Prussian T 3 - Design

Design

The T 3's had a wet steam engine with two cylinders that drove the centre coupled axle. The slide valves were worked by an outside Allan valve gear. The water supply was stored in a well tank between the frame under the boiler; the coal bunkers were on the left and right hand side of the firebox. In front of each one was a filler pipe for the water tank.

The springs on both front axles were linked with compensating levers, which were located above the running plate.

The early T 3's did not have a steam dome, but were equipped with a regulator housing on top, from which the admission pipes led directly to the cylinders outside the boiler. The axle load of this locomotive was about 10 t (see first photo).

Later batches (from 1887) had a steam dome, and the admission pipes were located in the smokebox. Due to the addition of the steam dome, the location of the sand box and sanders were changed. In addition the quantities of water and coal that could be carried were increased. The back wall of the cab was now straight and the lower section no longer sloped. The length over buffers increased from 8,300 mm to 8,591 mm, the axle load rose to 11 t (see second photo).

From 1903 the supplies were increased again and the T 3 could now carry 5 m³ of water and 1.9 t of coal. The axle load of this "strengthened standard class" or "Standard class (6t)" (Normalbauart (6t)) was 12 t.