Eingreif division

Eingreif division is a term for a type of German Army formation of World War I, which developed in 1917, which was responsible for engaging in immediate counter-attacks against enemy troops who broke through a defensive position being held by a "front-holding" division (Stellungsdivision). Attacks by the French and British armies against the Westheer on the Western Front had been met in 1915 and 1916 by increasing the number and sophistication of trench networks, the original improvised defences of 1914 giving way to a centrally-planned system of trenches in a trench-position and then increasing numbers of trench-positions, to absorb the growing firepower and offensive sophistication of the Entente armies.

During the Battle of the Somme (1 July – 18 November 1916), the use of defensive lines began to evolve into the defence of the areas between them, using the local troops of the trench holding divisions and relief divisions (Ablösungsdivisionen), held back beyond the range of Franco-British artillery to replace front line divisions as they became exhausted. In the winter of 1916–1917 the use of such divisions and the fortified zones between trench lines was codified and divisions trained in new defensive tactics. The training was based on the evolution of tactics in 1916 and the new principles of fortification, to provide the infrastructure for the new system of defensive battle by Stellungsdivisionen (line holding divisions) and Eingreifdivisionen (counter-attack divisions).

The new defensive principles and fortifications were used in 1917 to resist the Franco-British offensives and after the failures at Verdun in December 1916 and at Arras in April 1917, the system of fortifications defended by stellungsdivisionen and Eingreif divisions counter-attacking from the rear of the defensive position, was vindicated during he French attacks of the Nivelle Offensive. The continuation of British attacks at Arras in the wake of the French debacle on the Aisne, led to the highest rate of casualties per day of the war but the system failed again at the Battle of Messines. The system reached its ultimate refinement during the Third Battle of Ypres and was altered only slightly during the defensive battles of late 1918. In the interwar period, German defensive thinking incorporated the new technology of aircraft, tanks, anti-aircraft guns and anti-tank guns in a much deeper defensive system full of positions for delaying actions, until a couner-attack by armoured and mechanised formations.

German defensive tactics

1914–1916

Map of the Western Front, 1915–1916

German defensive tactics had been based on the publication Exerzier-Reglement für die infanterie of 1906 (Drill Regulations for the Infantry), which expected defensive warfare to be short periods between offensives. On the Somme front, the construction plan ordered by Falkenhayn in January 1915 had been completed. Barbed wire obstacles had been enlarged from one belt 5–10 yards (4.6–9.1 m) wide to two, 30 yards (27 m) wide and about 15 yards (14 m) apart. Double and triple thickness wire was used and laid 3–5 feet (0.91–1.52 m) high. The front line had been increased from one line to three, 150–200 yards (140–180 m) apart, the first trench (Kampfgraben) occupied by sentry groups, the second (Wohngraben) for the front-trench garrison and the third trench for local reserves. The trenches were traversed and had sentry-posts in concrete recesses built into the parapet. Dug-outs had been deepened from 6–9 feet (1.8–2.7 m) to 20–30 feet (6.1–9.1 m), 50 yards (46 m) apart and large enough for 25 men. An intermediate line of strong points (Stutzpunktlinie) about 1,000 yards (910 m) behind the front line had also been built.

Communication trenches ran back to the reserve line, renamed the second line, which was as well-built and wired as the first line. The second line was built beyond the range of Allied field artillery, to force an attacker to stop and move field artillery forward before assaulting the line. After the Herbstschlacht (Autumn Battle) in Champagne during late 1915, a third line another 3,000 yards (2,700 m) back from the Stutzpunktlinie was begun in February 1916 and was nearly complete when the Battle of the Somme began. German artillery was organised in a series of sperrfeuerstreifen (barrage sectors). The Somme defences were crowded towards the front trench, with a regiment having two battalions near the front trench system and the reserve battalion divided between the Stutzpunktlinie and the second line, all within 2,000 yards (1,800 m) of the front line.

