Though this sector had been for a long period a quiet one, the German artillery concentration opposite it was already great, especially in heavy long range guns, partly because the arc of many of their coast defence batteries covered more or less of the land front, and for the most part were already behind concrete emplacements. Normal trenches in this terrain were impossible, and both sides stood behind breastworks that in the dunes were merely gabions filled with sand; but here, as on the Ypres front, the liberal use of concrete by the enemy had given his front-line troops, as well as his batteries and command posts, the protection of many “pill-boxes” and concrete shelters of various forms. For a long period the French had held the sector comparatively lightly; consequently the whole of the titanic task of mounting a trench warfare offensive fell on the incoming corps. On such terrain the preparations presented extreme and unique difficulties, and those of Signals were enhanced by the fact that not only did the nature of the ground forbid deep cable buries, but very few shallow ones existed; while the existing communications—naturally inadequate—were almost entirely open wire to within four thousand yards of the front line, and sited along roads certain to be heavily shelled. British divisions began to arrive in the area on the 15th, bringing the absent cable sections of the Company with them, and between the 20th and 23rd the French divisions in line were relieved by the 1st and 32nd Divisions. Thereafter the Corps Heavy Artillery commenced to move in, the H.A. Signal Section and B.E. Section proceeding to the late French Heavy Artillery Headquarters, D.C.A.L. to a small copse about two miles south of Nieuport, and B.G. Section to Coxyde to prepare for the establishment of a forward exchange. After a rapid survey of the area, a communication scheme to meet the needs of Corps, Divisions, and the Heavy Artillery on a hitherto unprecedented scale was prepared. Meanwhile the various sections toiled at the familiar task of connecting up the units that were streaming into the area daily, and preparing the new Corps Headquarters at Bray-Dunes Plage—a small watering-place south of La Panne. The H.A. Section had, even with the assistance of B.E. Section, a particularly strenuous task in coping with the concentration of eleven groups of “heavies,” and found it necessary to endeavour to bring into use at once the incomplete French buries. By an evil stroke of luck, the material ordered for this purpose was delayed over a fortnight by the truck containing it being railed to Péronne instead of Dunkirk, owing to the extreme secrecy that enshrouded the movements of the Corps.