In message , Richard J.
writes
"Andy Spark, from the Jubilee Sailing Trust, said: 'We believed the
bridge was booked, but it didn't open - we don't know why yet.' ... But
the Corporation of London, which owns Tower Bridge, said: 'No lifting of
the bridge had been booked in.'

From having done a tour of the bridge I'm pretty sure that vessels
requiring it to lift have to call in on the radio, that all bigger
vessels have to carry. I wonder why the Tall Ship didn't (either have
such a radio, or use it).

The Thames bridges also have "traffic lights" for vessels, so this is
actually a SPAD as well!
--
Roland Perry