Estimating Pitch

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Estimating Pitch

Postby cheesehead » Wed May 14, 2014 9:09 am

What is a good way to get an eyeball estimate of pitch? I am not looking for some kind of instrument to do that. Just a reliable technique to get in the ballpark. And what are the angles generally considered steep? Or blue vs. black? I know difficulty is related to the path width, turning, terrain, etc. but, again, a ballpark -- is 30 degrees blue? 45 degrees black? And how many degrees is considered extreme? That great picture Harald uses on the home page of his blog, from someplace in Europe, how many degrees is that?

I am not looking for any precision, just to get an idea of how to translate degrees to "steepness" and how to judge the steepness of what I am skiing on.
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Re: Estimating Pitch

Postby Erik » Wed May 14, 2014 12:44 pm

cheesehead wrote:What is a good way to get an eyeball estimate of pitch? I am not looking for some kind of instrument to do that. Just a reliable technique to get in the ballpark. And what are the angles generally considered steep? Or blue vs. black? I know difficulty is related to the path width, turning, terrain, etc. but, again, a ballpark -- is 30 degrees blue? 45 degrees black? And how many degrees is considered extreme? That great picture Harald uses on the home page of his blog, from someplace in Europe, how many degrees is that?

I am not looking for any precision, just to get an idea of how to translate degrees to "steepness" and how to judge the steepness of what I am skiing on.


The designations of pitch can be confusing sometimes. A 45 degree slope is equivalent to 100% grade. (see:http://wiki.fis-ski.com/index.php/Image:Grades_degrees.png )Typically, anything over 50% grade (about 26 degrees) is rated as expert. So 45 degrees is seriously steep. A 45 degree slope requires a winch cat to groom it. Blues are often in the 12-25 degree range.

At http://www.3dskimaps.com you can see a mapping of slope angles at many well-known ski areas. The legend on the ski maps shows their mapping of slope to difficulty levels (which is a highly variable and subjective mapping from one resort to another). If you find one of those areas where you have skied, it may give you a reference point for the amount of slope on runs that you know. The mappings there may not capture some of the smaller-scale features that could have a higher slope.

One simple way to judge 45 degrees would be to stand sideways on the hill with the downhill pole tip just touching the snow. On a 45 degree slope, if you kept your hand in the same location and held the pole horizontally toward the slope, the tip would just be touching the slope uphill. If the slope was less than 45 degrees, the horizontal pole would be off the snow.
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Re: Estimating Pitch

Postby kirtland » Wed May 14, 2014 2:55 pm

To keep pitch steepness claims in perspective, I find it convenient to think in terms of the angle of repose of the material that makes up the slope. For the common materials granite (rock and boulders), basalt and andesite the angle of repose is 35 to 40 degrees, for and average of 37.5 degrees. So unless the slope is made up of of solid rock it is not going to exceed the angle of repose of the material which make up the slope.
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Re: Estimating Pitch

Postby milesb » Thu May 15, 2014 8:15 pm

That depends on the depth and condition of the snow on top of the material. 30 feet of snow is usually going to lessen a pitch. However, wind can shape that snow into a much steeper pitch, the extreme example being a cornice.
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