Following today's gala launch it would appear that Crossrail is to have a maximum operating speed of almost 187mph (300kph).
This from the RMT...
RMT said the project should be a public one in every sense, and should be the first step in the creation of a new-generation high-speed network that should also include a new spinal mainline linking London and Scotland.
At least overcrowding won't be a problem.
Passengers in the tunnelled section could just be sucked to their destinations.