Tactical revision, 1917

Winter 1916–1917

See also: Tactical development on the Western Front in 1917

New manuals

After the Battle of the Somme (1 July – 18 November), General Erich Ludendorff had German defensive doctrine revised. On 1 December, Oberste Heeresleitung (OHL, supreme army command) published new tactical instructions, Grundsätze für die Führung in der Abwehrschlacht im Stellungskrieg (Principles of Command for Defensive Battle), in which the policy of unyielding defence of ground regardless of its tactical value, was replaced. Positions suitable for artillery observation and communication with the rear were to be defended, where an attacking force would "fight itself to a standstill and use up its resources while the defenders conserve[d] their strength". Defending infantry would fight in areas, with the front divisions in an outpost zone up to 3,000 yards (2,700 m) deep behind listening posts, with the main line of resistance placed on a reverse slope, in front of artillery observation posts, which were kept far enough back to retain observation over the outpost zone. Behind the main line of resistance a Grosskampfzone (main battle zone), a second defensive area 1,500–2,500 yards (1,400–2,300 m) deep, also sited as far as possible on ground hidden from enemy observation, while in view of German artillery observers was to be built. A rückwärtige Kampfzone (rear battle zone) further back was to be occupied by the reserve battalion of each regiment.

Somme analysis

See also: Battle of the Somme

Erfahrungen der I Armee in der Sommeschlacht (Experience of the German 1st Army in the Somme Battles), written by Colonel Fritz von Loßberg, Chief of Staff of the 1st Army was published on 30 January 1917. During the Battle of the Somme, Loßberg had been able to establish a line of Ablösungsdivisionen (relief divisions), with the reinforcements from Verdun, which had arrived in greater numbers in September 1916. In his analysis, Loßberg opposed the granting of discretion to front trench garrisons to retire, as he believed that manoeuvre did not allow the garrisons to evade Allied artillery fire, which could blanket the forward area and would invite opposing infantry to occupy vacant areas. Loßberg considered that spontaneous withdrawals would disrupt the counter-attack reserves as they deployed and further deprive battalion and division commanders of the means to conduct an organised defence, which the dispersal of infantry over a wider area had already made difficult. Loßberg and other officers had severe doubts as to the ability of relief divisions to arrive on the battlefield in time to conduct a Gegenstoss from behind the battle zone. The sceptics wanted the Somme practice of fighting in the front line to be retained and authority devolved no further than the battalion to maintain control, ready for a Gegenangriff (organised counter-attack) after 24–48 hours, by the relief divisions. Ludendorff added the analysis to the new Grundsätze für die Führung in der Abwehrschlacht im Stellungskrieg (Principles of Command for Defensive Battle).

Field fortification

See also: Hindenburg Line

The Hindenburg Line at Bullecourt, 1920

Allgemeines über Stellungsbau (Principles of Field Fortification) was published in January 1917 on which new defensive fortifications were to be based, to provide the infrastructure for the new defensive tactics. By April an outpost zone (Vorpostenfeld) held by sentries, had been built along the Western Front. Sentries could retreat to larger positions (Gruppennester) held by Stosstrupps (five men and an NCO per Trupp), who would join the sentries to recapture sentry-posts by immediate counter-attack. Defensive procedures in the battle zone were similar but with greater numbers. The front trench system was the sentry line for the battle zone garrison, which was allowed to move away from concentrations of enemy fire and then counter-attack to recover the battle and outpost zones; such withdrawals were envisaged as occurring on small parts of the battlefield, which had been made untenable by Allied artillery fire, as the prelude to Gegenstoss in der Stellung (immediate counter-attack within the position). Such a decentralised battle by large numbers of small infantry detachments, would present the attacker with unforeseen obstructions. Resistance from troops equipped with automatic weapons, supported by observed artillery fire, would increase the further the advance progressed. A school was opened in January 1917 to teach infantry commanders the new methods.

Eingreif division

Battle of Arras, April 1917.

Eingreif is generally translated as counter-attack but the term had other connotations. In German military doctrine, it included a sense of intervening decisively and is better understood as interlocking or dovetailing. The term was adopted during the Battle of Arras (9 April – 16 May 1917) to replace Ablösungsdivision (relief division), to end confusion over the purpose of divisions held in readiness. Such methods required large numbers of reserve divisions, ready to move to the battlefront and were obtained by creating 22 new divisions, moving some divisions from the eastern front and by conducting in March 1917, Operation Alberich, a retreat to the Hindenburg Line (Siegfriedstellung). By the spring, the German army in the west had accumulated a strategic reserve of 40 divisions. The new system reflected the views of Carl von Clausewitz (1 June 1780 – 16 November 1831) that defensive battle should not be passive (kein absolutes Abwehren) but one of deflection and attack (eine Verbindung von Parade und Stoss), with the Eingreif divisions providing a "flashing sword of retaliation" (das blitzende Vergeltungsschwert).

