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The New Zealand Railways Magazine, Volume 5, Issue 4 (August 1, 1930)

History of the Canterbury Railways — How the Early Settlers Solved a Big Transport Problem

page 34

History of the Canterbury Railways
How the Early Settlers Solved a Big Transport Problem.

(Continued.)

Stephenson's Report on the Lyttelton-Christchurch Railway

Continuing his report on the subject of railway communication between Lyttelton and Christchurch, Mr. G. R. Stephenson states:-

“The mid-level route would ascend the western side of the Sumner Valley at an inclination of about 1 in 30 to a tunnel 800 yards long under Evans Pass, at an elevation of about 250 feet. It would descend from the tunnel by a side cutting to Polhill's Bay, thence by a tunnel half a mile in length through the point known as Sticking Point, to the Market Place at Lyttelton. It would reach the Market Place at an elevation of 100 feet above the sea, an arrangement of a very objectionable character in every way, and one which would involve perpetual charges for cartage, haulage, etc., between the high level station and the ship's side. The length of this line would be nearly eleven miles, and the tunnelling close upon 2,600 yards, and there would be heavy side cuttings. There are strong objections to this line. It appears a line might be constructed with less objectionable features; it is therefore unnecessary to offer further observations on this project.

The Low Level Route.

The low level route would ascend from the Sumner Valley by an incline of 1 in 200, 75 chains long, to the mouth of a tunnel under Evans Pass. This tunnel would be 1,320 yards in length, and would carry the line on an inclination of 1 in 200 to Gollan's Bay, where, according to the plans, it appears to stop. The length of this line, from Christchurch to Gollan's Bay, would be nine miles 16 chains, and the amount of tunnelling 2,253 yards. There are no detailed plans for carrying on this line from Gollan's Bay to Port Lyttelton, but presuming it is essential to carry it on, the line would probably skirt the shore in a rocky side cutting for a length of 50 chains, would then pass by a tunnel 110 yards long into Polhill's Bay; would cross the bight of that bay by 30 chains of cutting and embankment (or possibly viaduct) and, passing by a tunnel 946 yards long under Sticking Point, emerge at the level of the Lyttelton Quays east of the jetty, and enter a station ten chains further on. On this supposition the line would be in length 10 miles 60 chains from Christchurch, and would involve tunnelling to the extent of 3,309 yards, besides some difficult side cuttings.

Direct Line Favoured.

Coming now to the second proposition, passing Mount Pleasant to the west. This is unquestionably the most direct line between Christchurch and Lyttelton, as it involves a distance of only six miles of line from station to station, against 10 miles 60 chains by the shortest route to the east. Starting from Christchurch at the same point as the other line, and at an elevation of 15 feet above high water, it will rise five feet in the first mile, will fall eleven feet in the second mile, and will then be level to the foot of an incline of 1 in 50 which will lead to the mouth of a tunnel 34 feet above high water, and 29 feet above the level of Lyttelton station. It is proposed that this tunnel be carried through the mountain for the length of 2,882 yards, and having completely pierced it, the line will descend to the level of the quays at Port Lyttelton by an easy gradient of 1 in 200, and without any works being required of an extraordinary character.

In all respects (saving and excepting the tunnel), it admits of no doubt that this western route is the preferable route for a line of railway between Christchurch and Lyttelton. This line is very much shorter than any that can be carried to the east of Mount Pleasant; the works on either side of the tunnel are void of difficulty, and may indeed be described as light; there are no heavy side or other cuttings; no bad curves, as upon the eastern lines; no heavy embankments and no objectionable gradients. The stations are well situated both at Lyttelton and Christchurch, and are placed at points from which the line will admit of extension, either inland or to other shipping places, should the need of the colonists require it.

The construction, however, of a tunnel of such considerable length as that proposed on this route, renders it necessary to enter very carefully into consideration concerning the nature of the ground through which it is to be worked. I am instructed that the approaches at both ends will be through an alluvial deposit of clay with boulders. The mountain itself presents all the features of volcanic rock, exhibiting a series of lava streams dipping from 1 in 10 to 1 in 15 page 35 towards the north. The lateral breadth of these streams is not great, each stream consisting of from 10 to 30 feet of rock covered with from three to ten feet of ashes and scoria compressed into rock. These streams of lava vary in colour and hardness. Samples which have been brought to England, and which I have inspected, exhibit no indications of special difficulty except in one case; but from the position of the strata, that stone appears likely to be only occasionally met with, and although hard, it is by no means as hard as many through which I have had to tunnel. I am led to understand that it appears
Constructing the Christchurch-Lyttelton Tunnel. Photo, courtesy Lyttelton Harbour Board.) A view of the tunnel works, 1866, shewing Peacock's store on the left and the Union Bank on the right.

