|APT at Preston|
Whilst the Hydo Kinetic braking has not been further developed and used, alternate system such as the Eddy current braking used on the ICE3, have been. The addition of such system would allow faster running on virtually all electrified main lines. Though as a result of experience with the APT this would require the fitting of in-cab signalling, rather than current track side signalling, which becomes unreadable at high speed. The track side infrastructure that would enable this, is being installed by Network Rail at the moment as part of its ECTS 2/GSM (R) programme, and the in cab systems developed for other high speed lines and ETCS, are also available and have been tested in the UK on the Cambrian Line.
If an APT2 train was developed in place of High Speed 2's the proposed classic compatible it would extend the benefits over a far greater area, at a greater rate. Using the high speed network now in place across Europe as the core and providing higher speeds on existing lines.
An APT capable of 250mph on suitable lines and 155 on traditional lines, would be, on certain parts of the TGV network, faster than the TGVs due to the tilting especially in southern France. It may also find usage, with a different gauge on Ireland.
It would also provide further enhancement on the Greater Western lines and on any proposed Norwich, Bristol route and shorten the London Scotland journey times by an appreciable amount.
It would be best to develop this as the primary rolling stock rather than a train dedicated to the GC loading gauge, as these trains would be useful as soon as developed not dependent on HS2 at all and would bring the benefits forward as far as possible for as many as possible. Additionally, most of the initial trains that run on HS2 will spend more time on traditional lines, north of Birmingham, than on high speed ones.
While in the early 80s this was state of the art today, no part of it is novel, beyond the braking system and the market stretched far beyond the HS2 and far beyond the UK.
This is a case where a relatively small amount of additional money on top of the Classic compatible development would produce disproportionately great benefits.
Some more of My Thoughts on HS2 and Mesrseyrail.