First Battle of Passchendaele

The First Battle of Passchendaele took place on 12 October 1917 during the First World War, in the Ypres Salient in Belgium on the Western Front. The attack was part of the Third Battle of Ypres and was fought west of Passchendaele village. The British had planned to capture the ridges south and east of the city of Ypres as part of a strategy decided by the Allies at conferences in November 1916 and May 1917. Passchendaele lay on the last ridge east of Ypres, from the railway junction at Roulers, which was an important part of the supply system of the German 4th Army.
After a dry spell in September, rains began on 3 October and by the Battle of Poelcappelle on 9 October much of the British field artillery opposite Passchendaele was out of action due to rain, mud and German artillery-fire. The remaining guns were either left in old positions and fired at the limit of their range or were operated from any flat ground near wooden roadways or from platforms, many of which were unstable, where it was found impossible to move them forward. General Herbert Plumer and Field Marshal Douglas Haig were left under the impression that a big advance had been made towards Passchendaele ridge but most of the ground had been lost to German counter-attacks in the afternoon.
The British attack on 12 October began from the village instead of the originally thought by the British commanders. Air reconnaissance revealed the true position too late to make substantial changes to the plan. The main attack of the Second Army was by the two Anzac Corps, supported by the Fifth Army to the north. On Passchendaele Ridge, opposite the I Anzac and II Anzac Corps, the attack was repulsed or captured ground was recovered by German counter-attacks. The attack on the right flank of the Fifth Army was a costly failure but on the left, the fringe of Houthoulst Forest was gained. British attacks were postponed until the weather improved and communications behind the front were restored.
The battle was a German defensive success but was mutually costly and two German divisions were diverted to Flanders to replace "extraordinarily high" losses. In the worst weather conditions of the campaign, in the five weeks after the Battle of Broodseinde, the number of troops engaged by the British amounted to no more than those involved in the Battle of Pilckem Ridge on 31 July. British casualties in October 1917 were the third highest of the war, after July 1916 and April 1917.

Background

Tactical developments

Date	Rain mm	°F
10	2.5	48	dull
11	4.9	50	dull
12	7.9	55	dull

In July 1917, Field Marshal Douglas Haig began the Third Battle of Ypres campaign to advance from the Ypres Salient. At the Battle of Messines, the far side of the Messines Ridge had been captured down to the Oosttaverne Line and a substantial success gained in the subsequent Battle of Pilckem Ridge. At the Battle of Langemarck there was only an advance of around Langemarck village by XIV Corps and the French First Army on the northern flank. The failure of the Fifth Army to advance on the Gheluvelt Plateau in August, led Haig to send artillery reinforcements to the south-east, along the higher ground of the Gheluvelt plateau, Broodseinde Ridge and the southern half of Passchendaele Ridge. The Gheluvelt Plateau was taken over by the Second Army, which continued the evolution of bite-and-hold tactics that had been used in July and August.
The Second Army planned to attack with a succession of bodies of infantry on narrower fronts, to the first objective about forward; the second objective was beyond and the final objective was further on. Pauses on the objectives would become longer and attacks would be protected by a bigger, deeper, multi-layered creeping barrage. Standing barrages beyond the objectives were to be fired during pauses to obstruct German counter-attacks, to confront them with defensive areas based on the British objectives. The British infantry would be in communication with its artillery and have much more local support from the Royal Flying Corps. Beyond the "creeper", four heavy artillery counter-battery double groups, with and howitzers, covered a front, ready to engage German guns with gas and high-explosive shell. At the Battle of the Menin Road Ridge, Battle of Polygon Wood and Battle of Broodseinde, these methods produced a advance in two weeks, inflicted many German casualties. The Germans changed tactics several times against the refined British methods but all failed.
In the lower ground west of the Passchendaele Ridge, three months of shelling had blocked the watercourses that normally provided drainage. On the night of 4 October, it began to rain intermittently for the next three days. Much of the battlefield again became a quagmire, making movement extremely difficult. Had the German defence collapsed during the Battle of Poelcappelle on 9 October, the reserve brigades of II Anzac Corps were to have passed through later in the day, to advance to far side of Passchendaele village and the Goudberg spur to the north. On 7 October, the afternoon attack had been cancelled by Haig because of the rain and the final details of the plan for the renewed attack of 12 October, were decided on the evening of 9 October. Plumer had received misleading information about the progress of the attack that day and believed that "a sufficiently good jumping-off line" had been achieved, passing the erroneous information back to Haig. The decision was made to continue the offensive to gain higher ground for the winter, to assist the French with their attack due on 23 October and to hold German troops in Flanders for the Battle of Cambrai due in November.

