Simplify the following text for a Grade 10 native English-speaking person.
Original: They made various prototype trains like the British Rail Class 210 DEMU and the experimental high speed Advanced Passenger Train ( APT ) tilting during the 1970s and early 1980s .
Simplified: They made trains like the British Rail Class 210 DEMU and the The experimental Advanced Passenger Train ( APT ) tilting High Speed Train during the 1970s and early 1980s .