(a) Red ground flares will be used to indicate the infantry positions to contact aeroplanes. They will be lit by infantry in the most advanced line only.
(b) A contact aeroplane will fly along the line of the first objective at zero plus 2 hours 30 minutes. Flares will be called for by the aeroplane sounding a succession of "A's" on the Klaxon horn and by firing a white Very Light. If the aeroplane fails to mark the line accurately, it will repeat its call ten minutes later.
Should the infantry not have reached the line of the objective at the time laid down above, the contact aeroplane will return at half-hour intervals until flares are shown.
(c) A contact aeroplane will fly along the line of the second objective at zero plus 6 hours 30 minutes. It will call for flares, and the same procedure will be followed on this objective as on the first objective until the flares are seen.
(d) A contact aeroplane will fly over third objective at zero plus 7 hours, when the procedure laid down for the first objective will be observed until the flares are shown.
(e) Divisions will organize message-dropping stations in the vicinity of their Headquarters.
(a) Rifles.—Three or four rifles laid parallel across the top of the trench.
(b) Metal Discs.—Metal discs will be used as reflectors by flashing in the sun. This method has been successful even on days which have not been particularly bright.
The disc is most easily carried sewn to the Small Box Respirator, and can be used in this way without inconvenience.
(a) From zero hour counter-attack planes will be constantly in the air, with the object of observing hostile concentrations or abnormal movement.
(b) In the event of an enemy concentration indicating a counter-attack, the counter-attack aeroplane will signal this information to the Artillery by wireless. In the case of a counter-attack actually developing a white parachute flare will be fired by the aeroplane in the direction of the troops moving for the impending counter-attack, for the information of the Infantry.
(a) Aeroplanes will be detailed to transport ammunition from zero plus 2 hours 30 minutes.
(b) Vickers guns will display a white "V" at the point where ammunition is to be dropped. The arms of the "V" to be 6 feet in length and 1 foot in width. The apex of the "V" to point towards the enemy.
(c) Ammunition aeroplanes will have the under-side of the lower planes painted black for a distance of 2½ feet from the tips.
Battle Instructions No. 12
CONSOLIDATION
1. Divisions allotted to First Objective.
(a) Consolidation.—As soon as the first objective has been captured troops will dig in.
(b) Troops holding present front line.—The brigades of 2nd and 3rd Australian Divisions holding the line on the night prior to zero will remain in their battle positions until all troops detailed to the attack have passed through. They will then be organized and prepared to move to meet any emergency.
2nd Australian Division will be prepared to detach its brigade to act in support of 5th Australian Division, and 3rd Australian Division to detach its brigade in support of 4th Australian Division.
(c) Reorganization of Troops on First Objective.—As soon as the whole of the troops detailed to the capture of second (red line) and third (blue line) objectives have passed through the line of the first objective, 2nd and 3rd Australian Divisions will organize the defence of their sectors on the first objective in depth in each brigade sub-sector. Units will be reorganized, and those not detailed to the defence of the line will be withdrawn into support and held in readiness for eventualities. At least one battalion in each brigade sub-sector should be withdrawn in this way.
2. Second Objective.
Consolidation.—As soon as the second objective (the red line) has been captured, the position will be thoroughly consolidated. Arrangements will be made to ensure a supply of engineering material for this.
3. Main Line of Resistance.