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DRG Class 99.21
The plinthed 99 211
Type and origin Power type Steam Builder Henschel & Sohn Serial number 21442 Build date 1929 Total produced 1
Specifications Configuration: ​  • Whyte 0-6-0T  • UIC C n2t  • German K 33.6 Gauge 1,000 mm (3 ft 3+3⁄8 in) Driver dia. 800 mm (2 ft 7+1⁄2 in) Wheelbase: ​  • Axle spacing (Asymmetrical) 1,000 mm (3 ft 3+3⁄8 in) + 1,000 mm (3 ft 3+3⁄8 in) =  • Engine 2,000 mm (6 ft 6+3⁄4 in) Length: ​  • Over headstocks 5,500 mm (18 ft 1⁄2 in)  • Over buffers 6,400 mm (21 ft 0 in) Height 3,200 mm (10 ft 6 in) Axle load 6.1 tonnes (6.0 long tons; 6.7 short tons) Adhesive weight 18.3 tonnes (18.0 long tons; 20.2 short tons) Empty weight 14.8 tonnes (14.6 long tons; 16.3 short tons) Service weight 18.3 tonnes (18.0 long tons; 20.2 short tons) Fuel type Coal Fuel capacity 600 kg (1,300 lb) Water cap. 1.8 m3 (396 imp gal; 476 US gal) Firebox: ​  • Grate area 0.60 m2 (6.5 sq ft) Boiler: ​  • Pitch 1,850 mm (6 ft 7⁄8 in)  • Tube plates 2,550 mm (8 ft 4+3⁄8 in)  • Small tubes 41.5 mm (1+5⁄8 in), 90 off Boiler pressure 14 bar (14.3 kgf/cm2; 203 psi) Heating surface: ​  • Firebox 2.66 m2 (28.6 sq ft)  • Tubes 26.40 m2 (284.2 sq ft)  • Total surface 29.06 m2 (312.8 sq ft) Cylinders Two, outside Cylinder size 310 mm × 400 mm (12+3⁄16 in × 15+3⁄4 in) Valve gear Heusinger (Walschaerts) Train brakes Knorr compressed air Parking brake Counterweight brake
Performance figures Maximum speed 40 km/h (25 mph) Indicated power 140 PS (103 kW; 138 hp)
Career Numbers 99 211 Locale Wangerooge Delivered 1929 Retired 1960 Disposition Preserved, on static display

Built in 1929 by German locomotive builder Henschel & Son, the Deutsche Reichsbahn Class 99.21 was a unique narrow gauge 0-6-0T steam tank locomotive built for the Wangerooge Island Railway on Wangerooge, one of the German-owned Friesian islands in the North Sea.

For hauling eight-wheeled passenger coaches a more powerful locomotive was needed. After the procurement of diesel locomotives in 1958 she remained for a time as a reserve engine. She carried number 99 211.

Today the locomotive is restored and is displayed as a monument on Wangerooge.

The inner frame of the locomotive was also used as a water tank. She was designed as a saturated steam locomotive. The boiler had two shell rings and 90 heating tubes. The drive was achieved via a Walschaerts valve gear driving the third axle. The wheels on the centre axle were made without flanges to improve curve running.

The engine could hold 0.6 tonnes of coal in side tanks either side of the boiler, and 1.8 m³ of water in the frame and in an attachment to the coal bunker. The engine was first equipped with electrical lighting in 1953.

• List of DRG locomotives and railbuses

• Werning, Malte (1999). Wangerooge: Die Inselbahn und ihre Geschichte. Gülzow: Lokrundschau Verlag. ISBN 3-931647-09-9.
• Weisbrod, Manfred; Petznik, Wolfgang (1981). Dampflokomotiven deutscher Eisenbahnen, Baureihe 97–99 (EFA 1.4) (in German) (2nd ed.). Düsseldorf: Alba. pp. 131–133, 207. ISBN 3-87094-087-5.