Train services on the Lilydale, Belgrave and Glen Waverley lines will operate directly to and from Flinders Street and will not operate through the City Loop on Saturday 28 January.
The disruption to the service is due to the installation of emergency management equipment.
Passengers travelling to the City Loop should change at Flinders Street to a train on Platform 1.
From the City Loop, take a train from Platform 2 and change at Flinders Street.
From Southern Cross Station, take a train from Platform 12 or 13 and change at Flinders Street.
Buses will also replace trains on sections of the Belgrave and Lilydale lines between Camberwell and Box Hill from 8.30pm Friday 17 February until late-May. Rail replacement buses will also run at times between Box Hill and Ringwood from late-February until mid-May.
