Big Hill

Even though the Big Hill was replaced by the Spiral Tunnels in 1909, the area has long been a challenge to the operation of trains and remains so to this day.

[2] To complete the Pacific railway as quickly as possible, a decision was made to delay blasting a lengthy 1,400-foot (430 m) tunnel through Mount Stephen and instead build a temporary 8-mile (13 km) line over it.

It descended from Wapta Lake to the base of Mount Stephen, along the Kicking Horse River to a point just west of Field, then rose again to meet the original route.

The switches led to short spurs with a sharp reverse upgrade and they were kept in the uphill position until the operator was satisfied that the train descending the grade towards him was not out of control.

Field was created as a work camp solely to accommodate the CPR's need for additional locomotives to be added to trains about to tackle the Big Hill.

The improvement project was started in 1906, under the supervision of John Edward Schwitzer, the senior engineer of CPR's western lines.

The first proposal had been to extend the length of the climb, and thus reduce the gradient, by bypassing the town of Field at a higher level, on the south side of the Kicking Horse river valley.

It then descends the valley side in almost the opposite direction to its previous course before crossing the Kicking Horse River and entering Mount Ogden to the north.

[8] On February 4, 2019, two of the three locomotives and 99 grain hopper railcars of westbound Canadian Pacific train 301 derailed at Mile 130.6, just outside of the western portal of Upper Spiral Tunnel.