ONE TRAIN -
OWING to the mountainous nature of the country, railway engineering in New Zealand has always been a difficult business. The South Island in particular is a formidable proposition. Mountain ranges, capped with snow and ice, run down its western coast. So impenetrable was this barrier that until recent years the west side of South Island was, so far as railways were concerned, cut off entirely from the east side.
In 1923, however, the boring was completed of the famous Otira Tunnel, 5¼ miles in length, and the longest in the British Empire. This links up the eastern and western railways, and makes it possible to travel by train from Christchurch to Grey-
On the main line of the North Island, which connects Wellington, the capital, with the city of Auckland, far away in the northernmost peninsula beyond the Hauraki gulf, fifty miles of track are carried at an altitude of more than two thousand feet above the sea. Deep gorges are bridged by viaducts, some between 200 and 300 ft in height, and the summit level of the line, at Waiouru, 2,659 ft above sea-
During recent years the New Zealand Government, which owns all the railways, has been spending a great deal of money in attempting to flatten some of the steep gradients which could not be avoided when the first of her main lines were laid. For in those early days economy was essential, and the modest resources of the country compelled the laying of the lines with as little as possible in the way of major engineering works. It was for this reason that, almost from the start, a track gauge of 3 ft 6-
This contraction from the standard gauge of 4 ft 8½-
One of the original main lines in the North Island of New Zealand possesses one of the steepest gradients in the world worked by adhesion. It is so steep that a special form of traction was adopted at its opening, and this unique method is still in use. To the north-
A HUGE LOCOMOTIVE of the 4-
From the first it was realized that to attempt ordinary adhesion working up such an incline with anything like a reasonable load would be impossible. It was therefore decided to use a special system of traction, known as the Fell, which involved the laying of an additional centre rail between the two running rails. This centre rail is in profile like a dumb-
The purpose of the centre rail is to provide for additional adhesion, and the Fell locomotives, in addition to their ordinary driving wheels, are provided underneath with a pair of horizontal driving wheels, one on either side of the centre rail. By a powerful arrangement of springs, which are of cast steel with flat treads, these horizontal wheels can be pressed into contact with the centre rail when the engine is ascending the incline, and then swung clear while the descent is being made.
Because of the steepness of the gradient, it is necessary to use engines which are of comparatively light weight, and the Fell locomotives, therefore, weigh only 39 tons each. They have four-
A RAILWAY MAP of the North Island, New Zealand, showing the main-
It is also important, in ascending, that too severe a strain shall not be put on the couplings connecting the coaches, and the trains are so arranged, therefore, that a locomotive shall be pulling roughly the load for which it has been designed -
In descending the incline, the brake-
It will be seen, therefore, that the Rimutaka incline is a terrible handicap to the working of this section of the line. On the average it takes fifteen minutes to marshal the trains at Cross Creek before beginning the ascent, and another quarter of an hour to sort them out at the summit, while the actual climb occupies forty minutes; about an hour and a quarter has thus to be spent on no more than three miles of the journey. In recent years this delay has helped the motor-
A MAGNIFICENT EXAMPLE of the numerous steel viaducts in the North Island of New Zealand. The picture shows the Hapuawhenua viaduct, 222½ miles from Auckland, under construction. The viaduct is 147 ft above the river-
Plans have been prepared for a deviation of the line through the mountains, to cut out this troublesome section. This would be very costly to carry out; and despite the number of engines and brake-
Some remarkable developments are still being made along the principal North Island main line, which connects Wellington with Auckland, 426 miles away. Hitherto, the start out of Wellington has been a steep one. The old line has had to climb from the shores of Wellington Harbour, at the southern extremity of the island, to an altitude of 518 ft, near the suburban towns of Khandallah and Johnsonville, in no more than four and a half miles, before it could descend temporarily to the pretty coastal levels of Parirua Harbour and Plimmerton. This has meant practically unbroken 1 in 36 to 1 in 40 up gradients, as well as a six-
Work also continues, however, on a costly deviation scheme, which will lower the summit level from 518 to 195 ft, flatten the steepest gradient from 1 in 36 to 1 in 100, and reduce the distance by two and a half miles.
Reducing the Gradients
The new line, eight and a half miles long, leaves the harbour a mile farther along the harbour towards the suburban town of Hutt, and dives into a tunnel; there are two tunnels, the first three-
This work is being done purely to expedite and cheapen the main trunk service from Wellington. The heavy haulage up the steep gradients has been a costly business in the past and also has limited the size of trains. This stretch of line (between Wellington and Longburn) was originally owned by the Wellington and Manawater Railway Company, having been completed in 1887. It was purchased and taken over by the government in 1908, the date when through railway communication was established between Wellington and Auckland.
Another vast project which is being carried out by the railways of this progressive Dominion is the complete reconstruction, as one new central terminus and harbour station, of the existing Wellington termini -
LEAVING WELLINGTON. The New Plymouth express toiling up the 1 in 36 gradient from the shores of Wellington Harbour. The express is on the old track, but the trains will use the lower track for a mile farther when the new deviation comes into use.
To support the Wellington Station building itself, which will be a fine four-
It was in 1882 that a contract was let for the construction, southwards from Auckland, of what was ultimately to become part of the North Island trunk line. This was the forty-
South from Auckland, the journey is uninteresting for many miles. At Mercer the line enters the valley of the Waikato, New Zealand’s greatest river, 200 miles in length, coming down from the mountains in the centre of the island to the west coast.
Navigable for many miles, it was one of the chief waterways used by the Maoris in their 60 to 80-
Piercing this tunnel was a task of extraordinary difficulty. In order that it might be ready by the time the rails reached it, work was begun in the middle of an un-
A minor tragedy of this perseverance was that the tunnel was finished some years before the rails reached it from either side.
During this idle period, however, the bore was not entirely without use, for horsemen and packhorses made a practice of passing through it on their way to the King Country, running the risk of getting “bogged” in the stiff clay somewhere in the middle of this black hole in the hills. At this tunnel the railway, 146 miles from Auckland, is 1,128 ft above the sea.
TWO ENGINES have to be used to haul trains up the severe gradients -
After descending for some thirty miles, the line reaches Taumarunui on the Wanganui river, 478 ft above sea level This descent is made through the so-
The “K” class of engine is chiefly used. They are very powerful locomotives of the 4-
Having left Taumarunui, the North Island trunk line has to climb 2,086 ft in thirty-
At Waimarino the line now continues for more than fifty miles above the 2,000 ft level. Immense mountains are seen on either side of the line, such as the famous Ruapehu, 9,175 ft high and perpetually snow-
At Waiouru the railway reaches its highest level, 2,660 ft above the sea, and from here there is a steep incline. A fall of 1,748 ft in forty-
THE HIGHEST BRIDGE IN NEW ZEALAND. The Wellington-
You can read more on “The Otira Tunnel” in Wonders of World Engineering