The 'Battle of Fort Driant' was fought between US and German forces as part of the 'Battle of Metz' (27 September/13 October 1944).

The battle was on German-occupied French territory between the forces of Lieutenant General George S. Patton’s US 3^rd Army and General Otto von Knobelsdorff’s German 1^st Army.

Fort Driant was located 5 miles (8 km) to the south-west of the city of Metz, just to the west of the Moselle river. Originally built in 1902 by the Germans, to whom the area then belonged, and renamed in 1919 for Colonel Emile Driant after the French had resumed control of the area by the Treaty of Versailles, the fort was continually reinforced by both the French and German armies. Built of steel-reinforced concrete, the fort was surrounded by a deep dry moat and barbed wire entanglements, and accommodated five main batteries of 150-mm (5.91-in) guns, infantry trenches, and armoured machine gun and observation posts. Occupying a commanding position, the fort could unleash direct heavy fire on targets in the Moselle river valley, and was also able to bring down flanking fire that produced heavy casualties among the men of its attackers in 1944, who were troops of Major General Walton H. Walker’s US XX Corps of the 3^rd Army.

The 3^rd Army’s intelligence section had already determined that the Germans intended to exploit to the full the ring of forts around Metz, an ancient gateway city through which many invading armies had passed. Metz was to be the linchpin in the Germans' defensive strategy. No army had been able to take the city by direct assault since 1552. In the Franco-Prussian War of 1870/71, the city had been captured by Prussian forces only after a 54-day siege, and had been fortified by the Germans in World War I. However, the string of fortresses was left in ruins.

When the 3^rd Army reached Metz, it was quickly drawn into a stalemate situation with the German defenders for a period of several weeks as each side attempted to gain control of the city and its perimeter. After suffering heavy losses in their attacks on the fortifications, it was clear to the Americans that Fort Driant would have to be taken to establish effective control of the fortifications around the city. Patton declared the fort an easy target, and committed elements of Major General Stafford LeR. Irwin’s 5^th Division to the attack.

At 14.15 on 27 September, Republic P-47 Thunderbolt single-engined fighter-bombers, carrying 1,000-lb (454-kg) bombs and napalm, of Brigadier Otto P. Weyland’s XIX Tactical Air Command began to attack Fort Driant. Companies E and B of the 11^th Infantry, and the attached Company C of the 818^th Tank Destroyer Battalion, then began the land attack on the fort. Small arms, machine gun and mortar fire immediately began to fall on the attackers. Most of the fort was below ground, so the tank destroyers were ineffective against the heavily armoured pillboxes. After the initial attack had faltered, the Americans withdrew to the original position at 18.30. The attack was resumed two days later with bulldozers to fill in the fort’s trench line and the support of Company C of the 735^th Tank Battalion pushing explosive-filled 'snake' pipes in front of their tanks. The bulldozers and 'snakes' proved to be of little help as, during this second attack, the bulldozers suffered mechanical problems and the 'snakes' were either bent and thereby damaged, or would not work as intended. Despite the failed attempt to breach the perimeter, Irwin ordered the attack to start as scheduled at 12.00.

On reaching the perimeter, the US attackers found that the German defenders were ready. Company B of the 11^th Infantry managed to breach the wire in the fort’s south-western corner as the attached tanks led the assault. Company B bypassed pillboxes, which were to be mopped up later, on its way to the initial objective and, under the cover of the tanks, its engineers attempted to blast their way into the nos 3 and 4 concrete barracks buildings. By 14.00, Company B was on its objective, attempting to destroy the barracks. Fierce hand-to-hand fighting, involving grenades and bayonets, developed. Company E, under heavy fire and with its bulldozer-equipped tanks out of action, failed to breach the perimeter and dug in outside the wire for four days, losing 35 out of its 140 men.

