South Yorkshire firefighters will put their procedures to the test this weekend when they deal with a mock emergency incident involving a tram.
The training exercise on Sunday will take place on the tram tracks at Herdings and will affect Supertram's purple route services.
Passengers have been warned to expect disruption from 7.56am until 3pm.
Purple route trams will operate as normal, from mid morning, between Meadowhall, Sheffield Cathedral and Gleadless Townend.
A replacement bus service will operate between Gleadless Townend and Herdings Park.
Buses will run every 20 minutes to connect with purple route services at Gleadless Townend.
Buses will use stops opposite Sainsburys at Gleadless Townend, Norton Avenue/Bowman Drive and Raeburn Road/Raeburn Close.
A Stagecoach Supertram spokesman said: "Buses and trams are timed to connect at Gleadless Townend, however factors outside of our control mean we are unable to guarantee services will connect.
"Please note that replacement bus information and times will not appear on journey planning tools, bus stops or tracking services like YourNextBus.
"No other services are affected by these alterations and a normal Sunday service will continue on blue and yellow routes.
"We apologise for any inconvenience caused as a result of these temporary changes."
Anyone wanting more information should call Traveline on 01709 515151 or follow @SCSupertram on Twitter.