An intermodal service based on F3 Principles ideally needs a light freight locomotive with bi-directional capability.
Current main line freight locomotives are designed to haul 2,500 tonne coal trains, so are over-powered for FreightArranger’s F3 service. A lighter freight locomotive would save costs through being cheaper to build and cheaper to operate by consuming less fuel and incurring less track access charge.
A potential design for the light freight locomotive is TruckTrain®. Full details about TruckTrain are at http://trucktrain.co.uk