So if it's urgent, why are they waiting for the peak hour? Isn't it more logical to try and fix it before the afternoon peak hour, that way only one peak hour would be affected.
In respect to the repairs required on the Illawarra Line at Wolli Creek:-
Normally, all Down trains are tabled to use the Down Illawarra Main Line.
However, during Peak Hours "All Station" Services running on the Down between Sydenham and Hurstville will cross from the Illawarra Main Line at Wolli Creek to the Local Line.
The crossover at this Location is where the repair to the Infrastructure is being carried out.
Forcast for completion of repair work is 3 weeks.
To minimise delays, during Peak Hours, "All Station" Services will cross to the Local Line at Sydenham and hence will not be able to Stop at Wolli Creek Station.
In this way, Down Express Services can be maintained as per Timetable.
It should only cause minimal disruption, in the Peak Hours, to Passengers travelling from Tempe to Wolli Creek, or Passengers travelling from Wolli Creek to intermediate Stations between Wolli Creek and Hurstville.