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John · July 30th 07, 08:15 PM posted to uk.railway,uk.transport.london

In article ,
writes

"BH Williams" wrote in message
...
Yes, it does. Currently, both TVM signalling and OCS start just east of
Fawkham Junction, somewhat to the north of Ashford.

Do you mean to say that the entire line from St. Pancras will run this type
of signalling and power source? What will happen to the contact shoes,
interestingly enough?

Also, what is TVM and OCS?

OCS - Overhead Contact System - 25kV wires in the air. Three feeder
stations between London and Folkestone - the same as UK main lines
except that it can supply a higher current.

TVM - can't remember the French - basically a transmission system using
the rails and track circuits to send a speed code to the train. Train
picks it up and displays maximum speed, slow down, etc. to driver and
also controls the ATP (Automatic Train Protection) system.

OCS goes all the way to St Pancras International buffer stops, but the
last section has a lower current capacity (about 2km from tunnel portal
is the neutral section IIRC).

TVM stops at the tunnel portal and lineside signals are provided from
there backed by KVB (a balise based ATP system).

--
John Alexander,

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