The T 3 was a small three-axle tank locomotive that was developed together with the two-axle T 2. A special feature of their development is the fact that they were the first locomotives that were created according to the newly established standard patterns. Since the individual locomotives of a class often differed in detail from locomotive to locomotive, production could now take place according to mandatory design drawings without major deviations. Above all, this made maintenance easier, since spare parts were now interchangeable and did not have to be made individually for each locomotive.
The design of the T 3 was very simple in order to obtain a low-cost and easy-to-maintain branch line locomotive. All three axles were powered by a saturated two-cylinder engine and the cylinders were controlled by an external Allan valve gear. The first series did not have a steam dome, just an attachment for the regulator on the boiler. Another distinguishing feature was the kink in the back of the cab. Later series could be recognized by a steam dome and the straight back of the driver's cab and had a larger service weight.
T 3 of the later variant
Die Lokomotive, June 1924
Production ran from 1882 until after the turn of the century, with over 1,300 units being made for the Prussian State Railways. Others were created for various other operators, including works railways. The Reichsbahn took over 511 of the Prussian locomotives in 1925 and classified them as 89 7001 to 89 7511. The locomotives of the other operators were given numbers from 89 7512, although the numbering was partly interrupted by other types. Although the stock at the Reichsbahn had roughly halved by 1931, a larger number came to both German railways after the war.
The Bundesbahn received about 70 units and used them until 1963. There, the former T 3 shaped the public perception of the typical image of the old, small steam locomotive and thus it shows its silhouette in many places in all kinds of representations, including postage stamps. The original T 3 was used by the Reichsbahn until 1967. A special feature were four engines which were converted to tender locomotives in 1960. The first received a two-axle tender, but the others got a three-axle one, which the first also received in the end. These four locomotives lasted a year longer than the others. The Polish State Railways PKP also took over a total of 23 T 3 and designated them as Tkh1.
In addition to the machines that were formerly delivered to the Prussian state railways, the Reichsbahn of the GDR also took over many locomotives from private and works railways. These became the class 8962, but also received running numbers between 5901 and 6164, as well as 953. The Bundesbahn came into possession of two locomotives from the Schwerte repair shop, which were given the numbers 89 002 and 89 003.