Dave,
when the QE2 was refitted in 1986/87 I think the oil fired steam turbines were replaced with the sort of marine diesels used in the AGS. She lost some speed, but reduced fuel consumption massively.
I do wonder if the relatively low speed of AGS was one of the reasons for the decision to scuttle; the Captain didn't have the speed to out run the British fleet, even if he had the range. Exeter and similar ships could all do over 30kts, AGS 28.5 undamaged. In the condition she was in who knows.
