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Ja Class
CLASS  Ja    4-8-2

Introduced: 1946 Number in Class: 51

Ja Class Register

Photo : Mainline Steam

Locomotive Specifications

  1.  NZR Hillside (35)
  2.  North British Locomotive Works, Glasgow, Scotland (16)

Engine Weight:    69.1 tons Tender Weight:    
40.35 tons
Total Weight:    
109.45 tons
Adhesive Weight:    
44.75 tons
Length over Buffers:    
66' 11"
Total Wheelbase:    58' 0" Engine Wheelbase:    
33' 1"
Coupled Wheelbase:    14' 3"
Tender Wheelbase:    
15' 10"
Driver Wheel Dia.:    54" Cylinders HP:    
Two - 18" x 26"
Cylinders LP:    
Grate Area:    39.0 sq ft Evaporative Area:    
1469 sq ft
Superheated Area:    
283 sq ft
Working Pressure:    
200 psig
Tractive Effort:    
24960 lbs f
Coal Capacity:    6.0 tons Oil Capacity:     Water Capacity:    
4000 gals

Remarks:     Unlike the 'J's, the 'Ja's were built without streamlining. At the outset they were fitted with cross-compound air compressors, and most were equipped with roller bearings on all excpet one pair of crank pins. These locomotives became the mainstay of South Island operations and were rated to haul 1000 ton freight and 400 ton passenger trains on easy grades. Sixteen North British 'Ja's were built as oil-burners, and 35 built by NZR Hillside 1946-56 with similar data to 'J' class. 'Ja's were originally classified as a NZ built 'J' but an additional 16 were ordered from and supplied by North British. Both 'J' and 'Ja' classes were very successful engines fitting in between the 'Ab' and the 'K'.

Preserved Locomotives
  Mainline Steam,    Auckland -     Ja 1240,     NZR Hillside #363   Operating
  Glenbrook Vintage Railway,    Auckland -     Ja 1250 "Diana",     NZR Hillside #373   Operating
  Plains railway,    Tinwald -     Ja 1260,     NZR Hillside #383   Operating
  Mainline Steam,    Auckland -     Ja 1267,     NZR Hillside #390   Stored
  Steam Incorporated,    Paekakariki -     Ja 1271,     NZR Hillside #394   Operating
  Otago Settlers Museum,    Dunedin -     Ja 1274,     NZR Hillside #397   Display
  Mainline Steam,    Auckland -     Ja 1275,     North British #27104