Bob,
Think you will find they are "Kone" bucket wheel unloaders.
Doug.

They are Siwertell screw-type ship unloaders. At around the same period two each were also installed at West Thurrock and Kingsnorth power stations.

I well remember photographing this myself Bob, but hadn't realised it was 22 years ago! I still think of these as new. The latest kit for unloading biomass fuel certainly wont last as long because the Power Station is slated for closure in 2015. Also with its recent penchant for fires it may not even last that long!
Best Regards
John J.

They have been part of the scenery for so long,I can't
remember the original cranes.Must be photos somewhere on site.
Kind regards,
Doug.