The British plan of defence was built around the concept of defence in depth, and for this they relied on three zones, Forward, Battle & Rear.  A concept adapted from the Germans.

Paragraphs in red are from Sheriff’s ‘Journeys End.’

British defence layout Forward Zone Battle Zone How the Zones would fight 6th Division Front Comments on zones in Official History

British defence plan

During the winter of 1917 a new defensive philosophy had been evolved for the British units, it was to be tested in the fighting in March. One criticism of the new approach was that it had not been adequately explained to the soldiers who would have to fight to the new plan and this lack of understanding by the average soldier would have an effect on the number of men who surrendered and were captured on the first day of fighting.

The concept of the three zones that the British would use in their defence plan was one adapted from a German plan, the following is from the Official History; “There were excellent reasons for adopting the principles laid down by the German General Staff after nearly three years’ experience of the defensive on the Western Front.” The German manual was the “Allgemeines uber Stellenbau”, issued by the General Staff, 15th August 1917.  Copies were captured soon after they were issued.

The defensive area would be split into three “lines”; the Forward Zone (Blue line), the Battle Zone (Red line) and the rearmost would be the “Corps Line” (Brown line).  The Forward Zone had originally been called the ‘Outpost’ Zone but the name was changed as it gave the impression that the troops in it would be too much on their own. This nomenclature was used in a G.H.Q document of 14th December 1917, detailing the defensive measures to be put in place. In the event, when the battle opened on the 21st March very little had been done to prepare the Corps Line in either the Third or Fifth Armies, it was even referred to as the ‘Devasted Zone’ because of what the Germans had done there on withdrawal.  The Forward and Battle Zones were better prepared in the Third Army area than they were in Fifth Army;one reason for this was the length of the front in Fifth Army (42 miles against 28 in Third Army) and the fact that they had more recently taken over a large section of front from the French.

The Forward Zone.

The Forward Zone was immediately behind the front line, and was up to 2,000 yards deep.  It was relatively thinly manned with what should be well sited detachments of men and a few artillery pieces, to break up the initial enemy assault. In theory it should be strong enough to cause the Germans to need to bombard it, and attack with strong infantry units.  The defenders would then, theoretically, inflict heavy casualties before withdrawing to the Battle Zone.  The day would not follow this plan!

Stanhope: Next night we’ll start putting a belt of wire  down both sides of us.

Osborne: Down the sides?

Stanhope: Yes. We’ll wire ourselves right in. If this attack comes, I’m not going to trust the companies on our sides to hold their ground.

Act II, Scene I

The function of the Forward Zone was not explained to the soldiers in the trenches who were supposed to make the plan work. The soldiers were used to fighting in “line”, not in pockets, they always expected their adjacent units to cover their flanks.  Their confusion would be further compounded by the plan for the artillery units in the Forward Zone; to prevent the loss of these guns during an enemy attack they would be withdrawn to the Battle Zone before the infantry withdrew.  When the soldiers saw the guns withdrawn it reinforced the rumour that those of them in the Forward Zone were to be sacrificed in the enemy attack.  This would be one factor in the high number who were captured that day. “What the average junior officer and ordinary soldier were not told was that the new defensive policy did not include provision for counter-attacks to recover the Forward Zone”. (Middlebrook)

Osborne: Did the Colonel have much to say?

Stanhope: Only that when the attack comes we can’t expect any help from behind.  We’re not to move from here. We’ve got to stick it.

Act II, Scene I

The description of the Forward Zone in WO 95/2763; “The forward zone will also be organized for defence in depth and will be sufficiently garrisoned and strengthened to guard against surprise, to break up the enemy’s attacks and compel him to expend large quantities of ammunition, and employ strong forces for its capture.  The back-bone of the defence in this zone will be machine guns skilfully [sic] concealed in combination with wire entanglements.”

Battle Zone

This zone was some 2,000 yards behind the Forward Zone, and some 2-3,000 yards deep. Where the Forward Zone could be evacuated after the troops had blunted or held up the initial enemy attack, the Battle Zone had to be held at all costs. Over half of the forward troops would be concentrated in this zone, with strong artillery support

A heavy field gun firing.  Photo from “The War Budget”.

The description of the Battle Zone in WO 95/2763 “The battle zone will be organized for defence in great depth, varying from 2,000 to at least 3,000 yards and will consist of strong successive systems of defence. Diagonal switch lines , supporting points and defended localities must be constructed within the battle zone, with a view to preventing the enemy from spreading outwards and rolling up the position, should he succeed in temporarily penetrating the defences. The more important localities in the battle zone will be permanently garrisoned. Plans and preparations for the employment of troops both in the defensive battle and in counter-attack must be carefully worked out.  Not only must the troops permanently allotted to the various sectors be considered in preparing schemes, but also possible reinforcements arriving from elsewhere.”

