Freightliner's Class 66/6 diesels are low geared to produce a higher tractive-effort, ideal for the heavy coal trains they were intended for and the heavy stone trains they usually work today. 66617 was unusual power for 4M58, the 09:14 Southampton MCT to Garston FLT Freightliner on 11 July 2022, seen here passing Worting Junction, west of Basingstoke.