Pacer
At the beginning of the 1980s British Rail (BR) needed to make new trains to replace its old first generation diesel multiple units (DMUs) which had been built between the mid-1950s and early-1960s. These old trains had helped replace steam and were popular with the public at the time. But BR did not get much money from the government, so could not get new trains that were just as good as the old ones. BR created two kinds of new second generation trains: the Sprinter series, for use on city and longer-distance services, and the Pacer series as cheap DMUs built using bus parts for short-distance countryside and branch line services. The Pacers were intended as a cheap stopgap solution to the shortage of trains, and were not supposed to be used for more than 20 years.  BR set a challenge to several companies to design a cheap, lightweight train similar to railbuses. Since then, 165 Pacer trains (with 340 carriages in total) have been built. By 2015, some of these were over 30 years old.