(This statement originally appeared in the 1894 NZ Official Year Book and again in 1924).
Railways in Economic History
Economic historians have attributed a major part of economic growth in many countries in the nineteenth century to the advent and expansion of mechanical transport in the form of the railway. Railways made possible the cheaper transport of bulky goods to markets; their speed allowed perishable goods to be marketed; their reliability cut the need to hold large stocks as a precaution against irregular deliveries; they opened up new sources of supply for raw materials; and the skills developed in the design, construction and operation of the rail systems provided "spin off" to other sectors of the economy.
New Zealand’s early colonists from Britain came from a society which had experienced a railway boom and in which railways had become an accepted technology. (Railway construction in the United Kingdom peaked in 1847). They undoubtedly recognised intuitively if not explicitly the range of benefits a rail system would bring, and the introduction of steam locomotives to the colony is in the context not surprising.
Southland’s and Canterbury’s first locomotives were imported in 1863 and, in the North Island, the pioneer railway in Auckland started its brief life in 1866. An important rail-link between Christchurch and its port Lyttelton was completed in 1867 with the opening of a one and a half mile tunnel through the hills of Banks Peninsula. These provincial railways opted for different gauges and only 46 miles of track were operational when Julius Vogel became Treasurer of the central Wellington Government in 1869.
It was in his second financial statement in June 1870 that Vogel unveiled the grand plan with which the ‘Think Big’ set of energy decisions made in 1979/80 has been compared. Vogel’s plan was apparently more modest, he proposed to borrow 10 million pounds. He was keen to promote the settlement of his country and saw the Colony as wanting Public Works in the shape of roads and railways and immigration. While one Island (the South) was tolerably provided with ordinary roads, both were deficient in railways. He thought that the railways in each Island should be designed and constructed as part of a trunk line and should be no more expensive than necessary. In America ‘revenue railways’ were built "in the manner precisely suited to the traffic" and these were improved as increasing traffic demanded. A moderate speed was regarded as adequate, and expensive stations could be done without. These were his models.
Seven million pounds and the revenue from the sale of two and a half million acres of land would provide 1500 or 1600 miles of railway. Further land could be set aside for the railways and would increase in value as they were built. Its lease or sale would provide revenue for the repayment of loans. That at least was the intention.
Vogel and Think Big
As happened with "Think Big" in 1980, Vogel’s proposal involved committing the Government to introducing a new technology of potential benefit to the nation. Only the Government was in a position to take the risks of such major ventures. In both cases the action was an act of faith. Vogel considered how the cost of his proposal might be met, but his economic analysis was rudimentary; quite unlike for example the detailed cost-benefit studies carried out in advance of the decision to electrify the Palmerston North to Te Rapa section of the North Island Main Trunk Railway.
In both 1870 and 1980 though, large sums had to be borrowed. Which we might ask involved the greater commitment?
We can look at the question in two ways: based on typical wages, and in relation to the country’s ability to pay the loans back, i.e. to its overseas earnings. In Vogel’s day a workman might earn two pounds a week or one hundred pounds a year and the population was 250,000. On a per capita basis the borrowing of ten million pounds was equivalent to forty pounds a head and two-fifths of a yearly wage. If we take the 1980s borrowings abroad to be three billion and a typical 1980 annual income to be 10,000 dollars, then the borrowings per head would be 1,000 dollars or one-tenth of a year’s earnings. Alternatively if we consider overseas earnings, in 1870 ten million pounds was over twice the colony’s export earnings, while in 1980 three billion dollars was three-fifths of the value of exports.
The gamble was definitely greater in 1870.
Vogel was clearly aware of the long-term commitment he was proposing. In concluding his address to the General Assembly, he said "we shall be told that these proposals will entail on posterity an enormous burden. Granted – but they will give to posterity enormous means out of which to meet it."
A Special Breed of New Zealand Locomotives
Vogel’s economy approach to building the rail system was probably the only one that could be adopted in a country with limited population and difficult terrain. It was a complete contrast to that used in the United Kingdom, where large teams of ‘navvies’ working in relatively easy country built mainly level tracks with gradual curves on solid embankments or through cuttings. The tight curves and steep grades of the Vogel era remain today on the New Zealand rail system, curtailing speeds and frustrating engineers seeking increased efficiency. These factors, together with the choice of a narrow gauge and restricted loading gauge, and the loading restrictions on cheaply built bridges and viaducts, had an important influence on the development of railway technology in this country. They prevented the direct importation of conventional locomotive designs from abroad and led to a special breed of New Zealand locomotives.
