On Fri, 24 Sep 2004 04:46:28 -0700, David E. Belcher wrote:

SDO

Sorry for being think - what does SDO stand for?

Ta

Timbo

"Solar Penguin" wrote in message
...
...And the buffet serves something that's almost, but not quite, entirely
unlike tea. (Oh, wait. That already happens...)

At least you won't have to flollop with a matress on the platform if the
doors don't open... (Radio 4, H2G2 repeat, 11pm tonight (Thursday)).

--- "Chris Game" wrote:

Or one of those detector thingies they have on the back of BMWs to
detect an obstruction whilst you're backing..

No moving parts.


Why bother with a hardware solution at all? It can all be done with
software.

The onboard computer already has a list of stations that the train will be
calling at, for the scrolling electronic displays: "This train calls at..."
It also has to keep count of which stations it has already called at, so it
can update the displays each time: "The next station is..."

Just use that information to decide whether or not to open the doors at each
station. Problem solved.

"Solar Penguin" wrote in message
...

The onboard computer already has a list of stations that the train will be
calling at, for the scrolling electronic displays: "This train calls
at..."
It also has to keep count of which stations it has already called at, so
it
can update the displays each time: "The next station is..."

Just use that information to decide whether or not to open the doors at
each
station. Problem solved.

Until a security alert closes a station so the train doesn't stop there and
then the count is off by one.

Dave.

Tim wrote:

Sorry for being think - what does SDO stand for?

Selective Door Opening

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

--- "Dave Liney" wrote:


Just use that information to decide whether or not to open the doors
at each station. Problem solved.

Until a security alert closes a station so the train doesn't stop there
and then the count is off by one.


So how does it keep the count of "The next station is..." displays updated
when that happens? Presumably the driver just presses a button (or a
touch-screen display or whatever) to update the count and let it know the
train's not stopping. Or maybe the signal box does it by remote control.
Or something.

The details don't matter. The important thing is that there already has to
be some way of keeping the station count updated even when GPS isn't
working. So why not use that for the doors as well?

On Thu, 23 Sep 2004 22:32:22 UTC, TP wrote:

: James Christie wrote:
:
: The Russians have their own system called GLASNOSS

: You have to be joking.

Maybe he is. I think it's called GLONASS.

Ian

On Thu, 23 Sep 2004 18:25:33 UTC, "Gavin Hamilton"
wrote:

: It's been somewhat better than that for a while, since the "random error"
: was removed. IME the error is probably nearer 2 metres. Though the powers
: that be can reintroduce the random factor, or turn it off entirely, should
: they feel the need.

You have to be careful not to confuse the random precison errors with
the unrandom accuray ones. Civilian GPS is designed to be precise to
about +/- 10m, whereas military GPS, which uses different signals, is
precise to +/- 1m. Those errors are random - there is nothing you can
do about them. Selective availability was a deliberate degradation of
accuracy, done by effectively instructing satellites to tell porkies
in their signals, and thereby displace all GPS positions in a
particular area by an ordained amount. That's what doesn't happen
(much) any more, but the precision errors remain.

Ian
--

Solar Penguin wrote to uk.transport.london on Fri, 24 Sep 2004:


--- "Dave Liney" wrote:


Just use that information to decide whether or not to open the doors
at each station. Problem solved.

Until a security alert closes a station so the train doesn't stop there
and then the count is off by one.


So how does it keep the count of "The next station is..." displays updated
when that happens?

I don't think it does. My mother was travelling on a train from Clapham
Junction to Arundel; I don't know what had gone wrong, but the train she
was aiming for was cancelled, and the following train was only 4
carriages, not 8. As you can imagine, it was packed out, but luckily
someone gave her their seat, so she was all right. Anyway, she told me
afterwards that the electronic displays thought they were going to
London, not away from it, so that "The next station is" was totally out
of phase with reality! She said it was very funny.
--
"Mrs Redboots"
http://www.amsmyth.demon.co.uk/
Website updated 11 September 2004

Ross wrote to uk.transport.london on Fri, 24 Sep 2004:

And to further complicate matters, retention tanks require that the
contents be emptied, which means that they need somewhere with a
suitable cleaning pan and that in turn means that it's unlikely that
tanks can be cleared at every poxy little stabling point at which
trains get left overnight. In the case of the 170, the toilets will
lock themselves out once the retention tanks are full.

I think it is the same everywhere. Although, to be fair, Eurostars seem
to manage to have loos that flush for the whole journey and so,
normally, does the Shuttle. But there, I suspect, if one loo locks
itself out of service, the others don't, unlike on surface-only trains.
--
"Mrs Redboots"
http://www.amsmyth.demon.co.uk/
Website updated 11 September 2004