The New Zealand Railways Magazine, Volume 2, Issue 7 (November 1, 1927)
Tawa Flat Deviation. — The Way Through
Tawa Flat Deviation.
The Way Through.
When roads were laid according to the wandering fancy of the cows that the Brown family owned, no strain was placed upon human intelligence in the choice of ways, for the cattle ruled the routes.
But when the traffic question became pressing and such considerations as time and grades grew to have economic importance the Civil Engineer came into the picture and has stayed there ever since.
The choice of routes early gave rise to two schools of engineering thought. One believed in taking the shortest possible distance between any two points, contending that the extra capital cost would be more than recouped by the reduction of operating expenses. The other contended that the route should follow more nearly that of the contours of the country, the cheapness of construction compensating for the higher operating costs. This war is still going on, although the concessions made on each side have blurred the issue somewhat, resulting in contentions being confined to cases rather than to principles. Add to this the non-professional attitude-the natural human weakness which prompts people to take a keener interest in other folks' business than in their own, and it can easily be seen that the choice of route must give rise to much diversity of opinion. Kipling, in one of his earlier poems, pictured primitive man fighting with primitive weapons to prove that his was the “one best way” for doing things. Following this up with lines intended to indicate the present-day proneness to the vice, he says-
“Still we let our business slide,
As we dropped the half-dressed hide,
To show a fellow savage how to work.”
It is, therefore, not at all surprising that the new railway route out of Wellington should have awakened the keenest interest amongst all classes, and that a wonderful variety of opinion has been found to exist regarding the correct solution of this problem.
Tunnels, in particular, have a fascination of their own and this, in the case of Tawa Flat-where some sort of tunnel somewhere seems unavoidable-has added fuel to the ordinary routing discussion. In this connection it is worth recalling the situation which arose, over a hundred years ago, in England, and which gave rise to what is commonly known as “The Tunnel Legend of Tyler Hill.”
In 1824 a company was formed to build a railway from Canterbury to the coast at Whitstable. George Stephenson proposed to take the line through Blear village, a route giving easy gradients and light earth works. This survey, states, Mr. H. A. Vallance in “The Edgar Allen News,” was duly submitted to the Company and all seemed favourable when a most amazing trouble suddenly cropped up.
Dixon (Stephenson's assistant) had just drawn their attention to the lightness of the earth works when one of the wise-acres of the Committee blandly asked “And is there then no tunnel?” “No,” replied Dixon, “I am glad to say no tunnelling is necessary.” “Oh,” cried several others, “No tunnel? We must have a tunnell” Incredible as it may seem, Dixon's original survey was rejected and he was told to select a route containing a tunnel. This was not difficult to find. By shifting the whole location somewhat to the east, a tunnel was found at Tyler Hill about one mile to the north of the city.
“Thus” concludes Vallance, “the Canterbury people obtained their desired tunnel; but concomitant evils in the shape of steep gradients came with it.”