As we have some consideration happening, the train in the tunnel is called HS2. The tunnel passes close enough to CSH to pose structural problems because of the exact way they run un the tunnel at that point, shifting level after coming under the canal to convert speed into height inbound, and the opposite outbound, which puts a heck of a thump into the ground CSH stands on every couple of minutes, according to the project engineers. If they have to fix structural problems, CSH could be out of action for months if not years, and without reserves it cannot stand the loss of income.
True, HS2 doesn't start until 2025-6, most likely, but they have to get the problems fixed before they start tunnelling in 2017, not after. On the other hand, I think Katy may already have missed the budget boat, which means they'll pick up the pierces with any reverves left after the damage has been done, maybe as late as 2035. Thank the Lord the RVW wax cylinder recordings have been backed up, as they for certain won't stand the vibrations.