The battle was preceded by the greatest British artillery bombardment of the war. Some 1,600 guns were deployed (1,044 field guns and 593 heavy guns and howitzers), firing almost 1,000,000 shells over a comparatively short period of time. Included in these were more than 30,000
mustard gas shells (the first use of a British-made version of this weapon). These were specifically targeted at headquarters and groups of batteries. Many of the
high explosive shells fired had special fuses which made them very effective in destroying the German barbed wire. The British were greatly helped by the fact that they were in possession of highly detailed captured plans of the enemy defences (especially useful for the IX Corps sector). Monash's battle plan for 29 September envisaged breaking through the main Hindenburg Line defences, crossing the canal tunnel mound, breaching the fortified Le Catelet–Nauroy Line beyond that, and reaching the
Beaurevoir Line (the final fortified line) beyond that as the objective on the first day. Monash had originally intended to capture the Beaurevoir Line on 29 September, but Rawlinson removed this as a first day objective, considering it overly ambitious.
Attack over Bellicourt Tunnel On 29 September, the two American divisions attacked, followed by the two Australian divisions, with approximately 150 tanks of the 4th and 5th Tank Brigades of the British
Tank Corps (including the newly trained American
301st Heavy Tank Battalion, which was equipped with British tanks) in support of the four divisions. The objective of the Americans was the Le Catelet-Nauroy Line, a defensive line east of the canal. Here the Australian
3rd Division (behind the U.S. 27th) and
5th Division (behind the U.S. 30th) were intended to "
leapfrog" through the American forces and press on towards the Beaurevoir Line. Australian
2nd Division was in reserve. On the left of the front, where the U.S.
27th Division began at a disadvantage, none of the objectives were met on the first day and the Americans suffered severe losses. The
107th Infantry Regiment suffered the worst casualties sustained in a single day by any U.S. regiment during the war. Rather than leapfrogging through the Americans, the Australian 3rd Division became involved in a desperate fight for positions that should already have been captured had Monash's plan run to timetable. Despite some individual acts of heroism the lack of progress on the left of the front had an adverse effect on the progress of the right of the front too. As the American
30th Division and then the Australian 5th Division moved forward whilst the units to their left did not, they had to contend with German fire from the side and rear as well as from ahead. An added difficulty was thick fog across the battlefield in the earlier stages of the attack which led to American troops passing by Germans without realising that they were there, with the Germans causing severe problems to the Americans following the assault wave. Fog also caused problems for infantry/tank cooperation. The 30th Division broke through the Hindenburg Line in the fog on 29 September 1918, entering Bellicourt, capturing the southern entrance of Bellicourt Tunnel and reaching the village of Nauroy, where Australian troops joined them to continue the attack. The advancing Australians came across large groups of leaderless, disoriented Americans.
Charles Bean wrote: "By 10 o'clock Monash's plan had gone to the winds.... From that hour onward ... the offensive was really directed by Australian battalion or company commanders at the front..." The 30th Division won the praise of General
John J. Pershing, who wrote: "... the 30th Division did especially well. It broke through the Hindenburg Line on its entire front and took Bellicourt and part of Nauroy by noon of the 29th." There has since been considerable debate over the extent to which the American forces were successful. Monash wrote: "...in this battle they demonstrated their inexperience in war, and their ignorance of some of the elementary methods of fighting employed on the French front. For these shortcomings they paid a heavy price. Their sacrifices, nevertheless, contributed quite definitely to the partial success of the day's operations..." The objective of U.S. II Corps, the Catelet–Nauroy Line, was not captured by the Americans. During the battle, Monash was furious about the performance of the American divisions. Late on 29 September Rawlinson wrote: "The Americans appear to be in a state of hopeless confusion and will not, I fear, be able to function as a corps, so I am contemplating replacing them ... I fear their casualties have been heavy, but it is their own fault." Meanwhile, on the right of the Bellicourt Tunnel front, the Australian
32nd Battalion under the command of Major
Blair Wark established contact with the 1/4th Battalion,
Leicestershire Regiment, of 46th Division, which had crossed the canal and were now present in force east of the Hindenburg Line. By this stage in the war the Tank Corps had suffered greatly and there were fewer tanks available for the battle than had been deployed in the
Battle of Amiens in August. Eight tanks were destroyed when they strayed into an old British minefield but the 29 September attack also highlighted the high vulnerability of tanks to strong German anti-tank measures. In one instance, four heavy tanks and five medium tanks were destroyed in the space of 15 minutes by German
field guns at the same location. This was during the attempt to subdue severe machine gun fire coming from the Le Catelet–Nauroy Line in the vicinity of Cabaret Wood Farm (a tank fort – see map) and showed the danger posed by German field guns to tanks operating without close infantry support (because the crew had very limited visibility and often could not see a threat which those outside the tank could see). The tanks could protect the infantry but they also needed the close cooperation of the infantry to alert them to the danger of concealed field guns. In the case of this attack, the machine gun fire was so severe that the infantry were ordered to withdraw, leaving the tanks well forward of them and prey to the German field guns.
