Sign for famous spiral tunnels in western Alberta
Spiral tunnels were copied from the Swiss who use them extensively in the Alps.
A train enters a spiral tunnel.
In this image a train crosses over itself, entering the spiral tunnel at the top and exiting below - going down hill. See next view.
The spiral tunnels lengthen the path taken climbing the mountain, thereby lessening the grade. The original grade was on the order of 6%, very great for locomotives to climb.
Details on sign appear in next slides.
This sing illustrates how the tracks wind around to increase their effective length and decrease the climb.
Read about "Big Hill"
here — fascinating reading about construction of the tunnels and the obstacles to climbing over the Continental Divide that last into twenty first century.
Father west along the RR tracks is a small town with this little church.
