After some readjustments of frontage in December, the XV. Corps settled down to hold the sector in front of the Lys, from Houplines to Laventie, with the Portuguese Corps on the right and the Anzac Corps on the left. In January 1918 Corps Headquarters were shifted from Hinges to La Motte-aux-Bois in front of the Forest of Nieppe, and Heavy Artillery, with the H.A. and B.E. sections, to Estaires, where 51 Air Line was already established. A further reorganization of the Company now took place. As cable sections rarely, if ever, performed the mobile work for which their horse transport was provided, the decision was reached to disband one cable section in each Corps, to reduce the strength of the Corps air line section to forty-two all ranks with one heavy and two light lorries, and with the surplus _personnel_ so accruing form an additional air line for each Corps. B.G. section was, accordingly, converted into the nucleus of the new 91 Air Line Section, to which Lieutenant Dobson was appointed. At the same time, “Q” Wireless Section became an integral portion of the Signal Company, and was taken over by Lieutenant McArthur, with 2nd Lieutenant FitzGeorge as second officer, the Imperial _personnel_ being rapidly replaced by South Africans. A second officer was also authorized for the Heavy Artillery Section, and Lieutenant M. Cohen, who had been attached to a brigade of the 8th Division since his arrival from England in November 1917, was appointed. The communications here were such as would serve on a thinly held and lightly shelled front. Buries were few and becoming inefficient with age; the light open-wire routes which formed the bulk of the communication were run close up to the front line. The defection of Russia made it certain that the Allies would be thrown on the defensive in the spring; and as the Lys covered Hazebrouck and the direct route to Calais, it was probable that the sector would become a main front of attack. Ample and secure communications were, therefore, a first necessity, and a complete scheme was prepared on a scale of magnitude and thoroughness which surpassed any previous performance. All trenches were to be seven feet deep and carry no less than thirty pairs of wires.