Baden IX b

The Baden Class IX b were German rack railway steam locomotives with the Grand Duchy of Baden State Railways, whose cogwheel drive was designed for running on track with a Riggenbach rack system.

Baden IX b DRG Class 97.2
Baden 371 (Maschinenfabrik Esslingen 3546 of 1910)
Number(s)	DRG 97 201–204, 251–253
Quantity	7
Manufacturer	Maschinenfabrik Esslingen
Year(s) of manufacture	1910 (4), 1921 (3)
Retired	mid-1930s
Wheel arrangement	0-6-2T
Axle arrangement	C1′ n2(4v)zt
Track gauge	1,435 mm (4 ft 8 1⁄2 in)
Length over buffers	10.900 m (35 ft 9 1⁄4 in)
Height	4,248 mm (13 ft 11 1⁄4 in)
Overall wheelbase	5,050 mm (16 ft 6 3⁄4 in)
Empty weight	45.3–45.6 tonnes (44.6–44.9 long tons; 49.9–50.3 short tons)
Service weight	56.7–57.0 tonnes (55.8–56.1 long tons; 62.5–62.8 short tons)
Adhesive weight	42.8 tonnes (42.1 long tons; 47.2 short tons)
Axle load	14.3 tonnes (14.1 long tons; 15.8 short tons)
Top speed	Adhesion: 45 km/h (28 mph) Rack: 18 km/h (11 mph)
Driving wheel diameter	1,080 mm (3 ft 6 1⁄2 in)
Trailing wheel diameter	850 mm (2 ft 9 1⁄2 in)
Rack system	Riggenbach rack system
Valve gear	Heusinger (Walschaerts)
No. of cylinders	4
Cylinder bore	450 mm (17 11⁄16 in)
Piston stroke	550 mm (21 5⁄8 in)
Cogwheel drive cylinder bore	450 mm (17 11⁄16 in)
Cogwheel drive piston stroke	550 mm (21 5⁄8 in)
Boiler Overpressure	14 bar (1.40 MPa; 203 psi)
No. of heating tubes	178
Heating tube length	3,200 or 3,850 mm (10 ft 6 in or 12 ft 7 1⁄2 in)
Grate area	1.8 m2 (19 sq ft)
Radiative heating area	8.2 m2 (88 sq ft)
Tube heating area	89.43 or 107.5 m2 (962.6 or 1,157.1 sq ft)
Superheater area	25.15 m2 (270.7 sq ft)
Evaporative heating area	97.59–115.7 m2 (1,050.5–1,245.4 sq ft)
Water capacity	5,000 litres (1,100 imp gal; 1,300 US gal)
Fuel	Coal: 1.5 tonnes (1.5 long tons; 1.7 short tons)

The locomotive was produced in two sub-classes, which were designated as IX b¹ and IX b². In 1925 they were grouped by the Deutsche Reichsbahn as DRG Class 97.2 within their renumbering plan. The engines were employed on the Höllentalbahn in the Black Forest until they were eventually and later replaced by DRG Class 85 locomotives.