THE SPIRAL.

Dominion, Volume 4, Issue 1088, 29 March 1911, Page 16

THE SPIRAL.

boullcrs arc then traversed, and presently tho engine dashes into a tunnel of 19 chains in length. On emerging train passes over a high embankment a small creek (tho fourth time of crossing) and runs through another short tunnel 4£ chains long. By this tiipo an elevation of 193 ft. above the Rauriinu station has been attained. The length of tho track from tho station is two Diilcs, but in a direct lino tho intervening distance is only a quarter of a mile. Winding on round tho hill, through heavy boulder cuttings 60ft. in height, and across an immense embankment (which required 150,000 cubic

yards of earth to bring it to its height of 110 ft.), tho line describes almost an exact circle of some 50 chains in circumference. It then performs the' interesting feat of crossing its own track, tho top of tho first tunnel being passed over at a height of 70ft. above tho tunnel level. This is the great point of novelty in regard to tho line. There aro a number of similar constructions in North and South America, in India, and in Switzerland. On tho St!' Gothard lino in tho last-named country thero is n spiral line containing no fewer than seven circles. There is also olio in' Australia, but tho Raurimu spiral is the only work of its kind in New Zealand, and as such it possesses a distinct interest.