Men engaged in fitting jet units to the rear of a wagon on a snow encrusted stretch of line near Brecon, an ingenious way of clearing the disabling snow drifts preventing trains carrying coal on the Welsh railways during the winter of 1947, one of the harshest on record in Britain. The jets were in the charge of Flight Lieutenant Walton D.F.C and as they passed down the track, huge chunks of snow from rails and sleepers were hurled high in the air.