Constructing the Christchurch-Lyttelton Tunnel.
Photo, courtesy Lyttelton Harbour Board.)
A view of the tunnel works, 1866, shewing Peacock's store on the left and the Union Bank on the right.

the one tunnel in the direct route, as the former present a greater number of working faces, but in a place like Canterbury, where labour is not abundant, not so much weight can be attached to this consideration as might be the case elsewhere. It is estimated that the Sumner line could be constructed in three years and the direct line in five years, an opinion confirmed by consultation with experienced contractors.

Advantages of direct line.

The cost of the works is estimated as:–Sumner Valley line £327,632, direct line £245,071; from an examination of the ground, that where the lava has been too rapidly cooled it has not assumed the crystalline form, but is more friable and crumbly. The ashes and scoria are porous and may contain water, but I do not anticipate any difficulty whatever in dealing with it.”

Mr. Stephenson then deals with the question of a possible shortening of the tunnel by the use of steeper gradients, but concludes that the line now proposed is the best direct line that can be formed.

“A comparison of distances shows a saving in favour of the direct route of 4 miles 60 chains between Christchurch and Lyttelton, and a saving of 427 yards of tunnelling.

Considering the element of time in construction, it is admitted that the six tunnels on the Sumner route could be pierced in less time than difference in favour of direct line, £82,561.

Against this saving of about £80,000, has to be put the delay of two years in time of construction, a consideration of no small importance to a growing colony. Apart from this, however, the balance of advantage is altogether in favour of the direct line.

(1) It will be constructed for £80,000 less money.

(2) It will be the shortest line between all the points.

(3) It will be the cheapest line to work, entailing less rolling stock, less wear and tear, and less consumption of fuel.

(4) For the same reason it will be the least expensive line to maintain.

(5) And on all these grounds it is evident page 36 that it will be the best able to conduct its traffic at the lowest rate of charge.

On these considerations, then, I am of opinion that the proposed western, or direct line, is the line best adapted for a railway between Christ-church and Port Lyttelton, and is the line most suited to meet the wants of the inhabitants of both those towns, as well as of the colonists at large.”

Mr. Stephenson concluded his report with the following advice:–

“I make this report not only in conformity with my instructions to consider the best line of railway, but because Lyttelton is best served by this route, and because, on every account, I apprehend that Lyttelton is the desirable point to be reached. Lyttelton is at the present time the port of the colony. Any attempt to remove that port must involve the removal of its population and its interest. It is not probable that for many years, at least, there will be any considerable trade at any other points of Port Victoria. I would add, however, that if, at any time, a harbour should be formed at Gollan's Bay, and it should be considered desirable for shipping purposes to extend the line of railway from Lyttelton to Gollan's Bay, the direct line will place Gollan's Bay a mile and thirty chains nearer to Christchurch, via Lyttelton, than the two places can be brought together by the route via Sumner Valley. I consider, moreover, that, as the existing port, Lyttelton has not only a prior claim to
New Zealand Railways Big Northern Terminal, Seen From Aloft. (Photo, courtesy The “Sun” Newspapers, Ltd.) A recent aerial photograph of Auckland's new station buildings.

New Zealand Railways Big Northern Terminal, Seen From Aloft.
(Photo, courtesy The “Sun” Newspapers, Ltd.)
A recent aerial photograph of Auckland's new station buildings.

be served, but that any arrangement which did not serve it would inevitably cause an extent of inconvenience and a disruption of existing relations beyond all present calculation.

“In conclusion, I would desire especially to impress upon the inhabitants of the Province of Canterbury that, in dealing with this question, so all-important to their present interests and future prosperity, it is of the highest importance that they should not be deterred by minor considerations from at once adopting the best line they can possibly obtain. A line of railway from Christchurch to Port Lyttelton must inevitably be the key to the whole railway system of the province; and whilst probably at no part of the province will so much difficulty present itself to the construction of a railway, so no railway in the province can be expected hereafter to return anything equivalent to the returns of the line which will connect the shipping port of Canterbury with the centre of the settlement. To the development of the vast resources of Canterbury a railroad appears to be the one thing needful. I make this report in view of these considerations, and in recommending the colonists to provide that their road should be the best road possible, I do so in the conviction that I am recommending the measure which will be the most conducive to their future and their permanent prosperity, and which, whatever may be its present cost, will inevitably prove in the end the cheapest and most advantageous.”

(To be continued.)