It is suggestion if Ltt-Mao ac double decker was start from CSTM instead of Ltt then It will also superhit. I know because of some low heights bridges between Kurla Cst the Ltt-Mao double decker CSTM shift is not possible until the rebuild plan Or raise the heights of bridges with support of powerful monster hydraulic cranes. If this done then it will help to lift the speed restriction. also It will allow the all roller stocks with higher height coaches & locomotives.