Two tram services in Sheffield remain suspended this weekend after a three-metre wide hole was discovered next to the track seven days ago.
South Yorkshire Passenger Transport Executive said specialist equipment was being brought in to assess in greater detail the hole, which has opened up on an embankment on Park Square.
From Monday a shuttlebus is to be put on between the railway station and the city centre.
It will operate around every 10 minutes.
The blue and purple tram route services are affected between the station and the city centre until further notice.
But the yellow route from Meadowhall to Cathedral is unaffected – and replacement buses for passengers will continue to serve tram stops from Cathedral to Middlewood or Malin Bridge.
And passengers travelling between the city centre and Manor Top are able to use their existing tram tickets on the Stagecoach bus service number 120.
The passenger transport executive and Supertram have both apologised to customers for any inconvenience caused by the delay – which follows weeks of disruption due to rail replacement works across the city.