Signalling question

Andrew Moglestue

I was yesterday discussing railway signalling with some friends of mine who are not railfans but do IT system security.

We were wondering, in the hypothetical situation that on a certain line there was to be a total failure of the signalling system.
Not just the signals themselves but the computers behind it all. Maybe a power failure or a software crash or a hacker attack or terrorism. The cause is not important for the purpose of my question. I know there are also backup computer systems and so on, but suppose for the purpose of this question that those are also out of use.

Is there some way in which trains can be dispatched manually by telephone or something like that? Or maybe driven on line of sight at slow speed?

Has this ever happened?

Or would the line be down until the proper system can be restored?



Am 27.04.2015 um 13:50 schrieb Andrew Moglestue:
Or would the line be down until the proper system can be restored?
There are prcoedures, but I haven't studied them all. The most common case is a failure of the on-train equipment. In normally signalled land it is allowed to continue with speed restriction or with a second person in the cab. On ETCS-Level-2-Lines the driver can be allowed to continue at reduced speed, provided radio is still working.

Failures of the lineside equipment will regularly close down operation. Priority is then to bring passenger trains into a station. Some twenty years ago a manual operation with telephone and written orders would have started. Today it would theoretically be possible to do so over radio. But the number of employees doesn't allow such an operation today.

And finally, if the signal boxes are out, will there still be juice in the overhead line? The other way round, if 50-Hz current is off, it is possible to feed signalboxes from the 16.7 Hz overhead line.

Markus, Gürbetal

glenn allen

On Monday, 27 April 2015, 22:07, "Guerbetaler [SwissRail]" <> wrote:

There are procedures, <snip>.

Markus, Gürbetal

If it is the same as the UK then a lot would ride on the proving of the points, if you cannot guarantee the interlocking then you will not be going anywhere. A signal failure on the High Speed Line in the UK is dealt with by a procedure FREP, giving the driver authority to drive on sight and pass a closed Non-Passable block section marker, but only at 30kph maximum. On normally signalled lines, you could institute temporary block section working with the appropriate paperwork. But you would need clamped points and manned level crossing gates.
On KVB equipped lines the form is 'FASI' same speed restrictions.