First of all, I may be mistaken but I am reasonably sure that at one
station I saw a section of track with four of the spring clips missing
in a row from the shoes on the rail. I think shoes is the correct
name. Is this now the norm on the Underground...........

Smokeyone

Smokeyone wrote:
First of all, I may be mistaken but I am reasonably sure that at one
station I saw a section of track with four of the spring clips missing
in a row from the shoes on the rail. I think shoes is the correct
name. Is this now the norm on the Underground...........

See photo at
http://www.trainweb.org/tubeprune/Tr...ing%20Mark.htm

The term is "chair", not "shoe", and the spring clips are called "keys".

Where exactly did you see this? Did the chairs either side of these four
have the keys inserted?
--
Richard J.
(to e-mail me, swap uk and yon in address)

(Smokeyone) wrote in message . com...
First of all, I may be mistaken but I am reasonably sure that at one
station I saw a section of track with four of the spring clips missing
in a row from the shoes on the rail. I think shoes is the correct
name. Is this now the norm on the Underground...........

Smokeyone

Four missing keys in a row is not unsafe, and there's no danger of
derailment. Track has plenty of designed-in and built-in redundancy
for obvious safety reasons. That's why a few missing keys is no cause
for alarm. The same for coach screws (which hold the chairs fixed on
the sleepers), which is the one that gets ES reporters hysterical.
There's very high dynamic loading on rails, and keys continually get
dislodged or broken.
The tracks are patrolled every 48 hours, the patrolman will replace
them on his next round. Patrolmen replace keys routinely, sometimes
none, sometimes 20 or 30 in one shift, usually 5-10.
If there's more than 5 in a row missing, we'd be very grateful if
you'd inform the station staff, because then it could become
unsafe.......
So to answer your question: Yes, it's within the norms of Underground
standards, it's quite safe, but it is unusual.
John

"Richard J." wrote in message ...
Smokeyone wrote:
First of all, I may be mistaken but I am reasonably sure that at one
station I saw a section of track with four of the spring clips missing
in a row from the shoes on the rail. I think shoes is the correct
name. Is this now the norm on the Underground...........

See photo at
http://www.trainweb.org/tubeprune/Tr...ing%20Mark.htm

The term is "chair", not "shoe", and the spring clips are called "keys".

Where exactly did you see this? Did the chairs either side of these four
have the keys inserted?


So, they are called keys are they. Right then, just the four keys, I
did not notice anymore, I think some of them were lying loose on the
stones.
Edgeware road surface station, I believe Platform 3, about 20 yards
from the steps that leed down to the platform, rail nearest platform.
If you e-mail your telephone number to me at Cuttysark I will call
you.

Smokeyone

(JDikseun) wrote in message om...
(Smokeyone) wrote in message . com...
First of all, I may be mistaken but I am reasonably sure that at one
station I saw a section of track with four of the spring clips missing
in a row from the shoes on the rail. I think shoes is the correct
name. Is this now the norm on the Underground...........

Smokeyone

Four missing keys in a row is not unsafe, and there's no danger of
derailment. Track has plenty of designed-in and built-in redundancy
for obvious safety reasons. That's why a few missing keys is no cause
for alarm. The same for coach screws (which hold the chairs fixed on
the sleepers), which is the one that gets ES reporters hysterical.
There's very high dynamic loading on rails, and keys continually get
dislodged or broken.
The tracks are patrolled every 48 hours, the patrolman will replace
them on his next round. Patrolmen replace keys routinely, sometimes
none, sometimes 20 or 30 in one shift, usually 5-10.
If there's more than 5 in a row missing, we'd be very grateful if
you'd inform the station staff, because then it could become
unsafe.......
So to answer your question: Yes, it's within the norms of Underground
standards, it's quite safe, but it is unusual.
John

Hello

Thanks for the info, I have seen the odd key in the past missing but
thought four in a row strange and had not appreciated that several
keys can spring out
just by the loading of passing trains.

Smokeyone

JDikseun wrote:
(Smokeyone) wrote in message
. com...
First of all, I may be mistaken but I am reasonably sure that at one
station I saw a section of track with four of the spring clips
missing
in a row from the shoes on the rail. I think shoes is the correct
name. Is this now the norm on the Underground...........

Smokeyone

Four missing keys in a row is not unsafe, and there's no danger of
derailment. Track has plenty of designed-in and built-in redundancy
for obvious safety reasons. That's why a few missing keys is no cause
for alarm. The same for coach screws (which hold the chairs fixed on
the sleepers), which is the one that gets ES reporters hysterical.
There's very high dynamic loading on rails, and keys continually get
dislodged or broken.

Even in a platform mostly used for terminating trains at very low speeds?

