Simplify the following text for a Grade 8 native English-speaking person.
Original: The British Rail Class 23 Bo-Bo Diesel-electric locomotives ( also called ` Baby Deltics ' ) were a ten strong class of locomotives built by the English Electric Company in 1959 .
Simplified: The British Rail Class 23 were a class of ten Bo-Bo diesel-electric locomotives built by the English Electric Company ( EE ) in 1959 .