After the battle of Messines, the 2nd Brigade (A and B Battalions) had assembled at Ouderdom, so the present concentration only involved moving the 1st Brigade (D and G Battalions), and the 3rd Brigade (F and C Battalions) to Oosthoek. Seven trains were required for each of these Brigades.
At about this time it was decided that the 1st Brigade should be allotted to the XVIIIth Corps, the 3rd Brigade to the XIXth Corps, and the 2nd Brigade to the IInd Corps; brigade commanders were, therefore, instructed to place themselves in touch with these corps and commence preparations.
The preparations required varied considerably from those for former battles. The Ypres-Comines canal, running parallel to the front of attack, formed a considerable obstacle to tank movement; consequently, causeways had to be built over the canal as well as over the Kemmelbeek and the Lombartbeek. This work was carried out by the 184th Tunnelling Company, which was attached to the Heavy Branch for the purpose. The work this unit carried out, normally under severe shell fire, was most efficient and praiseworthy. Besides the building of these causeways and the usual supply preparations, thoroughly efficient signalling communication was arranged for, including the use of a certain number of tanks fitted with wireless installations.
The reconnaissance work of the battalions was greatly facilitated by that already carried out by the advanced headquarters party. Oblique aerial photographs were provided for each tank commander, and plasticine models of every part of the eventual battle area were carefully prepared, the shelled zone being stencilled on them as the bombardment proceeded. To facilitate the movement of tanks over the battlefield a new system was made use of by which a list of compass bearings from well-defined points to a number of features in the enemy’s territory was prepared, thus enabling direction to be picked up easily. The distribution of information was more rapid than it had been on previous occasions. Constant discussions between the Brigade and Battalion Reconnaissance officers led to a complete liaison; in fact, everything possible was done to make the tank operations a success; further, there was ample time to do it in.
The Fifth Army attack was to be carried out on well recognised lines; namely, a lengthy artillery preparation followed by an infantry attack on a large scale and infantry exploitation until resistance became severe, when the advance would be halted and a further organised attack prepared on the same scale. This methodical progression was to be continued until the exhaustion of the German reserves[25] and moral created a situation which would enable a complete break-through to be effected.
The number of tanks allotted to the three attacking Corps was as follows: seventy-two to each of the IInd and XIXth Corps, thirty-six to the XVIIIth, and thirty-six to be held in Army reserve. These were subdivided according to objectives, namely:
| IInd Corps. | XIXth Corps. | XVIIIth Corps. | |
| Black Line | 16 tanks | 24 tanks | 12 tanks |
| Green Line | 24 „ | 24 „ | 12 „ |
| East of Green Line | 8 „ | ||
| Corps Reserve | 24 „ | 24 „ | 12 „ |
The Corps objectives and the allotment of tanks to Divisions were as follows:
In the IInd Corps the 24th and 30th Divisions supported by the 18th Division were to attack on the right, and the 8th Division, supported by the 25th Division, on the left. The general objective of the operations was the capture of the Broodseinde ridge, and the protection of the right flank of the Fifth Army. The allotment of tanks to Divisions was: twelve to the 30th Division, eight to the 18th Division, twenty-four to the 8th Division, and four to the 24th Division.
In the XIXth Corps the 15th Division was on the right and the 55th Division on the left, with the 16th and 36th Divisions in reserve. The objective of this Corps was to capture and hold a section of the enemy’s third-line system known as the Gheluvelt-Langemarck line. Twenty-four tanks were allotted to each of the attacking divisions.