Mizter T wrote:

By security I take it you mean fare checking (or 'revenue inspection'
- but I dislike that phrase because I think it's very narrow) - not
quite the same thing in my mind but of course they overlap.
Interesting thought - I hadn't considered the difference six car
trains (or three car - depending on how you look at it!) might make to
checking tickets. Most DLR stations simply ain't set up to accomodate
tickets gates, so I dare say that if there is deemed to be an issue
then teams of roving inspectors would fit the bill - I don't think
I've ever come across such a thing on a DLR train actually, though I
have seen ticket checking teams at stations a few times.

I have a few times on the Stratford branch. Perhaps that's also because
Stratford is a nightmare for knowing how to use Oyster correctly when
interchanging (especially from tickets).