Kicking Horse Spiral Tunnels
Hi and welcome to Failurology; a podcast about engineering failures. I’m your host, Nicole
And I’m Brian. And we’re both from Calgary, AB.
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This week in engineering news, the Manitou Incline in Manitou Springs which is just west of Colorado Springs, Colorado.
The incline, which is made up of approximately 2,744 steps, ascends the east face of Pikes Peak.
Pikes Peak is a fourteener which is a peak with an elevation of at least 14,000 ft or 4,267m
There are 96 fourteeners in the US, 53 of which are in Colorado.
The Manitou incline doesn’t go all the way up though, but it reaches a peak incline of 8,590ft or 2,620m
Manitou is only 1.42km long and rated as extreme. And let me tell you, I can confirm.
It averages a 40% grade with the maximum grade being 68%.
The inline was first constructed as a funicular in 1907. It is a cable rail system where two counterbalanced carriages are attached to opposite ends of the cable, with the carriages moving synchronously, one goes up while the other goes down.
The funicular’s purpose was to give access to water tanks at the top of the mountain which provided gravity-fed water pressure to Manitou Springs and Colorado Springs.
In order for the funicular carriages to get up the mountain, they used a cog and rack system. I like to think of it like a zip-tie or zap-strap or whatever you call those things. The train rolls uphill to the next cog and once there it locks into place and can’t roll back down, then it goes up to the next cog.
Shortly after it was finished, the Manitou and Pike’s Peak Railway took over the cable car operation and ran it as a tourist attraction until a rock slide in 1990.
After some of the 900mm (3ft) wide tracks washed out from the rock slide, they decided not to repair the track and instead turned the incline into a fitness challenge.
There is what they call a “bail out” about 2/3s of the way out where the stair route connects to a switch back route that climbers can take back down; the switch back route is also available from the top.
The incline is said to be famous for its sweeping views. I will have to take their word for it because it was wildfire season when I was there and I couldn’t see much from the top but smoke.
We’ll include a link to the alltrails map in the sources for this episode so you can see exactly what we’re dealing with. And you can find the links to sources on the web page for this episode at failurology.ca
Now onto this week’s episode; number 60. We’re covering another engineering marvel as we do every tenth episode. We had been planning to work our way through the American Society of Civil Engineers' seven wonders of the modern world. So far from that list we have covered the Channel Tunnel, CN Tower and Panama Canal. Not on that list, we also covered the International Space Station and the James Webb Space Telescope. While we will probably go back to the seven wonders list for episode 70, Brian had a fantastic recommendation for this episode that we couldn’t pass up. Today we’re talking about the spiral tunnels of Kicking Horse Pass.
Kicking Horse Pass - Geography
Kicking Horse Pass is a high mountain pass across the Canadian Rockies, bridging Alberta and British Columbia.
For those of you that have driven the Trans Canada, AKA highway 1, from Alberta to BC, (and if you haven’t you can always follow along on google maps) you pass by Banff and Lake Louise on your way out of Alberta and go over the Kicking Horse Pass. Then you drop down into Field and Golden BC before climbing back up over Rogers Pass and coming down into Revelstoke and the Okanagan region. If you were carrying onto Vancouver, you might take the Coquihalla through the Cascade mountains, which is one of the more sketchy sections of highway I’ve personally driven on. It takes about 12 hours to drive from Calgary to Vancouver; or you can skip all of that and take a 90minute flight. Now that we’ve completed that western canada geography lesson, back to Kicking Horse Pass.
The pass has an elevation of 1,627m or 5,338ft and crosses the Continental Divide. Ok I spoke too soon, I wasn't quite done with the geography. I knew about the continental divide before moving to Alberta, learned about it in school, but I remember being in awe the first time I crossed the pass. The Continental Divide or Great Divide runs from northern Alaska to the southern tip of Mexico. The divide separates watersheds from those that drain into the Pacific and those that drain into the Atlantic. So all water that lands on the west side of the divide runs to the Pacific and all water that lands on the east side of the divide runs to the Atlantic and Arctic oceans.
The reason I find this so interesting is it's a really simple indication of direction. Just as the sun rises in the east and sets in the west, depending on which side of the divide you’re on, you can use the direction of water flow like a compass. I just always thought that was really cool. Ok I am done being a nerd for right now.
Kicking Horse Pass - Railway
While Indiginous peoples had known and used the pass for years, it was first explored by Europeans during the Palliser Expedition in 1858. James Hector, who was a geologist and surgeon on the expedition was kicked by his horse while attempting to rescue another horse that had gone into the river. Which is how the pass and adjacent Kicking Horse River got their names.
BC joined the Confederation in 1871 and officially became part of Canada. Prime minister John A Macdonald pledged to build a railway to link BC with the rest of the country.
