Development of the IC3 started in 1984, production started in 1986, and they entered service in 1991. However, its roots can be traced back further. In 1972, DSB celebrated its 125th anniversary, and at the same time made some large changes. First of all, two years later, in 1974, a completely new timetable system, the K74, was introduced. Secondly, the concept of "lyntog" were removed as the foundation of the long-distance traffic, and instead a new "InterCity" concept took over that role. After a few years, a new concept emerged, the so-called APOs, which were work-groups tasked with specific areas. There were groups for electrical locomotives, diesel-powered locomotives, and others, including the "long distance train" APO group.