Overview
The couloir is an obvious vertical line on the right from Migot spur.
Good condition to climb it is when it's cold.
Getting There
Approach the start of the route via glacier du Tour. The route is easy to find as it is an obvious vertical line on the right from Migot spur. ~2-3hr from Albert 1er hut.
There's a bergshrund crevasse which can be crossed via a snow bridge, depending on conditions.
Route Description
The Griffin guidebook description is very concise and mentions that the gully is climbed in two steep pitches. There's a bolt about the middle of the gully but belays are possible on rock sides of the ice couloir.
Start of the couloir is steep and mixed and it gets wider and less steep the higher it gets.
Climb sections:
0. Berg to the start of the couloir. Can be climbed via the middle or keeping left under rocks. R0-R1 on the topo.
1. Steep Mixed/ice up to 75/85deg 20m. Bottom section of R1-R2 on the topo.
2. Ice couloir 3-4 pitches ~60/65deg 100m. Bolt belay mid-couloir. R1-R2 on the topo.
3. Ice slope/wide couloir ~55deg 200m. R2-R3 on the topo.
4. Ice/snow slope below summit ~50deg 100m. R3-R4 on the topo.
Descent via normal route, starting from the summit via NW ridge for 40-50m then bearing right down a wide gully which is not steep. Descend keeping to the right for 70-120m and cross an unpronounced saddle to the right. Do not go left to a wide couloir which leads to Argentière glacier. GPS UTM 32 T 344989 5092527. Abseils possible from some in situ slings here or downclimb depending on condition. There are several options to abseil over rock drops towards Col Supérieur Adams Reilly from in situ anchors (one particular sling was found at GPS UTM 32 T 344935 5092556). After abseils, descend to glacier l'Épaule following steep snow slope, crossing bergshrund with care (the crevasse is wide and an abseil may be needed). Walk down to glacier du Tour keeping to the right from a rocky outcrop. ~4 hr summit to hut.
Even on summer the couloir never sees the sun and the slope above gets sun only in the afternoon.