SCHEME FOR ARTILLERY SUPORT.
The Artillery available will probably consist of the following:-
(a) 12, 18-pounder batteries of the 18th Division.
6, 18-pounder batteries of the “Z” Division.
(b) 3, 4.5” Howitzer batteries of the 18th Division
1, 4.5” Howitzer battery of the “Z” Division.
All batteries consist of 4 guns unless otherwise stated.
A total of 72 18-pounder guns and 16 4.5” Howitzers.
- OBJECTS TO BE ATTAINED BY DIVISIONAL ARTILLERY.
The objects to be attained by the Divisional Artillery will be
(a) Wire Cutting. The extent of wire to be cut amounts to rather more than 9,000 yards. On the assumption that the bombardment is to last for five days, 1,800 yards require cutting daily.
It is proposed to allot 15 4-gun 18-pounder batteries = 60 guns for this task.
An expenditure of 8 rounds per yard of wire is taken as the maximum amount required.
The following shows approximately the number of yards per battery, per gun, and amount of ammunition to be fired per gun per day for the purpose.
15 batteries = 120 yards per battery = 30 yards per gun = 240 rounds per gun per day.
(b) Destruction of trenches etc.
This will be undertaken by the heavy howitzers assisted by fire from the 4.5” howitzers, and considerable damage will be caused to the hostile parapets, etc., by the fire of the 18-pounders during the process of wire cutting. The 4.5” howitzers assisted by the 2” Trench Mortars on the hostile front trenches will deal with all known machine gun emplacements and sniper’s posts etc.
(c) Blocking of Communication Trenches.
This will be undertaken by the 4.5” howitzers assisted by enfilade fire from the 18-pounders.
(d) Preventing repair of the damage caused to the hostile trenches and wire entanglements. This will be carried out by the 18-pounders, assisted by machine gun fire.
(e) The shelling of roads and approaches in rear of the enemy’s position. These within range of the Field Artillery will be undertaken by the 18-pounders, those beyond by fire from the Counter Battery Group.
(f) Destruction of Observation Posts.
This will be undertaken towards the end of the bombardment.
(g) Protection of the present line in case of a surprise attack.
(h) To support the assault.
(i) To form an effective barrage of fire across the whole of the new front.
(j) To be able to place an effective barrage on both flanks of the attack should the occasion arise.
The Artillery of the 18th Division, reinforced by six 18-pounder batteries and one 4.5” howitzer battery of the “Z” Division, will be grouped as follows:-
Group Position of H.Q. Commander Composition
Right BILLON VALLEY Lt. Col D.G. Blois D.S.O. 3 18-pr Bties 84th Bde R.F.A.
1 4.5” Bty “ “ “
1 18-pr Bty 85th Bde R.F.A.
2 18-pr Bties “Z” Division
Total 7 batteries
Centre BILLON WOOD Lt. Col Seagram 3 18-pr Bties 83rd Bde R.F.A.
1 4.5” Bty 83rd Bde R.F.A.
1 18-pr Bty 85th Bde R.F.A. 2 18-pr Bties ”Z” Division
Total 7 batteries
Left BILLON FARM Lt. Col A. Thorp 3 18-pr Bties 82nd Bde R.F.A.
1 4.5” Bty 82nd Bde R.F.A.
2 18-pr Bties ”Z” Division
1 18-pr Bty 85th Bde R.F.A.
1 4.5” Bty ”Z” Division.
Total 8 batteries
This grouping of the Divisional Artillery and the positions selected for the Hd. Qrs. Of each group have been arranged with a view to simplifying the communications between the Artillery and the Infantry, and thus ensuring that, as far as may be possible, close touch is maintained between the two arms throughout the operation. The Artillery Group Commander thus becomes the LIAISON Officer at each Infantry Brigade Headquarters, as long as the latter remains in its present position.
The Right Group will be affiliated to the 55th Infantry Bde.
The Centre Group will be affiliated to the 53rd Infantry Bde.
The Left Group will be affiliated to the 54th Infantry Bde.
The zones allotted to the three Artillery groups are practically the same as the fronts told off to the Infantry Brigade to which they are affiliated.
One 18-pounder battery of each group and one 4.5” battery attached to the Centre Group will be sited within 1,600 yards of the hostile front trenches. These guns and howitzers will be available to open fire shortly before the attack, and will form the framework of the barrage of fire in front of the furthest objective. The range to this front being about 3,500 yards. In addition, the remaining guns of the Division will be capable of supporting from their present positions the new front at a range of about 5,000 yards. It should not be necessary, therefore, to have to move batteries forward during, or shortly after, the attack.
These have been prepared along PERONNE AVENUE, in vicinity ”U” Works, on Hill 124, and in square F.17.d.
These observation posts have been made as strong as possible, and provided with deep dugouts.
In addition to these each battery employed to cut wire will be provided with a post in the front system of trenches.
These will be duplicated in all cases and wherever possible triplicated. Those from Group H.Q. to batteries and from batteries to observing stations will be either placed dug in two feet below the bottom of communication trenches or else buried in separate trenches 6 feet deep.
Arrangements will be made for visual signalling from selected points in German lines to the Observation Stations.
An Artillery officer will be told off for this duty to each battalion taking part in the attack. Similarly, an officer from each Group will be detailed to act as Liaison Officer at Infantry Brigade H.Q. in the event of this H.Q. moving forward beyond present sites selected.
Each battery position will be capable of accommodating 1,500 rounds in the case of 18-pounders, and 1.250 rounds in the case of the 4.5” Howitzers. This amount should be sufficient for operations extending over 5 days.
Under instructions received up to the present, all battery vehicles will be kept full, 1,000 rounds per gun will be dumped at or near the guns, and a further reserve of 250 rounds per gun will be dumped in a Divisional Reserve in the BOIS DES TAILLES.
