(10 Sep 2014, 4:33 pm)Dan wrote As someone who has very little knowledge in this area (our Corbridge resident may have a better idea), I think the current engines will remain in place and the appropriate systems brought in place with the existing engines.
Yes, as I understand, the modifications are purely 'add-ons' to the existing power unit:-
The Gyrodrive system uses a high speed flywheel made of carbon fibre to store the energy generated by a bus as it slows down to stop.From:- http://www.gkn.com/media/News/Pages/GKN-...buses.aspx
It then uses the stored energy to power an electric motor which helps accelerate the bus back up to speed, generating fuel savings of more than 20%.
One of the early problems (in the late 1980s) with the Leyland energy-storage flywheel was containing an explosion (mechanical failure) of the carbon-fibre flywheel - the energy stored is significant and requires immense rotational speeds of the (low mass) flywheel.
I don't know how the GKN Gyrodrive flywheel compares (no doubt a couple of decades of development has improved the integrity of the flywheel) or whereabouts on the vehicle it will be installed, but it could herald a new phase of carbon emissions if it was to burst and breach the casing!