This shot is of the other end of the sector plate. The principle is the same as that employed in the full length plate. Both the full sector plate and the loco plate pivot at one point: in this case a bolt in a brass tube which forms a bushing to reduce wear. This located under the nose of the short hood on 4811. Power is fed permanently through this end of the plate. Use of DCC allows for just two wires for each track.
Morpeth In O-Scale 
After reading your recent article in AMRM re fiddleyard access I started looking tonight for further detail on the connection method. Will follow the leads, but wonder if you have a diagram and/or photo anywhere? Regards Barry Sherringham
Barry,
Are you sure you’re not talking about James’ layout Lambing Flat? I haven’t had anything in AMRM for a while. Or are you talking about 7th Heaven?