In the area of Third Army which contained 6 Division, British troops had been “in residence” for about a year so the Forward and Battle Zones were almost complete and pretty well manned.

The Rearward Zone. The following is from the G.H.Q dated 14 December 1917.  (WO 95/2763)

In addition to the Battle and Forward Zones of defence, a rear zone some 4 - 8 miles behind the battle zone will be selected and prepared for defence as labour becomes available. Arrangements will be made by G.H.Q. in conjunction with Armies to have this defensive zone reconnoitered, and the projected defences spit-locked. [This means that the trench is not much more than a scraping with the turf removed and piled in front.  Richard Holmes put me straight on that one.  J Dillon]

A British field gun being hauled to the front. Photo, “The War Budget”.

In the instructions issued by G.H.Q. on 14th December, 1917, the way the fighting was expected to go in the Forward and Battle zones was laid out.

“In describing the defensive policy to be pursued after the battle zone has been adequately prepared for defence, we must consider firstly the defensive action in the forward zone, and secondly the defensive action in the battle zone.

The troops allotted to the defence of the forward zone will do all in their power to maintain their ground against every attack.  Garrisons of works and localities will hold their defences at all costs, and local reserves will counter-attack immediately, without waiting for orders, should the enemy succeed in penetrating the defences.

Should the efforts of these troops fail to maintain or re-establish the line, it is for the higher commander to decide whether he will employ any of his general reserves to regain the lost ground.

Unless the enemy’s attack is weak, and his lodgment on a narrow front, the value of the ground to be recaptured will seldom be worth the cost involved.

The battle zone, being the ground on which it has been decided to give battle should the enemy attack in strength must be maintained.

Should the enemy succeed in penetrating this zone, and the immediate counter-attacks of local reserves fail to dislodge him, a deliberate counter-attack must be launched at the first possible moment.

Unless the penetration is on a narrow front and only at one place time will be necessary before a deliberate counter-attack is launched, in order that thorough preparations may be made, including possibly the co-ordination of two or more attacks.

The deliberate counter-attack should, when the enemy has expended his strength in the attack, not only aim at re-establishing the battle zone; arrangements should also be made to exploit the success, and inflict defeat upon him.”

[There is not much detail on how this successful counter-attack will be pulled together after the enemy has overrun the forward zone and penetrated the battle zone. JDillon]

The same G.H.Q instructions laid down the requirement for the troops to be trained in the counter-attack.

12 (a) Troops should be trained in open warfare and the spirit of the counter-offensive inculcated. Frequent practice in musketry and field firing is essential, so that the infantry may develop confidence in their power to stop the enemy by rifle, lewis and machine gun fire, even without the help of an artillery barrage.

(b)  Frequent practice of counter-attacks by reserves, large and small, should be carried out. The form of these attacks should be laid down in the defence schemes of formations and units, and practiced on the ground for which they are planned.

(c)  It should constantly be explained to the troops during training that the assumption of the offensive by the enemy would be the best possible opportunity of inflicting over-whelming loss on him and still further establishing our superiority in preparation for the renewal of the advance. [Amazing statement given what happened]

In preparing the defences it seems that there was a shortage of wire, highlighted by a G.H.Q. communication on 25th January, 1918.  O.A.D. 291/29 (WO 95/2763)

“It may be found impossible to provide enough barbed wire for the requirements of Armies.  The Engineer-in-Chief is trying to arrange for plain wire to be sent out from home to make up the deficiency; this, mixed with barbed wire can be made into a very fair obstacle. There is, in any case, a necessity for economy in barbed wire. The principles of wiring are well known; one is that against artillery it is better to make several belts of say 6 yards broad and 30 yards apart, than one belt say 20 yards broad. Another is that the wire obstacle can be thickened up too much; but the main point at the present moment is that excessive thickening uses up an enormous amount of wire, and should be prevented.”