Initially however, the locomotives used in New Zealand were British-designed and built. The workhorse of the early years of the Vogel railways, the F Class, was broadly specified in New Zealand in 1872 and the design detailed by English consulting engineers. A tank engine, the F was small by modern standards, weighing only 20 tons.
The design and construction of steam locomotives was very much a "pre-scientific" nineteenth century activity, indeed there is an often repeated saying that science owed more to the steam engine than the steam engine owed to science. Improvements tended to be evolutionary rather than the result of the application of new scientific ideas.
Stephenson’s Planet of 1830 had featured a multi-tubed boiler, the forced draught system to which steam railway locomotives owe so much of their character, and horizontal cylinders. Thus by the time that steam locomotives reached New Zealand, their technical basis had been crystallised for about forty years. Difference between engines existed in their size and wheel arrangements, but in all cases a horizontally oriented high-pressure non-condensing steam engine was used – small, compact and powerful. The technology was mature if not fully refined.
As new locomotives were built both in New Zealand and abroad for the New Zealand Government Railways, the trend until the demise of the steam engine was one of continual development of the design epitomised by the F class, towards greater tractive power and economy, with the designs in all cases being constrained by the nature of the New Zealand railway system.
New Zealand Locomotives
The detailed story of the development of the New Zealand locomotive is told elsewhere (eg "Steel Roads of New Zealand” and W W Stewart’s "When Steam was King"). It is an important example of the adaption by New Zealanders of an imported technology to meet their country’s needs.
In this story the chief participants were the Locomotive Superintendents or Chief Mechanical Engineers with their Chief Draughtsmen. These engineers had to work within the constraints already mentioned of weight restrictions, steep grades and tight curves, constraints typical of a mountain railway.
In 1877, a young man, Allison D. Smith, was appointed Locomotive Superintendent in Christchurch. He saw American practice as suitable for local conditions – not a surprising conclusion in view of Vogel’s conception of the railroads – and placed the first order for US-built locomotives. The Rogers Works of Paterson, New Jersey, built eight K engines.
In the early 1880s a major increase in power was sought. Designs were prepared by Allison Smith’s draughtsman, Robert J Scott, and put to tender by the London consulting engineer, John Carruthers.
Despite the success of the Rogers locomotives and of the T class locomotives obtained from the Baldwin works in Philadelphia, the contracts were awarded to the British firm of Nasmyth Wilson. Twenty engines were ordered and the first two had been shipped by October 1884. The Agent General in London cabled to say that the engines were on the water but also to say they were ten tons overweight! Since acceptance would have required the strengthening of all bridges, the Government refused to take delivery and eventually it was agreed the locomotives should be altered at the manufacturer’s expense, to bring them nearer specification.
Since this would take some time, a contract was negotiated with the Baldwin company in the USA to build twelve engines to the same specifications. Within five months of this order being placed all these engines were ready for shipment.
A Colonial Viewpoint
As with many of the 1980s projects, the early approach to the railways had been essentially a colonial one, with total imports of the technology, but the paucity of overseas exchange resulting from Vogel’s Public Works programme led to the decision to build locomotives locally. The expertise built up in the workshops, which had been established to carry out maintenance, provided the base for this move. Large numbers of workers, including many craftsmen, were employed in these workshops, which were the largest workshops of any industry in the colony.
Tolerances in the designs were necessarily generous and the building of a locomotive required extensive hand fitting, depending greatly on the skill of the individual craftsmen.
Railway engineering was not the only heavy mechanical engineering in the country though; in Dunedin, workshops developed considerable expertise in the manufacture of gold dredges. Not only did this expertise service the thriving local mining dredging industry, but it built dredges for export to New South Wales.
While steam reigned, locomotives of many types originating from a variety of sources were used throughout the country, not only in the Government railways but also in industries such as timber milling, quarrying and mining, and in freezing works.
A hundred years ago the railways had some of the glamour that the airways have had in more recent times. The civil engineering feats associated with the building of the rail system, together with the mechanical engineering associated with its operation, were the major technological enterprises of nineteenth century New Zealand and the manner in which these were carried out was a matter of great public interest. Like airline pilots in recent years, the drivers of the locomotives were an elite and given an importance which ignored the dependence of the system on a whole range of people with specialist skills.
New Zealand Manufacture
A proud period of steam locomotive manufacture in New Zealand began in 1887 when Scott Brothers in Christchurch built 10 for use on the Christchurch-Lyttelton service. Two years later the first of the nearly 400 locomotives to be built by New Zealand Railways in the period up until 1956 was manufactured at Addington. Other NZR workshops were at Petone, Hutt, Newmarket and Hillside. A further 123 locomotives were built by A & G Price Ltd in Thames, and others were built overseas to New Zealand designs.
