Action of the Cockcroft, 19 August 1917

The Action of the Cockcroft, 19 August 1917, took place in the First World War on the Western Front, during the Third Battle of Ypres. During the attack of XVIII Corps at the Battle of Langemarck (16–18 August), the German garrisons of blockhouses and pillbox outposts of the Wilhelmstellung (third position) had shot down the infantry of the 48th (South Midland) Division (Major-General Robert Fanshawe) and the 11th (Northern) Division (Major General Henry Davies) well short of their objectives. At a conference called by General Hubert Gough the Fifth Army commander, on 17 August, Gough and the corps commanders arranged for local attacks to be made at various points, to reach a good jumping-off line for another general attack on 25 August. The commanders of XIX Corps and XVIII Corps were to arrange advances to within about 200 yd of the Wilhelmstellung, to come into line with the XIV Corps on the left flank. II Corps, further south, was to capture Inverness Copse on 22 August.

At 4:45 a.m. on 19 August, five tanks of a composite company of the 1st Tank Brigade broke down or ditched but the other seven advanced up the St Julian–Poelcappelle road behind a smoke barrage, their noise smothered by low-flying British aircraft. The tanks were followed by parties of infantry of the 1/8th Battalion, Royal Warwickshire Regiment, ready to occupy the strongpoints and pillboxes as the garrisons were overcome by the tanks. At most of the strongpoints the Germans retreated as soon as they saw the tanks but at Triangle Farm, Maison du Hibou and the Cockcroft the garrisons defended themselves, suffering about 100 casualties and losing thirty prisoners. Two of the tanks were lost and two crew were killed along with 13–14 wounded; fifteen British infantry were also wounded. In 1996, Prior and Wilson wrote that the method was hard to repeat and created unrealistic expectations of the tanks. In 2017, Nick Lloyd wrote that the attack had been "a remarkable exercise in ingenuity and imagination" which raised Tank Corps morale.

German defensive tactics
In July 1917, the 4th Army system of defence in depth began with a front system of three breastworks Ia, Ib and Ic, about 200 yd apart, garrisoned by the four companies of each front battalion, with listening-posts in no-man's-land. About 2000 yd behind was the Albrechtstellung (second or artillery protective line), the rear boundary of the forward battle zone (Kampffeld). About 25 percent of the battalions in support were divided into Sicherheitsbesatzung (security crew) to hold strong-points, the remainder being Stoßtruppen (shock troops) to counter-attack towards them, from the back of the Kampffeld. Dispersed in front of the line were divisional Scharfschützen (sharpshooters) in the Stützpunktlinie (strongpoint line) a line of machine-gun nests prepared for all-round defence. The Albrechtstellung also marked the front of the main battle zone (Grosskampffeld) which was about 2000 yd deep, containing most of the field artillery of the Stellungsdivisionen, behind which was the Wilhelmstellung. In the pillboxes of the Wilhelmstellung were reserve battalions of the front-line regiments, held back as divisional reserves.

Battle of Langemarck
At the Battle of Langemarck, (16–18 August), the XVIII Corps (Lieutenant-General Ivor Maxse) had attacked at 4:45 a.m. with a brigade each from the 48th (South Midland) Division and the 11th (Northern) Division, supported by eight tanks. The tanks were ordered to keep off the roads but the approach to the front line was so boggy that the tanks were cancelled and sent back. The 48th Division attacked with one brigade and after a long fight managed to capture the last house at the north end of St Julien, taking forty prisoners and a machine-gun. The advance resumed and as the first wave went over a rise 200 yd east of the Steenbeek, it was caught in cross fire from Hillock Farm and Maison du Hibou 200 yd beyond. Border House and the gun pits either side of the north-east bearing St. Julien–Winnipeg road had been captured but attempts to press on were costly failures; parties that reached Springfield farm disappeared.

The 48th Division consolidated on a line from the village to the gun pits, Jew Hill and Border House. At 9:00 a.m., German troops massed around Triangle Farm and made an abortive counter-attack at 10:00 a.m. Another counter-attack after dark was repulsed at the gun pits and at 9:30 p.m., a counter-attack from Triangle Farm was repulsed. The Germans in Maison du Hibou and Triangle Farm opposite the 48th Division caught the right of the 34th Brigade of the 11th Division in enfilade fire as it was fired on from pillboxes to the front. The British captured Haanixbeer Farm and the cemetery but lost the barrage and were unable to capture the Cockcroft and Bülow Farm. On the left, the brigade dug in 100 yd north-east of Langemarck opposite the White House and Pheasant Farm and on the right dug in facing Maison du Hibou and Triangle Farm to the east. With observation from higher ground to the east, German artillery fire inflicted many casualties on the British troops holding the new line beyond Langemarck.

