Why is it that at St Pancras station we now have access to the international platforms that Eurostars mainly operate on?
Because with layers from LGV and I believe SKA (don't think it's HMA or SKW) you now get the possibility of TGVs and ICE3s appearing there at occasional points on the timetable. There is even a couple of timetabled runs on SEHS for the TGV as a public demonstration event.