I remember both the shafts but cannot remember which years they appeared. I wonder if they were drift mines or ventilation shafts One was opposite the entrance to Westlea and the other in a drive at Nedderton, who knows when others will appear. I understood lots of the farms were bought by the coal companies because of subsidence claims. The geological facts and the reality based on first hand knowledge is very interesting. How the seams fold, widen and are given different names is an area of knowledge just waiting for this generation to investigate. Obviously with the help of people like HPW and helpful hints from books like Steven Martin's