Introduction

This branch, also known as the Sheardrum Extension, was built by Robert McAlpine for the North British Railway at the expense of Wilsons and Clyde to serve their colliery Lethans Colliery Pit No 1. Near the south end the line crossed over a colliery tramway which served Saline Valley Colliery Pit No 4.

The line extended the older West of Fife Mineral Railway, now owned by the North British Railway around the east side of Knock Hill to South Lethans. It was a steep single track line with reverse curves at the southern (Steelend) end.

Prior to the railway, the area had been extensively mined for coal and ironstone over the years, and served by various minor tramways, notably for the Forth Iron Works.

The branch opened in 1906 and fell out of use in 1920, with official closure and dismantling years later.

Part of the former course of the railway has been incorporated into the Knock Hill Race Circuit, with racing occurring today where slow moving mineral trains once ran.