After the introduction of the J class locomotives in 1940 it became apparent that they were not only a good all-round engine, but capable of very fast running.
- Locomotive running number: Ja1271
- Designed by: New Zealand Railways
- Built at: NZR Hillside workshops, Dunedin
- Date built: 1956
- Builders number: 394/56
- Date entered service: April 1956
- Date withdrawn: 16 November 1971
- Returned to heritage operation: October 1997
- Current condition: Certified for operation on the national Network
JA1271 on its first day in Steam.
- Wheel arrgt: 4-8-2
- Driving wheel dia: 54 inches
- Cylinders: 18 inches Dia. 26 inches Stroke
- Valve gear: Baker, 9½ inch dia inside admission piston valves
- Working pressure: 200 psi
- Weight in working order: 110 tons
- Overall length: 67 feet
- Tractive effort: 26,520 pounds @ 85% boiler pressure
- Fuel: Coal (hand fired)
- Capacities: Fuel, 6 tons. Water, 4000 gallons.
There are numerous instances of the J class being recorded at sustained speeds of 70 miles per hour (and reputedly more) when hauling the South Island Limited across the Canterbury Plains south of Christchurch.
For an engine with 56 inch driving wheels this results in a rotational speed of 360 revolutions a minute or 6 revolutions a second. Quite an achievement for the 3 foot 6 inch gauge and a locomotive, that by world standards, falls in the "mixed traffic" class. In fact their driving wheels are smaller than those of many locomotives overseas considered to be freight engines.
As a result of these exploits, and the resulting wear and tear, various experiments were carried out with different forms of lubrication for the side rod bushes. Oil, soft grease and hard grease were all tried.
Ja1271 restoration and rebuild.
When additional locomotives were required these were initially built at Hillside and incorporated roller bearings on the connecting rod big end and the side rod on the driving wheel crank pin. The first in this series (Ja1240) was the subject of much experimentation by the NZR engineers. Both Timken taper roller and SKF spherical roller bearings were tried and when Ja1250 was built the connecting rod big end and all the side rod bearings except the intermediate crank pin incorporated SKF spherical roller bearings. The intermediate crank pins retained a plain bronze bush to prevent the side rods tilting over as allowed by the spherical bearings on the other pins.
Ja1271 was also one of the batch constructed at Hillside fully equipped with roller bearings. Every bearing on all the axleboxes, valve gear pins, side rods and connecting rods except for the crosshead pin and intermediate crank pin are either spherical rollers or needle bearings. This produces a very friction free and quiet running engine requiring the minimum of greasing and preparation time. The Ja class are very similar to the J class, employing the same frames, boiler, cylinders, wheels and the same basic motion arrangement except for the roller bearings. There are however major differences in the copper pipe layouts, to reduce costs, and some cab fittings are different. The Ja's were never streamlined.
Ja1271 was allocated to Invercargill depot and spent its entire working life there. Although taking its share of freight work, it was often to be found on the South Island Limited working as far north as Dunedin. It was only ever recorded twice as having travelled north of that town when in NZR service. The engine had a relatively short working life; being involved in a collision in October 1970 when it was withdrawn from service considered uneconomic to repair. It was officially written off in November 1971, having run only some 416,000 miles, and from then until December 1976 it served as the hot water washout boiler at Dunedin locomotive depot. It was sold to Steam Incorporated in March 1978 and subsequently towed to Paekakariki.
There was a confident expectation at the time that it would be running within two years but because of the damaged and incomplete state of the locomotive, it soon became apparent that its restoration was to become a long term project and the Society concentrated it's efforts on more pressing matters. Long before the acquisition of most of the missing parts, or the accumulation of sufficient funds to complete the restoration, it was decided that the restoration would be done to the highest standard achievable, and that the locomotive would be coal fired.
On its arrival at Paekakariki the locomotive presented a somewhat sorry sight. The left hand end of the motion bracket was completely missing, having sheared off flush with the frame in the collision. With it had disappeared the slidebars, the Baker gear frame, other valve gear components, the crosshead, and part of the running board. The headlight was missing and there were no connecting rods on either side. Having stood outside in the weather for several years the boiler cladding had suffered from the effects of corrosion and the engine had a distinct brown tinge, rather than the customary black.
Ja1271 at Paekakariki 2013.
The locomotive was eventually stripped to the bare frames with cylinders attached and the long job of restoration commenced. Wherever possible all welding, riveting, machining, repair and fitting was carried out by Society members. The only work carried out by commercial contractors or other organizations were those that required machine tools or facilities not possessed by the Society. The principal items contracted out were the manufacture of the new motion bracket, manufacture of the new left hand slide bars, welding of the firebox patches and other boiler welding where a certified operator was required, manufacture of new castings for pistons, valves, valve liners, ring drums and one new main steam pipe, manufacture of new coupling rod knuckle pins and bushes, the installation of new roller bearings on the four driving axles, re-grinding and quartering of the crank pins, manufacture of two new auxiliary main air reservoirs, complete overhaul of all engine and tender leaf springs, and manufacture of the special perforated plate for the cage spark arrester.
Because the locomotive had originally been built using available spare parts, and its last workshop repairs occurred during the last years of steam, some details of its construction varied somewhat from the official NZR drawings for the Ja class. Some aspects of it, particularly the front bogie, were an odd combination of J and Ja design. This, combined with the fact that some of the parts obtained to replace the missing components came from other locomotives, entailed a degree of re-design and manufacture of new parts to complete the assembly. This was particularly applicable to the crank pin bearings on the driving axle which are now a completely new hybrid arrangement. Wherever possible the locomotive has been restored to authentic Ja appearance.
