Complex sentence: Two viaducts south of Montrose were designed by Sir Thomas Bouch, the architect of the original Tay Bridge but due to delays in building the Tay Bridge and the line by Dundee, this work was not done until 1879.
Split into simpler sentences: Two viaducts south of Montrose were designed by Sir Thomas Bouch, the architect of the original Tay Bridge. Due to delays in building the Tay Bridge and the line by Dundee, this work was not done until 1879.