Anderman said:
Anthony G Williams had the idea to use RR Speys in a COGAG combination instead of the used COGOG on RN ships.
http://www.quarry.nildram.co.uk/Alternative%20RN.htm
Is this a realistic idea ? The Type 22 are much larger then Williams 2750 t frigate so would this ship had enough speed with two Speys?
And how much power would the RR marien Spey had have in the 70´s ?
The Marine Olympus was originally a Bristol Siddeley proposal, predating the 1966 merger with Rolls Royce. Consider that the Olympus was a mature program, in the correct category, with an assured future due to the sacrosanct Concorde program, and it isn't hard to see why there was a marine derivative. My suspicion is that the definitive versions of the Marine Olympus benefited from the development of the 593 for the Concorde.
In contrast, the Spey was a far less mature program during the mid 1960s, and it is unclear if Roll Royce was even actively pursuing the Marine Olympus after its selection. In many respects, the Marine Spey owed much to the later Tay, which itself was a Spey derivative, and even some aspects of the RB.211 if certain sources are to be believed. So it never was a simple case of a choice between a Marine Olympus and the Marine Spey as the two programs belong to two distinct time periods. Personally, I doubt that a Marine Spey would have been available before the 1980s, even if its development had been a fully funded priority. As it was, the development of the Marine Spey was pushed forward for the Type 23 frigate program, which is why it was fitted to the Type 22 class, with HMS Boxer representing an operation testbed.
In any case, the earliest opportunity for a 4 Marine Spey surface combatant was the Type 43, which fell victim to the Nott defence cuts, and there was no real subsequent opportunity for any subsequent destroyer program with this configuration. Similarly, there was no real opportunity for a small, hypothetical twin Spey surface combatant, as the Type 23 represented the minimum unit of its time period.
This post centers on pure speculation, so it is more suitable to Theoretical and Speculative Projects subforum.