Bulgarian State 0-10-0 Locomotives in Bulgaria

Class 49 Vers 1 (Locobase 1602)

[] (viewed 18 July 2003) for information and some date. (Other data from Durrant, 1966). The principal difference between the two classes, according to Trifonov, was this early group's smaller tanks. However, the data suggest that the Schwartzkopff batch (Locobase 1603) were an altered version of this design in several respects. In this first group, the boiler was larger but the grate smaller.

In both, the rigid wheelbase of 9 ft 2 in (2.8 m) was the same.

Class 49 Vers 2 (Locobase 1603)

[] (viewed 18 July 2003) for data and information. Firetube diameter is inner dimension.

Trifonov says that the rigid wheelbase (the 2nd to 4th driving axles) was 9 ft 2 in (2.8 m). Although Trifonov does not say so, the data shows a changed design from the earlier batch supplied by Hanomag (See Locobase 1602). In this later class, the boiler's smaller, the grate is larger and the adhesion weight has grown as well.

Class 500/28.001 (Locobase 1596)

Data from [] (viewed 18 July 2003). See also "Bulgarian Railway Locomotives," Railway Engineer, Volume 33, No. 12 (December 1912), pp. 386-388.

Based on Golsdorf's heavy freight designs, this class came in two versions, both of which were later superheated and refitted with poppet valves. This entry refers to the first 20 locomotives that were delivered in three batches: seven from Maffei in 1909, seven from Hohenzollern in 1910, and the last six from Hanomag in 1911. The plate frames held Golsdorf bearings, which allowed lateral play of 26 mm to either side in the first, third, and fifth axles. Possibly because of the lateral play, the valve gear was set back over the second axle, which was rigid.

The RE report commented that the low compounding ratio (2.3:1) suggested to the Bulgarian author that it was not "calculated for very high steam and coal economy."

All but one were renumbered by BDZ in 1936, 28.01-28.18 and, oddly, 507 redesignated 28.80.

Class 521/28.019 (Locobase 5659)

Data from [] (viewed 18 July 2003). See also L Renewal, "The Railways of Bulgaria", Cassier's Engineering Monthly, Volume 52, No 1 (July 1917), pp. 13-24 , esp Table of Principal Dimensions, p. 15.

Obviously the 1909 Goldsdorf 0-10-0s (501-520)--Locobase 1596-- were not big enough, so the bulk of the class had slightly larger cylinders and a bigger boiler. Only a few were retired before the 1936 renumbering, when these engines were designated 28.19 to 28.83.

Like the 501s, these were converted to a two-cylinder simple design using 600-mm (23.62") HP cylinders and 32 superheater flues of 5.24" (133 mm) diameter. Trifonov doesn't give the superheater heating surface area.

Class 94/35/50 (Locobase 5667)

[] (viewed 18 July 2003) for information. Tube diameters are inner dimension.

The rigid wheelbase was 9 ft 6 in (2.9 m). These tanks were procured for helper service on passenger and freight trains. Apparently the class was not ready when the engines were delivered because they were overhauled in the Karlowag-Varna factory first. In terms of tractive effort, they should have been suitable, but they were very short-winded and had undersized coal and water bunkers. So they served most of their 58 years as heavy switchers.