Pre-Owned 35-504SF Class 117 3-Car DMU L412 BR Blue - DCC SoundPre Owned Item, in as new condition. Test Run. The Class 117 3 Car Diesel Multiple Unit (DMU) is Bachmann Branchlines flagship First Generation multiple unit, equalled only by its single car Class 121 stablemate. Employing cutting edge technology, these high fidelity models boast a wealth of detail and era specific options to depict specific units at various points during their working careers which, for some, extended to almost 40 years in service.