Eurostar Acceleration and Deceleration

[qzdcg8]

Does anyone know the max acceleration/deceleration characteristics of the Eurostar?

e.g. how long/far does it take to get from 0 to 100mph, 0 to 186mph and similarly 100mph to zero and 186mph to zero

I know our departed friend BasilDD would have known the answer....

[455driver]

Not sure on exact timings as I have never driven one but have been on the footplate of a eurostar with a mate a while back for a cab ride and it just seemed like pretty standard acceleration and braking for any modern train - not quite as nippy as something like an electrostar but didn't seem at all sluggish like HST's can. Although just guessing I would imagen that they are pretty much the same as 390's.

Difficult to give times on acceleration for trains as, unlike cars, there are far more variables which can affect them - gradient, loading, railhead conditions, current limit index in that area etc.

[Kromaatikse]

A Eurostar set is a very long and (by passenger standards) heavy train, with (AFAIK) six powered axles at each end (compared to four at each end of a HST). The weight on these powered axles, compared to the total weight of the train, will be the main determinant of low-end acceleration performance, when combined with railhead conditions. This is a principle that has remained constant since the steam era.

At higher speeds (80mph+), the performance will be better defined by the continuous power rating and the aerodynamic resistance, though the total weight of the train is still important for acceleration.

As a >100mph capable train in the UK, the train must be capable of Enhanced Braking Performance. The HST is able to stop from 125mph (200km/h) within 2km on a slight falling gradient, which corresponds to 15%g. This performance requires triple disc brakes on all trailing axles and wheel-slide protection. (The HST thus requires a minimum complement of five Mk3 carriages to be permitted to run at full speed. A pair of power cars can run alone but under a severe speed restriction.)

My copy of the Modern Signalling Handbook quotes HS1 trains as requiring five 1.5km blocks to stop from 300km/h, with a sixth block being reserved for contingencies. The deceleration curve is quoted as 300-270-230-170-0 km/h at successive block boundaries, and this is baked into the TVM signalling system. The final block therefore assumes a deceleration of about 15%g. The average deceleration from 300km/h is about 12%g. Presumably this is assisted by rheostatic braking to help avoid overheating the friction brakes.