Why is Eurostar's travel time of 1h 51 min from Brussels to St Pancras when it is possible in 1h 43 min?

Question

Eurostar did a new record between Brussels and St Pancras, with a travel time of 1h43 without ever breaking the normal speed limits. Can someone explain me why their scheduled timetable has a fastest travel time of more than 1h51 and not the 1h43?

Thanks a lot

Answer 1

Recovery time and pathing allowance. The former allows for permanent way slacks (or speed restrictions) and any slight delays enroute. The latter allows for the fact that the train might have to give way to another train at a station or junction.

The 1h43 run was  staged so that the track would be perfect and no other train would be in the way.

Basically it allows the train to arrive on time.

Answer 2

If they times it at 1.43 it would regularly be late and people would complain.