Attack across the canal cutting The attack across the canal cutting, also known as the Battle of Bellenglise, saw IX Corps (commanded by Braithwaite), on the right of the American and Australian Divisions, launch its assault between Riqueval and
Bellenglise. The assault was spearheaded by the British 46th Division under the command of Major-General
Gerald Boyd. In this sector the St Quentin Canal formed an immense, ready-made anti-tank "ditch" and the main Hindenburg Line trench system lay on the east (German) side of the canal. IX Corps was supported by tanks of the 3rd Tank Brigade, which had to cross Bellicourt Tunnel in the American 30th Division sector and then move south along the east bank of the canal. IX Corps had to cross the formidable canal cutting (which increased in depth as it approached Riqueval until its very steep banks, strongly defended by fortified machine gun positions, were over deep in places), and then fight its way through the Hindenburg Line trenches. The 46th Division's final objective for 29 September was a line of high ground beyond the villages of
Lehaucourt and
Magny-la-Fosse. The British
32nd Division, following behind, would then leapfrog the 46th Division. Following a devastating artillery bombardment (which was heaviest in this sector), and in thick fog and smoke, the 46th Division fought its way through the German trenches west of the canal and then across the waterway. The
137th (Staffordshire) Brigade spearheaded the attack. The ferocity of the creeping artillery barrage contributed greatly to the success of the assault, keeping the Germans pinned in their
dugouts. The soldiers used a variety of flotation aids devised by the
Royal Engineers (including improvised floating piers and 3,000
lifebelts from cross-Channel steamers) to cross the water. Scaling ladders were used to climb the brick wall lining the canal. Some men of the 1/6th Battalion, the
North Staffordshire Regiment, led by Captain A. H. Charlton, managed to seize the still-intact Riqueval Bridge over the canal before the Germans had a chance to fire their explosive charges. The 46th Division captured the village of Bellenglise, including its great tunnel/troop shelter (which had been constructed as part of the Hindenburg Line defences). By the end of the day the 46th Division had taken 4,200 German prisoners (out of a total for the army of 5,100) and 70 guns. The assault across the canal met all of its objectives, on schedule, at a cost of somewhat fewer than 800 casualties to the division. The great success of the day had come where many had least expected it. The 46th Division assault was considered to be one of the outstanding feats of arms of the war. Bean described the attack as an "extraordinarily difficult task" and "a wonderful achievement" in his official Australian war history. Monash wrote that it was "an astonishing success...[which] materially assisted me in the situation in which I was placed later on the same day". Later in the day the leading brigades of the 32nd Division (including Lt
Wilfred Owen of the Manchester Regiment) crossed the canal and moved forward through the 46th Division. The whole of the 32nd Division was east of the canal by nightfall. On the right of the front in IX Corps sector, the 1st Division, operating west of the canal, had the task of protecting the right flank of the 46th Division by clearing the Germans from the ground east and north-east of
Pontruet. It met with fierce German resistance and heavy
enfilade fire from the south. On the evening of the 29 September orders were issued for IX Corps to seize the Le Tronquoy Tunnel defences to allow the passage of the XV French Corps over the canal tunnel. The following day, the 1st Division advanced under a creeping barrage and early in the afternoon the 3rd Brigade of the division linked up on the tunnel summit with the 14th Brigade of the 32nd Division, which had fought its way forward from the German side of the canal. File:Riqueval Bridge 1918.jpg|Brigadier General
John Vaughan Campbell VC addressing troops of the 137th Brigade (46th Division) from the Riqueval Bridge over the St Quentin Canal on 2 October 1918 File:Riqueval Bridge IWM Q9353.jpg|King George V at Riqueval Bridge, the scene of the exploit of the 137th Brigade when the 46th Division crossed the St Quentin Canal cutting on 29 September 1918 (photo taken 2 December). File:Riqueval2.jpg|Riqueval Bridge in 2003. The canal banks are much more overgrown than when the bridge was captured during the battle. ==Aftermath==