General Grandsard also positioned another infantry division, the 71st, between the 55th and 3rd North African to reinforce the Sedan front. The 55th had lost the battalion sent forward to assist the cavalry and was redistributing its troops. Both infantry divisions were short of antitank and antiaircraft guns, but the 55th Division possessed double its normal allocation of artillery. A number of corps-level artillery units were also attached to the 55th, giving it 140 guns under its control.
Also on May 12, Guderian met with his superior, General Ewald von Kleist, who ordered Guderian to force a crossing of the river by the following afternoon. Guderian was concerned about the 2nd Panzer Division, which still had not arrived. Kleist insisted on maintaining the offensive and believed the element of surprise could be achieved with a quick attack. Guderian agreed and made a hasty plan based on one he developed as an exercise the previous February. The 1st Panzer Division would make the primary effort. It would cross the Meuse just north of Sedan, seizing the high ground of La Marfee, which overlooked the city. To ensure success the division would be reinforced by the Grossdeutschland Regiment, a battalion of combat engineers, and the entire artillery pool of the three divisions in XIX Corps. The 10th Panzer would cross the river south of Sedan and protect the left flank of the corps while the 2nd Panzer would do the same on the corps’ right flank at the French town of Donchery, west of Sedan. Once across, the corps would be poised to strike west toward the coast, cutting off the Allied armies to the north and achieving the German operational objectives.
Preparation for the attack began on May 13, as each German unit struggled to get into its proper position for the afternoon attack. The limited road network still restricted their speed, and from across the Meuse French artillery fired at any target observers could find. One French general later wrote, “What a chance for the artillery to strike hammer blows, to put into practice the ‘swinging concentrations’ which are the crowning glory of the 500-page general instruction on artillery fire!”
Unfortunately for the French, their guns were restricted to only 30 rounds per day, greatly reducing the amount of fire they could mass upon the Germans across the river. The gunners had to limit their fire, feeling the need to conserve ammunition for later fighting. General Grandsard and his staff were still assuming it would take the enemy perhaps a week before they would be ready for a crossing attempt.
The German artillery was still trying to get into position through May 13, struggling with all the other supporting troops trying to get into their assigned places. Instead, the Germans used their marked superiority in air power to mount a heavy attack. The Luftwaffe used a combination of level bombers and Stuka dive bombers to lay down a barrage from the air, which shocked the French with its intensity. This allowed Lt. Col. Balck the reprieve he needed to get his panzergrenadiers across the Meuse.
It also tipped the commander of the French 55th Division, General Pierre Lafontaine, that the main enemy attack was coming soon. He signaled the corps commander, General Gransard. In response Gransard ordered his corps reserves, composed of a pair of tank battalions and two infantry regiments, forward so they could counterattack any German assault that developed. The French were still reacting too slowly, however. It took until dusk for the reserve units to even begin moving, and by then it was too late.
With the French artillery knocked out of the battle, the Germans moved up what tanks and antiaircraft guns they could to place the French river defenses under direct fire. At 4 pm, the boatloads of infantrymen began crossing the river, with Balck among those in the leading craft. Though his memoirs mention a lack of artillery support, other sources point out a short, sharp barrage laid down by German guns to suppress the defenders immediately before the crossing operation began.
Either way, the German infantry started across. Despite the artillery and air attacks, heavy fire greeted them, causing heavy casualties for the first few waves; one estimate placed the dead and wounded at fully half the infantry Balck took with him. Nevertheless, they pushed forward and seized a bridgehead. Their efforts paid off; they were able to knock out enough French bunkers to allow the following waves to get across practically unharmed. The engineers also got forward and began building a pontoon bridge at 6:30 pm. By sunset the heights on the southern bank were in German hands.
The 10th Panzer had a more difficult time but still managed to create a small bridgehead of its own. It took some casualties from a few French guns that had not been destroyed by the Luftwaffe. Some French bunkers were cleared by assault pioneers using demolition charges. The French defenders resisted fiercely, but by nightfall the Germans held the heights at Wadelincourt. The 2nd Panzer, on the XIX Panzer Corps right flank, was initially rebuffed in its attempt to cross the Meuse. That unit made another attempt and by 8 pm had created a small lodgment as well. Now there were three separate German forces across the river with the rest of Guderian’s corps pushing hard to expand the bridgehead. Guderian himself came across as soon as he could; being at the front gave him the best idea of what was happening. Expecting air attacks, he ordered the corps’ flak brigade brought forward as well.
Initially Guderian was ordered to maintain his position, consolidate his gains, and remove the remaining enemy threat to the German flanks. “I would not and could not put up with this order, as it meant forfeiting surprise and all our initial success,” he later said. He successfully argued for a continuation of the attack for another 24 hours to “widen the bridgehead.”
Back in the 1st Panzer Division’s area, Hermann Balck decided to continue his attack even though darkness had fallen. His troops were worn out from their earlier exertions, but once again Balck’s leadership spurred them to further efforts, as he would later speak of in a postwar interview. “At Sedan, my combat leaders told me that they were finished—that they just simply couldn’t advance anymore, and I said, ‘Fine. Whoever wants to stay here can stay here. I’m leading the attack on the next village,’ and of course, the entire regiment sprang up as one man to follow me.”
Balck’s determination paid off; that night the unit advanced unopposed six miles to the town of Chemery. This had further effects for the neighboring 2nd Panzer Division at Donchery. The French units resisting there became worried about being flanked by Balck’s troops and fell back. This allowed 2nd Panzer to seize its own high ground at Croix-Piot by 10 pm. The German lodgment was steadily growing deeper, and the engineers finished their pontoon bridge overnight, allowing armored vehicles to cross the Meuse.
The cumulative effect of these German successes was the disintegration of the French 55th Division. Many of the division’s men were older reservists with inadequate training, as unprepared for the rapidity of the German advance as their leaders. The French reserves, which finally started moving at nightfall, ran into the fleeing troops from the 55th Division, delaying their movement even further. In an attempt to stem the German tide, General Grandsard divided those reserves into two groups and instructed them to counterattack the German 1st Panzer Division’s bridgehead at 4:30 am on May 14.
Each French group contained an infantry regiment and a tank battalion. The first group, the 213th Infantry Regiment and 7th Tank Battalion, would strike at Chemery. The second group, the 205th Infantry Regiment and 4th Tank Battalion, would move through Bulson slightly to the southeast. If successful, the counterattack would catch Balck’s regiment in a bad position, exhausted and at the end of their advance.
Due to the confusion of the battle and the congestion on the roads, such a French victory proved elusive. Neither force was able to attack on time; the first group managed to advance at 7 am on May 14. By then, the Germans had managed to get antitank guns across the Meuse along with some of 1st Panzer’s tanks. Lt. Col. Balck still felt it was a critical moment when his regiment was in the most danger. At the time he believed a French armored brigade supported by aircraft was attacking his unit.