Conscious of its weakness in artillery material, the British Command hoped to compass the demoralisation of the foe by a discharge of gas along the front of the principal onslaught. This was the first occasion on which the British Army used gas,[7] and it was hoped that its effect would so paralyse the defenders that the assaulting troops would be able to secure with little resistance the German second line in spite of the wire that was too far distant for the artillery to cut.
The task of forming the northern defensive flank[8] of this attack was entrusted to the Ninth Division, which, after carrying the line Railway Work—Fosse No. 8—to Haisnes, was to push on to Douvrin. Similarly, the southern division of the IV. Corps was to form a defensive flank facing south near Loos. If these flanks were secured and consolidated, it was expected that the intermediate divisions of the I. and IV. Corps, supported by the XI., would be able to force their way between these flanks as far as the Deule Canal, and even farther if the resistance of the enemy was negligible.
There was a gap between the right of the British forces and the left of the Tenth French Army. In this area lay the colliery district of Lens, consisting of masses of miners’ cottages, pits, and slag-heaps, admirably adapted for an obstinate and protracted defence. During the French offensive north of Arras in May and June advance had been slow and losses heavy, owing to the stubborn opposition of the Germans posted in the villages of Carency, Givenchy, and Souchez. The Lens area afforded even greater advantages to the defenders, and it was decided that the French and British forces should work round the south and north of the town and join hands to the east of it.
An operation of importance involves an enormous amount of hard work and anxiety for all branches of the Staff, from G.H.Q. down to brigades. The Staff[9] is the brain of the Army, and its function is to supply everything—from bombs to operation orders. It consists of two distinct branches: the A. and Q. branch, which is responsible for discipline, procuring supplies, and making arrangements for the comfort of the troops in such matters as billets and baths; and the G. branch, which is concerned with training and operations. For success, the best devised plan depends greatly upon the care with which details are worked out. The actual attack is made by the infantry. Upon the dash and gallantry of the soldiers and the initiative and resource of the subordinate commanders, the Higher Command has to rely for the consummation of its hopes; but the arduous task of the infantry is considerably eased if the preliminary preparations are the best possible from the resources at the disposal of the Staff. Good Staff work consists in eliminating chance and hazard and in strengthening assurance of success.
The frontage on which the Ninth Division was to assault was 1600 yards. On the 16th August, the G.O.C., Major-General Landon, held a conference, when the proposed operations were discussed. It was decided to assault with two brigades, each with two battalions in the front line, the 26th on the right and the 28th on the left, with the 27th in reserve.
The objectives of the 26th Brigade were, first, the Hohenzollern Redoubt, Fosse Trench and Dump Trench; and second, a line on the east side of Fosse 8 through the Three Cabarets to the Corons de Pekin (first objective). Should this task be accomplished, the brigade was to go on to the neighbourhood of Pekin Trench (second objective). If at this stage the line was prolonged to the north by the 28th Brigade and the Second Division, the 26th and 28th were to advance east on Douvrin. Should, however, the Second Division fail, these brigades were to attack Haisnes and form a defensive flank facing north-east.
On the left, the 28th Brigade had first to secure the Railway line from the Corons de Marons to the junction of Les Briques and Train Alley (first objective), and then advance to its second objective in the neighbourhood of Pekin Trench. The further action of the brigade depended upon the progress of the Second Division.
The 27th Brigade was to be in reserve some 2000 and 2800 yards in rear of the front line. Its rôle was either to support the attempt on Fosse 8, or if that was successful, to move on to Haisnes and Douvrin. Battalion commanders were given a free hand as to the formations to be adopted, subject to the proviso that each unit was to be in three lines.
The date of battle, after several postponements, was eventually fixed for the 25th September.
The task of the Division in its first important engagement was not an easy one. In the excitement of battle even the best of soldiers are liable to go astray if they are required to change direction at any time during the advance. For this reason it is desirable that objectives should be allotted so that it is possible for the assailing troops to advance at right angles to their position of assembly. In the present case the advance in a north-easterly direction up to the line of the Fosse fulfilled these conditions, but from this point the Ninth was required to swing east and converge on a narrower front. Fortunately the difficulties of this operation were diminished by the presence of such conspicuous landmarks as the villages of Haisnes, Cité St Elie and Douvrin, but it was nevertheless an extremely complicated one for an untried division to undertake.