Commonwealth Naval projects

[Weaver]

Weaver with the 909 radar in that position it is more masked by the super structure. You could also shorten the deckhouse its on and reinstate the harpoos which give it a bit more reach and punch.

The deckhouse it's on is the standard 909 "office" which came as a pre-equipped module, so if you're sticking to the real hardware, then no, you can't shorten it. For the same reason, it couldn't go on top of the bridge, as per your original drawing, because the "office" would have been in the middle of the bridge underneath it: it would have to go behind the bridge in a similar fashion to the Type 42, and that would involve stretching the ship.

The bottom line is that Sea Dart is marginal on small ships like the Type 42 or the Iroquois: to get a really decent capability, you need something at least the size of a Type-82, or preferably bigger still.

[Weaver]

Replacing the huge Type 909s with a more sensible system seems a logical next step. Or even splitting the assembly; the 909s were built sa a unit with the office/equipment room underneath to facilitate testing, but there's no technical reason they can't be split.

Well the size of the Type 909 is governed by Sea Dart's range, which is in excess of 40 miles. That means that, although the missile is only Tartar/SM-1MR sized, it needs a Terrier/SM-1ER sized tracker, and an equivalent ultra-long range search radar. You could re-design it to split the tracker from the office, but that increases topweight and moves away from real hardware: I'm not aware of any real project to do such a split. Of course, you can do it in a whiff....

The Sea Dart VLS is an interesting idea, but I doubt having a magazine underneath the launcher is feasible. The Sea Dart is 4.4 m long, stacking them 2 high would mean the launcher is 10 m high, that's 4 decks.

The launch cylinder is above the weather deck (and armoured), so the magazine cylinder only takes two decks below it. The real Sea Dart magazines all stow the missiles vertically, and are much bigger than these 6-round drums, so it must be possible. The launchers in the drawing look shorter because the 01 deck extends around them, right out to the edge of the deck. The actual launchers would be about the height of the GWS-30 launcher on the back of the first drawing and at the same level.

[DarrenP]

Having the 909 radar and office colocated is logical however very short sighted as an Anti radiation missile strike to the system is likley to take the whole system out not just the emitter ie the antenna. remoting the Antenna therefore the more logical solution.

[Hobbes]

Well the size of the Type 909 is governed by Sea Dart's range, which is in excess of 40 miles. That means that, although the missile is only Tartar/SM-1MR sized, it needs a Terrier/SM-1ER sized tracker, and an equivalent ultra-long range search radar. You could re-design it to split the tracker from the office, but that increases topweight and moves away from real hardware: I'm not aware of any real project to do such a split. Of course, you can do it in a whiff....

Splitting the tracker from the office does not necessarily increase top weight. Top weight only goes up if you decide to place the aerial high up.

[Hobbes]

The UK was looking at a Joint destroyer design with the Dutch so maybethe Dutch might have come in or the Tromp might have been the basis?

Tromp looks good, but suffered problems due to its steel hull+ aluminium superstructure. Structural failures were common (I've seen accounts of tears wide enough to stick a hand through). Still, a Tromp class with Sea Dart aft and Sea Wolf forward would have been quite a sight.

[elmayerle]

The UK was looking at a Joint destroyer design with the Dutch so maybethe Dutch might have come in or the Tromp might have been the basis?

Tromp looks good, but suffered problems due to its steel hull+ aluminium superstructure. Structural failures were common (I've seen accounts of tears wide enough to stick a hand through). Still, a Tromp class with Sea Dart aft and Sea Wolf forward would have been quite a sight.

Steel and aluminum together in a salt water environment?  Damn, that's just asking for galvanic corrosion problems and structural deterioration without taking very major steps to prevent it.  It's bad enough in aerospace if you happen to mix incompatible materials like that just in fastener use; I can imagine mating whole structural sections like that and what troubles you could get into, even with the best of sealing compounds.

[DarrenP]

Th UK had problems with the Type 42's and 21's both needing structural reinforcement.
Have had a demonstration of aluminum burning when doing metalwork at school in 82 for obvious reasons. what happens to steel/aluminum in a salt water enviroment?

[Weaver]

According the D.K.Brown, the aluminium/steel problem was widely misreported and misunderstood in the aftermath of the Falklands War. The Type 21s (and the rest of the Vosper frigates) did indeed have aluminium superstructures on a steel hull, but the very obvious pitfalls of this lead to pre-emptive research at Vospers which completely cured the problem. Basically, the two structures were bolted together with an insulating strip in between which completely avoided galvanic corrosion.

The problem with cracking in the Type 21s wasn't caused by the aluminium per se, rather it was a failure of analysis. It was originally believed that even if the aluminium superstructure cracked completely, the hull would have sufficient strength to survive, but then, just before the Falklands (helpfully  ) National Physics Laboratory research demonstrated a previously unrecognised failure mode and the ships were advised to avoid excessive motions (i.e. heavy seas). Subsequent reinforcement cured the problem completely.

It's worth pointing out that cracking occurs in steel ships of all sorts and even total structural failure is still scarily common.

[elmayerle]

Have had a demonstration of aluminum burning when doing metalwork at school in 82 for obvious reasons. what happens to steel/aluminum in a salt water enviroment?

Without suitable preventive measures being taken, stell and aluminum together in a salt water environment are going to result in massive galvanic corrosion and weakening of the structure.  As I said, it's a major problem we have to watch in design, making sure that all the materials we use are compatible or that appropriate preventive measures are taken to prevent galvanic corrsion.

[Thorvic]

Back on subject with regard to commonwealth naval projects, i would keep the iTribal as an ASW design and only go for shart range SAM systems, But for profiles dont forget to play with the funnel layout as the large stack only came in with the refits.

For AAW maybe look at the YARD proposals for the RAN

G

[Aircav]

The problem with cracking in the Type 21s wasn't caused by the aluminium per se, rather it was a failure of analysis. It was originally believed that even if the aluminium superstructure cracked completely, the hull would have sufficient strength to survive, but then, just before the Falklands (helpfully  ) National Physics Laboratory research demonstrated a previously unrecognised failure mode and the ships were advised to avoid excessive motions (i.e. heavy seas). Subsequent reinforcement cured the problem completely.

It's worth pointing out that cracking occurs in steel ships of all sorts and even total structural failure is still scarily common.

Does that equate to work hardening because of flexing?

[Weaver]

Does that equate to work hardening because of flexing?

I'm not a metalurgist, but I think so, yes. The aluminium work-hardens and cracks much faster than steel which, with proper design, should last the life of the ship.

[DarrenP]

Doesn't Aluminum stretch when it bends and flexes?

[Weaver]

Here's a thought: if we've got a strong Commonweath axis going on here, how about an operational version of the CL-84 tilt-wing instead of the Seaking? By all accounts it did very well in test flying but had no political will behind it, but that might change if Britain was less keen on Westlands co-operating with America (and Westlands would be a damn useful partner on the CL-84!) and Australia was offered something that was not only useful for the navy but was also, effectively, a VTOL GAF Nomad. It would need a redesign to be a bit bigger and have V-22-style wing/engine fold, but that's doable....

[Hobbes]

Still, a Tromp class with Sea Dart aft and Sea Wolf forward would have been quite a sight.

Proof:



Premise: the Broomstick project isn't canceled. The Signaal SPS-01 ends up on sundry AAW ships in the Royal Navy. As part of the compensation package, the RNLN buys British weapons for its ships. The Tromp and Heemskerck class get Sea Dart and Sea Wolf with their associated trackers; the Kortenaer gets Sea Wolf.