Is anyone able to enlighten me as to why the clocks on the Docklands
Light Railway departure boards at all the stations I saw today were
about 6 minutes fast? Are they using a GPS NTP server? Too much snow
on the antenna? How are clocks synchronised on the real railway?

The online versions of the DLR PID's are here (the time appears to be
closer to the truth online):

http://www.dlrdaisy.co.uk/daisy/pop/pop05pid.htm
http://www.dlrdaisy.co.uk/daisy/caw/caw05pid.htm

substitute "pop" or "caw" (Poplar/Canary Wharf) for the station of
your choice and 05 for the day of the month.
or click on the map he http://goo.gl/w1oqm for today's live boards.

at 13:10:49 on Sun, 5 Feb 2012, 222103 remarked:
How are clocks synchronised on the real railway?

The original digital ones were synched to "Rugby" (now located at
Anthorn in Cumbria).

Analogue ones are increasing synchronised to the "correct twice a day"
source, popularly known as "stopped".
--
Roland Perry

On 7/2/12 12:20, in article , "Roland Perry"
wrote:

at 13:10:49 on Sun, 5 Feb 2012, 222103 remarked:
How are clocks synchronised on the real railway?

The original digital ones were synched to "Rugby" (now located at
Anthorn in Cumbria).

Analogue ones are increasing synchronised to the "correct twice a day"
source, popularly known as "stopped".

The second picture on this page:

http://www.subbrit.org.uk/sb-sites/s...o/index2.shtml

Shows a tuning coil at Rugby, which I think was the one for the time signal.
Low frequencies tend to require large coils, but I've never seen anything
like this.

In message , at 20:44:11 on Tue, 7
Feb 2012, Stephen Furley remarked:
The second picture on this page:

http://www.subbrit.org.uk/sb-sites/s...o/index2.shtml

Shows a tuning coil at Rugby, which I think was the one for the time signal.
Low frequencies tend to require large coils, but I've never seen anything
like this.

It seems to say that was for the 16KHz submarine transmissions, but MSF
is on 60KHz. (Or is the former a typo?)
--
Roland Perry

On 7/2/12 21:07, in article , "Roland Perry"
wrote:

In message , at 20:44:11 on Tue, 7
Feb 2012, Stephen Furley remarked:
The second picture on this page:

http://www.subbrit.org.uk/sb-sites/s...o/index2.shtml

Shows a tuning coil at Rugby, which I think was the one for the time signal.
Low frequencies tend to require large coils, but I've never seen anything
like this.

It seems to say that was for the 16KHz submarine transmissions, but MSF
is on 60KHz. (Or is the former a typo?)

I don't know; I seem to remember that it said that the time signal was the
only thing still (then) being transmitted from Rugby, but it isn't totally
clear whether this coil was for he time signal, or for some other service by
then ceased. Was there anything transmitted on a lower frequency than the
time signal?

On Tue, 07 Feb 2012 21:40:22 +0000, Stephen Furley
wrote:




On 7/2/12 21:07, in article , "Roland Perry"
wrote:

In message , at 20:44:11 on Tue, 7
Feb 2012, Stephen Furley remarked:
The second picture on this page:

http://www.subbrit.org.uk/sb-sites/s...o/index2.shtml

Shows a tuning coil at Rugby, which I think was the one for the time signal.
Low frequencies tend to require large coils, but I've never seen anything
like this.

It seems to say that was for the 16KHz submarine transmissions, but MSF
is on 60KHz. (Or is the former a typo?)

I don't know; I seem to remember that it said that the time signal was the
only thing still (then) being transmitted from Rugby, but it isn't totally
clear whether this coil was for he time signal, or for some other service by
then ceased. Was there anything transmitted on a lower frequency than the
time signal?

Down to 11.9 kHz :-
http://www.smeter.net/stations/vlf-stations.php
currently 19.6kHz in Cumbria ("Combria") for the UK

Rugby used to have 16kHz :-
http://www.youtube.com/watch?v=Unlg2gY2Zrs
http://www.subbrit.org.uk/sb-sites/s...io/index.shtml

In message , at 21:40:22 on Tue, 7
Feb 2012, Stephen Furley remarked:
The second picture on this page:

http://www.subbrit.org.uk/sb-sites/s...o/index2.shtml

Shows a tuning coil at Rugby, which I think was the one for the time signal.
Low frequencies tend to require large coils, but I've never seen anything
like this.

It seems to say that was for the 16KHz submarine transmissions, but MSF
is on 60KHz. (Or is the former a typo?)

I don't know; I seem to remember that it said that the time signal was the
only thing still (then) being transmitted from Rugby, but it isn't totally
clear whether this coil was for he time signal, or for some other service by
then ceased. Was there anything transmitted on a lower frequency than the
time signal?

The text adjacent to the picture talks about 16kHz submarine traffic.
--
Roland Perry

On Tue, 07 Feb 2012 20:44:11 +0000, Stephen Furley
wrote:




On 7/2/12 12:20, in article , "Roland Perry"
wrote:

at 13:10:49 on Sun, 5 Feb 2012, 222103 remarked:
How are clocks synchronised on the real railway?

The original digital ones were synched to "Rugby" (now located at
Anthorn in Cumbria).

Analogue ones are increasing synchronised to the "correct twice a day"
source, popularly known as "stopped".

The second picture on this page:

http://www.subbrit.org.uk/sb-sites/s...o/index2.shtml

Shows a tuning coil at Rugby, which I think was the one for the time signal.
Low frequencies tend to require large coils, but I've never seen anything
like this.

Cop this one then :-
http://www.nonstopsystems.com/radio/...-mil-tx-rx.htm
(tuning coil about 3/4 down the page)
now recycled by the Russian navy.

"222103" wrote

on the antenna? How are clocks synchronised on the real railway?

In the early 1960s the Didcot railway telephonist would connect via the
omnibus circuit to all teh signalboxes between there and Swindon just before
1100 each morning - and at 1100 would call out 'Time Time Time'. The
signalmen would then adjust there clocks (and, AIUI, had to record this in
the Train Register. Subsequently the signalmen would liaise with station
staff to regulate station clocks.

From the early days of the Irish Mail the train's guard was handed a watch
at Euston each evening - to enable the Queen's (or King's) time to be taken
to Dublin

Peter

"Peter Masson" wrote

From the early days of the Irish Mail the train's guard was handed a watch
at Euston each evening - to enable the Queen's (or King's) time to be
taken to Dublin

http://www.holyhead.com/irishmailtrain/index.html

Peter