London Banter - View Single Post - DLR

Peter Smyth[_2_] · April 27th 15, 06:52 PM posted to uk.transport.london

d wrote:

On Sat, 25 Apr 2015 23:14:31 +0100
"Clive D. W. Feather" wrote:
In message ,
d wrote:
Except the person who was killed fell on the track by accident
apparently 12 seconds before the train ran over her. Unless the
driver was asleep he'd have had no problem stopping the train in
time.

Is that so? It's not obvious: a main line train takes 90 seconds to
stop

Yes it is so.

from 100 mph at the braking rates the signalling is designed for.

A 3-unit DLR train is 84 metres long. The braking system is
designed for 0.6 m/s^2, so that means the train will enter the
platform at 10 m/s and take 16.7 seconds to stop. 12 seconds before
that the train is doing 17.2 m/s and is 162 metres from the start
of the platform.

A DLR train doing 17.2 m/s coming into a platform? In which universe?
Thats 38mph. If a DLR train ever got up to that speed it probably had
to go and have a lie down for a week. Say a far more realistic 20-25
mph which seems to be the top speed these days almost everywhere.

Train doing 10m/s, stops at 1.2m/s. Even with a 1-2 second reaction
time you're sorted.

DLR Bank - Lewisham, 11.06km, timetabled 26 min. Thats 7.1m/s average
including 14 intermediate stops, so the top speed must be much more
than 10m/s.

Peter Smyth