5 ms·

A large part of the problem, at least a few months ago, seemed to revolve around failures when switching between signalling systems.

• thu2111 7y ago
  There have been a lot of problems with the physical layers too. In the Heathrow tunnels there need to be multiple signalling systems operating simultaneously and apparently the radio signals have to be on very close frequencies. This in turn requires quite advanced signal processing software in the trains to clean things up and ensure reliable communication. The political problems are more straightforward. It's a repeat of the TSB problem. Non engineers often cannot psychologically accept that a project has an unknowable deadline and cost, so try to force people to estimate and then stick to their estimates, reality be damned. Crossrail's former management was so delusional, so psychologically unable to tell politicians and the public the truth, that they actually started shutting down the project a few months before construction was due to complete, e.g. by letting go of their external/internal communications teams. When Mark Wild took over he found he couldn't even update the project website or email all the contractors because the people who managed that had been let go - although many stations still hadn't even been built yet! Further delays occurred because contracts started expiring and scarce construction teams got reallocated to other projects in the capital. The entire effort was set up on the assumption that they could estimate project time and budget a decade in advance!