This was the locomotive's first run on the mainline in over 50 years. On 5 November 2017, 131 performed three mainline daytime tests to Carrickfergus and Belfast Central. The locomotive returned to mainline service in April 2018, in 1920s black with red lining livery, hauling tender No.37 which has been rebuilt with a new body.
This was the locomotive's inaugural mainline journey in over five decades. On November 5, 2017, 131 conducted three daytime tests between Carrickfergus and Belfast Central. The locomotive resumed its mainline service in April 2018, with a livery inspired by the 1920s—black with red lining—and pulling tender No.37, which had been recently refurbished.