Having been producing on and off track railway model kits since the late 50's and noting a gap in the market for more detailed models Airfix entered the 'ready to run' range of model railways in 1976.

Due to its popularity the newly formed 'Airfix Railway System' soon expanded its range to include engines as well as a comprehensive range of rolling stock.

In 1979 to differentiate from Airfix models the name was changed to 'GMR' (Great Model Railways) but with the parent company failing at the begining of the 80's the Rail system was sold to Palitoy who continued to market under the 'Mainline' banner.

By the mid 80's Palitoy closed its European operations and 'Mainline' was acquired by Dapol who eventually sold the ex Airfix range to its present owner Hornby.