Side portrait of the "Mother Bear" 46 03 resting at the Podkova station. The 46 03 is a standard gauge superheated simple-expansion locomotive. The 3rd and 4th axles have flangeless wheels. The 46 class was designed to haul heavy coal trains on steep mountain gradients which they did very successfully. The locomotives of the 46 class appear to be the most powerful steam locomotives built in Europe. Remarkably, the 46 03 has been preserved and restored to working order. Two batches of the 46 class were built, with some significant differences. The first batch of 12 engines was built in 1931 by Cegielski in Poznan (Poland). These had two cylinders of 700 mm diameter. The second batch of 8 was built by Schwartzkopff in Berlin. These locomotives had three cylinders of 550 mm diameter.