Apologies for the lazy referencing. By replacing C2s in the Carribbean I meant the Type 22 Batch IIIs and stripped-down Type-23s (without Towed-Arrays as I see it).
As for the expensive propulsion option within the Type-45, is that no a prerequistie for the C1/ASW-option? Add-in expected economies-of-scale then surely the sale-price and maintenance implications should favour a one-size-fits engineering solution.
On the C3, I don't like the River/Clyde compromise. A 3k tonne solution with suitable hangarage - if only for a US Coast-Guard 'copter - adds in flexibility. I'd hate to have a Royal Navy patrol in the WIndies without such support, especially at a time like now. [Is emergency relief refundable from the Development Budget?]
Ah, I see.
The IEP on the T45 really is expensive, & apparently isn't the only thing. It can be done cheaper, & supposedly much cheaper, while still retaining an efficient IEP (something I think the RN is now very keen on). I think that the idea is that there's a better chance of economies of scale by designing a common C1/C2 basic ship which is exportable, than from building a T45 based C1. Partly, this is because a T45 based C2 is just plain wrong. C2 is supposed to be cheap. You can't build a cheap ship on a top-notch & & top-dollar large hull with grade A (& priced accordingly) propulsion. Therefore, if C1 & C2 are to share the same basis, it can't be T45.
That said, some people advocate that C1 should use a T45 hull, & C2 should be smaller & cheaper, with a degree of commonality with C3. i.e. a relatively big C3, & C2 being the same basic design, but stretched, up-engined (could be done with the same basic propulsion system, but extra units) & of course more heavily armed & with better sensors. While I consider that a position with some merit, it seems the RN has rejected it. The debate on whether C1 & C2 should be based on the same generic hull
Richard Beedall mentioned in early 2007 seems to have ended, & the answer is apparently a firm "Yes", if various articles quoting RN sources are to be believed..
It's worth looking at what Beedall reported then, straight from the horse's (i.e. S2C2 team leader Commodore Dick Brunton's) mouth:
* a Force Anti-Submarine Warfare (ASW) Combatant (known as C1)
* a Stabilisation Combatant (C2)
* an Ocean-Capable Patrol Vessel (C3).
"The plan we have developed takes eight existing classes down to just three. The capability currently delivered by the Type 22s and Type 23s would be replaced by C1 and C2, while C3 would replace the capabilities of our existing mine warfare fleet but also offer additional capability for maritime security tasks."
And -
C3 is currently envisaged as a vessel of approximately 2,000 tonnes displacement with a range of 7,000 nm for constabulary and minor war vessel tasks. Cdr Brunton said "We see this vessel being used for maritime security and interdiction operations. It would also have a large mission bay aft, reconfigurable for special forces, MCM or a Lynx helicopter."
AFAIK, this is still the clearest statement on C3 from any official source, & the larger proposals, e.g. Khareef or Venator, are just that: proposals.