Hi all,
I'm looking for a hiking and scrambling grade conversion chart (if one exists) or help in creating one. There are plenty of examples online and in guidebooks of climbing grade conversions, but none of these go below the level of technical rock climbing to include scrambling and off-trail hiking. I've found some information about some of the commonly used grading systems such as the Swiss Alpine Club scale and the Ashton system used in the UK. Based only on reading the descriptions and looking at example pictures, I've attempted to put my own grade conversion chart together.

Since I only have experience in the Yosemite Decimal System, I don't know if my conversions are actually reasonable. Feedback from the members of the summitpost community who have experience with multiple systems could be very helpful in improving this chart. In particular I'm looking for suggestions or references on converting between any two systems and other grading systems that I may have omitted. What I have so far is included below. I've also created a google spreadsheet that anyone can edit simply by copying the first sheet to a new sheet of their own.



This task is a bit challenging not just because of the subjectivity in any one of these systems, but because some of them incorporate different factors into the grade such as length, elevation gain, or exposure. Ideally, I'd like to best match each system to the Swiss Alpine Club scale which only considers difficulty and exposure, and ignore other factors (e.g. length or elevation gain) that might exist in another system.

The primary reason I'm interested in obtaining or creating such a chart is to aid mapping of these routes in OpenStreetMap. For those of you who don't know, OpenStreetMap is an open data initiative where anyone can contribute to a global database of geographic features, and maps can be rendered from these features in different styles for different purposes (there are many more applications too). Hiking trails in OpenStreetMap (lines tagged as highway=path) can be tagged with a difficulty rating in the Swiss Alpine Club scale (e.g. sac_scale="alpine_hiking"). Using a single system should enable consistent tagging and map creation for everywhere on the globe. The problem is that mappers such as myself are sometimes confused as to how to translate from their local system into the SAC scale. I've noticed some routes in my local area which appear incorrectly tagged. For example, the standard route up Mount Elbert is tagged as sac_scale="alpine_hiking" (or T5) even though this is a class 2 hike that most people could complete with their hands in their pockets. My initial goal is to reduce incorrect tagging in OpenStreetMap, but a conversion chart might also be helpful to other summitpost users hiking abroad.

Thanks for the help and sorry for the long first post,
Steve

stevenf wrote:For example, the standard route up Mount Elbert is tagged as sac_scale="alpine_hiking" (or T5) even though this is a class 2 hike that most people could complete with their hands in their pockets.

Actually, the 2 easiest routes on Elbert would be class 1 as they are both maintained trails.

It's been almost a month since my original post.
No one on this forum has experience with scrambling in multiple parts of the world? I find that hard to believe.

Unfortunately I can't think of another online forum that might be more helpful, backpackinglight maybe?

Maybe there is a reason that none of the ratings go below the level of technical rock climbing. I think the US 1-4 scale is accurate enough and people, knowing their skills will then factor in distance, time and elevation to come to a personal conclusion. Can you really have two levels of level 2 hiking?

I'll add that if you look at terrain or climate I guess you can argue that a class I in death valley is different than a class 1 in Antarctica but is one harder than the other. A walk at 14k is harder than a walk at 3k but I'm not sure you can work that into a universal scale.

In the US Yosemite system hiking is separated into class 1 which is on trail and class 2 which is off trail and may involve using your hands for balance. Class 3 is scrambling and Class 4 is scrambling/easy climbing with high exposure.
From what I can tell the other systems are fairly similar to the Yosemite system in the way they rank difficulty. There are some subtle differences in where grade separations occur between the systems though. That's why I was hoping someone with more experience could help me translate between them.