The Canal du Nord Plan

Robertson rejoined his unit on 9 September 1918, arriving in camp about seven in the evening after a stop at Savy. The next day the unit's lines were shelled and the officers' bivouac destroyed, and it pulled back that evening to 1st Brigade Canadian Engineers headquarters at Hendecourt. Then the diary stops. It stays stopped for thirty-five days: across the whole of the Battle of the Canal du Nord and the Hundred Days fighting that followed it. These three sheets, kept clipped together in his papers, are what his brigade was planning during that silence.

The Canal du Nord was an unfinished canal, dry along much of its length, that the Germans had built into their defensive line north-west of Cambrai. The Canadian Corps was to force it on a narrow frontage near Inchy-en-Artois, fan out behind it into open ground, and carry the advance through Bourlon Wood, the plan that opened at 5.20 a.m. on 27 September. The 1st Canadian Division attacked on the left, with the 1st Brigade, C.E. (its three Engineer Battalions and Robertson's Bridging and Transport Section) responsible for the roads forward, the water supply, the clearing of dugouts and booby-traps, and above all the bridges: hasty crossings for the guns within hours of zero, then heavier ones for two-way lorry traffic, and one-way cork-pier footbridges for the infantry.

The papers come in the order they were written. First a draft (“Instructions No. 1,” 17 September) setting out the battalions' tasks against a map and an aeroplane photograph that showed the canal “practically dry” near Lock No. 4, with a proposal to send an engineer officer up in an aircraft to confirm it. Then, on 18 September, a Canadian Corps intelligence sheet reading the German defences off a week's air photos: the front trench in fair order but thinly held, the rear trenches barely dug (many only spitlocked), the dugouts shallow, and the real strength lying in “several broad belts” of wire. That sheet carries the Bridging and Transport Section's own rubber registry stamp; it is his unit's copy.

Then the formal instruction, “Canal du Nord and Bourlon Wood Instructions No. 1,” 21 September, marked Very Secret and running to six pages: army and corps plan, the Red, Green and Blue objective lines, the infantry brigades' tasks, each Engineer Battalion's sector and roads and bridges, the water company, the reserve bridging company, the report centre, the liaison officers, the advanced brigade headquarters. Its last page names three further bridges (a heavy bridge and two pontoon bridges) to be reconnoitred and made ready but not built “until further orders.” It is signed not by the Brigade Major who signs the summer's move orders, Lieutenant-Colonel J. P. Mackenzie, but by an acting one (a Captain, whose signature is illegible) who signs the covering note two days later as well; Mackenzie was away for a stretch of the third week of September and back at the desk by the 24th.

Four more sheets from the same bundle carry the plan the rest of the way to zero hour. A covering note of 23 September (addressed to Robertson's Bridging and Transport Section by name, with “Map to follow” scrawled across it in red crayon) is the slip that sent his unit its copy of the instruction. On the 24th Mackenzie, back in the Brigade Major's chair, issued a “Continued” amendment: the canal crossings now lettered and timed (a horse bridge here by three hours after zero, a gun crossing there by four) and the roads behind them to be handed over to the other two engineer brigades once the advance had passed. The 1st Canadian Division's own administrative staff added their piece on the 22nd, a memo on lorry routes and water signed by the divisional “A and Q,” Lieutenant-Colonel J. Sutherland Brown. And at a quarter past four on the evening of the 26th the brigade issued Operation Order No. 111: four sentences, the whole plan compressed to a map reference and a code word, “Mauve,” to be wired back when each unit was ready. The attack opened thirteen hours later.

The attack went in on schedule. The division crossed the dry canal, the engineers threw the bridges in behind the infantry, and the Corps was into Bourlon Wood the same day and fighting towards Cambrai over the following week, at a cost of more than ten thousand Canadian casualties in five days. His private diary says nothing of it. The unit's own war diary for September and October, which he wrote and signed as its officer commanding, does (see below), and a letter to Doris weeks later has the mood: “For the last month or so have hardly been located in one place for any length of time … Things have been moving right along.”

The unit's war diary for September records his part in the attack itself. On 26 September wagons from four bridging units, the 1st, 2nd, 3rd and 4th, and the 1st Pontoon Park assembled at his unit's lines and moved forward in the afternoon, fifteen trestle wagons with their superstructure, twelve pontoon wagons and five empty ones in all. An appendix written in his hand describes what happened on the 27th. Two convoys were formed from the combined lot: one "in charge of Capt. A.M. Robertson and Capt. Niall" and one under his Lieutenant, C.J. Fox. Zero was at 5.20 a.m. The 3rd Battalion, C.E. was to build four light bridges for horse transport (the D, E, F and G crossings) and four infantry footbridges. Fox's convoy carried the material for D and E; "Capt. Robertson's convoy" carried the material for F and G and the footbridges. The first wagons off were four loaded with cork rafts for the infantry crossings, each in charge of an N.C.O. of the 3rd Battalion who was to build the footbridge, and the account singles out their drivers for "great commendation": the enemy had not yet been cleared from the east bank of the canal, and they delivered their loads on the west bank under heavy machine-gun fire. The wagons for the F and G crossings were held back "in Buissy until the eastern side of the canal had been mopped up." The next day, 28 September, his page of the diary records that the remaining wagons of the combined units "moved forward under Capt. A.M. Robertson, M.C. to vicinity of Bourlon, where they parked", and that the whole detachment was placed at the disposal of the 3rd Brigade, C.E. for further work on the Canal de l'Escaut, with "considerable bombing in vicinity." The 3rd Battalion, C.E., whose companies received these wagons and built the bridges, was commanded by October 1918 by Lieutenant-Colonel E. Pepler, Robertson's old company commander from the 3rd Field Company; its own war diary for October records his report on "Lessons learned during the recent advance." That detachment is the one described in his own report below.

The first appendix to the October volume of the war diary is his own typed report on the detachment he took forward. Three pontoons and three trestle wagons in his charge reported to the 3rd Brigade, C.E. on 28 September and were placed at the disposal of the 7th Battalion; the 29th and 30th were spent standing to, in wet and cold weather. On the morning of 1 October, after the 2nd Division's attack, the wagons moved forward in convoy to the Raillencourt area to await developments, but a heavy counter-attack on the left flank about noon made the bridging programme impossible. They went back to a forward location near Bourlon, bivouacked there on the night of 1 to 2 October, and rejoined the unit at 3.30 p.m. on the 2nd, near Inchy. A later sheet, dated 21 October, is a message from Lieutenant-Colonel Rolston, commanding the 2nd Battalion, C.E., thanking the unit's Lieut. Woods, Sergeant-Major Plant and the drivers attached to the battalion for the speed with which they went into action during the advance, and for the crossing they provided for the guns over the Canal de la Sensée.