The New Zealand Railways Magazine, Volume 13, Issue 4 (July 1, 1938.)
Railway Features. — Dead-straight Lines
The world's record for the longest stretch of straight railway belongs to the Transcontinental Railway of Australia, which is dead-straight for 328 miles across the Nullarbor Plain, but not dead-level. Next in order, probably, comes the Junin and McKenna stretch of the Buenos Aires and Pacific Railway of Argentina, which is dead-straight for 205 miles and level also. In the United States the longest straight section of the New York Central lines is 70 miles. There is also a 70 miles straight stretch in Rhodesia. In England there is no straight longer than 18 miles.
New Zealand's principal straight length of railway lies on the Canterbury main line. Between Lyttelton and Rolleston there is a double line. On the up line from Islington to Rolleston and continuing on the single line from Rolleston to Dunsandel there is an unbroken straight run of 18 miles. Further to the south there is a straight run of 151/2 miles from Rakaia to about a mile north of Ashburton. There are twenty-three other stretches of straight track of five miles or more in length, of which eighteen are in the South Island and five in the North Island.
These 25 straights have a total length of 1851/2 miles, a fraction over 51/2 per cent, of the total number of miles open for railway traffic.
There are, of course, numerous short lengths of straight, of varying sizes, under five miles; but, after taking these short sections into consideration, it will be realised how curved or deviating is the contour of our rail-road track and the adverse effect such a physical condition has on operating costs.
Then, too, there are 581/2 miles of bridges and viaducts on the New Zealand Railways which add to the difficulties encountered in train-running in the Dominion. Tunnels, also, are a disability, more or less. Of these subterranean passages, there are 96 in the North Island with a total length of 21 miles 73 chains; and 56 in the South Island with an aggregate distance of 16 miles 15 chains.