"John Rowland" wrote in message
...
"Boltar" wrote in message
om...

What next , GPS controlled toilets that won't
flush on certain parts of the network

Actually, that's a truly great idea!

Rowland, you fool, that's a terrible idea! Retention tanks are a truly great
idea.

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes

"Colin McKenzie" wrote in message
...
Jack Taylor wrote:
...
GPS is only there to cope with short platforms
and to tell the train *which* doors to open.

Which begs the question:
Is it accurate enough to know if the driver mischievously or
carelessly stops with the _rear_ 7 cars in the platform?!

The obvious solution seems to be individual doors which check that there is
a platform adjacent before opening. The basic idea seems very easy to
implement, although a foolproof system which could never mistake the sides
of a bridge for a platform might be harder to implement, but in combination
with driver control it should be safe enough.

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes

John Rowland wrote to uk.transport.london on Thu, 23 Sep 2004:

"John Rowland" wrote in message
...
"Boltar" wrote in message
om...

What next , GPS controlled toilets that won't
flush on certain parts of the network

Actually, that's a truly great idea!

Rowland, you fool, that's a terrible idea! Retention tanks are a truly great
idea.

Except that IME trains that use them invariably have their loos locked
out of service, so you are crossing your legs for the entire journey....
why can't modern trains have loos that work?
--
"Mrs Redboots"
http://www.amsmyth.demon.co.uk/
Website updated 11 September 2004

On Thu, 23 Sep 2004 13:57:48 +0000, Charles Middleton wrote:


"Jack Taylor" wrote in message
...

GPS is only there to cope with short platforms and to tell the train
*which*
doors to open. For example, when stopping an eight-car train at a
seven-car-length platform the software will lock out the rearmost
doors,
to
prevent passengers from hurling themselves onto the track. Apparently
it's necessary in these litigious days when anyone stupid enough to
attempt to alight from a door that is not at a platform will try to sue
the TOC,
rather
than accept personal responsibility for doing something so dumb in the
first
place.

What if it was dark? Some platforms are very poorly lit. Seems like a
good idea to me.

CM.

Here's what I would propose:

Use a passive RF responder stuck on the side of the platform edges - you
know, like those things that tell the shop if you've been nicking stuff.

I think the RF responders are dirt cheap so the main expense is kitting
out transponders adjacent to each door on the train.

Simple concept though - one transponder per door and it interlocks
directly with that door's local circuit. The RF is short range and you
just stick loads of the passive tags all the way along each platform edge.

Simple - much simpler than GPS. The RF tags don't mind if they're
wet/dirty/painted etc. They are also very thin. OK - there's an outfit
cost to install the tags at every station - but it's a quick job -
probably almost as quick as painting the white lines.???

Hmm

Timbo

"John Rowland" wrote in message
...

The obvious solution seems to be individual doors which check that there
is
a platform adjacent before opening. The basic idea seems very easy to
implement, although a foolproof system which could never mistake the sides
of a bridge for a platform might be harder to implement, but in
combination
with driver control it should be safe enough.

Something along the lines of a transponder at the start of each platform
which is detected by each door and enables the doors on the appropriate
side, and another one at the end of each platform which disables each door.
Other interlocking means that doors cannot actually open until the train has
stopped, and failsafe precautions could cancel the enabling if the train
hasn't stopped within, say, one minute of passing the transponder. Some
complications for platforms on reversible lines, but I can't help thinking
that something like this has the potential for being more reliable than the
GPS technology (Can GPS identify which line the train is on if adjoining
platforms are different lengths?)
Peter

Peter Masson ) gurgled happily, sounding much
like they were saying :

The problem is to ensure that only doors adjacent to the platform open
at stations with short platforms. There is a perceived risk with
relying on the driver's or guard's memory, though signs on short
platforms on the Salisbury - Exeter line seem to me to be an adequate
aid to memory.

They also seem to work very nicely on the Metropolitan Line at Euston Sq
and Gt Portland St.

thinks
Mebbe that's what was meant by GPS & short platforms?

"Peter Masson" wrote in message
...
"John Rowland" wrote in message
...

The obvious solution seems to be individual doors which
check that there is a platform adjacent before opening.

Something along the lines of a transponder at the start
of each platform which is detected by each door and
enables the doors on the appropriate side, and another
one at the end of each platform which disables each door.
Some complications for platforms on reversible lines

Ware springs to mind, and most termini. That sounds high-tech enough to
break down a lot, and requires fitting of kit at stations, which are the
most easily vandalised part of the railway. I was thinking of a projecting
metal arm under each train door which prods the platform.

--
John Rowland - Spamtrapped
Transport Plans for the London Area, updated 2001
http://www.geocities.com/Athens/Acro...69/tpftla.html
A man's vehicle is a symbol of his manhood.
That's why my vehicle's the Piccadilly Line -
It's the size of a county and it comes every two and a half minutes

On Thu, 23 Sep 2004 15:57:55 +0000, Peter Masson wrote:

(Can GPS identify which line the train is on if adjoining
platforms are different lengths?)

Not with any certainty.

Of course, what happens if the Pentagon decided to turn off GPS for
civilian use without warning (which they've always stated they have the
right to do)?

Or worse, they have a war and introduce deliberate errors into the system
designed to confuse the enemy?

I can see it now on the 9:24 from Tonbridge: "We will shortly be arriving
at Copenhagen, please mind the step"

I know that Europe is going to deploy it's own GPS sats, but I don't know
when that will be.

Timbo

"Ian Johnston" wrote in message
news:cCUlhtvFIYkV-pn2-9bQzpFIyRbud@localhost...

On Thu, 23 Sep 2004 13:05:59 UTC, "Jack Taylor"
wrote:
: Most visually impaired people are intelligent enough to make enquiries
: before they join trains and join them at the appropriate place to
disembark

Well, what's so wrong with arranging things so they don't have to?

Yebbut that still won't make things any more convenient for them as they
will still end up stuck at a station where they can't alight if they're in
the wrong part of the train. Unless loads of money is spend lengthening the
platforms at all these stations, but I can think of many locations where
this would be bordering on the impossible due to level-crossings, river
bridges, et cetera.

In message , Peter Masson
writes

"John Rowland" wrote in message
...
Snip
Something along the lines of a transponder at the start of each platform
which is detected by each door and enables the doors on the appropriate
side, and another one at the end of each platform which disables each door.
Other interlocking means that doors cannot actually open until the train has
stopped, and failsafe precautions could cancel the enabling if the train
hasn't stopped within, say, one minute of passing the transponder. Some
complications for platforms on reversible lines, but I can't help thinking
that something like this has the potential for being more reliable than the
GPS technology (Can GPS identify which line the train is on if adjoining
platforms are different lengths?)
Peter


With difficulty, because GPS has an accuracy of +/- 100m, unless of
course you are using Differential GPS, but that is mainly a maritime
system.
--
Regards,

James Christie

"In the beginning the Universe was created. This has made a lot of people very
angry and been widely regarded as a bad move."
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