Cambrai

A German map of the Cambrai battlefield

Among the war weary belligerents of late 1917 there was an eager search for new approaches, different tactics, breakthrough – above all for surprise. The Germans had taken advantage on the chaos on the eastern Front to develop their ‘Hutier’ tactics. For those unaware of the first success of these at the capture of Riga in September, the news now reaching the Allies of the Italian collapse at Caporetto, brought the first evidence (see previous post 13/11/2017). At the same time the very worst example of relentless slaughter by attrition was continuing at Ypres, as the Empire troops inched their way towards Passchendaele.

On 29^th October, Lloyd George addressed the British Parliament on the need for such a breakthrough, just as news from Caporetto was arriving alongside Haig’s exaggerated claims of progress in Flanders. Yet, only a week before Haig himself had approved a plan demonstrating Britain’s willingness to innovate. Sir Julian Byng, now C-in-C of the 3^rd Army at the southern end of the British sector (and successor to Allenby who had been transferred to the Middle East (see Post 23/7/2017)) had submitted a bold plan to Haig in September. Byng had done well in the Battle of Arras, culminating in the Canadians capture of Vimy Ridge. He wanted the British to capitalise on the favourable terrain they now held in order to use the British equivalent to ‘Hutier tactics’ – the tank. Now, the tank’s record to date was not unblemished. After a striking debut in the Somme battles (some said too little, too soon – see post 18/8/2016) the tanks had proved mechanically unreliable, and currently were underperforming in the muddy morass of Flanders. Byng argued that the latest, improved tanks deserved a chance over better terrain. He proposed an attack on Cambrai*, a town that had come into play since the German strategic withdrawal to the Siegfried Line (see Post 18/4/2017). He argued the following in support: the advance to the Siegfried Line had allowed some ground cover for the British line, particularly in the trees of Havrincourt Wood where tank build up could be concealed; the ground to be attacked was open and relatively dry; the German defences although strong were (relatively) undermanned, and Cambrai itself was an important hub for German movement of forces behind their front line.

Thus, a novel proposal to break the new German defensive line. However, the consent from Haig, when it came, was rather predictable. As usual he overestimated the possibilities, and revived his dream of a cavalry breakthrough to open country behind the lines.  He preferred to push north of Cambrai to high ground. This, despite the knowledge that his reserves were weak – many of them still bogged down at Ypres – and his men must necessarily come under strong counter-attacks within 2-3 days when German reinforcements arrived. Haig was becoming Micawber like in his desperation for a break through.

Byng prepared his assault along a six mile front from just north of the Bapaume (Roman) road south-eastwards to Gonnelieu and Vendhuille (see map). He had six infantry Divisions and nearly 500 tanks. He hid the latter wherever he could find suitable shelter, with the majority in the welcome cover of Havrincourt Wood (On the Somme battlefields barely a tree stump remained, but this area had not yet been torn to shreds). Secrecy was essential, and British air superiority and misty autumn weather helped to preserve it to a remarkable degree. The plan was for the tanks to cut through the intimidating barbed wire barriers – no less than 50m wide on any part of the 6 miles – with the infantry following close behind, all of them being protected by a creeping artillery barrage. The 115,000 men of Byng’s divisions outnumbered the defenders by nearly two to one, but even after the barbed wire they would still have to overcome the Siegfried line and a second line that was heavily tunneled.

Communication trench to the
front line - Cambrai 1917

At 6.20am on 20^th November came a solitary shot that was the signal for the advance. There had been no pre-bombardment, but the creeping barrage started within minutes. The surprise element prospered. Within four hours the central section had overwhelmed the Siegfried line and was battling in the tunnels of the second line. Flesquières and Ribaucourt were taken by the stars of the day the 62^nd Division. Just to the south, Marcoing and Neuf Wood fell to the tanks of the 29^th Division; pushing through a gap created by the first wave. Even the Cavalry got in on the act, and were pushing north ahead of the infantry to capture Anneux and Cantaing. Unfortunately they could not get across the canal at Masnières, a vital crossing. However, the advance of the British on that first day was their greatest in a single day of the war to date. When news reached London, church bells were rung across the country for the first time since 1914. On the 21^st the cavalry were still in play, but the essential targets of the Bourlon ridge in the north, and the canal crossings in the centre at Rumilly and Crevecoeur could not be forced.

Tanks made life easier for the Infantry on Day 1

By the third day, all effects of surprise were gone, as had the chances for a cavalry coup. Inevitably, German reinforcements were pouring into the area. Haig faced a decision to order Byng to press on, or pull back to a defensible position. Inevitably, he chose the former, and most of the battle’s 45,000 British casualties occurred in the next few days of brutal combat. By the 27^th, one week in, the British had captured some 10,000 prisoners of war, and nearly 150 heavy guns. They had gained ground over a rectangular salient ten miles wide and six miles deep. But the men were exhausted, and vulnerable to counter attacks.

On 29^th Marwitz, C-in-C of the German II Army, issued a rallying cry to his men to reverse the gains and “turn their embryonic victory into a defeat by an encircling attack”. The next morning at 7.30am the Germans surged on to both flanks of the British salient, employing storm troopers and gas attacks and overwhelming the improvised British defences. It was only a heroic defensive action in the centre by men of the 29^th Division (who had also performed with distinction at Gallipoli and at the Somme) that prevented a rout. By the evening the 29^th had managed a staged withdrawal from Masnières to la Vacqerie, linking with the British line on either side to form some sort of defensive front. Both sides were now exhausted, and after two further days of inconclusive local actions Haig bowed to the inevitable and shortened his line by drawing back from the Bourlon ridge areas, for which the men had fought so hard.

By 7^th December the withdrawal had been achieved and the battle for Cambrai was over. The British held around one quarter of the area they had gained on days 1-3 – on a line from Flesquières to Ribecourt. At the northern end they were back at their starting point, and to the south of Gonnelieu they had actually been pushed back beyond their starting line by up to a mile.

The Battle of Cambrai was over by 8^th December. Militarily it must be judged a score draw. Both sides had around 45.000 casualties. The British tanks had demonstrated their ability to break through the enemy’s strongest defence lines. But their  lack of reserves and follow up resources (the cavalry were not quite up to it) enabled the Germans to respond devastatingly with their own innovations. It was a bittersweet ending to the last major action on the Western Front in 1917. The church bells had rung, but not for long.

* Cambrai was a historically important junction. A Roman road to the west linked to Bapaume 16 miles away (the strategic aim of the Somme campaign) and another to the east to Le Cateau (15 miles), the place of 2 Corps heroic stand on the Great Retreat in 1914)