This first tunnel served the railways for 53 years, until the track was re-laid in 1929 to diminish a curve to accommodate larger locomotives.
In the process a new concrete lined curved tunnel was sunk alongside the original.
Since another crossing place had also become necessary, a siding named Tunnel was fashioned just east of the tunnel by laying two level dead-end spur tracks that branched directly off on opposite sides of the main line.
This allowed trains to wait in one or the other of these sidings to allow an opposing train to pass.
This latter tunnel remained in use for sixty years, until the line across the pass was closed to rail traffic in 1989.

Despite its quick and relatively cheap construction, the Hex River rail pass served the South African Railways (SAR) for more than a century.
It was the starting point of the country's first railway line to the Witwatersrand and opened the way for Cecil Rhodes' colonisation thrust into central Southern Africa.
This first tunnel served the railways for 53 years, until the track was re-laid in 1929 to diminish a curve to accommodate larger locomotives. In the process a new concrete lined curved tunnel was sunk alongside the original. Since another crossing place had also become necessary, a siding named Tunnel was fashioned just east of the tunnel by laying two level dead-end spur tracks that branched directly off on opposite sides of the main line. This allowed trains to wait in one or the other of these sidings to allow an opposing train to pass. This latter tunnel remained in use for sixty years, until the line across the pass was closed to rail traffic in 1989.
Despite its quick and relatively cheap construction, the Hex River rail pass served the South African Railways (SAR) for more than a century. It was the starting point of the country's first railway line to the Witwatersrand and opened the way for Cecil Rhodes' colonisation thrust into central Southern Africa.
Hex River Tunnels