The BEF’s preparations for and conduct of the defensive battles during the spring of 1918 – Part 9

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Operation Michael

The fog on the morning of 21 March 1918 caused problems to both sides.  With its Forward Zone paralysed, much of its artillery suppressed, and communications severely disrupted by the initial German barrage, the fog proved more problematic to the BEF.  Within the first few hours of the German infantry assault 47 battalions, deployed in the Forward Zone, had disappeared from the BEF’s order of battle (Gray, Kaiserschlacht 1918, p 36.).  At the end of the first day Maxse, XVIII Corps commander, was to report to Gough that all nine of his battalions deployed in the Forward Zone had been almost annihilated (Gough, The Fifth Army, p 267.).  When the fighting stopped at the end of the first day German stormtroopers had penetrated up to 8,000 yards behind the British front in some places.  The greatest losses were experienced at the southern end of 5^th Army’s front where III Corps, outnumbered eight to one, had been pushed out of its Battle Zone (J.P. Harris, Douglas Haig and the First World War (Cambridge: Cambridge University Press, 2008), p. 447 and, Middlebrook The Kaisers Battle p. 274.).

GHQ was slow to appreciate the true impact of the days fighting.  Chief of the General Staff, Lawrence, during a phone call with Gough, went so far as to speculate that:

‘the Germans would not come on again the next day’.  Gough, The Fifth Army p. 271.

The two GHQ reserve divisions, earmarked as 5^th Army reserves, had been released to Gough and were being fed piecemeal into the line.  The promised French divisions were not immediately available.  French G.Q.G believed a German offensive in Champagne was highly likely having been misled by a German signals deception plan that created a false Army opposite the French front.  The first French division arrived on 22 March.  Additional BEF reserves were to be moved south with 3^rd Army receiving the first divisions, 5^th Army would have to hold on with what it had.  Gough had little choice but to implement his ‘gradual retirement’.  At 10.45 a.m. on 22 March 1918 he authorised a general retreat.  At this stage the ‘fog of war’ descended on both sides.

Confusion over Gough’s withdrawal orders compounded by growing command dislocation within 5^th Army on 22 March resulted in Maxse’s XVIII Corps retiring prematurely to the Somme river, leaving Watt’s XIX Corps to its north with an exposed right flank, and Butler’s III Corps the same problem on its left.  Coincident with this, and perhaps because of it, Ludendorff decided to switch the main focus of the German attack to the south to take advantage of the success against III Corps; the aim was to force a split between the French and British armies.  It was arguably this switch in focus that doomed the offensive to failure.

By the 26 March with the BEF on the verge of pulling back and northwards, effectively abandoning 5^th Army, after 3^rd Army’s withdrawal from the Flesquieres salient had left a gap between 3^rd and 5^th Armies (the Flesquieres salient had been held by Byng’s 3^rd Army against Haig’s better judgement), and the French looking to cover Paris, the allies finally unified their commands under General Foch.  Whilst not necessarily saving the day the appointment of Foch as ‘Generalissimo’ served to steady both Haig and Pétain, improved allied understanding and coordination, and prevented a catastrophic split between the two allied armies.

Next: Operation Mars

The BEF’s preparations for and conduct of the defensive battles during the spring of 1918 – Part 8

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British Misapplication

The memorandum issued by GHQ on 14 December 1917 outlined defensive principles heavily based on captured German documents (L.E. Kiggell, ‘GHQ Memorandum on Defensive Measures’, 14 December 1917, National Archives CAB 24/38 Image No 0011.).  British attempts to emulate this system resulted in fundamental differences in both interpretation and application.  In the Outpost Zone, called the Forward Zone by the British, the BEF approach differed from the Germans in three key respects; location, manning, and withdrawal authority.  The BEF like the Germans defended their Forward Zone from a succession of trench lines and strongpoints but, unlike the Germans, these defences were based around the original front line trench systems so minimal consideration could be given to the essential elements of terrain and observation.  Manning levels also differed; on average BEF divisions occupying the Front allocated approximately 30% of their infantry strength, 3 battalions, to defend the Forward Zone as compared to the Germans who would allocate only 15%.

Inconsistencies between neighbouring BEF units resulted in over 50% of the manpower being allocated to the Forward Zone by some divisions.  On 3^rd Armies southern boundary 140^th Brigade [47^th (2^nd London) Division, V Corps], holding the line alongside 26^th Brigade [9^th (Scottish) Division, VII Corps, 5^th Army], had be directed ‘to fight for and hold the front line at all costs’.  26^th Brigade had been instructed ‘to fight for the battle zone not for the forward zone’ (Travers, How the War was Won, p. 57.).  Inconsistencies were not just evident between armies.  In 5^th Army there were differences between corps and even between divisions within the same corps.  XVIII Corps were ordered to hold the line in depth whereas the neighbouring III Corps were to hold the front in strength (Travers, How the War was Won, p. 64.).  In fairness to III Corps part of the reasoning for them having to strengthen the Forward Zone was linked to the fact that their Battle Zone had not been completed, being the last section of the line to be taken over from the French.  In VII Corps Congreve, the corps commander, believing that 16^th (Irish) Division was vulnerable to a surprise attack over ruled the division commander and pushed 5 of the division’s battalions into the Forward Zone (Middlebrook, The Kaisers Battle, p 200.).