I had a good look at the site this afternoon (Platform 3 at Edgware Road
Circle Line, as identified by Smokeyone in another post). It was only
possible (as it was dark) to inspect the rail nearest the platform, but
that had a total of 15 missing keys. In the middle of the platform was
this sequence, where o = missing key and K = key present:

o K o K o o o K o K K o K K K K K o o o K K K o

Note that the first 12 chairs in this sequence had 7 missing keys!

The tracks are patrolled every 48 hours, the patrolman will replace
them on his next round. Patrolmen replace keys routinely, sometimes
none, sometimes 20 or 30 in one shift, usually 5-10.

One problem here may be that trains are stabled in the platform overnight.

If there's more than 5 in a row missing, we'd be very grateful if
you'd inform the station staff, because then it could become
unsafe.......

There weren't more than 3 in a row, but I thought 7 missing in 12 was
worrying, so I found the station supervisor and told him. He said he
thought that one train was stabled overnight alternately in platforms 2 and
3. It occurs to me that if the track is patrolled on the same days every
week, e.g. Tue, Thu, Sat, it could be that there is always a train on
Platform 3 at the time. (Platform 2 had only one missing key on the rail
nearest the platform.)

Smokeyone said he saw 4 in a row, but I assume he actually miscounted part
of the above sequence.

It will be interesting to see how long it takes LU/Metronet to fix it!
--
Richard J.
(to e-mail me, swap uk and yon in address)

"Richard J." wrote in message ...

Even in a platform mostly used for terminating trains at very low speeds?

I had a good look at the site this afternoon (Platform 3 at Edgware Road
Circle Line, as identified by Smokeyone in another post). It was only
possible (as it was dark) to inspect the rail nearest the platform, but
that had a total of 15 missing keys. In the middle of the platform was
this sequence, where o = missing key and K = key present:

o K o K o o o K o K K o K K K K K o o o K K K o

Note that the first 12 chairs in this sequence had 7 missing keys!

The tracks are patrolled every 48 hours, the patrolman will replace
them on his next round. Patrolmen replace keys routinely, sometimes
none, sometimes 20 or 30 in one shift, usually 5-10.

One problem here may be that trains are stabled in the platform overnight.

If there's more than 5 in a row missing, we'd be very grateful if
you'd inform the station staff, because then it could become
unsafe.......

There weren't more than 3 in a row, but I thought 7 missing in 12 was
worrying, so I found the station supervisor and told him. He said he
thought that one train was stabled overnight alternately in platforms 2 and
3. It occurs to me that if the track is patrolled on the same days every
week, e.g. Tue, Thu, Sat, it could be that there is always a train on
Platform 3 at the time. (Platform 2 had only one missing key on the rail
nearest the platform.)

Smokeyone said he saw 4 in a row, but I assume he actually miscounted part
of the above sequence.

It will be interesting to see how long it takes LU/Metronet to fix it!

Yup, even in low-speed areas keys work loose (due to dynamic loading
and vibration) or break (they fatigue over time).

7 out of 12 missing is unusual, though. Looks like the patrolmen have
problems getting access when the trains are parked there.
I'm also keen to see how long it takes to get them replaced!
John

Well, my mistake in counting four keys, my only excuse is I was in a
moving crowd on the platform at the time. We'll have to see how long
it takes to replace the missing ones. I am in London in a couple of
weeks and will make a detour to visit Edware road unless someone can
visit sooner.........

Smokeyone

In article ,
(Smokeyone) wrote:

Well, my mistake in counting four keys, my only excuse is I was in a
moving crowd on the platform at the time. We'll have to see how long
it takes to replace the missing ones. I am in London in a couple of
weeks and will make a detour to visit Edware road unless someone can
visit sooner.........

Smokeyone

Although unlikely, it may have been that there was on-going track
maintenance where the keys were being replaced. When this happens, there
are often many of the keys missing over a section and the train is
restricted to a temporary speed restriction over that area by a
handsignalman. However they are normally all replaced within a very short
time period (e.g. during that shift).

Roger

wrote:
In article ,
(Smokeyone) wrote:

Well, my mistake in counting four keys, my only excuse is I was in a
moving crowd on the platform at the time. We'll have to see how long
it takes to replace the missing ones. I am in London in a couple of
weeks and will make a detour to visit Edware road unless someone can
visit sooner.........

Smokeyone

Although unlikely, it may have been that there was on-going track
maintenance where the keys were being replaced. When this happens,
there are often many of the keys missing over a section and the train
is restricted to a temporary speed restriction over that area by a
handsignalman. However they are normally all replaced within a very
short time period (e.g. during that shift).

There was no evidence of any other track work in progress and no TSR (but I
think it's 15 mph anyway into Platform 3 at Edgware Road). The keys had
been missing for at least 2 days, and the station supervisor appeared not
to be aware of the problem.
--
Richard J.
(to e-mail me, swap uk and yon in address)