In message , Paul Scott
writes

The SLL service will run into a new platform 2, which will be the
current platform 2 extended out by one track width over half its
length, at the Wandsworth end. The WLL will run from the existing
platform face, which will be renumbered as P1.

Handy diagram he

http://www.sucs.org/~cmckenna/diagra..._2a_and_2b.png

It describes the SLL platform as 2b and the WLL as 2a, but the latter
may well be renumbered as 1, as there is no hope of getting the original
platform 1 back in service.

The important thing is that there is easy and step-free interchange
between the two segments of the orbital route.
--
Paul Terry