With my observations at some new London Stations (e.g. Meridian Water, London Bridge), the newly built platform seems not built to the level of trains, which have caused significant height gap between trains and platform. It is particularly relevant to some platforms only to be served by newly built trains (e.g. London Bridge Platform 4-5: Class 700).
Are they any particular reason why the same height level for both trains and platform cannot be achieved?
Are they any particular reason why the same height level for both trains and platform cannot be achieved?