Looking at National Rail site there appears to be blasted engineering works in the South west. Train from Waterloo to Southampton Airport Parkway, bus to Bournemouth (50 mins) and back on the train to Dorchester South. Alternative Train from Paddington to Westbury then train to Dorchester West. In both cases it gives a journey time of about 4 hours from Kidbrooke. Advance purchase tickets shown (currently) at £15 each way.