In the course of the work it became apparent that for some jobs special jigs and tools would be desirable to ensure consistency of dimensions, to enable work to be done by less than skilled workers, or simply to obtain the advantages of using modern technology where appropriate. For example; a machining fixture was made so that all the bogie spring hangers could be re-machined to the same length; the removal and replacement of the many roller bearings was expedited by making several sizes of hydraulic nuts to fit the various bearing sleeves; special pressing-in plates were made to correctly locate the side rod roller bearings so that no measurement was required.
Once stripped to its bare bones the frames were leveled and aligned, keep plates fitted and the new motion bracket accurately located and fitted. All liner surfaces were re-ground and the driving axle centre line accurately located. All frame mounted pivot points for suspension and brake gear were re-bushed and new case hardened pins fitted. The cylinders were re-bored, new valve liners made and fitted and new valves and pistons made. Re-alignment of the cylinders and motion work was made relatively easy once the frames were cleaned down and the original centre line marks found on the frames.
In common with most steam locomotive restorations, the boiler was the biggest single item. Repairs entailed considerable patching of the inner firebox, re-riveting of the foundation ring, cutting, swaging, and installing a complete set of new tubes & flues, manufacture and installation of around 200 new stays, installation of new staycups, manufacture and installation of a new dry pipe, fitting a new superheater header, manufacture of a half set of new superheater elements, and repair of the other half, manufacture and installation of a new ashpan, grate and brick arch. A complete set of new boiler cladding was made and all of the boiler mountings completely overhauled.
All the engine and tender bogies were completely stripped, repaired and squared up. Hardened steel liners were made and fitted to the axlebox guides and, where required, new roller bearings were fitted before re-assembly.
Two spare but brand new sets of Baker valve gear, purchased from NZR several years previously, were fitted to the motion bracket and this saved a considerable amount of repair work. The rest of the motion work was completely rebuilt including a redesigned main crank pin bearing arrangement that was required because the connecting rods (from another engine) required a different size of bearing from that needed to match the crank pins.
Most of the large copper pipe work, strangely, was still on the engine when it arrived, so these only needed softening and re-fitting. All of the small copper pipes in the cab were replaced with new material, as was the severely corroded steel brake piping.
Work in the "auxiliaries" department included a complete overhaul of air reverser, overhaul of the Sellars lifting and Davies & Metcalfe exhaust steam injectors, manufacture of new sections of running boards, a new cab floor, new front cowls and new cab window frames. In the smokebox a new cage-type spark arrester was fitted and the attendant modifications made to the funnel and blast pipe.
The brake gear required the manufacture of some new parts, and overhaul of the brake cylinders. The cross-compound air compressor was completely rebuilt, requiring manufacture of new pistons, rings and piston rods. The piston rods were subsequently hard chrome plated and ground to prevent corrosion when out of use, and the packings modified to improve steam and air sealing. All the Westinghouse brake equipment (brake valves, brake stand, feed valves, distributor and compressor governor) were completely rebuilt.
The electrical system was similarly treated, entailing complete re-building of the steam turbo-generator, headlights, conduits, fittings and renewal of all electrical wiring. A radio, data logger, battery and battery charger were fitted in the cab.
In the tender there was much replacement of steel plate in the bunker and water spaces. Ground level water filler pipes were installed together with a pneumatic water contents gauge in the cab to avoid the need to climb on the tender to determine the water level. At the front end of the underframe a lot of the corroded steel work was replaced including a new headstock and subsequent re-riveting of the dragbox.
The locomotive operated under its own power for the first time in 26 years on 11th October 1997 when it made several runs up and down the yard at Paekakariki. Less than two weeks later it ran in steam, light engine, the 39km to the locomotive depot in Wellington, where the locomotive was weighed and the connecting rods removed. That night it crossed Cook Strait and the following day was towed to Christchurch. On 24th October it hauled its first excursion train the 593km from Christchurch to Invercargill and was subjected to its official load test on the way. On the rising gradient south of Dunsandel it generated a rail power output in excess of 1200 horsepower while, to those on the footplate, not seeming too bothered by the effort.
Ja1271 in regular excursion train service. 1271 has had a longer working life for Steam Incorporated than for NZR.
It was expected that some deficiencies would reveal themselves during the four days of running. However, apart from the inevitable minor steam leaks, the odd nuts that worked loose, and air leaks in the smokebox there were few faults. Almost without exception these could be dealt with during the normal servicing stops, or fixed overnight. However the locomotive was in exceptionally sound working order and a welcome addition to the small fleet of main line certified steam locomotives in New Zealand.
The original aim of Steam Incorporated had been to carry out a thorough and complete restoration of a main line steam locomotive. We believe that this was achieved and the locomotive was expected to give at least 10 years mainline service completely free of any major maintenance work. It is estimated that the total cost of the project was of the order of NZ$300,000. Of this, NZ$40,000 was received from the NZ Lotteries Grants Board, some NZ$5,000 came from miscellaneous grants and donations, and the remainder was raised entirely by the Society from its excursion train operations.
In 1998 Steam Incorporated was awarded the A & G Price Restoration Award, for the second time, for their efforts in restoring Ja1271 for main line operation.
Ja1271 has since been used for many excursions in the North and South Islands. With Da1431 and Ab608, they form the society's current main line operational locomotive fleet.
Apart from renewing the valve liners, re-tubing the boiler in 2006, and replacing the flues in 2011, very little major work has been required to keep the locomotive in operational order.