Re Jeffs Posting. The Opening times for the Ham Wall car park are: 01/10 - 28/02 0700 - 1830 01/03 - 31/05 0700 - 1930 01/06 - 30/09 0700 - 2100 The barrier has a timed automatic electric lock so there will be no lee-way involved - you will be locked in if you are late.