"Bob" wrote in message ...


It's about 70 miles St Pancras to the tunnel, so:

180 mph = 23 min
160 mph = 26 min
150 mph = 28 min
140 mph = 30 min
90 mph = 47 min

Trains running at 140 mph adds only 5 min, but makes the commuter
problem much, much easier.

(Velocities are max, I know average speeds will be less, but the logic
is the same).

In my world, 30-23 is 7 not 5.

Sorry - but anyway, St Pancras to Ebbsfleet, and the North Downs
tunnel, speeds will be limited by tunnel design. Assuming the same
acceleration, a train desinged for 140 mph would only be a few minutes
behind a 186 mph train by the time they get to Ashford.

As pointed out elesewhere, this is well within the frequency
requirements of the line, especially after Ebbsfleet.


Anyway, the point of the line is to cut as much as possible off the journey
time between London and Paris / Brussels. Running trains at 186mph is the
plan - your commuter trains at 140mph would get in the way.

Since the technology exists for 186mph running, why not just build the damn
trains instead of messing things up with a stupid fudge. Your kind of
thinking is why things always turn to crap in this country.