AMMoffat wrote:It looks like the person locking that bike (or should I say wheel ) was really stupid but you tell me how a U lock can be used to lock the frame (or anything other than a wheel) to that bike stand.
There is another inverted U sticking up from the left side of the channel further back (not shown in that picture) for securing the rear triangle and rear wheel. It's still not a great design for loads of reasons (including that the rear locking point often collides with centre and prop stands), but it does allow the frame to be secured. I think it's a pretty widespread design used by Thameslink/Southern/Great Northern and Greater Anglia. See the picture below for the same design at another station - if you zoom in, you can just about see the rear locking point on the bike to the right and a D lock used on the bike to the left.
If you've got only one lock, then you should lock the frame far enough back that the bike cannot be moved backwards enough to liberate the front wheel - or simply use the Sheffield stands around the corner!