Fifth Army
Major-General Oliver Nugent (36th (Ulster) Division), reported that German artillery could not bombard advancing British troops in the German forward zone, in which the defensive positions were lightly held and distributed in depth. The advance of British troops following-up had been much easier to obstruct but helping the foremost infantry was more important than counter-battery fire, even if it had failed to suppress the German guns. Nugent wanted fewer field guns in the creeping barrage and the surplus firing sweeping barrages (from side-to-side). Shrapnel shells should be fuzed to burst higher up, to hit the inside of shell holes and creeping barrages should be slower, with more and longer pauses, during which the barrages from field artillery and 60-pounder guns should sweep and search (move back-and-forth).

The infantry should change formation from skirmish lines to mobile company columns, equipped with a machine-gun and Stokes mortar and advance on a narrow front, since skirmish lines were impractical in muddy crater fields and broke up under machine-gun fire. Tanks to help capture pillboxes had bogged down behind the British front-line and air support had been restricted by the weather, particularly by low cloud early on and lack of aircraft. One aircraft per corps had been reserved for counter-attack patrol and two aircraft per division for ground attack. Only eight aircraft had been available to cover the army front and engage German counter-attacks. Signalling had failed at vital moments and deprived the infantry of artillery support, making German counter-attacks much more effective where the Germans had artillery observation. The 56th Division report recommended that the depth of the advance be shortened, to give more time for consolidation and to minimise the organisational and communication difficulties caused by the muddy ground and wet weather. Artillery commanders asked for two aircraft per division exclusively to conduct counter-attack patrols.

British preparations
On the XVIII Corps front at the Battle of Langemarck, the machine-gunners of German blockhouses and pillbox outposts of the Wilhelmstellung, with British names like Hillock Farm, Maison du Hibou, Triangle Farm and the Cockcroft, had shot down the infantry of the 48th (South Midland) Division and 11th (Northern) Division well short of their objectives. At a conference with the Fifth Army corps commanders on 17 August, Gough complained that troops had failed to hold captured ground and considered court-martialling some NCOs and officers. Gough also thought that divisions had been relieved too frequently, which had exhausted fresh divisions before the attack. The corps commanders were asked for proposals for attacks to reach the final objectives where their divisions had fallen short on 16 August. Lieutenant-General Claud Jacob (II Corps) wanted to attack the brown line and then the yellow line, Lieutenant-General Herbert Watts (XIX Corps) wanted to attack the purple line but Maxse (XVIII Corps) preferred to attack the dotted purple line, ready to attack the yellow line with XIX Corps. The attacks were intended to reach good jumping off points for an attack by II, XIX and XVIII corps on 25 August but attacking in different places at different times, risked defeat in detail. Infantry tactics would also be irrelevant if the artillery insufficiently suppressed the German defenders while the infantry had to struggle through mud and waterlogged shell-holes. During the conference, another 48th Division attack on Maison du Hibou failed.

XVIII Corps plan
After the Battle of Langemarck, the British outpost line in the XVIII Corps area ran east and north of St Julien and 1000 yd beyond the St Julien–Poelcapelle road ran northwards and the Zonnebeke–Langemarck running north-west, crossed. The roads formed a triangle with a road eastwards out of St Julien which cut the Zonnebeke–Langemarck road at the Winnipeg strongpoint. There was another east–west road 250 yd from the point of the triangle. The objectives were inside the triangle except for Maison du Hibou west of the triangle 300 yd along the fourth road and the Cockcroft 450 yd further north up the Zonnebeke–Langemarck road. The British artillery had made many attempts to destroy the German fortifications but field gun shells were ineffective and heavy artillery insufficiently accurate.

A dry spell had begun on 16 August and some of the fortifications were near roads, which the Germans had kept in good condition, making it possible for tanks to drive on them. Three of the objectives were fortified farm buildings; Maison du Hibou had an eighty-man garrison and the Cockcroft even more, Triangle and Hillock farms being smaller. Maxse was told by the 48th Division brigadier-generals to expect 600–1,000 casualties in an attack on the strongpoints. In June the 1st Tank Brigade (Colonel C. D'A. B. S. Baker-Carr) had been allotted to XVIII Corps, the 3rd Tank Brigade to XlX Corps and the 2nd Tank Brigade to II Corps. Maxse consulted Baker-Carr, who claimed that a tank attack could take the farms and blockhouses for half the cost in casualties, provided that there was a smoke barrage instead of artillery-fire.

