Complex sentence: In 1977, British Rail introduced the Class 253 High Speed Trains onto the Great Western Main Line displacing the Class 50 fleet onto other routes, such as services to Birmingham New Street from London Paddington and Bristol Temple Meads.
Split into simpler sentences: In 1977, British Rail introduced the Class 253 High Speed Trains onto the Great Western Main Line. The Class 50 fleet was therefore partially redeployed onto other routes, such as services to Birmingham New Street from London Paddington and Bristol Temple Meads.