For duty with the Services of Supply, the 106th Engineers, without Train, relocated from Le Havre to Brest on 4 October. Once in France, the 31st was planned to become the seventh depot division, a cadre formation responsible for processing replacements. Due to a personnel shortage caused by heavy casualties suffered in the Meuse–Argonne Offensive, the 31st Division was ordered skeletonized on 17 October, and two days later the division headquarters, both infantry brigades, the 116th Machine Gun Battalion, 106th Supply Train, and 106th Train Headquarters and Military Police moved to Le Mans, with some units relocating through the Loches area, while the remaining units were detached from the division when they arrived at Brest. The division was ordered reduced to a record cadre on 29 October, although the 56th Field Artillery Brigade was detached to Camp Coëtquidan for training. The 106th Trench Mortar Battery of the brigade relocated to Vitrey on 4 November, preceded by the 106th Field Signal Battalion, which left for the Signal Corps Replacement Depot at Cour-Cheverny on 30 October.