Baker-Carr formed a composite company from G Battalion, 1st Tank Brigade and held rehearsals in which the tanks attacked the fortifications from the rear, where they were most vulnerable and the garrisons' lines of the retreat would be blocked. The infantry was to follow in platoons 250 yd behind each tank, waiting for a shovel waved out of the manhole in the roof as the signal to move up to the strongpoint. The gun pits, Hillock Farm, Vancouver, Triangle Farm, Maison du Hibou and the Cockcroft were to be attacked by one tank each; two more tanks were to attack Winnipeg Cemetery and Springfield, with one floater and four tanks in reserve at California Trench. The infantry of the 1/8th Battalion, Royal Warwickshire Regiment (1/8th Warwick) of the 143rd Brigade, 48th Division, were to occupy the strong points once the tanks signalled that the defenders had been silenced. The smoke barrage was due to begin on 19 August at 4:45 a.m., as the tanks drove out of St Julien up the St Julien–Poelcappelle road followed by the 1/8th Warwick. The advance was to be shrouded by a smoke barrage and aircraft flying low to disguise the sound of the tanks.

German defences
On 31 July, the German front line north of the Ypres–Roulers railway and the Kampffeld had been overrun and the garrisons lost. The front line had been pushed back between the Albrechtstellung and the Wilhelmstellung, behind which was the rearward battle zone (rückwärtiges Kampffeld). The main defensive engagement had been fought in the Grosskampffeld by the reserve regiments and Eingreif divisions, against depleted, tired and disorientated attackers, whose advance had been slowed by the forward garrisons. The new German front line was a line of shell holes backed by the fortified farms, strongpoints and pillboxes in the Grosskampffeld in front of the Wilhelmstellung. On 16 August, the British had tried to capture the Wilhemstellung but in the XVIII Corps area, the British artillery had destroyed few of the pillboxes and fortified farms in the Grosskampffeld or overcome the German artillery, which inflicted 81 percent of the wounds suffered by the infantry of the 11th (Northern) Division. The division had captured most of its objectives but the 48th Division on the right barely advanced 100 yd After 16 August, the Germans increased the size of regimental sectors to enable even more dispersal and divided the field artillery, one part to be kept hidden and used only during big attacks.

Action
Only seven tanks of the composite company, one male and six female, were operational when the operation began at 4:45 a.m. the others having already broken down or bogged. The tanks drove out of St Julien one at a time towards Hillock Farm, about 550 yd up the road, which took until 6:00 a.m.; the farm was empty and occupied by the 1/8th Warwick. Tank G. 29 (Second-Lieutenant A. G. Barker) reached the road junction at Triangle Farm but could not turn left down the road for Maison du Hibou as it had been obliterated. G. 29 was driven another 125 yd along the Poelcappelle road, which brought the tank to the rear of the strongpoint. The crew tried to approach cross-country and at 250 yd, opened fire with the 6-pounder in the left sponson. After firing forty times, about sixty Germans fled from Maison du Hibou, half being shot down and the remainder taken prisoner by the 1/8th Warwick. From the road, the crew of tank G. 31 engaged the blockhouse with its Lewis guns but then returned to the rally-point with engine trouble. G. 29 bogged down but was able to engage the Germans in the Wilhemstellung with the gun in the right sponson, until the tank sank too far into the mud to bring the gun to bear and around 11:15 a.m. the crew disabled the 6-pounders, dismounted the Lewis guns and handed them to the 1/8th Warwick.

