Every model is test run with a train of brass coaches on Cliff Williams track. The track is an oval, which is loosely laid (ie not pinned down) with peco track and points including a peco curved point. There is a section which has foam underlay and a section without underlay, this causes a dip in the track. The test track is laid this way so the models have to negotiate bumps and wiggles whilst running. Always having a train attached shows up any issues of pulling or the engine being pushed.All are tested on DCC which is more sensitive to short circuits etc. We also take time to video a small clip of each and every model. 25 loco's takes 6 hours including unpacking and packing again. its worth the effort so we know each model runs before it's shipped.