The commander of Company B discovered, after repeatedly throwing grenades into a bunker, that its occupants had withdrawn to the main fort through an underground tunnel, and then used a phosphorus grenade and two fragmentation grenades to assault a concrete structure, prompting its occupants to emerge and surrender. One of the surrendering German troops was identified as a member of the officer candidate regiment to which the majority of the fort’s defenders belonged. Growing desperate to maintain the momentum of the attack, a self-propelled gun was brought to the front and fired at the barracks from a distance of only 30 yards (27.5 m), but to no avail. By then, neighbouring forts had started to shell the attackers, and artillery fire from batteries hidden in the surrounding forest caused the attackers' casualties to mount. Their momentum was regained as a private of Company B climbed on top of the no. 3 barracks and located several ventilator shafts. Kicking off the shafts' covers, the private began to push bangalore torpedoes into the them, forcing its occupants to flee via underground tunnel to the no. 4 barracks. In response, the defenders trained their guns at the roof of the no. 4 barracks to prevent it from being destroyed in the same manner as no. 3 barracks. One of the self-propelled guns managed to blast in the door of the no. 4 barracks at short range, allowing the four surviving members of the platoon to enter and begin clearing the bunker. Company B established its command post in the remains of the no. 3 barracks, inside a perimeter of tanks and infantry.

At 17.00, Company G of the 11^th Infantry, which had previously been held in reserve, was ordered to destroy the two northern artillery batteries. As a result of poor visibility and the defenders' continued small-arms fire, Company G failed to reach its objective. During the night, the Germans were probably reinforced as they still held the Mance ravine and the road from Ars sur Moselle. Stumbling through the maze of pillboxes in search of its objective, trenches and tunnels, Company G was almost routed by German counterattacks during the night, before being reinforced by Company Kof the 2^nd Infantry. Facing mounting casualties, the 11^th Infantry was ordered to continue the attack. Patton refused to accept that the attack might stall and was quoted as saying that 'if it took every man in the XX Corps, [he] could not allow an attack by this Army to fail'. As the second day of the attack began, the 11^th Infantry’s Companies B and E has suffered 110 casualties, representing about 50% of their strength. The only objectives that had been secured were not essential to the capture of the fort.

In the following days, more attempts were made to enter the artillery batteries and main barracks, but none was successful. During daylight hours, German artillery fire from all surrounding areas focused on defending the fort and it became impossible to sustain the attackers who were already only narrowly holding the positions they had seized. The attackers' only resort was to transport supplies in the tanks of their attached artillery forward observers. During the nights, the artillery barrages ceased and German troops emerged from the maze of concrete tunnels and counterattacked the US toehold on the fort, in the process completely isolating the attackers from any support. On 5 October, the commanding officer of Company G sent a desperate message to his battalion commander detailing the dire state of the attack: the company commander was well respected in the battalion as a courageous and competent leader, and his message was not disregarded. Given the desperate reports from the front and mounting casualties, Irwin decided that a task force of fresh troops commanded by Brigadier General Alan D. Warnock, the 5^th Division’s assistant divisional commander, would be needed: the 1/10^th Infantry, 3/2^nd Infantry and the whole 7^th Combat Engineer Battalion thus relieved the battered 2/11^th Infantry. It was decided that the attack would restart on 7 October.

Preliminary bombardment of the fort by US 240-mm (9.45-in) and 8-in (203.2-mm) howitzers, the largest such weapons in the US Army’s inventory, failed to yield any effects on the fort’s artillery batteries, which were covered with steel domes, with only the tips of the muzzles visible, and were found to be impervious to indirect fire. In response, US 155-mm (6.1-in) self-propelled howitzers would engage in direct-fire skirmishes with the batteries, and through quick and accurate direct fire force the batteries to retract into safer non-firing positions. None of these fortified batteries were destroyed by these engagements, but they were effectively suppressed completely by use of this tactic.

