WWI Centennial: Surprise Attack At Cambrai

Erik Sass is covering the events of the war exactly 100 years after they happened. This is the 294th installment in the series.

November 20, 1917: Surprise Attack At Cambrai

By fall 1917 the basic pattern of attack on the Western Front was well established, with a huge artillery bombardment, sometimes lasting days or weeks, preceding a mass infantry assault across No Man’s Land—the model employed at Passchendaele. Then on November 20, 1917, at the Battle of Cambrai, the British tried something radically new: scrapping the lengthy artillery bombardment—which also warned the enemy an attack was coming—in favor of a stealthy surprise attack with tanks.

Since their debut at the Somme in 1916, the new wonder weapons had proved a little less wonderful than hoped—prone to frequent breakdowns, “ditching” or getting swamped in mud, and with limited range under the best of circumstances. However, a number of spectacular successes confirmed the temperamental vehicles’ potential in the right circumstances. Could new tactics, with massed tanks and no preparatory bombardment, deliver a breakthrough, ending the stasis of trench warfare?

With the British Expeditionary Force to the north exhausted after Passchendaele, it was left to General Julian Byng’s British Third Army, including Canadian and South African troops, to execute the giant live fire experiment. They would mount a surprise attack spearheaded by almost 400 tanks and two corps of infantry, using “infiltration” tactics similar to stormtroopers’. The attack targeted the town of Cambrai—a key supply hub for German forces holding the Hindenburg Line to the south.

The initial attack was more successful than the British could have hoped: at 6 a.m. on November 20, 1917, hundreds of tanks began crossing no man’s land with six divisions of British infantry, supported by a simultaneous bombardment by just over 1000 artillery pieces of various sizes. The tanks cleared the way through barbed wire for columns of infantry who followed close behind, overrunning enemy trenches and surrounding strongpoints while the tanks pushed ahead. Meanwhile a smoke screen helped prevent the Germans from directing artillery fire on to the tanks. William Watson, a British tank officer, recalled:

In front of the wire, tanks in a ragged line were surging forward inexorably over the short down grass. Above and around them hung the blue-gray smoke of their exhausts. Each tank was followed by a bunch of Highlanders, some running forward from cover to cover, but most of them tramping steadily behind their tanks … Beyond the enemy trenches, the slopes from which the German gunners might have observed the advancing tanks were already enveloped in thick white smoke. The smoke-shells burst with a sheet of vivid red flame, pouring out blinding, suffocating clouds. It was as if flaring bonfires were burning behind a bank of white fog. Over all, innumerable aeroplanes were flying steadily to and fro. The enemy made little reply.

The sudden appearance of the tanks, emerging from the early morning mist, took many of the German defenders by surprise, surrendering to British infantry advancing close behind. Watson wrote:

Odd bunches of men were making their way across what had been No Man’s Land. A few, ridiculously few, wounded were coming back. Germans in twos and threes … were wandering confusedly towards us without escort, putting up their hand in tragic and amazed resignation, whenever they saw a Highlander. The news was magnificent. Our confidence had been justified. Everywhere we had overrun the first system and were pressing on.

By the end of the day the British attackers had advanced up to five miles in places—a huge win by the standards of the First World War. Watson described scenes in captured German positions well behind the front line:

We walked up the road, which in a few yards widened out. On either side were dug-outs, stores, and cook-houses. Cauldrons of coffee and soup were still on the fire. This regimental headquarters the enemy had defended desperately. The trench-boards were slippery with blood, and fifteen to twenty corpses, all Germans and all bayoneted, lay strewn about the road like drunken men.

However, the success at Cambrai also highlighted, once again, the shortcomings and basic limitations of tanks: as Watson noted, by the end of the first day four out of his 11 tanks were knocked out, three had ditched, and the remainder were short on gas.

Meanwhile the advantage of surprise had been used up and the Germans were rushing fresh troops to the battlefield to reinforce the beleaguered Second Army under General Georg von Marwitz. On November 23, the British continued the attack with an assault on Bourlon Wood, which they had identified as a key position, but already German resistance was stiffening. Watson left this impressionistic description of the British attack at Bourlon Wood on November 23:

At 10:30 a.m. the barrage fell and we could see it climb, like a living thing, through the wood and up the hillside, a rough line of smoke and flame. On the hillside to the left of the wood we could mark the course of the battle—the tanks with tiny flashes darting from their flanks—clumps of infantry following in little rushes—an officer running in front of his men, until suddenly he crumpled up and fell, as though some unseen hammer had struck him on the head—the men wavering in the face of machine-gun fire and then spreading out to surround the gun—the wounded staggering painfully down the hill, and the stretcher-bearers moving backwards and forwards in the wake of the attack—the aeroplanes skimming low along the hillside, and side-slipping to rake the enemy trenches with their guns.

