Sea Dart Mk 2 (GWS 31)

[Martes]

I tried to locate any data or graphical representations of how the Mk2 Sea Dart (the one that was planned for Type 43 destroyer) could look, but apparently without success.

Are there any? What where the differences with the original missile and how should it have looked, especially if adopted for vertical launch?

 

[Zoo Tycoon]

From what I remember the missile itself was externally the same as the original. Internally it had an INS, autopilot allowing optimal trajectory, and an IR prox fuse (upgrades that were included in the SD mk1 via a few upgrades), thus enabling terminal phase guidance. The booster was larger (longer) with TVC offering off the rail manoeuvres but also burning for a second or so longer. Testing was done with Shelldyne (Boron enhanced fuel) to increase range but I don’t recall that being within the SD mk2 baseline.

The Mk2 as contracted, was not vertical launch;- the enhanced “off the rail”manoeuvrability was to cover otherwise vulnerable arcs around the ship. That said a lot off thought and study had gone into vertical launch which resulted in a preferred method. I’ve previously put comments on this site that I was told by one of the guys who participated in the SD mk2 vertical launch concept, principally that the safety case demanded the launch cells had to be at the ships stern. However, someone with no declared detailed knowledge of the SD mk2 development, told me I was wrong, offering little more than other very different systems, decades later, possibly different safety objectives didn’t require such a consideration.

 

[Martes]

Many thanks for this information!

So effectively later upgrades to Mk1 duplicated Mk2 functionality?

That said a lot off thought and study had gone into vertical launch which resulted in a preferred method. I’ve previously put comments on this site that I was told by one of the guys who participated in the SD mk2 vertical launch concept, principally that the safety case demanded the launch cells had to be at the ships stern.

Would this variant mean collapsible wings to reduce the size of the container?

 

[Zoo Tycoon]

Not from memory, but the booster fins folded out upon launch even on the mk1. The mk1 was fired from a box without any mods, see. https://www.secretprojects.co.uk/th...cancelled-applications.218/page-4#post-438359

 

[Martes]

Yes, I saw that thread and this plan -

https://www.secretprojects.co.uk/threads/sea-wolf-and-sea-dart-unbuilt-derivatives-and-cancelled-applications.218/post-438146

and thought that wings take quite a lot of space, that could be reduced if they were folded - Harpoon style. But I have no idea if anybody considered it, at least for Mk2.

 

[Dilandu]

and thought that wings take quite a lot of space, that could be reduced if they were folded - Harpoon style. But I have no idea if anybody considered it, at least for Mk2.

The main problem is not the wingspan, but a finspan. While wings of Sea Dart are immobile, the fins are used to control missile during Mach 2 supersonic powered flight. Making them foldable are certainly possible, but would likely require significant redesign.

 

[Martes]

Making them foldable are certainly possible, but would likely require significant redesign.

a lot off thought and study had gone into vertical launch

The question is whether this was ever considered - either for VLS Mk2 or any modifications of Mk1 - or it was assumed the VLS cell would be identical in size to the launcher container depicted above.

 

[Zoo Tycoon]

I don’t recall any mention of making the missile fins fold for either box fire or vertical launch or rail launch TVC. The main concern was achieving some fairly tight parameters for ramjet ignition while doing a curved boost phase.

 

[Martes]

I don’t recall any mention of making the missile fins fold for either box fire or vertical launch or rail launch TVC.

Thanks, those were exactly the details I was looking for.

 

[Yellow Palace]

I don’t recall any mention of making the missile fins fold for either box fire or vertical launch or rail launch TVC.

Given that Sea Dart has a narrower span than Standard, which AFAIK also doesn't fold for vertical launch, I'm not sure it's a major issue.

 

[TomS]

Given that Sea Dart has a narrower span than Standard, which AFAIK also doesn't fold for vertical launch, I'm not sure it's a major issue.

Standard Missile tail fins do fold, actually. The fin span is ~42 inches; the diagonal of a 21-inch canister is about 31 inches.

 

[Dilandu]

Standard Missile tail fins do fold, actually. The fin span is ~42 inches; the diagonal of a 21-inch canister is about 31 inches.

Standard originated from Tartar, which was from the very beginning aimed to avoid the Terrier main problem - manual finnig, which sloved the reload and required an additional room between magazine and launcher. Foldable fins were the solution.