Warnock received a set of detailed plans of the fort, and decided the attack would take the form of a subterranean assault via a tunnel that connected the barracks held by US troops to the main barracks by way of the artillery batteries, with an attack on the surface to prevent the defenders from focusing their efforts on preventing the underground assault. The combined efforts of 1/10^th Infantry and 3/2^nd Infantry retook most of the southern area of the fort, but lost two platoons, and the commander of Company B of the 1/10^th Infantry, and two forward observers were taken prisoner. After this, no further meaningful gains were made on the surface. The subterranean attack continued although the attached French adviser, who was the expert on the fort, advised against it. An iron door blocked the way of Company C of the 1/10^th Infantry into the tunnel, which was 3 ft 3.5 in (1 m) wide and 6 ft 7 in (2 m) high. After the engineers had blown a hole in the door, it was discovered that it was backed by more than 20 ft (6.1 m) of scrap metal, concrete and wrecked equipment, which had been stacked to the from floor to ceiling. Welding equipment was brought into the tunnel to cut away the debris, which had finally been removed by the morning of 8 October, revealing another iron door, which was believed to be the last barrier blocking the tunnel. The presence of fumes created by the constant welding and detonation of charges forced the besiegers on several occasions to evacuate the tunnel, and the use of ventilators and the construction of ventilation shafts proved ineffective. As a result of the constant sound of digging on the German side of the tunnel blockage, the Americans feared they would be counter-charged, and placed a 60-lb (27.2-kg) beehive charge against the door. Its detonation required the tunnel to be evacuated for two hours to allow the intense fumes to subside: even so, fumes drifted back into the barracks where the US wounded were being treated, and men rushed to gulp air through rifle slits in the barracks above, with some even running into the open where artillery shells exploded all round them. Finally, an engineer officer crawled back into the tunnel to discover only a small hole had been opened by the charge. Before more explosives could be brought in, the Germans opened fire along the tunnel, forcing the Americans to erect a sandbag parapet with a machine gun mounted on it. On the surface, another futile attack was launched on the southern artillery batteries, but the bloodied attackers were still beaten back by swarms of German infantry emerging at night. Between 3 and 8 October, 21 officers and 485 US troops were killed, wounded or went missing.

On the morning of 9 October, Patton convened a meeting with Irwin, Walker and Warnock, sending Brigadier General Hobart R. Gay, the 3^rd Army’s chief-of-staff, as his own representative. Warnock suggested surrounding the fort and attacking it via tunnels, but Gay declined as the XX Corps lacked the manpower to do so. The 5^th Division’s men were now believed to be on the edge of battle fatigue, and other line connecting operations were taking place around Metz with much greater success. With Patton’s agreement, Gay gave the order to abandon the attack on Fort Driant. At about 16.50, a massive explosion ripped through the tunnel, killing four and almost fatally gassing another 23 US troops. It was unknown if the explosion was an accident or intentionally caused by the Germans. The stalemate continued for another three days until the night of 12/13 October. The evacuation proceeded with almost no intervention by the Germans. Six tanks were abandoned and destroyed by US artillery. Engineer detachments with the rearguard placed more than 6,000 lb (2722 kg) of explosives on any concrete fortifications they could find. The last US troops left the fort at 23.30, and the last explosions detonated on the inside of the fort about one hour later.

The Germans had lost approximately one-quarter of the fort before the Americans withdrew after losing 734 troops.

Irwin was blamed by some for the failure at Fort Driant on the grounds that he had been 'moving too slow' and 'removing the drive' of the battalion early during the initial attacks in September. On September 28, however, Patton had in fact instructed Irwin to use the lull in the fighting to recuperate losses in his regiments. Walker suggested that a lack of aggressive leadership at the battalion and regimental levels led the attack to stall, to which Irwin pointed out that up until the attack had begun, the fortifications at Fort Driant had never been observed from the ground, and the attack’s planners were thus unaware of the fort’s pillbox fortifications and the layered barbed wire entanglements surrounding the perimeter. When Metz fell in December 1944, Fort Driant capitulated to the 5^th Division at 15.45 on 8 December, surrendering uncaptured. It was discovered that among the prisoners were several units of SS-Standartenführer Hans Linger’s 17^th SS Panzergrenadierdivision 'Götz von Berlichingen', along with the remnants of the 1217^th Grenadierregiment and the 3/Offiziersausbildungsregiment, which may have contributed to the Germans' stiff resistance.

Lieutenant General Omar N. Bradley, commander of the US 12^th Army Group and Patton’s immediate superior, recorded the following exchange with Patton in which he expressed his frustration with Patton’s initial refusal to bypass the fort: 'During October, [Patton] undertook an unauthorized pecking campaign against the enemy fortress position at Metz. When I found him probing those battlements, I appealed impatiently to him. ''For God’s sake, George, lay off,'' I said, ''I promise you’ll get your chance. When we get going again you can far more easily pinch out Metz and take it from behind. Why bloody your nose in this pecking campaign?'' Patton replied "We’re using Metz to blood the new divisions."' Bradley remarked on this exchange that 'Though I was nettled over George’s persistence in these forays at Metz, I declined to make an issue of it.' Patton’s comment referenced the 5^th Division as a formation saturated with new troops, as it had suffered heavy casualties at Dornot months earlier, with some battalions almost entirely destroyed.