In message , at 21:34:48 on Tue, 21 Sep
2010, Roy Badami remarked:
Also the Plaistow signalling irregularity, which was quickly found to
have been caused by 'a defective component'.

ITYM 'an incorrect component'

Thanks - sorry about that - probably thinking of the previous
discussions as I wrote it...

In many ways an incorrect component is rather less disturbing than a
defective component, as the latter would indicate a wrong side failure.

I'm not sure why an incorrect component (which would seem to have
performed, or rather failed to perform) in the same way as a defective
one) is any better.

Obviously incorrect installation or maintenance is still a concern,
but at least we now have a better idea as to the underlying cause.

I'd say that fitting an incorrect component is much worse, because the
incorrect component had to be procured and fitted, and pass
commissioning checks and subsequent maintenance checks. Some of these
could be 'excused' if the documentation clearly specified the incorrect
component, but that in itself would be a worry.

Also, in that context, the comment about checking that similar
components are not present at other sites makes more sense.

Checking other sites for an incorrect component is easier than checking
for [potentially] defective correct components, I agree.
--
Roland Perry

On 22 Sep, 06:58, Roland Perry wrote:

Assuming the RGT broke down before 5am, that's an extremely long time to
get it there.

Does the RGT operate permanently on the Underground, or is it just
hired in when required? Who was responsible for knowing the correct
procedures for recovering the train if it should fail and could not be
fixed on site, and for ensuring that those procedures were correctly
followed? was any form of emergency coupling equipment or special
tools required, and if so were they carried on the RGT or did they
have to be brought to the site from elsewhere? The BR DMU driver
training films did cover how to deal with various failures, but these
involved getting the train moving again, at least far enough to clear
the line, or being rescued by another similar train, or a steam
locomotive. This is rather different to using a normal tube train to
recover a special one-off train like the RGT. Obviously a normal tube
train driver will not have been trained in such procedures; will the
crew of the RGT, or will somebody with the specialised knowledge have
to be brought to the site to deal with it?

Who had to be informed, or give permission before the recovery could
be carried out? If the train was hired in as required, did the owners
have to be informed, approve procedures, provide equipment or
engineers before it could be moved? By it's nature this sort of work
is going to involve unusual procedures which are not carried out every
day. There will be risks involved, and care will need to be taken to
ensure that everything is done correctly.

I wouldn't be surprised if it took several hours to recover the RGT
and return it to Neasden Depot after the first failure.

It seems that the speculation in this group as to what happened after
the second failure was broadly correct, but there are still any
questions to be answered. It also does sound as if the RGT, with all
brakes isolated, an not even a hand brake capable of being operated by
those on board, was simply coupled to another train, and hauled up the
gradient towards East Finchley, but I find it difficult to believe
that this was actually done.

Incorrect Component : Relay



On 21/09/10 20:57, Paul Scott wrote:



"Roy Badami" wrote in message
...
On 21/09/10 16:54, Paul Scott wrote:

Also the Plaistow signalling irregularity, which was quickly found to
have been caused by 'a defective component'.


In many ways an incorrect component is rather less disturbing than a

On Wed, 22 Sep 2010 00:06:30 -0700 (PDT) someone who may be Stephen
Furley wrote this:-

It also does sound as if the RGT, with all
brakes isolated, an not even a hand brake capable of being operated by
those on board, was simply coupled to another train, and hauled up the
gradient towards East Finchley, but I find it difficult to believe
that this was actually done.

It does sound like it. The Prohibition Notice [1]
http://www.rail-reg.gov.uk/upload/pdf/prohibition-notice-tubelines-160810.pdf
seems like a sensible response to this by the RI. I find it
difficult to believe that anyone considered this a safe system of
work, particularly on what is ISTR a considerable gradient.


[1] the link is not a copy of the notice just a summary.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000...#pt3-pb3-l1g54

On 22 Sep, 12:40, David Hansen
wrote:

It does sound like it. The Prohibition Notice [1]
http://www.rail-reg.gov.uk/upload/pdf/prohibition-notice-tubelines-16...
seems like a sensible response to this by the RI. I find it
difficult to believe that anyone considered this a safe system of
work, particularly on what is ISTR a considerable gradient.

Arhcway station is in tunnel, as are the platforms at Highgate which
are still in use. The tracks come to the surface just South of East
Finchley station. The centre tracks at East Finchley used to lead to
the 'high-level' surface platforms at Highgate, and eventually,
Finsbury Park. They now just lead to Park Junction, from where trains
can reach the sidings which were alonside the Alexandra Palace
branch. Alexandra Palace is one of the highest points in london, and
it is not far from East Finchley. The ground level rises between
Archway and East Finchley, and since the tracks rise from underground
to the surface in this section they must be on a steeper gradient. I
assume that the intention once it reached East Finchley was to either
reverse the RGT down the centre tracks, and then reverse again into
the sidings, or just leave the train in one of the centre platforms
until it could be recovered later in the day.

As I understand it, the RGT was being hauled North on the wrong, i.e.
Southbound, line, so that when it ran away it was at least in the
right direction; things could have been even worse if it was being
hauled on the Northbound line.

In article ,
Paul Scott wrote:
One of the board papers for the 22nd Sept meeting is a four page summary of
the recently discussed incidents:

http://www.tfl.gov.uk/assets/downloa...-Incidents.pdf

I have asked Tfl for a copy of the report on the Mile End incident and
a list of incident reports.

http://www.whatdotheyknow.com/reques...e_end_incident
http://www.whatdotheyknow.com/request/list_of_firs

--
Ian Jackson personal email:
These opinions are my own. http://www.chiark.greenend.org.uk/~ijackson/
PGP2 key 1024R/0x23f5addb, fingerprint 5906F687 BD03ACAD 0D8E602E FCF37657

On 21 Sep, 23:47, Stephen Furley wrote:

I interpreted that differently, i.e. there was some expected
difficulty with the recovery, not just that the recovery caused
delays, which would, obviously, have caused delays.

Sorry, I meant to say 'some UNexpected difficlty'