The Germans in Triangle Farm held their ground until the 1/8th Warwick, covered by a tank (possibly G. 31), got inside and fought the garrison hand-to-hand. Tank G. 34 (Second-Lieutenant Coutts) headed for the Cockcroft, the most distant objective, 2400 yd from St Julien, up the Zonnebeke–Langemarck road. It took until 6:45 a.m. to reach the fortification, the crew and the garrison exchanging machine-gun fire for about 15 minutes, when about fifty Germans emerged from the Cockcroft and dugouts nearby, only to be shot down by machine-gun fire from the tank. G. 34 ditched south of the Cockcroft soon after and the crew set up the Lewis guns in shell-holes nearby. As the 1/8th Warwick were nowhere to be seen, Coutts sent a messenger pigeon back with the news and two of the crew to find the troops. The 1/8th Warwick refused to advance until Coutts came back and found an officer to order sixty men forward, to dig in along the Lewis gun cordon. The crew remained until 5:25 p.m. then retired after putting a guard of three rifle-bombers in the tank and camouflaging it. At the other fortified farms and strongpoints, merely the arrival of tanks induced the garrisons to run and the British were able to establish their own line of outposts up the west side of the St Julien–Poelcappelle road, five of the seven tanks engaged surviving to reach the rally-point. The 1/8th Warwick suffered only 15 wounded and the tank crews, two men killed and 11 wounded, inflicting about 100 casualties on the Germans and taking 30 prisoners.

Analysis
After the action, Lieutenant-Colonel J. F. C. Fuller wrote a memorandum Minor Tank and Infantry Operations against Strong Points, in which combined conventional minor tactics with the methods used by the Tank Corps that had succeeded during the battles around Ypres, published on 23 August and influential in the adoption of the "Single File Drill". In 1919, Williams-Ellis and Williams-Ellis wrote that the action was memorable and that a German officer had been found hanged by his men in one of the strongpoints. In 1931, Gough called the attack a "very successful little operation...." In 1995, J. P. Harris called the attack on the pillboxes "One brilliant little feat of arms....", which justified Haig's decision to keep some tanks in Flanders, even after the heavy rains began in August; in 2008 Harris described the operation as "brilliant" and "amazingly low cost". In 1996, Prior and Wilson wrote that in just over two hours Maxe's "novel stratagem" had captured five formidable fortified posts but the method was not feasible in most of the salient. On 22 August, XVIII Corps attacked with tanks again but the objectives were too far from the roads and the tanks ditched when the crews tried to drive closer. In 2014, R. A. Perry wrote that the operation was spectacularly successful but that it created unrealistic expectations of what the tanks could do. In 2017, Nick Lloyd wrote that the action had been "a remarkable exercise in ingenuity and imagination" and that the success raised the morale of the Tank Corps.

Casualties
In 1919, Williams-Ellis recorded 15 wounded among the infantry and two killed, 14 wounded among the tank crews. In the official history volume (1948), J. E. Edmonds, the official historian recorded slight infantry casualties with three killed and that two of the seven tanks in the attack had been lost. In 1996, Prior and Wilson wrote that the British had 28 casualties, 15 infantry and 13 Tank Corps.

Subsequent operations
On 20 August, a special gas and smoke bombardment took place on Jehu Trench, beyond Lower Star Post on the front of the 24th Division (II Corps). The 61st Division (XIX Corps) took a German outpost near Somme Farm and on 21 August, the 38th Division (XIV Corps), pushed forward its left flank. At 4:45 a.m. on 22 August, XIX Corps and XVIII Corps attacked again to close up to the Wilhemstellung, ready for the general attack due on 25 August. The three-brigade attack on the XIX Corps front by the fresh 15th (Scottish) Division and the 61st (2nd South Midland) Division, was a costly failure. Four tanks to support the 45th Brigade on the right flank of the 15th Division ditched short of the front line on the Frezenberg–Zonnebeke road and four of the six survivors, starting west of the Pommern Redoubt, ditched in the front line. The 15th Division advance was soon stopped by fire from the Potsdam, Vampir, Borry Farm and Iberian Farm fortified farms and blockhouses but infantry who pressed on closer to the objective disappeared. On the left flank, troops of the 44th Brigade managed to advance some way up the slope of Hill 35 assisted by two tanks, until stopped short by machine-gun fire from Gallipoli Farm. The 184th Brigade of the 61st Division managed to advance about 600 yd and captured Pond Farm, Somme Farm and Hindu Cottage. On the XVIII Corps front, the 48th Division and the 11th Division were to have advanced in a thin skirmish line preceded by tanks. Ten tanks were allotted to the 48th Division but behind the British front line, on the St Julien–Poelcappelle road, six tanks bogged or were hit by shells. The remaining four tanks assisted the 143rd Brigade to capture Keerselare, Vancouver Farm and Springfield Farm, the latter being re-taken soon after; two tanks helped troops of the 33rd Brigade, 11th Division capture Bülow Farm.