6th Division front

According to the Official History the “Forward Zone was difficult to hold, being exposed to enemy view and direct fire.”  Also “the Zone had less depth than was the case on most other parts of the line, especially in front of Lagnicourt and northwards, where it was only 500 yards.” Preparation of the zone was not all that it should have been; “There had been some difference of opinion as to the best method of defence between the commanders of the two divisions which had held the sector before the 6th, with the unfortunate result that the necessary work had never been completed. In the Forward Zone underground shelter was insufficient - not a matter of importance, as it happened, for many men were caught in the dug-outs, the entrances having been blown in - and the machine guns had indifferent protection. In places there was no reserve line, or only such as had been constructed in a hurry; there were few communication trenches and none organized for defence against a break-in. Only the left of the front of the Battle Zone had dug-outs, and it was not wired. One battalion commander speaks of the sector as “the most disgusting” he had ever met, with little cover to fall back upon, once the Forward Zone had been lost, except a few strongpoints and the old “Corps System”, that is, the front line of the Battle Zone.”

The following is taken from the 2nd Battalion History;

The front held by the 6th Division was generally on a forward slope opposite the villages of Queant and Pronville.  No-Man’s-Land averaged three-quarters of a mile in width. The whole area was downland and very suitable for the action of tanks. The position lay astride a succession of well-defined, broad spurs, and narrow valleys (like the fingers of a partially opened hand), merging into the broad transverse valley which separated the British line from the two villages above mentioned.  All the advantages of ground lay with the defence, and it seemed as if no attack could succeed, unless by the aid of tanks. A large portion of the front line, notably the valleys, was sown with 2-inch trench-mortar bombs with instantaneous fuses, which would detonate under the pressure of a wagon, but not of a man’s foot. In addition five anti-tank 18-pounder guns were placed in positions of vantage. The wire was very broad and thick. The position would indeed have been almost impregnable had there been sufficient time to complete it, and had there been separate troops for counter-attack.

The ground was a portion of that wrested from the enemy in the Cambrai offensive of November-December, 1917, but had only improvised trenches. A month’s hard frost in January had militated against digging, and though there was a complete front trench and reserve trench, the support trenches hardly existed, and dug-outs were noticeable by their absence.  The front was 4,500 yards in extent, the three brigades in line - 18th on right, 71st in centre, 16th on left (with 2nd York & Lancs) - approximately on equal frontages. The depth from front or outpost zone to reserve or battle zone was about 2,500 yards.  With only three battalions in a brigade, there was no option but to assign one battalion in each brigade to the defence of the outpost zones, and keep two battalions in depth in the battle zone.  With battalions at just over half strength, and with the undulating nature of the ground, the defence resolved itself everywhere into a succession of posts with a very limited field of fire.

A good Corps line, called the Vaulx-Morchies Line, had been dug, the nearest portion a mile behind the reserve line, and this was held by the Pioneers and Royal Engineers, owing to scarcity of numbers.

The following was the disposition of the 2nd Battalion The York and Lancaster Regiment in the front line at the time of the German offensive:-

“A” Company, from Wakefield Alley to the junction of Cornhill and front Line.

“B” Company, the Sunken Road, Lagnicourt, to the Noreuil Road.

“C” Company, the Reserve Line from the junction of Wakefield Alley to Leeds Reserve.

“D” Company, the Sunken Road, Lagnicourt, to the Noreuil Road.

See also the C.O’s report of the days action.

Comments on the zones in the Official History.  The Official History has a summary of the reasons why the German offensive broke through on the 21st, and they believe one reason was that the British, while adopting the German idea of zones, had deviated from the German plan.

“That defence must be in depth admitted of no doubt whatever; but one of the first principles of the German instructions could not be observed: their Forward Zone was only a means of delaying the enemy.  Its basic difference from the Battle Zone was that the defences of the latter must be ‘more carefully developed and more numerous’.  Actually, the British Forward Zone, the old front system, was stronger in every way than the zones in rear of it.  Had the Battle and Rear Zones been elaborated by a labyrinth of trenches and switches, tiers of wire, and hundreds of ‘pill boxes’, machine-gun nests and deep dug-outs, after the German model, they would no doubt have been capable of a prolonged defence; but time and labour had been lacking to do in six weeks what had taken even the Germans months if not years. Although the fighting troops had been overwrought by work with pick and shovel, none of the machine-guns, on which the defence depended, were in ferro-concrete emplacements, a few had not even splinter-proof cover, and deep dug-out accommodation for detachments and weapons was rare.”

The following comments are from WO 95/717, the IV Corps war diary in the National Archives.  They are the points made verbally by the Army Commander to B.G.G.S IV Corps, who then repeated them to the IV Corps commander;

1. Work on the Battle Zone is of paramount importance (more so than the Front Line).

2. Front Line is to be held as thin as possible commensurate with safety (chiefly by Lewis Guns).

3. Defence in depth. Every Line and every battery position and every communication trench protected by wire - scattered wire without any connection with trenches is good.