Most crevasse rescue texts (and classes) suggest rigging in the same manner for all glacier travel. However, common sense and some experience tells you that there is a very wide range of risk involved in glacier travel, and that complex rigging takes time to put on and take off. Sometimes you’ll be on a mellow glacier like the Hayden on the east approach to Middle Sister in Oregon, with low angles, consolidated summer snow and just a few easily seen open crevasses. Other times, you may be on Rainier in late season, walking on what feels like a minefield, probing every step with the real possibility of a big plunge.
Consider different rigging for these different scenarios. You might think of the risk level as ‘green – yellow – red”, with green being easy travel, and red being the riskiest.
A few examples in the Pacific NW:
Green: Hayden Glacier, summer conditions, Middle Sister, Oregon Cascades. Have prusiks and anchor gear accessible on your harness, but not necessarily on the rope.
Yellow: Coleman Deming, Mt. Baker, WA Cascades. Moderate fall potential, crevasses plentiful and mostly visible. Waist prusik on rope, leg prusik not on rope but accessible, anchor gear accessible.
Red: Emmons Glacier Mt. Rainier, after a late summer storm barely covers plentiful wide open crevasses. Each team member has waist and leg prusiks on rope, full anchor building gear ready to go, leader has an extended trekking pole with basket removed to probe suspect areas.
This tip is from book, “Alpine Climbing: Techniques to Take You Higher” by Mark Houston and Kathy Cosley, The Mountaineers Press