High Peaks Engineering by L.D. Cross

Author:L.D. Cross
Language: eng
Format: epub
ISBN: 978-1-927527-81-8
Publisher: Heritage House
Published: 2014-07-08T00:00:00+00:00

CHAPTER

6

The Schwitzer Solution

THE SPIRAL TUNNELS NEAR FIELD, BC, are an engineering feat unique in North America. They were the CPR’s solution to halving the grade of the Big Hill descent by doubling the distance. This was achieved in 1909 through the construction of two tunnels through Mount Ogden and Cathedral Mountain, which reduced the gradient from 4.4 percent to 2.2 percent. Inspired by the Baischina Gorge tunnels in Switzerland, John Edward Schwitzer, an assistant chief engineer for CPR’s western lines, created this masterpiece of engineering by designing a pair of looping tunnels in a figure-eight pattern. An eastbound train leaving Field climbs a moderate hill, passes through two short, straight tunnels on Mount Stephen, under the Trans-Canada Highway, across the Kicking Horse River, and into the Lower Spiral Tunnel through Mount Ogden. Once inside, it spirals upward and to the left for 891 metres, emerging 15 metres higher from where it entered. The train then crosses back over the Kicking Horse River, under the highway a second time, and into a 991-metre tunnel in Cathedral Mountain. There, it spirals to the right, emerging 17 metres higher, and continues to the top of Kicking Horse Pass. In all, the line crosses the valley three times and the Kicking Horse River four times on four different bridges.

The construction of the Spiral Tunnels took two years, from 1907 to 1909, and required one thousand workers, $1.5 million, and the excavation of 54,000 cubic metres of rock. All four tunnel entrances were started at the same time. Without the luxury of modern technology or computers, workers carved out the tunnels from both ends, finishing at the centre within five centimetres of their targeted point of completion. By the way, the story that Schwitzer realized a week before the tunnelling was complete that his calculations were off and the shafts would never meet is an urban legend. His numbers were correct. He did not shoot himself in a fit of despair. He went on to create other engineering marvels.

Route followed by CPR trains through the Spiral Tunnels in Kicking Horse Pass. From the CPR menu cover, circa 1920–29.

GLENBOW ARCHIVES NA-4594-1

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