Complex sentence: The small fleet size together with maintenance costs of the non-standard Rolls Royce engines ensured their early withdrawal following the introduction of the class 150/2'Sprinters' on the Calder Valley route in 1986.
Split into simpler sentences: The small fleet size together with maintenance costs of the non-standard Rolls Royce engines ensured their early withdrawal. Class 150/2'Sprinters' were introduced on the Calder Valley route in 1986.