Ulster and Irish divisions fight side by side at Messines

A successful assault was the fruit of meticulous planning and the largest mine explosions ever, writes Tom Burke

Before any British offensive from the Ypres salient in 1917 could begin, the Wijtschate-Messines ridge at the southern end of the salient had to be taken first. By comparison if the third battle of Ypres, or Passchendaele as the offensive became known, was a three-act drama, the battle of Wijtschate-Messines ridge would be act one, scene one.

Planning for the attack on Wijtschate and Messines had gone through several ideas scrutinised by senior British generals. The task was ultimately assigned to Lieut- Gen Sir Herbert Plumer and his Second Army in Flanders. Meticulously prepared by Plumer and his staff, the plan consisted of a series of bite and hold operations, with a minimum time required to reorientate the artillery between stages.

Implementation of the plan was compiled into a set of operational instructions presented to commanders to adapt and apply to the section of the ridge they were assigned to take. When the time came to launch the infantry attack, Plumer’s commanders would sing from the one hymn sheet.

The Second Army consisted of three infantry corps comprising of 80,000 to 100,000 men. One corps of that Second Army was Ninth Corps, made up from the 19th (Western) Division; the 16th (Irish) Division and 36th (Ulster) Division, whose collective objective was to pinch out the salient around the village of Wijtschate and push the Germans beyond the village and off the ridge.


An Anzac Corps was assigned the task of taking the adjacent village of Messines.

Quieter sector

To recover from their dreadful losses at the Somme in July and September 1916, both Irish divisions came to the quieter southern sector of the Ypres salient around the Flemish villages of Loker and Dranouter. In an effort to stem the falloff in Irish recruitment, both divisions were placed alongside each other in the lines facing the Germans occupying Wijtschate.

The disastrous Somme campaign of 1916 had taught the British army numerous lessons in battle planning, communications, logistics, all-arms integrated tactics and consolidation. All of these were codified into training manuals issued to divisional commanders and used to train their troops for the attack on Wijtschate.

Models of the German lines at Wijtschate were built by the Royal Engineers for infantry and artillery commanders to study.

As part of Plumer’s battle tactics, by June 1916, 24 mines had been dug beneath the Wijtschate-Messines Ridge to depths of 20-30 metres and packed with almost 396,530kg of explosives.

The end points of the tunnels in which the explosives were placed were located under German strongpoints, such as machine-gun positions and redoubts along their line. At zero hour, 3:10 am on June 7th, these mines would be blown.

Between June 1st and 6th, British artillery began bombarding the German lines in front and behind Wijtschate. The objectives of this week-long bombardment were, in addition to killing as many Germans as possible, to thoroughly demoralise and starve out their troops holding the trenches.

To achieve that objective, using 2,266 field guns and howitzers, the British fired 3,561,530 shells into the German defensive zone of some 15,500 metres long. By rough comparison, the British fired 1,732,873 shells during the opening barrage of the Somme campaign in June 1916 over a 22,800 metre front, using 1,537 similar artillery weapons.

Little protection

Unlike German trenches and deep dugouts on the Somme, which gave some protection, their lines at Wijtschate were mostly above ground on account of the high water table in the region, and gave little protection. The British artillery achieved its objectives in that week-long bombardment.

On Sunday night, June 3rd, some 2,000 British incendiary oil drums were fired on the Bois de Wijtschate. The drums were filled with a mixture of aluminium powder and magnetic oxide of iron, which, on bursting, combine to form a combustible material that produces a temperature high enough to melt steel and indeed human skin. This terrifying projectile was devised by the Royal Engineers and used to flush out German machine-gun posts in the wood.

To gain some last-minute intelligence on the German lines and examine the effect of the barrel bombs, the following night 250 men of the Sixth Connaught Rangers raided the German trenches in the Bois de Wijtschate. Apart from losing three officers – two dead and one blinded for life – the raid went well for the Rangers. They brought back seven prisoners, one of whom was wearing an Iron Cross.

As this raid was going on, the nuns at the convent in Loker laid on a dinner organised by the officers of the Seventh Leinsters. In attendance were officers from the 16th and 36th Divisions, along with French and Belgian officers. It was at this dinner that Willie Redmond "prayed for the consummation of peace between North and South" of Ireland.

All throughout the next day, Tuesday, June 6th, thousands of Irish troops moved up into their jump-off trenches in preparation for the attack on Wijtschate.

Before he set out, one young officer from Carrick Hill in north Co Dublin wrote an emotional and reassuring letter home to his mother. He told her the Germans were surrendering under the stress of the bombardment. They wanted to know had the British gunners let hell loose. He had been to Mass, but his own nerves were shattered.

Back at Second Army headquarters at Cassel, Gen Sir Douglas Haig paid Gen Plumer a visit and wished him and his staff the best of luck for the next day's attack. There was an air of confidence amongst Plumer's men.

Press briefing

Gen Tim Harrington, Plumer's chief of staff, briefed the gentlemen of the press corps about the forthcoming battle. The Daily Telegraph's William Beach Thomas and Philip Gibbs were in attendance. Harrington was asked whether he thought tomorrow's battle might help change the course of the war. He smiled, thought for a moment, then answered: "Gentlemen, I do not know whether we shall change history tomorrow, but we shall certainly alter the geography."

Throughout the day Willie Redmond, accompanied by Lieut-Col Roche-Kelly and Maj Charles Taylor, went to each company of the Sixth Royal Irish and spoke “encouragingly to all”. For the previous three nights, Redmond had slept in a cellar under the chapel at the hospice in Loker.

