Gravity, Steam and Steel: An Illustrated Railway History of Rogers Pass. 2009. Graeme Pole, Fitzhenry and Whiteside.
The Selkirk Range. 1905. A. O. Wheeler, Ottawa Printing Bureau.
September 15, 2016
December 18, 2016
CPR construction engineers faced the same problem immediately west of Rogers Pass that they did west of the Kicking Horse Pass. The grade dropped precipitously, in this case more than 4.5% down the Illecillewaet River Valley in the first four miles. Even though Major Rogers initially proposed the north side of the river for route for the rail line, it was predisposed to avalanches, particularly along the face of Mount Cheops where the line would have to cross almost two miles of avalanche prone slopes. Chief Engineer James Ross estimated that 2,400 feet of tunnels and 8,350 feet of show sheds would be needed to build the line on the north side of the Illecillewaet River. To Ross it was also clear that the line needed to be taken down to the valley floor as soon as possible so that avalanche slopes could be avoided by routing the line back and forth across the Illecillewaet River.
The solution was the same as that used to replace the Big Hill east of Field, BC in the Kicking Horse River Valley. Lengthen the line and thereby reduce the grade. But unlike the Spiral Tunnels, which were built to replace the Big Hill 24 years after initial construction of the rail line, Ross, in a letter dated March 4, 1885 to William Cornelius Van Horne, General Manager of the CPR, proposed rerouting the line before initial construction had begun.
Ross proposed using two valleys immediately west of Rogers Pass on the south side of the Illecillewaet River Valley. The first accommodates the upper reaches of the Illecillewaet River itself. Called Glacier Creek at the time of construction, the Illecillewaet River initially flows north out of its source, the Illecillewaet Glacier, through a short valley, then turns west. The second accommodates a creek that became known as Five Mile Creek because after construction the creek was five railway miles from the crest of Rogers Pass.
He then proposed that the line turn almost 90° west to follow the face of Mount Abbott for almost a mile through 8 snow sheds (#21 - #28) then up the valley of Five Mile Creek.
Looking west down the Illecillewaet River with snow sheds on the slopes of Mount Abbott (left).
Click on image to enlarge/reduce.
Here the line would cross Five Mile Creek on a trestle, do a 180° turn, then re-cross Five Mile Creek on a second trestle heading east back up the Illecillewaet River Valley.
The line would then make another 180° turn and cross the Illecillewaet River for a second time to follow the north side of the river west through 3 snow sheds (#29 - #31).
Finally, the line would cross the Illecillewaet River for a fourth time on yet another trestle.
Ross’s proposal lengthened the line by almost 4 miles and added curvatures amounting to almost 7 complete circles. It required construction of 4 massive wooden trestles, six bridges and 14 snow sheds. But, it was $500,000 cheaper that Major Roger’s original line, a big plus for a company that at the time was rapidly going bankrupt.
Van Horn agreed to the new route and the decent from Rogers Pass became known as “The Loops”.