Prelude

British preparations

Encouraged by the unusually high German losses during the Battle of Broodseinde and reports of lowered German morale, Haig sought quickly to renew the Allied offensive and secure Passchendaele Ridge. The Battle of Poelcappelle began on 9 October and was costly to both sides; most of the ground captured opposite Passchendaele was lost later in the day to German counter-attacks. News of this German defensive success was slow in reaching the higher British commanders, because the usual collapse of communications during an attack was exacerbated by the rain and mud. Late on 9 October, Plumer erroneously informed Haig that II Anzac Corps had reached the first objective, which made a good jumping-off position for the attack due on 12 October. Many British guns had sunk in the mud, bogged down while being moved forward or run short of ammunition. German artillery fire had become much heavier as British heavy artillery counter-battery fire almost ceased from 9 to 12 October, as attempts were made to move the guns forward, although the defenders were still caused considerable difficulty by British bombardments.
The 3rd Australian Division and the New Zealand Division relieved the 66th Division and the 49th Division on the night of Patrols discovered that the 49th Division had reached the Wallemolen spur east of the Ravebeek creek but the advance beyond had been stopped by new barbed wire entanglements around the Flandern I Stellung. The 66th Division, on the right flank, was found to be back near its start line of 9 October. The New Zealand Division made hurried preparations to restore communications and reconnoitre the ground, because information from the 49th Division headquarters was insufficient; some wounded were still stranded in no-man's-land when the attack began on 12 October. Many field guns needed for the attack remained bogged in the mud and other field guns were placed on improvised platforms, when their new sites had proved impossible to reach, from which they fired slowly and inaccurately or sank into the mud. A German bombardment took place on the morning of 11 October and later in the day the British shelled the German defences on Wallemolen spur, to little effect. Some progress was made in the building of plank roads since the attack on 9 October and a few more guns had reached their new positions by 12 October. The Commander, Royal Artillery of the New Zealand Division reported that adequate artillery support for his division could not be guaranteed.
Plumer discovered that the line near Passchendaele had hardly changed and that the main reason for the failure on 9 October was uncut barbed wire deep, in front of the pillboxes at the hamlet of Bellevue on the Wallemolen spur. The New Zealand Division commander, Major-General Andrew Russell, later wrote that accurate information had arrived too late to ask for a postponement or radically to alter the barrage plan and unit orders. The true position of the front line meant that the advance of to the final objective would actually have to cover. The opening barrage line planned for the 3rd Australian Division was moved back but this still required the infantry to advance for to reach it. Duckboard tracks had been extended to the line held on 9 October, which allowed infantry to move up on the night of 11 October in time for the attack, despite rain and a German gas bombardment on Gravenstafel spur. High winds and heavy rain began about zero hour and lasted all day.

British plan

The II Anzac Corps and the Second Army headquarters were misinformed as to the extent of the advance achieved on 9 October. The objectives set for 12 October required an advance of to the final objective, rather than the intended. The I Anzac Corps with the 4th and 5th Australian divisions, in place of the exhausted 1st and 2nd Australian divisions, was to provide a flank guard to the south. The I Anzac Corps was to advance across the Keiberg Spur and dig in on the flank of the main assault, at the first and second objective lines only, and forward.
The main attack was to be undertaken by the Second Army, with the 3rd Australian Division and the New Zealand Division of the II Anzac Corps, on a front of. The 3rd Australian Division would attack Passchendaele ridge and the village and the New Zealand Division was to capture the Bellevue Spur. The first objective was practically the same as the second objective of the attack on 9 October, forward, beyond the Bellevue pillboxes. The second objective was beyond, at the junction of the Wallemolen Spur and was the jumping-off line for the attack on the village of Passchendaele. The final objective lay beyond the village.
Although short of fresh troops, the Fifth Army was to establish the northern flank of the main attack. In the XVIII Corps area, the 26th Brigade of the 9th Division was to advance to the ridge north of the Goudberg re-entrant and the 55th Brigade of the 18th Division was to attack for a similar distance north of the Lekkerboterbeek creek. In the XIV Corps area, the 12th Brigade of the 4th Division, the 51st Brigade of the 17th Division and the 3rd Guards Brigade of the Guards Division, were to advance beyond Poelcappelle and close up to Houthoulst Forest, on the boundary with the French First Army.
In the New Zealand Division sector, the two attacking brigades each had a machine-gun company and three other machine-gun companies were to fire a machine-gun barrage. The division had the nominal support of a hundred and forty-four 18-pounder field guns and forty-eight 4.5-inch howitzers The artillery was expected to move forward after the final objective was gained, to bombard German-held ground from positions beyond Passchendaele village. On the southern flank, the I Anzac Corps was to capture ground south of the Ypres–Roulers railway, the X Corps and IX Corps attacking on the right.