Den was based at Simonsbath Sawmill and really enjoyed working there. In particular, he loved the Ruston Hornsby diesel engine which he kept in perfect working condition. The engine had been installed in 1952 after flooding had damaged the system that brought water to the old turbine. When Den arrived in Simonsbath in 1960 the engine was only 8 years old and he looked after it for more than thirty years - by far the longest period that anyone has cared for it and the time during which it is was in most regular use. The fact that the engine is still in such good condition today owes much to the dedicated care and attention Den devoted to it during his time at the sawmill. (After Den died, in 1992, the engine was rarely used. When the National Park Authority bought the sawmill in 1996 Stan Curtis, who had recently retired from his job as a tractor driver with the Fortescue Estate, looked after it in his capacity as the NPA's Honorary Warden for the Simonsbath area. After the NPA restored the mill in 2002/03 the engine was again used to power sawmilling operations but these ended in 2010. Since then the mill has not been in regular operational use and the engine is looked after by a small group of volunteers who currently run it about twice a month for demonstration purposes).