Simplify the following text for a Grade 11 native English-speaking person.
Original: The InterCity 125 train is made up of two power cars , one at each end of a fixed formation of Mark 3 carriages , and is capable of 125 m , making the train the fastest diesel-powered locomotive in regular service in the world .
Simplified: The InterCity 125 train is made up of two locomotives , one at each end of a fixed formation of carriages , and is capable of 125mph in regular service .