The Bengal Nagpur Railway class NM was a class of ten 4-8-0+0-8-4 Garratt locomotives manufactured by Beyer, Peacock & Company in England. This was modified N class Garratt. It had Thermic siphon and arch tubes for better performance. It worked on the Bilaspur-Katni line and Anuppur-Chirmiri branch line for hauling coal. Probably because of Poppet valves, they retired early.[1]

Class NM
Type and origin
Power typeSteam
BuilderBeyer, Peacock & Company
Serial number6705–6714
Build date1931
Total produced10
Specifications
Configuration:
 • Whyte4-8-0+0-8-4
Gauge5 ft 6 in (1,676 mm)
Driver dia.4 ft 8 in (1.422 m)
Axle load17.5 long tons (17.8 t)
Adhesive weight138.55 long tons (140.77 t)
Loco weight204.15 long tons (207.43 t)
Fuel typeCoal
Fuel capacity8 long tons (8.1 t)
Water cap.6,000 imp gal (27,000 L; 7,200 US gal)
Firebox:
 • Grate area67.6 sq ft (6.28 m2)
Boiler pressure210 psi (1.45 MPa)
Heating surface2,961 sq ft (275.1 m2)
Superheater:
 • Heating area642 sq ft (59.6 m2)
CylindersFour, outside
Cylinder size20 in × 26 in (508 mm × 660 mm)
Valve gearLentz or Caprotti
Valve typePoppet
Performance figures
Tractive effort69,660 lbf (309.86 kN)
Career
Operators
Numbers
  • BNR: 826–835
  • →IR: 38826–38835
LocaleEast Central Railway zone
First run1931
Last run1960
Withdrawn1960
Preserved0
Scrapped1960
DispositionScrapped
Technical specifications
Boiler diameter 7 ft 1+1316 in (2.18 m)
Heating surface of firebox 330 sq ft (31 m2)
Maximum train load 3,000 long tons (3,000 t) on level track

References

edit
  1. ^ "5brinkster". Archived from the original on 2013-10-23.