JL - 15.8.23 66149 6T23 Immingham Ore Terminal - Santon, Santon

In the thick of British Steel's Scunthorpe complex, immaculate DBS 66149 snakes around the unloading point at Santon with 6T23 loaded iron ore from Immingham ore terminal. After setting back into the unloading shed, the loco would run around both ore trainsets to lead the already unloaded rake out as 6K23 Santon - Immingham. I'm curious about the operations here, it looked like there is some way the loaded trucks are propelled through the unloading depot without the need for a loco or shunter. But how this was done was not visible. This shot was published in a magazine but I can't remember which.