In article ,
Robin May wrote:
I've got no idea. The Jubilee line platforms are gated off from the
rest of the station, even though to get to the Jubilee line gates you
have to go through a set of gates at the entrance to the station
anyway.

Or get on a NLL train at - say - Hackney (with no gate in sight!).

--
Good night little fishey-wishes.... I've counted you, so no
sneaky eating each other.
-- FW (should I worry?)