In 1884 the main line of the Canadian Pacific Railway was constructed between Lake Louise, AB and Field, BC. They also looked at Yellowhead Pass through Jasper National Park to the north but preferred the Kicking Horse route.
The section between the summit of the pass and Field, BC was known as “The Big Hill '' with a grade of 4.5%, making it the steepest stretch of main line railway in North America. The Big Hill consisted of a 330m ascent over 16km.
To avoid frequent accidents and expensive engines that had the power to bring the train up the hill, the railway built two spiral tunnels on either side that opened in 1909. They added some length to the track, but reduced the grade to 2.2%.
The initial plan was to bore (or blast) a 430m long tunnel through Mount Stephen, but to complete the railway as soon as possible they built a temporary 13km line over it. A temporary line that became permanent until the spiral tunnels were built.
This is why I say that you can never assume something will be temporary, you have to design it like it will be permanent, because once it’s in, you have no control over it.
The first construction train that went over the pass ran away on the descent and landed in the Kicking Horse River, killing three. The railway added three safety switches or runaways to protect against runaway trains. The switches were short uphill spurs controlled by the operator and trains had to complete elaborate brake testing before descending the hills. Speed was restricted to 13kph for passenger trains and 9.7kph for freight.
Despite all of these safety features, accidents still occurred frequently.
There are also runaway lanes for vehicle traffic. I’ve never seen it in use, but it’s nice to know it's there.
The town of Field, BC was created as a work camp to accommodate the extra locomotives needed to tackle the Big Hill. And I mean this in the nicest way, but driving through Field, it looks like a work camp.
In Field they built a stone roundhouse with a turntable, known as the Third Siding before being renamed Field in 1884 after a Chicago businessman that the railway wanted to invest in the region. Spoiler alert, he didn’t. Fun fact about Field the businessman, he also invested in the first transatlantic telegraph cable that we talked about in episode 31.
Prior to the rail track across the big hill, standard steam locomotives were 4-4-0s. These were fine for the prairies, but not for the bill hill and a new engine was needed which led to production of hundreds of 2-8-0s over the years.
After 24 years of the temporary line they decided they needed to improve the route. They looked at a few alternate routes that were shallower grade, but the areas were prone to avalanches, rockfall and mudslides which caused worse delays and disruptions than the accidents.
And so the spiral tunnels were born; the brainchild of railway engineer J.E. Schwitzer. They are two tunnels driven in three quarter circles. We will include pictures on the webpage for this episode at Failurology.ca.
The higher tunnel, called number one, is 910m long and runs under Cathedral Mountain south of the original track. The train heads south into the tunnel and when it emerges it doubles back 17m under itself, heading north, and crosses back across the valley and across Kicking Horse River.
It then enters Mount Ogden to the north of the original track in the lower tunnel, called number two. This one is a bit shorter than number one but the descent is similar at 15m. The train enters the tunnel going north and exits heading southwest and meets back up with the original track and heads into Field.
The contract for the tunnels was awarded to a Vancouver engineering firm and work started in 1907 with 1000 workers and a cost of $1.5 million. Which is about $47 million today. Pretty low price based on the cost of construction projects today.
The Kicking Horse Pass was designated a National Historic Site in 1971.
Today, an average of 25-30 trains pass through the tunnels every day. You can see them in two spots.
From the viewpoint 7.4 km east of Field on the Trans-Canada Highway, you can see the Lower Spiral Tunnel in Mt. Ogden.
The Upper Spiral Tunnel in Cathedral Mountain can be seen from the pull-off 2.3 km up the Yoho Valley Road.
I think I will check those out next time I’m driving through.
Accidents still happen, although less so with the tunnels. There have been 64 derailments between Calgary and Field between 2004 and 2019. On February 4, 2019 two of the three locomotives and 99 grain hopper railcars heading westbound derailed just after the upper tunnel. Three crew members were killed in the accident.
So there you have it, the Spiral Tunnels of Kicking Horse Pass. An fantastic engineered solution to the dangerous mountain pass that’s still in use 115 years later. Too bad it’s not used for passenger travel, I would love to ride on this route.
For photos, sources and an episode summary from this week’s episode head to Failurology.ca. If you’re enjoying what you’re hearing, please rate, review and subscribe to Failurology, so more people can find us. If you want to chat with us, our Twitter handle is @failurology, you can email us email@example.com, you can connect with us on Linked In or you can message us on our Patreon page. Check out the show notes for links to all of these. Thanks, everyone for listening. And tune in to the next episode where we will be talking about wind turbine failures. We will also have a special guest joining us for this episode. You don’t want to miss it.
Bye everyone, talk soon!