HS2 in perturbation

Earlier this week, train services on Britain’s East Coast Main Line were severely disrupted by overhead line damage near Hitchin, which is around 50 km north of London.

[Daily Mail, 17 December 2012, updated 18 December] Train operator East Coast cancelled all trains out of London King’s Cross and ran diversionary train and replacement bus services to the North after electric power lines near Hitchin were mysteriously damaged.
[…]
National Rail said at least 14 ‘droppers’ – part of the overhead wire – have been broken and contact wires damaged, causing further damage to passing trains.

The failure caused all services from the South – leaving London at a rate of up to four an hour – to be cancelled and forced services from the North to end at Peterborough subject to diversions or replacement buses.

Currently, the East Coast Main Line carries most or all London-bound passenger traffic from North East England, Eastern Scotland, Yorkshire and Lincolnshire. However, under the government’s vision for high speed rail in the year 2032, long distance high speed (LDHS) services from the West Midlands, East Midlands, Northern England, and Scotland, would be transferred onto the new-build Y network, with 18 trains per hour operating on each track.

Re-routeing the LDHS trains away from the East and West Coast Main Lines would supposedly “free up capacity for more regional, local, and freight services”. However, on their busiest sections near London, much of the East and West Coast lines have long had separate Relief (‘Slow’) tracks for local and regional services.

Concentrating LDHS trains onto the twin-track London — West Midlands HS2 trunk would pose difficulties for service reliability and resilience. On the classic network, disruption incidents might be handled by measures such as diverting trains, de-training passengers at intermediate stations, and / or dispatching rescue diesel locomotives. How such options could be implemented on HS2 Ltd’s railway, is entirely unclear. My guess would be that Alison Munro, David Begg, and Andrew Adonis haven’t given the topic a moment’s thought.

In the current Y network plans

• there is no mention of trains having a self-rescue capability, yet with 14 to 18 trains an hour on each track, it would be difficult to get rescue diesel engines to where they need to be
• opportunities to de-train large numbers of passengers en route would seem to be almost non-existent, and
• most trains could not be diverted, because their loading gauge would not be compatible with the classic network.

In continental Europe

• high speed lines tend not to be worked particularly intensively, and
• diversionary routes are generally available (because their loading gauges are the same).

It seems reasonable to conclude that an effective recovery strategy for a Hitchin-style event on HS2, is unlikely to be feasible.