1000m. The route winds it way up the North face (Nant blanc face) of the Aiguille sans Nom. Start at the toe of the buttress to the right of the charlet - platanov route. A few tricky mixed pitches on this buttress (M4-5) then on to the ice slope pretty much straight up for 300m at about 60 degrees with short sections 70-75 degrees, to a head wall. Climb some steep gullies with ice up to 90 degrees exiting onto the main ridge. Head up to the Aiguille Verte and down the Whymper Couloir.
Cohen & Collister 1976