T F Rotheram was the Locomotive Superintendent and G A Pearson the Draughtsman for the W class, the first to be built at the Addington workshops. The W was followed by the U, which had the wheel configuration 4-6-0, that is, two pairs of leading wheels with three coupled pairs of driving wheels. Different versions were built by the NZR workshops, Sharp Stewart in Scotland and Baldwins.
The “Pacific Configuration”
In 1901 A L Beattie, as the Chief Mechanical Engineer, was faced with the problem of providing a more powerful engine. He conceived the idea of adding a trailing "Bissel" truck to the long-boilered configuration of the U locomotive. He requested that an order for twelve locomotives, which had been placed with Baldwins, should be changed accordingly. Thus the Q was born and the 4-6-2 "Pacific" configuration which was to characterize most NZR mainline locomotives came into existence.
A leading bogie provided good tracking – six coupled driving wheels good adhesion, and the low wheels of the trailing bissel truck provided space to accommodate a deep ashpan for long runs and a wide fire box for rapid and continuous steaming. (Grate area was an important factor in determining locomotive power). The Pacific type of locomotive was subsequently adapted and successfully developed for express locomotives in America and around the world.
The ultimate world record with steam of 126 miles per hour (now 203.5 km/hr) was achieved in 1938 by Sir Nigel Gresley’s streamlined Pacific "Mallard".
The Q’s successor, the A class, was built in 1906, and was used on the North Island Main Trunk expresses between 1909 and 1930. All but one of the As were compound locomotives, i.e. work was obtained from the steam in two stages in cylinders in series. Compounding increased the efficiency but added complexity. Authorities are divided on whether or not it also reduced power. Fifty-seven of the A class were built in all, seven at Addington and fifty by A & G Price in Thames.
A Classic Steam Locomotive
The next Pacific class to be built, in 1914, was the Aa, followed by the Ab, "easily the most successful locomotive to steam on New Zealand tracks." (Great Steam Locomotives of All Time – O.S. Nock Blandford Press 1976). H.H. Jackson was the Chief Mechanical Engineer and his chief draughtsman, S.H. Jenkinson, when in 1915 the first of this classic class rolled out of the Addington workshop. A further 140 would be built in both New Zealand and the United Kingdom.
Jenkinson’s proudest achievement was the Ab. An anonymous, almost self-congratulatory article in the English journal, Engineering, describing the Ab’s design is most probably by him.
Pride in the new locomotive was undoubtedly justified. Like the A class, the Ab had the Pacific (4-6-2) wheel configuration but, in contrast to it, reverted to a simple engine, doing away with the complications of compounding. Its thermodynamic efficiency was however increased by the inclusion of the one major technical advance that improved steam locomotives in the twentieth century: superheating. (Superheating raises the temperature of the steam above that of water boiling at the same pressure.)
The Ab could haul passenger trains of up to 400 tons and, in easy country, goods trains of up to 750 tons. It is said to have been the first locomotive in the world capable of developing one horsepower for every 100 pound of engine weight.
Writing in the New Zealand Journal of Science and Technology on "The Future Development of the Locomotive in New Zealand", Jenkinson described the famous trials which took place in 1915-16 when the simple superheated Abs were pitted against compound saturated A class locomotives in both the North and South Islands. Comparison of the performances between Christchurch and Timaru and Wellington and Taihape showed the Ab used markedly less coal and water per ton-mile run with the coal–saving ranging between 13 percent and 33 percent.
A Limit to Locomotive Design
He maintained that taking into account the practical limitations, maximum fuel efficiency had been obtained in the latest locomotive design and that, without fundamental changes, improvements in locomotive economy could only occur through developments outside the control of the locomotive designer.
He was right for, although the age of steam would continue for another thirty years, with the advent of superheating the steam locomotive had advanced as far as it ever would.
In 1930 after the Ab had served as the mainline workhorse for a lengthy period, R.J. Gard designed a powerful successor to meet the requirements of Locomotive Superintendent (later Chief Mechanical Engineer) P.R. Angus. To accommodate a large boiler and at the same time meet the weight restrictions imposed by the civil engineers, the K class used a 4-8-4 wheel arrangement.
Thirty Ks were built in the Hutt workshop between 1932 and 1936. They were followed by thirty-five of an improved version (Ka) between 1939 and 1950.
In terms of power, the K and Ka were the ultimate development of the steam railway locomotive in New Zealand.
The final locomotives in the saga (classes J, Ja and Jb) were smaller than the K’s, being designed for secondary routes. Thirty-five Ja’s for the South Island were built at Hillside between 1946 and 1956. They were the last steam locomotives built for the New Zealand Railways and signaled the end of a technological era.