Original: The British Rail Class 303 electric multiple units, also known as "Blue Train" units, were introduced in 1960 for the electrification of the North Clyde and the Cathcart Circle lines in Strathclyde.
Simplified: They are also known as "Blue Train" units. They were introduced in 1960 for the electrification of the North Clyde and the Cathcart Circle lines in Strathclyde.