National rail in a challenge

[FelixJ20000]

I've read the full rules, but there is a bit of ambiguity:

What is the policy on riding a National Rail train between stations. For example, would traveling West Brompton > Shepherds Bush on Overground count as doing Olympia? What about running that same route, entering then leaving the station and recording the time as entry to the station (TfL owned space or within ticket barriers) What about arriving by one method and leaving by another?

Also, is taking Nation Rail as a 'fast line' (not traveling on same tracks), for example c2c between Upminster and West Ham as a shortcut back, is that valid? Would a Barking visit be valid that way?

[Urzzz1871]

In a word, no.

You have to visit Olympia using the District line. Remember you have to arrive at and/or depart from a station by train to count.

Using the c2c to get back to West Ham from Upminster as a short cut back is fine though, despite different tracks, as you have ticked off all the required stations on your way out on the District. Your stop at Barking is, in effect, irrelevant,

[FelixJ20000]

I can see that being irksome. Time to consult WTTs.

[Urzzz1871]

Yes, you need to either pick an exhibition day when the trains to Olympia run all day, or plan your route to pick up one of the early morning or late evening trains that run every weekday.

[The Orange One]

Yes, you need to either pick an exhibition day when the trains to Olympia run all day, or plan your route to pick up one of the early morning or late evening trains that run every weekday.

Hence the 5:02 from Heathrow T4 start (then to T5 and then straight into town) - if it goes as planned, you have time to get to any train out of the 0606 to HSK, the 0615 to HSK, the 0624 to Dagenham East and the 0632 to Edgware Road - you won't make the 0550 to Edgware Road of course, but this is a very popular start for people who want to guarantee Olympia. I am told that if you miss the connection at T123 and catch the next one, if you run like hell from Barons Court you can still make the 0632.