My mother told me that it was called Black Rock because the waste tar left over from gas production at the gasworks just inland was simply - in those pre-environmental days - dumped over the cliff edge onto the beach.

Volks never actualy went beyond Black Rock. The rocks are the remains of the old daddy long legs train that ran from Banjo groin to a jetty at Rottingdean. Lots of info can be found at: http://www.volkselectricrailway.co.uk/ anf here: http://www.urban75.org/railway/brighton-sea-railway.html I do hope this helps.

My nan remembers the Volks railway running much past Black Rock, so I don't think this is true.