...[1] accelerate the finishing work of P11. Without this P10 is now the bottleneck - for trains and passengers
[2] determine a way for more London bound mains to use the new platforms to relieve pressure on P10
Once P11 is opened (planned for August bank holiday but even if it was speeded up) clearly P10 will then have to close for quite a long period of time to be rebuilt in its final position. So there'll still be a bit of a bottleneck until both platforms are available together.
However they already do have a method of running High Speed services round an obstructing service in P10, they'll cross to the up relief at Tilehurst and use P15; then back over to the up main at Kennet Bridge Jn. This can be seen happening in the realtimetrains advanced service listings, and I also saw it yesterday during the afternoon when a
XC▸ Newcastle - Southampton service was reversing in P10.
BTW▸ the interim layout
Industry Insider posted (on page55) shows all movements possible at Kennet Bridge Jn - but it's well out of sight of the station...
Today's timetable shows a number of Bristol - Paddington trains using P15, and early on there were trains that originated in Hereford and Cheltenham that used P15 - presumably they'd be
HSTs▸ too?
...For example the 18:20 stopper to Oxford was leaving P12B and was shown/displayed at escalator CIS▸ at 18:05. But on P13B the 19:27 stopper was also displayed - a full 80 minutes before departure ! Will unfamiliar travellers see P13B first and think that was the next stopper service....
The chap on the mobile information desk noted this down for me on his comments sheet, and I've also sent them a feedback form about this, but based on similar observations about the XC Newcastle service. In this case the 1340 was waiting in 14B, and the 1540 was also showing on the 'escalator display' of 13B. They just need to suppress the later display until the previous train has left. This is really only a disadvantage of the additional 'escalator display' because of course displaying trains in a few hours time was fairly common on the old '3 line displays' hanging above the platforms, but in that case the later trains come up in the third line of three and are quite obviously in the future.
Paul