agreed Baz, the end of Rye Pier is high enough for me too!... and that's at high tide!
And this guy filming did the "walk" with such confidence... I'll just overtake you, or walk across the beam at 200 metres high. I noticed he was wearing special rock climbers shoes so he's obviously used to it.
From the site that Saratoga linked "Access to other climbs can be attained by walking through
the train tunnels and following the train tracks, preferably between trains"