The “Great Zigzag” for years stood as a striking monument to the ingenuity responsible for the work, for it is even more daring than Meiggs’ famous V-switches. As time passed and the railway traffic of the State increased, the heaviness of the grades, the sharpness of the curves and the time occupied in negotiating the zigzag, reacted more and more adversely upon the economical operation of the line. Moreover, it constituted a serious menace to safety, although fortunately it never was the scene of an accident. Still, a proposal for its abolition was advanced so far back as 1885, although it was realised that heavy and costly reconstruction was the only alternative.
The proposed deviation was discussed more or less for several years, but was deferred from motives of expense. But when the traffic had gained the respectable proportions of some 2,585,000 tons in 1908, it was recognised that the inevitable could be postponed no longer. It was pointed out that if there were no zigzag the number of goods trains using this part of the line could be cut down by over 30 per cent., since a single locomotive would be able to handle a heavier load and longer train than was possible at that time, while so far as passenger traffic was concerned, no less than 686 hours could be saved every year, and operating expenses could be reduced 50 per cent, upon this division.
BEFORE THE EXPLOSION THE BLAST
THE CLIFF-FACE DISLODGED THE CLIFF-FACE BROKEN UP
A HUGE BLAST
35,000 tons of rock were dislodged by 10,125 lb. of explosives.
Accordingly the deviation was commenced. The surveys for the new line had been prepared by Mr. Henry Deane, M.INST.C.E., while engineer-in-chief for railway construction. He proposed a series of tunnels built on a gradient of 1 in 90 running through a number of spurs projecting from the main range, and although these were intercepted by gulches the latter could be filled with the rock excavated from the tunnel borings. The line in many places hugs steep precipices where the land falls away vertically for a distance of 1000 feet or so into the Kinambla Valley.
THE PUTTAPA GAP BRIDGE, 200 FEET IN LENGTH