Opened in 1826 to the Scotch gauge of 4 ft 6 in, the Monkland & Kirkintilloch engineered by Thomas Grainger and John Miller was the first in Britain with the right to operate locomotives written into its Act of Parliament. With its specially malleable iron rails, it was also the first in Scotland to operate them successfully (trials with a heavier one, The Duke, having broken those on the Kilmarnock & Troon).