After the failure of British tanks in the thick mud at Passchendaele, Colonel John Fuller, chief of staff to the Tank Corps, suggested a massed raid on dry ground between the Canal du Nord and the St Quentin Canal. General Sir Julian Byng, commander of the Third Army, accepted Fuller's plan, although it was originally vetoed by the Commander-in-Chief, Sir Douglas Haig. However, he changed his mind and decided to launch the Cambrai Offensive.
Brigadier-General John Charteris, the Chief Intelligence Officer at GHQ was involved in the planning of the offensive at Cambrai in November 1917. Lieutenant James Marshall-Cornwall discovered captured documents that three German divisions from the Russian front had arrived to strengthen the Cambrai sector. Charteris told Marshall-Cornwall: "This is a bluff put up by the Germans to deceive us. I am sure the units are still on the Russian front... If the commander in chief were to think that the Germans had reinforced this sector, it might shake his confidence in our success."
Haig, who was not given this information, ordered a massed tank attack at Artois. Launched at dawn on 20th November, without preliminary bombardment, the attack completely surprised the German Army defending that part of the Western Front. Employing 476 tanks, six infantry and two cavalry divisions, the British Third Army gained over 6km in the first day. Progress towards Cambrai continued over the next few days but on the 30th November, 29 German divisions launched a counter-offensive.
By the time that fighting came to an end on 7th December, 1917, German forces had regained almost all the ground it lost at the start of the Cambrai Offensive. During the two weeks of fighting, the British suffered 45,000 casualties. Although it is estimated that the Germans lost 50,000 men, Sir Douglas Haig considered the offensive as a failure and reinforced his doubts about the ability of tanks to win the war.
An official inquiry carried out after the military defeat at Cambrai blamed Brigadier-General John Charteris for "intelligence failures". The Secretary of State for War, the Earl of Derby, insisted that Haig sacked Charteris and in January 1918, he was appointed as deputy director of transportation in France. Haig wrote at the time: "He (Charteris) seems almost a sort of Dreyfus in the eyes of our War Office authorities."
At 6.30 am on that memorable day, 20th November. We heard the sound of tank engines warming up. The first glimpse of dawn was beginning to show as we stood waiting for the big bang that would erupt behind us at the end of the count down. The tanks, looking like giant toads, became visible against the skyline as they approached the top of the slope. Some of the leading tanks carried huge bundles of tightly-bound brushwood, which they dropped when a wide trench was encountered, thus providing a firm base to cross over. It was broad daylight as we crossed No Man's Land and the German front line. I saw very few wounded coming back, and only a handful of prisoners. The tanks appeared to have busted through any resistance. The enemy wire had been dragged about like old curtains.
The battle has continued today, and our troops and tanks have been engaged in heavy fighting round Borlon Wood and at Fontaine-Notre-Dame, to the east of it, which we lost yesterday for a time, after a sharp counter-attack upon our Seaforth Highlanders, who entered it on Wednesday night with tanks.
Tanks and cavalry co-operated in this attack, and the tanks were a most powerful aid, and cruised round and through the village, where they put out nests of machine-guns. The cavalry then went on into Anneux; but the first patrol had to retire because of the fierce machine-gun fire that swept down the streets.
We thought these tanks were going to win the war, and certainly they helped to do so, but there were too few of them, and the secret was let out before they were produced in large numbers. Nor were they so invulnerable as we had believed. A direct hit from a field gun would knock them out, and in our battle for Cambrai in November of 1917 I saw many of them destroyed and burnt out.
But after the German retreat from the Somme battlefields it was the tanks who broke the Hindenburg Line, which the enemy had believed impregnable. They had dug a wide anti-tank ditch too broad for any tank to cross. But the commander of tanks, General Hugh Elles, had thought that out. He ordered the gathering of vast quantities of twigs and small branches of trees. They were tied into bundles like the Italian fasces. He called them fascines. Each tank advanced upon the Hindenburg Line with one of those bundles on its nose. By working a pulley the skipper could drop it into the ditch, then by nosing forward he could get the front part of the tank on to the bundle and so reach across.
The English attack at Cambrai for the first time revealed the possibilities of a great surprise attack with tanks. We had had previous experience of this weapon in the spring offensive, when it had not made any particular impression. However, the fact that the tanks had now been raised to such a pitch of technical perfection that they could cross our undamaged trenches and obstacles did not fail to have a marked effect on our troops. The physical effects of fire from machine-guns and light ordnance with which the steel Colossus was provided were far less destructive than the moral effect of its comparative invulnerability. The infantryman felt that he could do practically nothing against its armoured sides. As soon as the machine broke through our trench-lines, the defender felt himself threatened in the rear and left his post.