On Jun 18, 6:38*am, Roland Perry wrote:

In message , at 00:06:13 on Thu, 18
Jun 2009, Peter Smyth remarked:

Just seen on another forum that members are arranging a Zone 1
(except *Blackfriars) 'Tube challenge' where they aim to visit all
stations in *the shortest possible time for a competition between
members (not a *world record attempt or anything).

It has been raised that there may be problems with Oyster PAYG and
that users should instead buy a z1-2 Travelcard. What would happen if
someone touched in and didn't touch out again for say 3 hours, even
then they may touch out at a different location? Would there be the £4
minimum charge or would something else happen?

You would be charged two £4 fares. The system would consider the touch
in and touch out to be two separate journeys as they are more than 2.5
hours apart.

But there must be some opportunities for "quick touches". For example at
Farringdon where there are validators on the platform (for transfer to
Thameslink).

I assume touching one of those twice would end one journey then start a
new one.

You assume wrong. Standalone validators can be set up in different
ways - those within paid areas, such as the ones on the platform at
Farringdon will (almost certainly) be set up in 'interchange mode' -
if there is an open journey on the Oyster card, then touching on one
of these provides a 'soft exit' from the system, i.e. it means that if
that's that the journey will be regarded as resolved, however it also
leaves the journey open should the passenger merely be interchanging
and then travelling onwards. Note that at the moment this does *not*
top-up the original journey time-limit - presently that stays at two
and a half hours from the original touch-in to the system, though come
September the whole system of calculating the maximum allowable time
for a journey gets rather more sophisticated.

Note that these validators within paid areas are essentially only
there so as to provide a way of allowing people who have arrived with
a National Rail paper ticket to touch-in their Oyster without having
to exit and then re-enter the gates (or v.v. so they can touch-out of
the Oyster system and end their journey before using their NR paper
ticket). However come September when modifications to the system are
due to occur, one may be able to touch on one of these standalone
validators when interchanging so as to ensure one pays for a cheaper A-
to-B journey - e.g. if one has avoided zone 1 (the classic location
for doing this would be Willesden Jn).

These standalone validators have been subject of much previous
discussion here on utl including contributions from a man who knows a
fair bit about them (to say the least) so my words are not mere
speculation.