Positions are at present being prepared for 4 7 6 Batteries of Medium Trench Mortars distributed along the front of attack. These mortars will be employed in destruction of wire and first line trenches.
Positions have been selected for four Heavy Trench Mortars. These positions are so sited as to cover the whole front of attack to a depth of from three to five hundred yards at their maximum range. Junctions of trenches and dug-outs in rear of front line will be dealt with by these mortars.
- Definite tasks will be allotted to all Heavy and Medium Trench Mortars, and time-table of tasks issued to all Trench Mortar Batteries.
- In order to minimise the chance of trench mortars being located by the enemy, it is proposed to keep these batteries silent during the first day of the bombardment.
- Up to the hour of assault all Medium and Heavy Trench Mortar Batteries will be supervised and controlled by the Divisional Trench Mortar Officer, who will be in CARNOY for this purpose and in telephone communication with Divisional Artillery H.Q.
- After the assault, certain Medium Trench Mortar Batteries will be controlled by Infantry Brigades, and used for forward work.
- FIVE DAYS PRELIMINARY BOMBARDMANT.
During the five days previous to the Assault, the Divisional Artillery will be engaged on the following tasks:-
It is proposed in the first place to engage the wire on the front trench (and support trench when the latter is close) with Medium Trench Mortars, and to complete the work on any portion of uncut wire with 18-pounders.
For details of wire cutting by 18-pounders, see Appendix A.
(b) DESTRUCTION OF TRENCHES.
Heavy and Medium Trench Mortars will be employed for this task on the front system of trenches, assisted by the 4.5” Howitzer Batteries, who will also engage points further in rear.
(c) PREVENTING REPAIR OF WIRE AND TRENCHES AT NIGHT.
18-pounders and 4.5” howitzers will be responsible for definite fronts, and subject the portions of the enemy’s trenches which have been previously destroyed to irregular bursts of fire throughout the night.
The Divisional Artillery will be assisted by machine guns in this task.
(d) SHELLING OF APPROACHES.
All approaches within range of Divisional Artillery will be subjected to barrages at irregular intervals.
(e) DEFENSIVE BARRAGE.
Definite defensive barrages will be allotted to 18-pounder batteries, in such a manner as to be able to establish a heavy barrage in the event of any German attack or minor enterprise.
- PROGRAMME OF PRELIMINARY BOMBARDMENT.
The following is the proposed programme for five days preliminary bombardment.
1st Day. 18-pounder wire cutting in accordance with Appendix A. 4.5” howitzers.
“U” communication trenches, trench junctions, strong points, approaches etc. Heavy and Medium Trench Mortars remain silent to avoid detection.
2nd Day. 18-pounder wire cutting in accordance with Appendix A.
“V” Approaches and communications.
4.5” howitzers, same as first day.
Medium Trench Mortars, wire on front trench.
Heavy Trench Mortars remain silent.
3rd Day. 18-pounders, wire cutting in accordance with Appendix A.
“W” Approaches and communications.
4.5” howitzers same as before.
Medium Trench Mortars, wire cutting on front & support trenches.
Heavy Trench Mortars, special points allotted to them.
4th Day. 18-pounder, wire cutting on front & support trenches to complete work ”X” carried out by Medium Trench Mortars.
4.5” howitzers, as before.
Medium Trench Mortars, destruction of trenches and machine gun emplacements.
Heavy Trench Mortars, same as 3rd day.
5th Day. 18-pounder, wire cutting on any portions of wire left uncut. All approaches.
”Y” 4.5” howitzers, as before.
Medium Trench Mortars, same as fourth day.
Heavy Trench Mortars, same as 4th day.
A definite daily time table will be worked out in conjunction with XIII Corps H.A. to ensure batteries not interfering with each other in the execution of these various tasks.
- SUPPORT OF INFANTRY SUPPORT
The five wire cutting batteries from each Group will have a strip of German defences allotted to each battery, and will be responsible for engaging all German trenches within this strip in accordance with the time table of lifts.
These strips will be exactly similar to those allotted to batteries during wire cutting, consequently, all registrations arrived at during wire cutting will form part of the general registration for support of the assault.
The Divisional Artillery lifts will be so timed as to be clear of assaulted trenches one minute previous to stipulated time for the Infantry to reach the trench in question. The lifts of the Divisional Artillery are shown in attached map, marked “B”. During the last minute previous to each lift, H.E. ammunition (5 rounds HE per gun?????) will be used exclusively by 18-pounders, it is hoped that this may act as an indication to the assaulting troops that a lift is impending.
The fire of the forward batteries situated in the CARNOY valley will, in the initial stages, be kept as a reserve to deal with any unforeseen contingencies, and to deal with special portions of the line.
Any small intermediate lifts other than the Divisional lifts will be arranged direct between Infantry Brigade Commanders and Officers Commanding their respective Groups.
- Barrages to ensure Consolidation of Positions Gained.
It will at any moment during the assault be possible to establish an effective barrage, to check counter attacks and assist in consolidation of ground.
The five batteries per Group with strips of front allotted to them will be responsible for establishing a barrage at any point along their respective strips as required. In addition, the forward batteries in the CARNOY Valley will be in a position to form the backbone of any barrage required at longer ranges, such as for instance in the vicinity of CATERPILLAR WOOD should the final objective be obtained.
- PREPARATION FOR FORWARD MOVE.
Two batteries from each Group will be detailed to hold themselves in readiness to move forward to reinforce batteries in CARNOY Valley should occasion arise. The possible positions for these batteries are being selected, roads to them reconnoitered and necessary bridges erected.
As far as is possible, positions further in advance, on the POMMIERS RIDGE, will be selected and roads of advance to them reconnoitered with a view to their possible occupation at a later stage in the operation.