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.

There is a validator on platform 9(&10) where the carpark entrance is.
And there are validators in the subway joining the platforms.

AFAIAA there are no validators on any of the other platforms.

But, you are correct, you do not have to exit and reenter the barriered
zone to touch.

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.