"Tom Anderson" wrote in message
h.li...

One thing that i do wonder about, though: immediately after the failure at
0926, we're told "Initially, three eastbound trains were stalled in
section between Lancaster Gate and Marble Arch"; we find out later on that
the first is number 33, the second is number 5, and that there's one more
train behind that (we're not told the name, but from what comes later, i'd
guess it was number 3). Now, after the first train (number 33) has got
over the points and they've broken again, and the second train (number 5)
has approached the points, we're told "This train and a further two trains
were then queued in the tunnel" (the train i'm thinking is number 3, plus
what i assume is number 42). So, there are now two trains behind number
5 - implying that between in the time between the failure and number 5's
attempt at the points, a fourth train entered the section.

Why on earth was a train allowed to enter a section of tunnel leading to
points which were known to be broken, with three trains ahead of it?

Still cant tell...as i said above its only a preliminary report. However
there was a question regarding a faulty radio in control that may have meant
the T/Op got a signal and left.
Wait for final report for all the details it may be different - I'm sure
bowroaduk@yahoo will oblige.

Mal

On Wed, 8 Jun 2005, Malcolm Pinnell wrote:

"Tom Anderson" wrote in message
h.li...

Why on earth was a train allowed to enter a section of tunnel leading
to points which were known to be broken, with three trains ahead of it?

Still cant tell...as i said above its only a preliminary report. However
there was a question regarding a faulty radio in control that may have
meant the T/Op got a signal and left. Wait for final report for all the
details it may be different - I'm sure bowroaduk@yahoo will oblige.

Good point. I do hope we hear when it gets more solid. I fully expect my
concerns to be proved entirely misplaced!

tom

--
never mind your fingers, i've got blisters on my brain

Like I said it a previous post , if it had been a hot day god knows
what
could have happened.


It wasnt,so shut up your moaning,

Oh well thats ok then. Just so long as LU use their special extra quick
Hot Day precedures if this happens again on a hot day we're sorted.

Were you on the train ? So what you moaning for ?

No. But I was stuck on a met line train last week for a considerable
amount
of time and that was unpleasent enough.

B2003

The queue in such a situation would be jam all the way back to White
City as that is the next nearest turning point. Reversing trains

I don't know if this is an issue on the central line but it does seem
on
some lines that some connects between the running lines have been
removed for no obvious reason , leading to less flexibility in the
service
if theres a screw up. Convent garden on the piccadilly line spings to
mind , not to mention the connection at finsbury park being lost due to
the victoria line using an ex-picc tunnel. So if theres a problem on
the line you get huge sections closed. Doesn't seem like a good
situation.

B2003

Oh well thats ok then. Just so long as LU use their special extra quick
Hot Day precedures if this happens again on a hot day we're sorted.

Were you on the train ? So what you moaning for ?

No. But I was stuck on a met line train last week for a considerable
amount
of time and that was unpleasent enough.

B2003

I dont understand why people like yourself moan so much, do you think
sending posts this group is going to make the slightest difference.When you
send in your angry posts, people take time and try to explain the situation
and you still dont take it on board.to be honest at the end of the day its
going to get worse unless get the olympics, so relax !

In message , Clive D. W. Feather
writes
In the case of the Central, reversing also means driving in Restricted
Manual, because there are no codes for that direction. Stopping the
next train is also harder, because there may be no signal between it
and the station.

Overall, it could easily take 15 to 20 minutes to get a train reversed
to the previous station.
All this surprises me, I thought reversing in tube was banned under any
circumstances.
--
Clive

On Thu, 9 Jun 2005, Boltar wrote:

The queue in such a situation would be jam all the way back to White
City as that is the next nearest turning point. Reversing trains

I don't know if this is an issue on the central line but it does seem on
some lines that some connects between the running lines have been
removed for no obvious reason , leading to less flexibility in the
service if theres a screw up. Convent garden on the piccadilly line
spings to mind , not to mention the connection at finsbury park being
lost due to the victoria line using an ex-picc tunnel. So if theres a
problem on the line you get huge sections closed. Doesn't seem like a
good situation.

I was thinking about this this morning. Yes, if there were more
crossovers, connections and whatnot, there would be more flexibility in
reversing trains; if lines were signalled for reversible running, it'd be
faster to back them up; if every line had overlap protection, it'd be
faster to get trains past failed signals.

BUT! Every component you add to the system is a new point of failure.

Think about it - what was it that caused the whole Central line problem in
the first place? A set of points! Would you really want to double the
number of points on the line, knowing it would double the failure rate?
Similarly, if you built a fully belled-and-whistled line with all mod
cons, i think you'd find the failure rate was even higher. You'd be able
to deal with the failures better, but it's far from clearthat you'd get an
overall better level of service. Plus, more gizmos means more maintenance
cost, which in practice means a limited budget being spread more thinly,
which drives up the failure rate even more. That's not to say that LU
wouldn't be better off with more gizmos than it has at present, but
deciding the optimal level of complexity is not a trivial problem.

The way out of this conundrum is to add complexity that's fail-safe, so
things that are good when they work don't become bad when they don't work,
they just become nothing. I don't think there's any way to build fail-safe
points, though.

tom

--
The number of Adam's children, as says the old tradition, was thirty-three
sons and twenty-three daughters

In message , Tom
Anderson writes
The number of Adam's children, as says the old tradition, was thirty-three sons and twenty-three daughters
That's one of the best reasons I heard of for contraception.
--
Clive

In message , Clive
writes

Overall, it could easily take 15 to 20 minutes to get a train reversed
to the previous station.
All this surprises me, I thought reversing in tube was banned under any
circumstances.

Oh no, but you do have to be in possession of a 'Wrong Direction Move
Form' duly signed by an Operating Official, cut out various bits of
safety equipment (and of course be in the 'right' cab) before you can do
the move.
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)

In message . com,
Boltar writes

I don't know if this is an issue on the central line but it does seem
on
some lines that some connects between the running lines have been
removed for no obvious reason , leading to less flexibility in the
service
if theres a screw up. Convent garden on the piccadilly line spings to
mind , not to mention the connection at finsbury park being lost due to
the victoria line using an ex-picc tunnel. So if theres a problem on
the line you get huge sections closed. Doesn't seem like a good
situation.

Covent Garden (and York Road) reversing crossovers were removed when the
link to the Northern line was built (1930s??) and a crossover was added
at Kings Cross.

There aren't really that many occasions when either of these would have
been useful and justify all the expense in maintaining them, although I
do remember an occasion a few months ago when I shut Kings X eastbound
down it would have been a bit handy!
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)