The CMGIR was built 1803-05 and ran from Merstham in Surrey to Croydon where it formed an end on junction with the Surrey Iron Railway (built 1801-03) which ran to the Thames at Wandsworth. The CMGIR was a textbook Outram line. The CMGIR primarily served limeworks and a stone quarry at Merstham, and also carried other goods such as timber, coal, fullers earth and miscellaneous goods. It is likely to have carried stone from the Godstone quarries, using a siding at Purley. After the Croydon Canal was completed in 1809 traffic was diverted to it instead of the SIR via a short linking line usually called the Pitlake Tramway. The CMGIR was closed around 1838 when it was bought by the London and Brighton Railway. Few relics remain. What little survived at Merstham has mostly been buried by the M23. There are some archaeological remnants surviving. The underground stone quarries contain a few CMGIR related artefacts. Some rails ended up underground at Godstone where they were reused as an underground tramway in a firestone quarry.
Merstham terminus: TQ299539
Cutting (Protected Monument) TQ287545