The hospital, sited in the Padarn Country Park, Llanberis, was opened in 1860 to tend to the injuries of the 3,000 quarrymen at Dinorwig quarry.
Due to the many crush injuries from the quarry the surgeons became experts in limb salvage and brain operations.
There were on average 40 accidents a month, five per cent of which were very serious.
The hospital acquired an X-ray machine only two years after its invention in 1898.
Dr Thomas Hughes, at Llanberis from 1875 to 1890, was a great fan of the Lister spray which applied carbolic acid to ward off wound infection.
A special strecher was built to transport an injured quarryman down from the rockface via the narrow guage railway which ended near the hospital.
The hospital was paid for out of the quarrymen's wages and was not for the general use of their families.