The overall picture was further complicated by the establishment of coal depots in South London by the "northern" companies, mainly the MR and GNR, which enabled them to take control of the whole transit of the coal from colliery to local distributor. These depots were served by dedicated workings from the yards on the MR and GNR - latterly Brent Sidings and Ferme Park – via the Widened Lines and running powers established at various dates. Further details can be found in an article by Edwin Course in "Railway Magazine".