Once again, tanks delivered some impressive gains but they remained vulnerable to unexpectedly unfavorable ground conditions, mechanical breakdowns, and fuel shortages. Of course, despite their heavy armor they were hardly immune to enemy fire, and a single lucky shot by field artillery could spell the end of a vehicle and its crew. Watson described one terrible scene:

Flames were coming from the rear of the tank, but its guns continued to fire and the tank continued to move. Suddenly the driver must have realised what was happening. The tank swung towards home. It was too late. Flames burst from the roof and the tank stopped, but the sponson doors never opened and the crew never came out … When I left my post half an hour later the tank was still burning.

By the end of November the British had chalked up major gains that threatened German logistics in northern France and jeopardized the integrity of the Hindenburg Line. But between hundreds of casualties, mechanical issues, and dwindling fuel, the tanks were largely a spent force—and there was no way the Germans were going to leave the British to enjoy their conquests. Even worse, the Third Army’s new positions formed a vulnerable salient, exposed to enemy counterattack on both flanks.

On November 30, 1917 the Germans unleashed their biggest attack (or rather counterattack) on British forces on the Western Front since 1915, with a crushing artillery bombardment followed by infantry advances against all fronts of the salient southwest of Cambrai. The German counterattack displayed their own tactical evolution with stormtroop assaults, employing trench mortars, grenades and machine guns, closely coordinated with artillery to break up barbed wire entanglements and force enemy infantry to take shelter.

Over subsequent German counterattacks from December 1-7, the recently captured salient collapsed under the weight of superior numbers, reflecting the determination of the German general staff, which was determined to contain the threat to the Hindenburg Line. Private William Reginald Dick described outnumbered British defenders preparing for a German counterattack at La Vacquerie, a village south of Cambrai, on December 3, 1917:

Around and above is a turmoil of noise; the mighty roar of dropping shells, the incessant rending crashes of the explosions, the scream and thud of whizz-bangs, and permeating all, the booming thunder of the guns. In this battering inferno of sound, we have to shout to make ourselves heard. The earth quivers continuously under the metallic flail. Across the shattered soil behind our position, a barrage is falling, a vast unbroken curtain of spouting bursts, spraying up earth, smoke and steel in a dark and furious barrier, half veiled by dense black fumes that writhe, heave, and trail upward in a mist of dirty grey … The Lewis-gun team beside me crouch below their deadly charge; it is tilted up ready to heave on the parapet; a drum is fixed for immediate firing.

The German infantry, led by stormtroopers, advanced boldly into a wall of British fire:

I see the wide waste of the shell-churned soil, the tattered wire, and, well over, a dark and far-flung line of gray-clad stormers; behind them others rising fast, apparently springing from the drab earth in knots and groups, spreading out, surging forward. Simultaneously from our trench bursts a great roar of fire. I fire with fiercely jerking bolt, round after round merged into the immense noise …

As the German infantry approached, firing and throwing grenades, the British defenders were forced to withdraw to another trench in the rear:

Suddenly I hear faintly a medley of confused shouts. I see the men on the fire-step firing fast again, and up the trench they are firing both to front and flank … I see bomb smoke above the parapet to the right, I see men leap back from the fire-step and merge with another little rush of consumed wounded. The platoon sergeant waves his arm urgently, “Down the trench!”

Of course the formidable German stormtrooper units suffered heavy casualties during the German counterattack as well, according to the German novelist Ernst Junger, who described grenade duels with British troops in adjoining trenches at Cambrai in his novel and memoir, Storm of Steel:

The British resisted manfully. Every traverse had to be fought for. The black balls of Mills bombs crossed in the air with our own long-handled grenades. Behind every traverse we captured, we found corpses or bodies still twitching. We killed each other, sight unseen. We too suffered losses. A piece of iron crashed to the ground next to the orderly, which the fellow was unable to avoid; and he collapsed to the ground, while his blood issued on to the clay from many wounds. We hurdled over his body, and charged forward.

Junger described the unique thrill, and terror, of combat with grenades:

One barely glanced at the crumpled body of one’s opponent; he was finished, and a new duel was commencing. The exchange of hand-grenades reminded me of fencing with foils; you needed to jump and stretch, almost as in a ballet. It’s the deadliest of duels, as it invariably ends with one or other of the participants being blown to smithereens. Or both.

During the course of the Battle of Cambrai, the Germans suffered around 45,000 casualties, compared to around 44,200 British. Today the Cambrai Memorial commemorates 7000 British and South African soldiers who died during the battle and were buried in unknown graves.

See the previous installment or all entries.