux, or a steerable nozzle. That is a complication.

Tony Williams: Military gun and ammunition website and discussion forum

The ultimate limiting factor in producing a vertical launch Sea Dart was chronology.

It was developed with early to mid 1960’s technology, which needed to be maintained. The electronics were valve/vacuum tube not solid state electronics, also the missile itself was liquid fueled. These factors mean that Sea Dart could not be treated as a round of amunition in the same way as more modern missiles. The missile had to be accessible for maintenance.

Also there is the technical problem of how to gather the missile onto the target after launch. Far easier to point the missile in the general direction of the target, especially if the target was approaching at a low level. On NavWeapons, someone has just posted that the most difficult aspect of the development of VLS Seawolf was tipping the missile onto the target and that was with two decades worth of development in electronics.

Quite a lot might have been possible: http://www.quarry.nildram.co.uk/Alternative%20RN.htm

🙂

Tony Williams: Military gun and ammunition website and discussion forum

I might agree with many of your conclusions, but I do have to wonder about some of the real technical factors at play.

For instance, was Sea Wolf VLS development protrated by technical issues or funding issues? In hindsight, the VLS concept is intuitively superior.

I do have to disagree with you when it comes to the topic of marine gas turbines and the number of shaft a warship should have.

As far as I know, the Marine Spey is hardly a straightforward derivation of the early 1960s Spey turbofan. It occurs to me that the development of the Marine Spey depended on the core of the later Tay turbofan, which itself was Spey derived.

It should be remembered that development of amarine gas turbine is dependant on development of the aero-engines it is based on, and not the other way around. The development of the Concorde’s Olympus 593 resulting in a Marine Olympus with nearly twice the original output.

I would also disagree with your suggestion that Invincible class carriers should have had 3 or 4 shafts. Multiple shafts invite vibration issues and sometimes it is better to resort to gearing than to trail unpowered shafts. Thankfully, we now live in the age of massive waterjets and Mermaid podded propulsors.

Yes, D K Brown’s ‘Rebuilding the Royal Navy’ shows the general arrangement of the Sea Dart launcher and magazine on the various designs floating around at the time but I wonder what could have been done if a VL system had been decided on from the start.

Quite a lot might have been possible: http://www.quarry.nildram.co.uk/Alternative%20RN.htm

🙂

Tony Williams: Military gun and ammunition website and discussion forum

The Sea Dart Magazine isn’t directly below the launcher as in the Soviet VLS and the Mk13 Launcher. There is an intermediate stage directly below the launcher where the missile is warmed up, and the magazine is below that.

Yes, D K Brown’s ‘Rebuilding the Royal Navy’ shows the general arrangement of the Sea Dart launcher and magazine on the various designs floating around at the time but I wonder what could have been done if a VL system had been decided on from the start.

The Sea Dart Magazine isn’t directly below the launcher as in the Soviet VLS and the Mk13 Launcher. There is an intermediate stage directly below the launcher where the missile is warmed up, and the magazine is below that.

The Soviet VLS systems use a gas generator to launch the missiles from the tubes a “cold launch”, in the same way as an SLBM is launched. Western VLS SAMS are hot launched, which requires venting of the rocket motors exhaust.

GWS30 Sea Dart magazine isnt exactly the bin/drum layout like the russian 303 VLS. The ramjet missile needs a little more attention below decks before its hoisted up into the launcher.

I thought it was Sea Slug that required the pre-launch preparation?

What was there to stop the RN using the rotating drum as a VLS similar to the Soviet SA-N-9 with the rotating drum firing out of a single apeture rather than feeding them to the trainable launcher or even making the whole drum a VLS equivalent to the Mk41 or Sylver but in service far sooner than any of these.

Britain pioneered the VLS concept with Sea Wolf, although the concept wasn’t fielded in a timely manner.

The Russian rotary fed VLS also remains unique. It is hard to judge Soviet era concepts, especially when an attempt is made to compare them with their western equivilents.

GWS30 Sea Dart magazine isnt exactly the bin/drum layout like the russian 303 VLS. The ramjet missile needs a little more attention below decks before its hoisted up into the launcher.

They, BAE, did come up with a sealed box launcher eventually for the type and I have a very distant memory about a cell-based VLS for the system when it started to become fashionable.

The T42, T82 and CVS installations did not lend themselves to easy conversion to rotary VLS’s as in the SA-N-6 model.

I’ve read the 64 cell Mk41 takes up roughly the same volume as the Mk26 Model 1 trainable launcher and 44 missiles on the first three Tico’s.

The Mk13 is much more compact.

Probably a much simpler/cheaper solution. Take the Mk13 single-arm launcher for the Standard MR. You can fit 40 missiles in a smaller space than 40 VLS cells and they don’t have to waste energy turning from vertical to the correct direction. On the other hand you’re limited to a certain size missile.

I’ve read the 64 cell Mk41 takes up roughly the same volume as the Mk26 Model 1 trainable launcher and 44 missiles on the first three Tico’s.

Sea Dart is stored vertically on the Type 42’s as it was on the Type 82 in rotating drums (presumably 11 Sea Dart per drum on the Type 42 if the figures on magazine capacity are correct).

Does anyone know why when they had the missle in the ‘correct’ orientation it was decided to throw that away and use a trainalble launcher?

Probably a much simpler/cheaper solution. Take the Mk13 single-arm launcher for the Standard MR. You can fit 40 missiles in a smaller space than 40 VLS cells and they don’t have to waste energy turning from vertical to the correct direction. On the other hand you’re limited to a certain size missile.