In message , "
writes
Does an illuminated speed restriction sing on LUL indicate that a train
is entering a speed controlled area?
The digits on the speed restriction are white on a black background, I
notice.
I have seen such cases on the District Line's eastbound track between
Monument and Tower Hill, just before the points leading into the bay
track at the latter, and just by the starter on WB2 at Gloucester Road.
Are there many such speed controlled signals on LUL? I'm not talking
about draw up signals, such as those we might see at Baker Street,
Kennington or eastbound at Whitechapel.
I also wonder what the difference is between speed-controlled signals
and another one that I saw just by the portal at Golders Green. In this
case, the signal simply had a sign next to it that said TS15,
indicating that it was a timed signal and to approach it at that speed.
I don't know about now, but back in the 60s and 70s just about every
tube station on both Northern and Central Lines had speed control
signals. The norm was five signals approaching a station the first
cleared when you were down to 25mph the second cleared when you were
down to 20mph and the last three cleared as the train in front
accelerated away from the station. The last signal being a cars length
into the station but under the platform so only the driver could see it.
Unlike BR with fixed overlaps, the tube used overlaps that would bring a
train to a stand before reaching the one in front if the tripcock
tripped. The first overlap was usually about 5mph which is why when
entering a shut down station the train slows to 5mph passed the starter
before accelerating again.
--
Clive