"Richard J." wrote in message ...
I was there this afternoon, and the track is still in the same state,
namely a total of 15 missing keys on the rail nearest the platform in
Platform 3, Edgware Road, including this sequence (corrected from previous
version):

o K o K o o o K o K|K o K K K K|K K o o o K K K o

where K=key, o=missing key, |=rail joint.

It's now 5 days since I reported it to the station supervisor. Can
JDickseun advise whether a temporary speed limit would be expected for such
a sequence, and if so what speed? (The normal limit here is probably only
15-20 mph.)

You wouldn't put in a speed restriction, since keys can be replaced
very quickly (!). Speed restrictions are used when a repair would take
a long time and cause severe delays to services. By restricting speed
the service can still run, but there'll usually be delays.
The safety limits are not more than 3 keys missing out of any 5 in a
row, and/or 30 out of 100. The keys are meant to be replaced within 4
weeks. The sequence above does contravene the safety standards, and
should (theoretically) be repaired within a month. What does scare me
is that if the second key, or the third key, dislodges / breaks, then
there's 5 in a row missing. They should be attended to immediately,
especially since they'll be very heavily loaded because all the other
keys are missing.
HTH
John