The German army distinguished between a hasty counter-attack (Gegenstoss) to prevent an opponent from consolidating captured positions and an organised counter-attack (Gegenangriff), an attack after a delay for reconnaissance and preliminary artillery fire. Eingreif divisions were to wait in readiness at the rear of the defensive zone to join the more immediate Gegenstoss engagements, if troops held in reserve by the Stellungsdivision were insufficient to restore the position. With the increasing Allied superiority in munitions and manpower, attackers might still penetrate to the second (artillery protection) line, leaving German garrisons isolated in Widerstandsnester (Widas, resistance nests), still inflicting losses and disorganisation on the attackers. As the attackers tried to capture the Widas and dig in near the German second line, Sturmbattalions and Sturmregimenter of the Eingreif divisions would advance from the rückwärtige Kampfzone into the battle zone, in an immediate counter-attack (Gegenstoss aus der Tiefe). If the immediate counter-attack failed, the Eingreif divisions would take 24–48 hours to prepare a Gegenangriff (organised counter-attack), if the lost ground was essential for the retention of the main position.

To spread the new defensive thinking, on 1 January 1917, General Otto von Moser was appointed to the command a new Divisionskommandeur Schule at Solesmes not far from the Belgian border, with a training ground and a Testing and Instructional Division at full establishment for demonstrations. The first course from 8–16 February was attended by about 100 officers of the Westheer who attended morning lectures and afternoon exercises and a second course run from 20–28 February was also attended by some officers from the Eastern Front and three Austro-Hungarian army observers. The third course from 4–12 March included officers from other armies of the Central Powers and then Moser took over command of the XIV Reserve Corps. Many of the students accepted the new defensive thinking but Loßberg and other dissenters objected to discretion to retreat being given to the front garrison and a second school was set up at Sedan for the officers of Heeresgruppe Deutscher Kronprinz.

Third Battle of Ypres

31 July

The British advance in the centre of the front had caused serious concern to the German commanders. Penetration of the defensive system was expected but the 4,000-yard (3,700 m) advance in the centre of the attack was unexpected. At noon the British advance in the south had been stopped by the local German defenders and their artillery but regiments of the 221st and 50th Reserve Divisions, the Eingreif divisions at the rear of the Group Ypres defensive zone, was able to advance from behind the Broodseinde–Passchendaele ridge, unseen by British reconnaissance aircraft. The Eingreif regiments of Group Ypres began their advance from 11:00–11:30 a.m. and the German artillery began a creeping barrage at 2:00 p.m. along the centre of the British front. The Eingreif regiments drove back the three most advanced British brigades, inflicting 70 percent casualties, recaptured the Zonnebek–Langemarck road and St Julien, before the advance was stopped by mud, artillery and machine-gun fire. The Eingreif divisions had little success on the northern flank of the Anglo-French attack, where the attackers had time to dig in but managed to push back a small British bridgehead on the east bank of the Steenbeek, after losing many men to British artillery-fire, as they advanced around Langemarck; the French repulsed the Germans around St Janshoek and followed up to capture Bixschoote. Counter-attacks in the afternoon by the Stellungsdivisionen on the southern flank, intended to recapture Westhoek Ridge, were able to advance a short distance from Glencorse Wood, before British artillery-fire and a counter-attack pushed them back again.

22 September

German defensive system, Flanders, mid-1917

The leading regiment of an Eingreif division was to advance into the zone of the front division, with its other two regiments moving forward in close support. The support and reserve assembly areas in the Flandern Stellung were termed Fredericus Rex Raum and Triarier Raum, an analogy with the formations of a Roman legion (hastati, principes and triarii). Eingreif divisions were accommodated 10,000–12,000 yards (9,100–11,000 m) behind the front line and began their advance to their assembly areas in the rear zone (rückwärtige Kampffeld), ready to intervene in the main battle zone (Grosskampffeld). After the defeat of Menin Road Ridge, the German defensive deployment was changed. In August, German Stellungsdivisionen had two regiments of three battalions each forward, with the third regiment in reserve. The front battalions had needed to be relieved much more frequently than expected, due to constant British bombardments and the weather, which had caused units to become mixed up. Reserve regiments had not been able to intervene quickly, leaving front battalions unsupported until Eingreif divisions arrived, some hours after the commencement of the attack. The deployment was changed to increase the number of troops in the front zone. By 26 September all three regiments of the front-line division were forward, each holding an area 1,000 yards (910 m) wide and 3,000 yards (2,700 m) deep; one battalion was placed in the front-line, the second in support and the third in close reserve.

