In 1954 the skipway and tramway was replaced by a tunnel driven from the escarpment at the head of the company's private railway between Mount Nebo and Mount Kembla. In 1955 the mine was renamed Kemira (from "Kem"bla and Ke"ira"). Longwall mining was introduced in the 1960s. Peak production was reached in the year ending November 1979 with . In 1982 a downturn in the steel industry resulted in 189 employees (60% of the workforce) being retrenched, resulting in a 16-day "sit-in" protest by 30, and mining finally ceased on 27 September 1991.