Mizter T wrote:
The NLL has seemingly turned from a forgotten backwater of London's
rail system to become a very popular orbital link, but it's now almost
too popular for it's own good.

I put much of its popularity down to lack of proper 'revenue
protection'. When teams of grippers are in action those packed NLL
carriages can empty rather rapidly with people abandoning the train ASAP
or flitting between carriages. The forthcoming station developments,
gates et al, may help clamp down on this and so the three car trains
could prove sufficient for a while longer.

ESB