Simplify the following text for a Grade 8 native English-speaking person.
Original: The British Rail Class 10 diesel locomotive was a variation on the Class 08 diesel-electric shunter in which a Blackstone diesel engine was fitted instead of one made by the English Electric company .
Simplified: The British Rail Class 10 diesel locomotive was a variation on the Class 08 diesel-electric shunter . A Blackstone diesel engine was fitted instead of one made by the English Electric company .