On Thu, 18 Jun 2009 06:28:01 -0700 (PDT),
Mizter T wrote:

On Jun 18, 1:33*pm, Tim Woodall wrote:

On Thu, 18 Jun 2009 13:18:56 +0100,
* * Recliner wrote: I'll be taking a train to Watford Junction next week using Oyster
pre-pay, and then continuing the journey on a charter train (paper
ticket) -- would I be correct in assuming that there are Oyster
validators on the platforms so I don't have to leave and re-enter the
barriered zone (and vice versa on my return)?

There are validators on platforms 1-4 DC line (I think - I almost never
use those platforms)

There are validators on the DC line platforms, yes.

Yes. I'm 99% certain there are some there but I could be imagining
things. I can never think of any circumstance where they would make
sense for me to use therefore, while I'm pretty sure I've seen them I've
not made a mental note "that is where they are"

Word of warnings - if you touch on a validator in the subway and then
decide to temporarily leave by the manual gate but touch again you'll
"reenter". (I found this out to my cost when the manual gate validator
had been broken for several days. I touched in the subway on my way out
but then was told to touch again on the manual gate - because it had
been repaired - and ended up with an unresolved journey)

(Dont know what will happen if you touch in the subway and then leave by
the automatic barrier - presumably in that case it's intelligent enough
to realize that Exit-Exit is just a single exit, it's just
"Exit?Entry-Exit?Entry" where it gets confused.)

It should treat a touch on a standalone validator and then another one
on the gate as an exit, yes - this is how it works elsewhere (the
point being that the gates are definitively unidirectional - you're
either exiting the system or entering the system). Again, if you touch-
in on the gates then do so again on a standalone validator then it
should just treat them both as entries to the system.

N.B. The validator next to the manual gate (and possibly those next to
the car park) might be configured differently to the other standalone
validators - the validator at the manual gate providing a definitive
'hard' exit or entry to the system, whilst the other validators may
well be in 'interchange mode' and so just provide 'soft' entries and
exits, so you can touch on them as many times as possible with no ill-
effect. Err... that said, if that was the case then touching-out on
the validator in the subway then again on the reader next to the
manual gate shouldn't have caused a problem- not according to my logic
at least. Hmm.
I've no idea how it is configured, and I'd assumed that two touches, on
in the subway followed by one on the manual gate would be an exit. You
cannot touch multiple times on the manual gate and have it register an
entry then an exit or vice-versa because I tried to immediately touch
out again but I couldn't (I suspect I could have touched on one of the
barriered gates)

Here's my Journey history (of course things might well have changed now)

09/04/08 19:57 Watford Junction Entry - £3.00 £20.40
19:56 Watford Junction Exit £2.00 £23.40
19:27 Euston NR Entry - £5.00 £21.40

The exit plus entry didn't even count as a continuation of my journey as
it charged me another three pounds. (I did actually reclaim this and I
got it credited back but usually I cannot be bothered to reclaim when
things go wrong)

I'm surprised it's configured like this because it seems to allow an
easy fraud for people coming in on the St-Albans line. Touch "in" in the
subway and then "out" at the gate and (I think) it's 1.00. Similar will
(presumably) apply for peak hour journeys into Euston where the barriers
are now open.[1] (This is the only time I've ever touched on more than
one validator so I've got no data for what happens in other cases)

Tim.

[1] I suspect I've actually seen this happen because sometimes people
walking the same way as me touched on the validator at the bottom of the
stairs. It could, of course, have been a genuine misunderstanding or
they could have come in on the StAlbans line and then gone up to the
ticket window inside the barrier line before going to the platform.

--
God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t,"
and there was light.

http://www.woodall.me.uk/