The battalions were to move forward successively, to engage fresh enemy battalions, which had leap-frogged through those that had delivered the first attack. The Eingreif divisions were to deliver an organised attack with artillery support later in the day, before the British could consolidate their new line. The change was intended to remedy the neutralisation of the front division reserves, which had been achieved by the British artillery on 20 September, so that they could intervene before the Eingreif divisions arrived. On 22 September, new tactical requirements were laid down: more artillery counter-bombardment was to be used between British attacks, half against British artillery and half against infantry, increased raiding was ordered to induce the British to hold their positions in greater strength, giving German artillery a denser target; better artillery observation was demanded in the battle zone, to increase the accuracy of German artillery fire when British troops advanced into it and quicker counter-attacks were to be made.

30 September

Following the costly defeats of Menin Road on 20 September and Polygon Wood on 26 September, the German commanders made more changes to the defensive organisation and altered their counter-attack tactics, which had been negated by the British combination of limited attack and much greater artillery fire-power than August. German Eingreif divisions had engaged in "an advance to contact during mobile operations" in August, which had achieved several costly defensive successes. German counter-attacks in September had been "assaults on reinforced field positions", due to the short British infantry advances and emphasis on defeating Gegenstosse ("instant-immediate counter-attacks"). The period of dry weather and clear skies which began in early September, had greatly increased the effectiveness of British air observation and artillery fire. German counter-attacks were defeated with heavy casualties, after arriving too late to take advantage of disorganisation. The British changes meant that a defence in depth had been swiftly established on reverse slopes, behind standing barrages, in dry, clear weather, with specialist air reconnaissance for observation of German troop movements and improved contact patrolling and ground-attack operations by the RFC. German artillery which was able to fire, despite British counter-battery shelling, became unsystematic due to uncertainty over the whereabouts of German infantry and British infantry benefitted from the opposite. On 28 September Albrecht von Thaer, Staff Officer at Group Wytschaete wrote that the experience was "awful" and that he did not know what to do.

Ludendorff later wrote that he had regularly discussed the situation with General Hermann von Kuhl and Loßberg, to try to find a remedy for the overwhelming British attacks. Ludendorff ordered a strengthening of the forward garrisons by the ground holding divisions and all machine-guns, including those of the support and reserve battalions of the front line regiments, were sent into the forward zone, to form a cordon of four to eight guns every 250 yards (230 m). The Stoss regiment of each Eingreif division, was placed behind each front division in the artillery protective line behind the forward battle zone, which increased the ratio of Eingreif divisions to Stellungsdivisionen to 1:1. The Stoss regiment was to be available to launch counter-attacks while the British were consolidating; the remainder of each Eingreif division was to be withheld for a Gegenangriff (methodical counter-attack) on the next day or the one after. Between British attacks, the Eingreif divisions were to make more spoiling attacks.

A 4th Army operation order of 30 September, pointed out that the German position in Flanders was restricted by the local topography, the proximity of the coast and the Dutch frontier, which made local withdrawals impossible. The instructions of 22 September were to be followed, with more bombardment by field artillery, using at least half of the heavy artillery ammunition, for observed fire on infantry positions in captured pill-boxes, command posts, machine-gun nests, on duck board tracks and field railways. Gas bombardment was to be increased, on forward positions and artillery emplacements,whenever the wind allowed. Every effort was to be made to induce the British to reinforce their forward positions, where the German artillery could engage them, by making spoiling attacks to recapture pillboxes, improve defensive positions and harass the British infantry, with patrols and diversionary bombardments. From 26 September – 3 October, the Germans attacked and counter-attacked at least 24 times. British intelligence predicted the German changes, in an intelligence summary of 1 October and foresaw the big German counter-attack planned for 4 October.

7–13 October

Third Ypres, map showing the British advance

On 7 October, the 4th Army abandoned the reinforcement of the front defence zone, after the "black day" of 4 October. Front line regiments were dispersed again, with reserve battalions moved back behind the artillery protective line and Eingreif divisions organised to intervene as swiftly as possible, despite the risk of being devastated by the British artillery. Counter-battery fire against British artillery was to be increased to protect the Eingreif divisions as they advanced. Ludendorff insisted on an advanced zone, (Vorfeld) 500–1,000 yards (460–910 m) deep, to be occupied by a thin line of sentries with a few machine-guns. The sentries were to retire on the main line of resistance (Hauptwiederstandslinie) at the back of this advanced zone when attacked, while the artillery was quickly to barrage the area in front of it. Support and reserve battalions of the front-line and Eingreif divisions, would gain time to move up to the main line of resistance, where the battle would be fought, if artillery-fire had not stopped the British infantry advance. An Eingreif division was to be placed behind each front-line division, with instructions to ensure that it reached the British before they could consolidate. If a swift counter-attack was not possible, there was to be a delay to organise a methodical counter-attack, after ample artillery preparation.

