The 537-metre-long (1,762 ft)[2] tunnel (together with 'Six Chain') was built through the Little Liverpool Range on a section of narrow gauge railway from Grandchester to Gatton.

The railway opened in June 1866, being delayed when the excavation of the tunnel revealed unexpected geological difficulties, requiring the tunnel to be lined with 3 layers of bricks.

That resulted in the tunnel having restricted clearances, which limits the loading gauge (size of rolling stock) on this section of the Queensland Railways network, and the floor of the tunnel was lowered by 150 millimetres (5.9 in) in 1985 to improve that situation.

There are a total of 11 single track tunnels on the line between Ipswich and Toowoomba, all built around the same time in 1865, all with a tight profile that are too small to take 2.9-metre-high (9.5 ft) ISO shipping containers.

It is now proposed to improve the loading gauge of these tunnels by lowering the floors.