A Cog Is...

So What is a Cog?

A cog, or rack, railroad uses a gear, "cog wheel", meshing into a special rack rail (mounted in the middle between the outer rails) to climb much steeper grades than those possible with a standard adhesion railroad.

See the middle part of the railroad track? Where there are 3 parallel lines instead of the standard two? That's where those cog's are. This helps climb the steep sections and keep a slow decent on the way down.

An adhesion railroad (regular train on flat distances) can only climb grades of 4 to 6%, with very short sections of up to 9%. This is measure as the number of feet in elevation gained for every 100 feet in distance. A "rack" railroad can climb grades of up to 48% (such as in Switzerland), depending upon the type of rack system employed.
Here is the explanation from the US Department of Transportation.

Q-2. What is the maximum grade hill a railcar can climb?
A. Railroad
grades are more or less determined by available locomotive horsepower and
traction efforts required to pull a specified number of railroad cars up a
grade, as well as the braking effort required to control the movement when going
down the grade.

Railroad grades are expressed in terms of the rise or fall of elevation
over distance. For instance, a 1 percent grade would be a one-foot rise or fall
of elevation over a distance of 100 feet.

The Manitou and Pikes Peak Railway Cog can travel at up to a 25% grade going up the mountain. It reaches a top speed of 9 miles per hour.

Above the clouds at the top of the mountain. There were 2 cog's running the day of our trip. There are sections where the two can pass on parallel tracks on the mountain.

Learn more by going to the Pikes Peak Cog Railway Site.
Pssst! Did you see the new pictures in the slide show on the left side of the blog?

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