Waiting for my usual 06:42 to Waterloo and heard a familiar chug from the distance. Managed to capture an old Steam train on video coming through, headed towards Bournemouth, complete with loads of carriages.
Having re-read the OP and realising he was in Christchurch and not Waterloo, it would have been 70000 Britania with The Bath Spa Express on it's way to Poole for an excursion to Bristol and back.