Amid the noise, the mud caused by a brief thunderstorm, and fear among men waiting for the unknown, could be heard the voice of an Irish Jesuit priest. At about 1am on June 7th, Fr Willie Doyle SJ, accompanied by Fr Frank Browne SJ, offered Mass in a temporary sandbag chapel at the rear of the Dublin Fusiliers assembly trenches. At 2.30am the two chaplains put on their battle kit and headed for their respective first aid posts.

By 3am the countryside around Wijtschate began to quieten. Men spoke in whispers to each other. Nightingales were heard singing in what was left of Rossignol wood. The countdown to zero hour began. Minutes passed away slowly; even the final seconds seemed to drag.

Zero hour was set for 3:10am. It had been carefully chosen as 1½ hours before dawn, and a visibility of 100 metres had been estimated as the first light glimmered on the eastern horizon. The half-light before dawn was seen as an advantage to the attacking Irish troops. The rain had stopped and an almost full moon shone in a clear sky.

At seven seconds before zero hour, the first of the mines went up in the Anzac sector. Within seconds, the rest exploded. The time officially recorded between the firing of the first and last mines along the front line was 19 seconds.The mine facing the Ulster Division went off 15 seconds after zero hour.

Huge mounds of clay the size of farm carts were thrown into the air, forming a crater 130 metres in diameter. The shock wave resulting from the explosion of 396,530kg of ammonal along the front led local people to believe they had experienced an earthquake.


Immediately after the last mine exploded, British artillery opened up on what was left of the German defences and battery positions along the ridge. Fr Edmond Kelly noted that: "Our artillery was so terrific that I heard several of our men express compassion for the enemy who were holding the trenches opposite."

Following the blasts, many of the leading assaulting troops found it impossible to see more than a few metres ahead of themselves, as the air was thick with dust and smoke. The Royal Engineers had estimated 20 seconds for the mine debris to fall back to earth but in reality the dust did not settle for two hours. Visual and oral communications were near impossible.

The worst effect of the mine explosions was the fumes, which caused many of the Irish troops to vomit. In the haze units crossed each other. Confused, high on adrenaline, blinded and choking with dust, they battled their way across no man’s land under a creeping barrage to take their first objective on the western edge of Wijtschate. Here they dug in and began to consolidate their gains

Some of the leading Ulster battalions had begun their advance just after zero hour and were in no man’s land when the Spanbroekmolen mine in front of them went off. Some of the 14th Royal Irish Rifles were caught by falling debris from the mine explosion and were killed.

They are buried practically where they fell at the British Commonwealth War Graves cemetery named Lone Tree Cemetery behind the Spanbroekmolen crater now named the Pool of Peace.

Shortly after 5:50am the second wave of Irish infantry took on the attack to their objectives, which ran through the eastern edge of Wijtschate. In their enthusiasm to get forward, one group of Munster Fusiliers advanced beyond the line of their own creeping barrage and suffered casualties as a result.

Within six hours of the first assault, parties were already at work making roads through shell holes across the mutilated zone and even laying water pipes to get water up to the new front line. At around midday, three battalions of the Dublin Fusiliers and Seventh Royal Irish Rifles came into the fray for the third and final stage of the operation to take Oil Trench near the village of Oosttaverne on the eastern slope of the Wijtschate ridge.

Objectives achieved, this was where the Irish advance stopped. The diarist of the Sixth Royal Irish Regiment, thought that the “attack was a complete success which even exceeded the wildest dreams of the General Staff”. The exploding mines “nearly spoiled the show”.

Friendly fire

However, late in the evening of June 7th, tragedy hit the 33rd Brigade of the 11th(Northern) Division, a reserve brigade attached to the 16th (Irish) Division. Battalions of this brigade that were out beyond Wijtschate suffered casualties from their own artillery due to the slowness/breakdown of communications round the battlefield.

It was self-inflicted carnage. Their casualties reported at 11pm amounted to 24 officers and 423 other ranks killed, wounded or missing. This was 40 per cent of the casualties suffered by the entire 16th (Irish) Division between midnight on June 6th/7th and midday June 9th, being 1,183 officers and other ranks killed, wounded or missing.

The British front line advanced three kilometres east when night fell on June 7th. Some 5,650 German prisoners were taken along the entire frontage during the attack, and their losses were estimated to be almost 20,000, of whom half were missing. Second Army casualties on June 7th were fewer than 11,000. The 16th (Irish) Division placed eight German officers and 674 men in their holding camps and passed on 300-400 others to neighbouring divisions. The 36th (Ulster) Division captured 31 officers and 1,208 other ranks.

The number of casualties suffered by the 16th (Irish) Division at Guillemont and Ginchy in September 1916 at the Somme campaign came to 4,330 killed, wounded or missing. In contrast, the casualty figures for the division between midnight on June 6th/7th to midday on June 9th at Wijtschate were nine officers killed and 56 wounded,125 men of other ranks killed and 844 wounded, with 149 missing: a total loss of 1,183.

Losses to the Ulster Division between midday on June 6th and midday on June 9th at Wijtschate were 61 officers and 1,058 other ranks killed, wounded and missing, which was a total of 1,119. On July 1st, 1916, losses to the Ulster Division at Thiepval had been 5,104.

Act one scene one in this drama at Wijtschate was successful for the Irish divisions. However, their demise awaited them in act two at Frezenberg ridge two months later.