The revised defensive scheme was promulgated on 13 October, against Rupprecht's objections. Artillery-fire was to replace the machine-gun defence of the forward zone as far as possible, which Rupprecht believed would allow the British artillery too much freedom to operate. The thin line of sentries of one or two Gruppen (thirteen men and a light machine-gun each) in company sectors proved inadequate, as the British were easily able to attack them and lift prisoners. At the end of October, the sentry line was replaced by a conventional outpost system of double Gruppen. The German defensive system had become based on two divisions, holding a front 2,500 yards (2,300 m) wide and 8,000 yards (7,300 m) deep, half the area that two divisions previously were expected to hold. The necessity of such reinforcement was caused by the weather, devastating British artillery-fire and the decline in the numbers and quality of German infantry. Concealment (die Leere des Gefechtsfeldes) was emphasised, to protect the divisions from British fire power, by avoiding anything resembling a trench system, in favour of dispersal in crater fields. Such a method was only made feasible by the rapid rotation of units; battalions of the front-divisions were relieved after two days and divisions every six days.

Cambrai, 1918 and post-war

Map of the Siegfried Line, 1939

The German development of the defensive battle reached its culmination at the Third Battle of Ypres and in late November, Ludendorf ordered its adoption by the rest of the Westheer. The counter-offensive at Cambrai was a conventional Gegenangriff and in 1918 only minor changes to nomenclature and the Vorfeld and Hauptwiederstandslinie system brought on by mechanisation. The Vorpostenfeld (outpost zone) was renamed the Kampffeld (advanced battle zone), behind which was the Hauptkampffeld (main battle zone), then the Grosskampffeld (greater battle zone) and the Rückwärtige Stellung (rear position) then the Rückwärtiges Kampffeld (rear battle zone). Eingreif divisions were based from 10,000–12,000 yd (9,100–11,000 m) behind the front line and expected to fight the main defensive battle in the Grosskampffeld. The Kapmpffeld was held with as few troops as possible, exploiting flanking fire from machine-guns and single field guns. The front line was along the forward edge of the Grosskampffeld and covered the field artillery positions supporting the troops in the Kapmpffeld. Further back were positions for the counter-attack troops of the stellungsdivision, to be held to give time for the Eingreif divisions to close up and counter-attack with the local reserves.

On 20 July 1918, Loßberg was sent by Ludendorff to report on the conditions in the Marne Salient and found that the system devised for the operations in Flanders in 1917 was unworkable in the terrain of the Vesle and Aisne valleys. The unspoilt countryside was full of trees and standing crops and the dispersed system of defence was incapable of resisting tank attacks from the flanks and rear, with so much cover available to the attackers. The defensive scheme was returned to a line of observation groups in front of the main line of resistance, the groups having increased firepower to force an attacker to deploy sooner. Delaying actions moving back through lines of observation were developed into a holding action (hinhaltendes gefecht). The relative success of the defensive system at Ypres in 1917 was not repeated in 1918 on the Santerre in Picardy or the downlands west of Cambrai. The scattered outposts of the Vorpostenfeld could be overrun behind creeping barrages at night or in twilight and there was an insufficient number of Eingreif divisions to counter-attack, those present being capable only of local attacks or reinforcing the defenders. German divisions were smaller than earlier in the war, had more machine-guns and better command arrangements but the system of linked Stellungsdivisionen and Eingreifdivisionen was most demanding of manpower; British attacks in late 1918 rarely outnumbered the defenders, relying on keeping the initiative and surprise.

Writing in 1939, Wynne described contemporary German defensive principles that resembled the defence of Flanders in 1917, with the depth of the defensive position increased to about 30 mi (48 km) filled with lines of resistance (Sicherungs-Widerstandslinie) from which to fight a delaying action. Static defences would be backed by mechanised and motorised Eingreif divisions ready to use speed, firepower and shock in a Gegenstoss auf der Tiefe. Inside the defensive position, anti-aircraft and anti-tank guns and mobile anti-tank guns would deplete tanks and aircraft supporting the infantry attack but the fixed defences of the Siegfried Line were less important than the "flashing sword of retaliation".

References

Books

Theses

External links

• German defensive tactics (Wayback machine)