The Sheffield to Rotherham tram-train, which crashed on its first day of service, has been hit with further difficulties.
The service has been forced to run a reduced timetable while one of the vehicles is tested.
Stagecoach Supertram, who are operating the £75 million pilot project, said the services departing Parkgate at nine minutes past the hour and Cathedral at 39 past the hour were not able to operate.
In a statement, the firm said it expected normal services to resume by around 9.30am.
The project launched on Thursday – almost three years late and at five times its original cost.
It was then involved in a crash with a lorry carrying gas canninsters later that day.
Four people were injured in the incident, with one taken to hospital.
South Yorkshire Police said no arrests had been madeand added the investigation had been passed to the Rail Accident Investigation Branch (RAIB).
Stagecoach Supertram, who operate the service, have requested specialist engineers from manufacturer Stadler, based in Spain, assess the damage to the vehicle.
Passengers said the tram-train lifted around 1m in the air before derailing and landed around 6m to the left of the tracks.
In a statement, the RAIB said it was aware of the incident and was making initial inquiries.