This single track mineral railway ran from Straiton Sidings on the Edinburgh, Loanhead and Roslin Railway to the Pentland and Straiton oil works. The line passed under the A701 by a bridge/tunnel.
These locations are along the line.
The box controlled access to the Pentland and Straiton Oilworks Railway for Straiton Oil Works and Pentland Oil Works. The signal box, 'Straiton', was on the east side of the line at the junction. It opened in 1877. The branch was accessed from the north.
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This oil works was on the east side of the A701 in Straiton, ultimately owned by the Clippens Oil Company. The site was rail served by a branch from the Edinburgh, Loanhead and Roslin Railway.
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This large oil works was on the west side of the A701. It was owned by the Clippens Oil Company, owners of the Clippens Oil Works.
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