These inconsistencies can to a degree be attributed to the variable status of the BEF Battle Zone.  GHQ had provided clear direction on this:

 ‘Until the battle zone has been strengthened there can be no alteration in existing, methods of defence.’.  Kiggell, ‘GHQ Memorandum on Defensive Measures’, p. 3.

Arguably the difference that was to have most effect was that of withdrawal authority.  Unlike the German system local commanders in the BEF could not make the decision to withdraw.  Orders from GHQ stated:

‘The troops allocated to the defence of the outpost zone [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 cost, and local reserves will counter-attack immediately, without waiting for orders, should the enemy succeed in penetrating the defences.’.  Kiggell, ‘GHQ Memorandum on Defensive Measures’, p. 3.

These differences in interpretation and application led the BEF to treat the Forward Zone as little more than a heavily defended trench line with little tactical flexibility.  During Operation Michael this was to prove catastrophic.

Confusion over the function of the Battle Zone also existed. The emphasis on holding ground also pervaded here compromising the key element of the defence-in-depth system, the counter attack:

'The battle zone has been designed to include all ground which for various reasons should be held at all costs, and with a view to the main resistance being made, as far as possible, on ground favourable to us.'.  Kiggell, ‘GHQ Memorandum 3 January 1918’, National Archives CAB/24/38 Image No 0011, pp. 5-6.

'The battle zone, being the ground on which it has been decided to give battle should the enemy attack in strength must be maintained.'.  Kiggell, ‘GHQ Memorandum on Defensive Measures’, p. 3.

Each front line BEF division had at least 3 battalions available to man the Battle Zone, with a fourth in reserve for local counter attacks (Randal Gray, Kaiserschlacht 1918 The Final German Offensive (London: Osprey,1991), p 33.).  This allocation of 25% of the infantry strength as counter attack forces in the Battle Zone was significantly less than the German 80%.  The German system also stipulated that reserve divisions located in the Rear Zone were kept close enough to beat an attacker to the Battle Zone.  What BEF reserves there were, during the Michael offensive, were kept at least 10 miles behind the Battle Zone arriving too late to fulfil a counter attack role.  The key elements of the German system; flexibility and the counter attack were compromised by the BEF's fixation on holding ground:

' ... the Germans viewed a defensive system primarily in terms of the men and weapons deployed in the zone, allowing reorganization to be rapid and easy, the British appear to have thought of the defensive system more in terms of the physical defended positions, such as earthworks and wire. To reorganize such a system required enormous amounts of labour and was a slow process.'.  Martin Samuels, Doctrine and Dogma: German and British, Infantry Tactics in the First World War (New York:Greenwood Press, 1992), p 54.

Travers' assessment that the BEF, particularly in the area attacked on 21 March 1918, had failed to emulate the German defence-in-depth system was correct.  What is open to debate however is whether the defensive system, even correctly applied, could have withstood the scale of the German assault on 21 March 1918.

Next: Operation Michael

The BEF’s preparations for and conduct of the defensive battles during the spring of 1918 – Part 7

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Defensive Doctrine

The need to revert to the defensive on the Western Front in 1918, following three years of continuous offensive action, prompted the BEF to review and update its defensive doctrine.  Convinced by their Third Ypres experience of the efficiency of the German ‘Defence-in-depth’ system the BEF attempted to copy it.

The German ‘Defence-in-depth’ system was based around the following principles:

‘The defender must not surrender the initiative to the attacker.

The defence must rely on firepower, not large numbers of troops.

The defender must not hold ground at all costs.

The defender must consider depth for all construction and positions.’.  Timothy T. Lupfer, ‘The Dynamics of Doctrine: The Changes in German Tactical Doctrine during the First World War’, Leavenworth Papers, July 1981, p. 12.

