For the German troops near the French town of Cambrai, the world exploded into terror and flame on the morning of November 20th, 1917. 1,003 guns of the British army opened in unison at 6:10 AM that day, in an intense and destructive barrage which lasted only ten minutes. It was quickly followed by one of the most terrifying sights anyone could have imagined.
As the early morning fog rolled through what was once farmland, but was now desolate earth, thundering steel beasts followed in its wake. The German troops that morning awoke to find themselves facing an entirely new type of warfare: a massed tank assault.
This battle was the brainchild of John Fuller, commander of the British Tank Corps, and Sir Julian Byng. Fuller and his supporters in the British Army Staff convinced Byng that an armored breakthrough was the only substantive way to break the stalemate of the first world war. Byng was convinced, and secretive planning for a surprise attack was put into motion.
The town of Cambrai was chosen as this attack’s objective. Cambrai was an important supply line junction for the German army in the region, connected by both rail lines and river. It also had fairly open land in front, necessary for a massed armored assault. But what was most important was that it was a reachable distance from Byng’s section of the line.
Building up to the battle, the British began massing troops behind their lines. They slowly moved up their new Mk. IV tanks, running them in low gear. While this meant that all progress was slow, it also meant that they were much quieter. To cover any possibility of detection by noise, the British flew constant aerial sorties up and down the German line. This had the added effect of giving them an up-to-date view on German positions and holdings. Finally, by the 19th of November the British 3rd Army, and the 473 tanks they accumulated, had readied themselves. Unbeknownst to most of the men there that day, warfare would change the next morning forever.
The bombardment opened up at 6:10 AM, with the tanks and infantry advancing at 6:20 AM. Even the bombardment was a display of new technology. By teaching their artillerymen and NCOs ballistics, and some of the more complicated mathematics behind calculating bore wear (which limited the range of artillery guns) the British were able to fire accurately without the need for ranging shots. This meant that when their guns let loose their first volley, they were on target without any indication that a bombardment was coming.
As the barrage crept forward, it was followed by continuous waves of tanks and infantry. This was the first mass armored assault of the war, and no one was entirely sure how it would go. Prior attempts to use tanks decisively had often proved disastrous. Often used piecemeal and only in support of massed infantry, the tanks were exposed. German artillery, or even troops with specialized hand grenades, were able to pick off any tanks which got too close, and then they would simply mop up the remaining infantry. But at Cambrai, the tanks just kept coming.
As this mass assault pushed forward, the tanks crushed the wire, and pounded the German defenses. While the German troops retreated in the face of these beasts the British infantry would pour into the lines. Finally, the front lines had been broken, and the British began pushing for their initial objectives before they pushed forward to the town of Cambrai proper.