First Great Western
Class 68 (Fictional)
Requires: ScotRail Class 68 Loco Add-on from Steam: https://store.steampowered.com/app/376930/Train_Simulator_ScotRail_Class_68_Loco_Addon/
Class 156 (Fictional)
Requires: Class 156 Diesel Multiple Unit Pack from Armstrong Powerhouse: https://www.armstrongpowerhouse.com/rolling_stock/multiple_unit2/class_156_diesel_multiple_unit_pack
Class 170 (Fictional)
Requires: BR Class 170 ‘Turbostar’ DMU Add-on from Steam: https://store.steampowered.com/app/208364/Train_Simulator_BR_Class_170_Turbostar_ DMU_AddOn/
AND Class 168/170/171 Enhancement Pack from Armstrong Powerhouse: https://www.armstrongpowerhouse.com/class_168-170-171_enhancement_pack
Class 172 (Fictional)
Requires: North London & Goblin Lines Route Add-on from Steam: https://store.steampowered.com/app/500211/Train_Simulator_North_London__Goblin_Lines_AddOn/