On Aug 13, 12:00*pm, Mizter T wrote:
On Aug 13, 11:23*am, Paul wrote:

Sounds like a serious screw up, thankfully no-one got hurt. RAIB will
of course be involved.

The RAIB have announced their investigation, with some preliminary
details and a picture of the unit involved:
http://www.raib.gov.uk/publications/...te_runaway.cfm

Something that I don't think had previously been released:
The crew of the grinding unit, who had no means of re-applying the
brake, jumped off the unit as it passed through Highgate station.