Original: As opposed to the previous Pullman Car Company locomotive-hauled carriage trains , and the Brighton Belle electrical multiple units , the Blue Pullmans were the first diesel-electric multiple units designed for high-speed Pullman train services incorporating several novel features .
Simplified: Although not entirely successful in their own right , the Blue Pullmans demonstrated the possibility of high-speed fixed-formation multiple-unit Inter City train services and inspired the later development of the Inter City 125 .