DR Class 22

The steam locomotives of DR Class 22 were reconstructed passenger train locomotives in service with the Deutsche Reichsbahn in East Germany after the Second World War.

DR Class 22
Number(s)	22 001 – 22 085
Quantity	85
Manufacturer	RAW Meiningen
Year(s) of manufacture	1958–1962
Retired	1971
Wheel arrangement	2-8-2
Axle arrangement	1′D1′ h3
Type	P 46.18
Track gauge	1,435 mm (4 ft 8 1⁄2 in)
Length over buffers	23,700 mm (77 ft 9 in)
Service weight	107.5 tonnes (105.8 long tons; 118.5 short tons)
Adhesive weight	74.0 tonnes (72.8 long tons; 81.6 short tons)
Axle load	18.7 tonnes (18.4 long tons; 20.6 short tons)
Top speed	110 km/h (68 mph)
Indicated Power	1,690 PS (1,240 kW; 1,670 hp)
Driving wheel diameter	1,750 mm (5 ft 8 7⁄8 in)
Leading wheel diameter	1,000 mm (3 ft 3 1⁄4 in)
Trailing wheel diameter	1,100 mm (3 ft 7 1⁄4 in)
Valve gear	outside valve gear with Winterthur slide
No. of cylinders	Three
Cylinder bore	520 mm (20 1⁄2 in)
Piston stroke	660 mm (26 in)
Boiler Overpressure	16 bar (1.60 MPa; 232 psi)
No. of heating tubes	112
No. of smoke tubes	36
Heating tube length	5,700 mm (18 ft 8 1⁄2 in)
Grate area	4.23 m2 (45.5 sq ft)
Radiative heating area	21.3 m2 (229 sq ft)
Tube heating area	185 m2 (1,990 sq ft)
Superheater area	83.80 m2 (902.0 sq ft)
Evaporative heating area	206.30 m2 (2,220.6 sq ft)
Tender	2′2′ T 32/34 (22 001 with 2′2 T30 from 25 001)
Water capacity	2′2′ T 32: 32.0 m3 (1,130 cu ft) or 32,000 litres (7,000 imp gal; 8,500 US gal) 2′2′ T 34: 34.0 m3 (1,200 cu ft) or 34,000 litres (7,500 imp gal; 9,000 US gal) 2′2′ T 30: 30 m3 (1,100 cu ft) or 30,000 litres (6,600 imp gal; 7,900 US gal)
Fuel	Hard coal: 10 tonnes (9.8 long tons; 11 short tons)
Train heating	Steam
Features	22 001 was given a Knorr feedwater heater and Riggenbach counter-pressure brake instead of the MV equipment

These engines were rebuilt from DRG Class 39.0-2 locomotives and appeared between 1958 and 1962 as part of the reconstruction programme. The latter had a significant problem: the boiler did not generate enough steam and the steam pipes were too winding, which considerably reduced the maximum power of the engine. A total of 85 examples were equipped with a new combustion-chambered boiler with an IfS mixer-preheater. The locomotive frame had to be extended to accommodate the new engine. The wider outer firebox meant that the driver's cab needed a modified rear wall. The locomotives were given operating numbers 22 001–085 and were mainly homed in the Reichsbahn divisions of Dresden and Erfurt.

The DR employed the locomotives on heavy express train duties in the schedules for the DRG Class 01, which led to overloading of the original components (frame cracks, piston damage). As a result, early retirement followed. In 1968, 50 of the 85 Reko boilers from the Class 22 were used for the reconstruction of the DRG Class 03.

In 1970 the engines were allocated to Class 39 under the DR's new computerised numbering scheme. However, in 1970 only a few machines were still working, at Halberstadt and Saalfeld. In 1971 the last one was withdrawn. Up to the early 1990s, nine engines were used as steam generators.

The vehicles were equipped with 2'2' T 32 or 2'2' T 34 tenders.