.........and ISTR the escape options for the new Heathrow CTB at the time of design were:
1. Special high-speed lift.
2. Flash Gordon type shuttle capsule on a guy-wire.
3. Individual inertia-reel escape harnesses which were to stop 6' from the concrete.
Sadly I got flushed out of the old CTB across the M4 by the 'Thames Flood' of July 2003 and never got to experience the wonders of the new CTB. Maybe someone could fix it for HD and me....