This is a converted Fort/Park - the Canadian version of the Liberty ship. She was used by the RN as a submarine support/repair vessel and has been inactive for many years. She is now in the disposal line at Fareham Creek and was used for SBS training.
She is the only vessel left in the UK with the standard Liberty ship VTE of 2500 hp driving a single screw. Her future is bleak to non-existent.

Not a good picture. There are two excellent pictures elsewhere in here.