Hawkes Shaft engine house has the tallest engine house stack in Cornwall From 1826 – 1860 Killifreth produced copper from shallow workings, it was then taken over by a new company who then began to mine for tin. It wasn’t until the 1860’s that Killifreth used steam power unlike many of its neighbours The new company deepened the mine to 100 fm below the County Adit and obtained an excellent yield. but like many Cornish mines the collapse of the price of tin forced the mine to close in 1897. Another contributory factor to Killifreth’s closure was according to Brown and Acton in their book “Exploring Cornish Mines” Vol 2 “the breakage of the bob of the main pumping engine”. At its peak Killifreth never employed more than 281 men and only produced a fraction of the ore that mines in other parts of Cornwall excavated.
For a short time the mine was used as a training ground for the Truro Mining School then in 1911 it reopened when arsenic was produced by the same company that owned the nearby Wheal Busy Mine. It was during this last reworking that the brick built stack was doubled in height to create extra draft for the four boilers serving the new 85 inch cylinder engine. The price of arsenic on the open market was as volatile as that of the price of tin and the new venture failed within a few years. One further attempt to reopen Killifreth in 1927 failed because parts of the engine and the wooden headgear at Hawkes Shaft had been vandalised.
Eventually the plant was broken up and used as scrap during the Second World War, although there is reportedly still plenty of tin underground at Killifreth.