Hi Peter,
Geograph was offline. Now it's back, the tracks are/were used for the assembly of undersea pipeline (picture dated 2003): http://www.geograph....uk/photo/354508
There is a works at the other end of the tracks, described thus in 2004:
Oil, not water. More info: http://www.subsea7.com/cms/files/File/Wick_Base_(FSS)(2).pdf
From which:
Martin.