These engines had a somewhat higher steam consumption than the first ten units of the DRG Class 43 procured in parallel for comparison purposes, and which were equipped with two cylinders.

During the Second World War an austerity variant was built with simplified construction and delivery, known as the Class 44ÜK (one of the so-called Übergangskriegslokomotive).

This primarily used home-produced materials; components were simplified, both in manufacturing methods and design, or left out completely.

The most striking features of the ÜK locomotives were the omission of the smoke deflectors (that from 44 013 was standard) and also the forward side windows of the driver's cab.

[3] Until their replacement by modern diesel and electric locomotives, the Class 44 engines were the backbone of heavy goods train duties in Germany.

In order to simplify the work and hold its power steady, 32 locomotives were converted to oil-firing by the DB in 1958 and 91 by the DR in 1963.

Following the 1973 oil crisis, all oil-fired engines in the DR were reconverted to coal-firing, because they were indispensable for operations.

At the 'traditional locomotive shed' at Stassfurt (Traditionsbetriebswerk Staßfurt), stands number 44 1486, the only current representative of her class in Germany.

In addition, number 44 1593 remains operational with the Veluwsche Stoomtrein Maatschappij (VSM) in Beekbergen, Netherlands.

In 1932 and 1933 the firm of Henschel built two trial locomotives designed for a raised boiler overpressure of 25 bars (25.5 kgf/cm2; 363 psi) and equipped with four-cylinder compounding, which were also incorporated into Class 44.