BNR class P

The Bengal Nagpur Railway class P was a class of four 4-8-2+2-8-4 (“Double Mountain”) Garratt locomotives. It was developed from BNR class N and BNR class NM. The Anuppur-Chirmiri section had severe curves and it needed an engine with a trailing bogie. Its boiler was slightly enlarged similar to the NM.

BNR Class P
Type and origin Power type Steam Builder Beyer, Peacock & Company Serial number 6931–6934 Build date 1939 Total produced 4
Specifications Configuration: ​  • Whyte 4-8-2+2-8-4 Garratt  • UIC (2′D1′)(2′D1′) h4t Gauge 5 ft 6 in (1,676 mm) Driver dia. 4 ft 8 in (1.422 m) Axle load 17 long tons (17 t) Loco weight 230 long tons (230 t) Fuel type Coal Fuel capacity 10 long tons (10 t) Water cap. 7,500 imp gal (34,000 L; 9,000 US gal) Firebox: ​  • Grate area 70 sq ft (6.5 m2) Boiler pressure 210 psi (1.45 MPa) Superheater: ​  • Heating area 661 sq ft (61.4 m2) Cylinders Four, outside Cylinder size 20+1⁄2 in × 26 in (521 mm × 660 mm)
Performance figures Tractive effort 69,655 lbf (309.84 kN)
Career Operators Bengal Nagpur Railway →Indian Railways Numbers BNR: 855–858 →IR: 38855–38858 Locale East Central Railway zone First run 1939 Disposition Scrapped

It could haul 1,500 long tons (1,500 t) load up a 1 in 91 gradient.

Technical specifications

Boiler diameter	7 ft 1+13⁄16 in (2.180 m)
Heating area in firebox	330 sq ft (31 m2)
Boiler area	3,120 sq ft (290 m2)
Adhesive weight	136 tonnes
Maximum train load	3165 tonnes on level track