NZR JB class
Encyclopedia
The NZR
JB class steam locomotives were all originally members of the J class
of 1939. Built by North British Locomotive Works, Scotland
, they all initially burned coal and wore distinctive bullet-like streamlining.
the railways suffered problematic coal shortages, especially in the North Island. Approval was gained to convert 12 of the J class locomotives into oil-burners, to burn heavy fuel oil which was available in plentiful quantities at the time. The conversion saw the installation of a two-nossle burner in the firebox, removal of the grate and ashpan which was replaced with a firepan lined with bricks, shortening of the superheater tubes in the boiler, removal of the spark arrester in the smokebox, removal of the brick arch, addition of the related controls and gauges for the oil burning equipment, and the tender modified to carry an oil bunker and associated steam piping. Similar to the K
and KA
Classes which were converted to oil burning at the same time, the JB Class utilized a separate, removable tank which sat in the former coal space. However, the full-width coal bunker of the J-type's Vanderbilt tender was cut down so that the oil tank was visible at the sides, with distinctive vertical supports below. The conversion process generally coincided with the removal of the streamlining, but not always. Once converted, the locomotives were re-classified JB in recognition of the conversion, however they retained their original J class
numbers.
nor any of the other J variants. Some of the JB Class received cross-compound Westinghouse pumps in place of the twin single-phase pumps, but others did not. The JB Class only ever saw service in the North Island, as in the South Island coal supplies were plentiful. Some years after conversion to oil, the fuel oil being used became considerably dearer than the coal supplies then being sourced, and there was no longer a coal shortage. However re-conversion back to coal burning did not occur due to objections from the various railway Unions.
. In addition, preserved J class
locomotive No.1236 has been restored as a JB class oil burner by its owners Mainline Steam
, although this particular locomotive spent its entire NZR career as a coal-burning J Class. Preserved locomotive J 1211, also owned by Mainline Steam
, has been converted to oil burning in the same manner as the JB Class, but has not been re-classified to reflect that change.
New Zealand Railways Department
The New Zealand Railways Department, NZR or NZGR and often known as the "Railways", was a government department charged with owning and maintaining New Zealand's railway infrastructure and operating the railway system. The Department was created in 1880 and was reformed in 1981 into the New...
JB class steam locomotives were all originally members of the J class
NZR J class (1939)
The NZR J class steam locomotives were a class of locomotive used in New Zealand. Following the success of the K class on NZR main lines, there was an urgent need for a modern, powerful locomotive capable of running over secondary lines laid with lighter rails. Thus a new "Mountain" 4-8-2 type...
of 1939. Built by North British Locomotive Works, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
, they all initially burned coal and wore distinctive bullet-like streamlining.
Conversion to oil burning
After World War IIWorld War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
the railways suffered problematic coal shortages, especially in the North Island. Approval was gained to convert 12 of the J class locomotives into oil-burners, to burn heavy fuel oil which was available in plentiful quantities at the time. The conversion saw the installation of a two-nossle burner in the firebox, removal of the grate and ashpan which was replaced with a firepan lined with bricks, shortening of the superheater tubes in the boiler, removal of the spark arrester in the smokebox, removal of the brick arch, addition of the related controls and gauges for the oil burning equipment, and the tender modified to carry an oil bunker and associated steam piping. Similar to the K
NZR K class (1932)
The NZR K class of 1932 was a class of mixed traffic 4-8-4 steam locomotives that operated on New Zealand's railway network. The locomotives were developed following the failure of the G class Garratts...
and KA
NZR Ka class
The NZR KA class of 1939 was a class of mixed traffic 4-8-4 steam locomotives that operated on New Zealand's railway network. They were built after the success of the K class to meet the increasing traffic demands of the New Zealand Railways Department...
Classes which were converted to oil burning at the same time, the JB Class utilized a separate, removable tank which sat in the former coal space. However, the full-width coal bunker of the J-type's Vanderbilt tender was cut down so that the oil tank was visible at the sides, with distinctive vertical supports below. The conversion process generally coincided with the removal of the streamlining, but not always. Once converted, the locomotives were re-classified JB in recognition of the conversion, however they retained their original J class
NZR J class (1939)
The NZR J class steam locomotives were a class of locomotive used in New Zealand. Following the success of the K class on NZR main lines, there was an urgent need for a modern, powerful locomotive capable of running over secondary lines laid with lighter rails. Thus a new "Mountain" 4-8-2 type...
numbers.
The JB Class in service
In service the JB class performed well, but did not distinguish themselves above the unconverted J classNZR J class (1939)
The NZR J class steam locomotives were a class of locomotive used in New Zealand. Following the success of the K class on NZR main lines, there was an urgent need for a modern, powerful locomotive capable of running over secondary lines laid with lighter rails. Thus a new "Mountain" 4-8-2 type...
nor any of the other J variants. Some of the JB Class received cross-compound Westinghouse pumps in place of the twin single-phase pumps, but others did not. The JB Class only ever saw service in the North Island, as in the South Island coal supplies were plentiful. Some years after conversion to oil, the fuel oil being used became considerably dearer than the coal supplies then being sourced, and there was no longer a coal shortage. However re-conversion back to coal burning did not occur due to objections from the various railway Unions.
Withdrawal and disposal
Some members of the JB Class were among the first of the J 4-8-2 types to be withdrawn, due to the faster wear and tear suffered by the locomotives as a result of oil burning. The last of the class was withdrawn from service by March 1968, by which time steam haulage in the North Island had essentially finished anyway. All of the class were scrapped, although many items from the locomotives were retained as spares for the other J type locomotives still in service in the South Island.Preservation
None of the JB Class were Preserved. However, the tender from JB 1203 is held by Steam IncorporatedSteam Incorporated
Steam Incorporated, often abbreviated to Steam Inc., is a railway heritage and preservation society based at the Paekakariki Railway Station, Paekakariki at the southern end of the Kapiti Coast, approximately 50 minutes north of Wellington on the west coast of New Zealand's North Island. Unlike...
. In addition, preserved J class
NZR J class (1939)
The NZR J class steam locomotives were a class of locomotive used in New Zealand. Following the success of the K class on NZR main lines, there was an urgent need for a modern, powerful locomotive capable of running over secondary lines laid with lighter rails. Thus a new "Mountain" 4-8-2 type...
locomotive No.1236 has been restored as a JB class oil burner by its owners Mainline Steam
Mainline Steam
Mainline Steam is a New Zealand organisation devoted to the restoration and operation of historic New Zealand Railways mainline steam locomotives. Regular day excursions and multi-day tours are operated over rail lines throughout New Zealand...
, although this particular locomotive spent its entire NZR career as a coal-burning J Class. Preserved locomotive J 1211, also owned by Mainline Steam
Mainline Steam
Mainline Steam is a New Zealand organisation devoted to the restoration and operation of historic New Zealand Railways mainline steam locomotives. Regular day excursions and multi-day tours are operated over rail lines throughout New Zealand...
, has been converted to oil burning in the same manner as the JB Class, but has not been re-classified to reflect that change.