Letter : Engineering a better brake by design

From Mr C. Horncastle

Sir: With regard to the debate on the bad braking of British Rail trains, safety controllers should take a look at trams on the Continent. Trams are also "light", "short", "have disc brakes", experience a "leaf fall season" and have "lots of stopping and starting, which means there is more opportunity for over-runs".

In the confusion of a city such as Amsterdam, how is it that trams avoid sliding into the droves of cyclists that suddenly cross the tracks, not to mention the occasional tired or emotional pedestrian? Answer: each tramcar has, for emergencies, a long block brake which acts on the track, not on the wheel. Third-form geometry tells us the area of friction here is many times greater than that between the wheel and the track.

Yours faithfully,


Esling, Norfolk