The G 72 arose from the idea of developing a locomotive with a compound engine from the G 71. This should lead to greater efficiency on long stretches and make it possible to transport freight trains of up to 1,400 tonnes at a speed of 40 km/h, which was sufficient at the time. 690 tonnes and 30 km/h were still required on gradients of 0.5 percent.
55 800 in the year 1953
Bundesarchiv / Bild 183-15765-0024 / CC-BY-SA 3.0
The compound design with only two cylinders meant that the right cylinder received the high-pressure steam and then the left the low-pressure steam. Despite the greater effort involved in manufacture and maintenance, this design proved its worth in comparison to simple steam expansion, and a total of 1,642 units were produced by various manufacturers between 1895 and 1911 for Prussia alone. From 1914 Linke-Hofmann manufactured eleven more for the Mecklenburg Friedrich-Franz-Eisenbahn.
Sectional drawing
Die Lokomotive, April 1910
The Reichsbahn took over 691 units in 1923 and designated them as 55 702 to 55 1392. As with its sister, however, it soon became clear that a locomotive with a top speed of 45 km/h was too slow for freight transport on the line. However, since the complicated compound engine was not suitable for shunting service, almost all of them were retired before the start of the Second World War. After the war, there were larger numbers on both German railways that had returned to Germany after the Polish campaign. However, in contrast to the G 71, these no longer played a major role and disappeared by 1961.