The GE 44-ton switcher is a 4-axle diesel-electric locomotive built by General Electric between 1940 and 1956. It was designed for industrial and light switching duties, often replacing steam locomotives that had previously been assigned these chores. This locomotive's specific 44-short ton weight was directly related to one of the efficiencies the new diesel locomotives offered compared to their steam counterparts: reduced labour intensity. In the 1940s, the steam to diesel transition was in its infancy in North America, and railroad unions were trying to protect the locomotive fireman jobs that were redundant with diesel units. One measure taken to this end was the 1937 so-called "90,000 Pound Rule" : a stipulation that locomotives weighing 90,000 pounds (41,000 kg) – 45 short tons – or