The Germans applied these principles through the use of three successive interrelated zones: the Outpost Zone, the Battle Zone, and the Rearward Zone.  The Outpost Zone with a depth varying between 500 and 1000 metres depending on the terrain, comprising a number of lightly held trench lines, was designed to slow an enemy down and provide early warning.  This was done by carefully positioning this zone such that the subsequent Battle Zone was hidden, on a reverse slope where possible, and beyond enemy artillery range.  The Battle Zone, 1.5 to 3 km in depth, began with a Main Line of Resistance (MLR) that comprised of a series of, usually three, trench lines.  Behind the MLR were a number of carefully positioned mutually supporting strong-points arranged in depth.  At the rear of the Battle Zone were another series of trench lines called the artillery protection line behind which the Germans located their artillery.  Behind the artillery protection line came the Rearward Zone, an area extensively prepared that could be turned into a Battle Zone if required, that was home to the German reserves.  The defence principles when applied did not mean that the German soldiers deployed in the Outpost Zone or along the MLR were given authority to evacuate their positions at the first opportunity.  They were expected to shift their position, usually into shell holes, to escape artillery fire, and to survive ready to inflict casualties on the subsequent infantry assault.  The corner stone of this defence-in-depth system was the counter attack.  At every level the principle applied was shift, bend, and snap back, leaders at all levels were given the authority to decide whether to counterattack immediately or to fall back.  NCO’s at the squad level were expected to make battlefield decisions, delaying actions in the Outpost Zone, counterattacks in the Battle Zone.  Specialist counterattack units were also formed, the stormtroop detachments.  Within the Battle Zone as many as 80% of the German infantry were appointed as counterattack forces.

The theory behind the German defence-in-depth was relatively simple.  An enemy, with artillery support, would penetrate the Outpost Zone, where they would be delayed and harried.  They would then enter the Battle Zone disorganised and unprotected by their artillery to find themselves subjected to German artillery fire and counterattacks launched from both the Battle and Rearward Zones.

Next: British Misapplication

The BEF’s preparations for and conduct of the defensive battles during the spring of 1918 – Part 6

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The German Plan

The reality was that Ludendorff planned a series of successive inter-related attacks that would together force the collapse of the allied armies.  The BEF, perceived by the Germans as tactically clumsy but stubborn, were seen as the backbone of the allies; if defeated the rest would collapse.  From the winter planning process three options appeared to meet Ludendorff’s requirements.  The first ‘George’ was aimed to break through the BEF front near Armentiéres, in Flanders, and advance on Hazebrouck with a subsidiary attack ‘George II’ to isolate and overcome the BEF in the Ypres salient.  The second ‘Mars’ was to be directed against Arras.  Lastly ‘Michael’ would be an attack against the BEF 3^rd and 5^th Armies either side of St Quentin with the aim of wheeling north once the defences had been breached and pushing the BEF back towards the sea.  ‘George’ would not be an option until the assault area had dried out; April at the earliest.  The BEF defences around Arras were perceived as being too strong for the initial assault, so, on 21 January Ludendorff selected ‘Michael’ as his principle assault:

‘I favoured the centre attack [Arras]; but I was influenced by the time factor and by tactical considerations, first among them being the weakness of the enemy.’.  Erich Ludendorff, Ludendorff's own story, August 1914-November 1918; the Great War from the siege of Liège to the signing of the armistice as viewed from the grand headquarters of the German Army (London: Harper & Brothers, 1919), Vol 2. p.161.

German Tactical Doctrine

During the 1918 assaults the Germans applied the results of a significant doctrinal change in tactics.  The genesis of the "infiltration tactics" were grown from the German examination of the attacks with "limited objectives" in the west, coupled with techniques learned during the more open warfare on the Russian and Italian fronts.  These techniques, combined with the German artillery tactics from the Russian and Italian fronts, were successfully applied at Riga (September 1917) and Caporetto (October 1917) convincing Ludendorff that they could be applied to large scale operations on the Western Front to make a strategic breakthrough.

The new German tactical doctrine, or "infiltration tactics," emphasized the squad as the manoeuvre unit.  Squads were to by-pass resistance and to continue to attack deep to the rear of the enemy positions.  The Germans organized their artillery fire support plans to capitalize on surprise and shock effect.  Extremely violent but short artillery preparation fires culminated in a rolling barrage to protect the infantry advance.  Regular infantry formations followed the infiltration units to reduce by-passed strongpoints and to keep the leading units supplied.

A massive training programme was necessary to produce the required number of trained divisions for the breakthrough.  The German High Command (OHL) dedicated the winter of 1917-1918 to training such a force.  In the time available the increased level of training required could not be attained by every German soldier.  This led to the formation of "attack" and "trench" divisions.  The OHL appointed approximately one quarter of the German divisions as "attack" divisions.  These divisions were withdrawn from the line, issued the best equipment, and subjected to intensive training.  The remaining three quarters of the German army served in "trench" or "sector" divisions manning the defensive zone.  By the spring of 1918, 56 "attack" divisions were trained in stormtroop tactics, fully mobilized with vehicles and draft animals, and modernized with new weapons.  These divisions were prepared to spearhead the assault.  This double standard caused morale problems and would ultimately impact on the German tactical performance as the casualties experienced by the “attack” divisions could not be easily replaced.  The German tactically based offensive was to cruelly expose all of the BEF weaknesses despite the fact that they had been exposed to them at Cambrai during the German counterattack.

Next: Defensive Doctrine