Going under the Dapol 3500gall tender looks challenging as there is a weight, water scoop and brake rodding in the way. If my physics is correct, on a 15VACC DCC system a 2 *330uf capacitor stay alive (which is what I'm using) will store 0.075J of energy giving 0.5s of power at 0.1A, equating to about 5mm of travel at a scale 5kmh in N. That might be enough to overcome the intermittent tender pickup issue, so I'll see how that goes.