Built by Harland & Wolff, Belfast, one of a series of four sister ferries for British Rail.
They were powered by a pair of 16-cylinder Crossley-Pielstick 16PC2-5V-400 four-strokes on two screw shafts. The lead ship, ST. ANSELM, built for the Dover-Calais route, had major vibrational problems with these engines but these were sorted out in time for the delivery of the later ships, ST. CHRISTOPHER, ST. DAVID and this one.
After having sailed on the maiden (press-preview) voyages of both the ANSELM and CHRISTOPHER (I appeared on TV's Blue Peter on the CHRISTOPHER trip - but didn't get a badge!), would avoid the Townsend Thoresen ships like the plague (even before thr HERALD disaster).
As a ship photographer since the year dot, the attraction of these Sealink sisters was the open passenger deck right forward on the superstructure (except in really rough weather, when it was shut off). Away from the vibarations from the engines an propellers, it made a great platform for photographing ships in the Dover Strait
You are right. Galloway Princess was the first. Anselm was just the first I sailed on.
As to the different speeds: they all had the same engines. I suspect that Lloyd's Register may have got a bit confused between the engines' MCRs and NSRs, and trial speeds and service speeds. Lloyd's did (and still do) tend to do that.
Not Lloyd's Bob, but a master, who served in the Galloway and the "Saints". He lamented in Ferry Publications' "The Saints Go Marching On" that the "Galloway" had "much less power in her engines and bow thrusts with the result lots of us had occasions to envy the other vessels on many a winter's night".
This is also mentioned by her designers in the book Designing Ships for Sealink. They said the speed of the "Saints" was a knot higher than the Galloway Princess due to higher powered engines.
Agree they were the same engines - except the Galloway's were Mk 2 8,000 bhp while the "Saints" had Mk 5 10,400 bhp.