The BNB VIb (six-B) was a class of two branch line tank locomotives of the Bohemian Northern Railway Company (Böhmische Nordbahn-Gesellschaft) for use on the Böhmisch Leipa-Steinschönau railway line. They later passed to the Imperial Austrian State Railways, who classified them as kkStB 265.

BNB VIb
kkStB 265
ČSD 312.7
Type and origin
BuilderErste Böhmisch-Mährische Maschinenfabrik, Prague
Build date1907
Total produced2
Specifications
Configuration:
 • Whyte0-6-2T
Gauge1,435 mm (4 ft 8+12 in) standard gauge
Driver dia.930 mm (36+58 in)
Carrying wheel diameter840 mm (33+18 in)
Wheelbase:
 • Overall4,800 mm (15 ft 9 in)
Length:
 • Over beams9,836 mm (32 ft 3+14 in)
Adhesive weight35.2 t (5.1 long tons; 5.7 short tons)
Empty weight32.3 t (31.8 long tons; 35.6 short tons)
Service weight44.6 t (43.9 long tons; 49.2 short tons)
Fuel capacity4.7 m3 (170 cu ft) of coal
Water cap.7.0 m3 (1,500 imp gal; 1,800 US gal)
Boiler:
No. of heating tubes192
Boiler pressure12 kgf/cm2 (1,180 kPa; 171 lbf/in2)
Heating surface:
 • Firebox1.66 m2 (17.9 sq ft)
 • Radiative6.1 m2 (66 sq ft)
 • Tubes79.6 m2 (857 sq ft)
 • Evaporative85.7 m2 (922 sq ft)
Cylinders2
Cylinder size420 mm (16+916 in)
Piston stroke480 mm (18+78 in)
Loco brakeVacuum brake
Performance figures
Maximum speed45 km/h (28 mph)
Indicated power352 PS (259 kW; 347 hp)
Career
Numbers
  • BNB: 126, 127
  • kkStB: 265.01, 265.02
  • ČSD: 312.701, 312.702
  • DRB: 90 301, 90 302
Retired1949

The two locomotives were built in Prague in 1907 by the Erste Böhmisch-Mährische Maschinenfabrik (later part of ČKD).

The locomotives spent their entire lives on their home line. In 1924 the Czechoslovakian State Railways (ČSD) grouped the engines into their ČSD Class 312.7. After the Second World War the Deutsche Reichsbahn gave them the designation DR Class 90.3.

On the introduction into service of new ČSD Class M 131.1 railcars, these locomotives were retired in 1949.

See also

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References

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  • Hütter, Ingo (2021). Die Dampflokomotiven der Baureihen 60 bis 91 der DRG, DRB, DB, und DR (in German). Werl: DGEG Medien. pp. 462–463. ISBN 978-3-946594-21-5.
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