Operation Undertone facts for kids

Quick facts for kids Operation Undertone
Part of the Western Allied invasion of Germany in the Western Front of the European theatre of World War II
Date 8–24 March 1945 Location sector from Luxembourg to Alsace Result Allied victory
Belligerents
United States France	Germany
Commanders and leaders
Jacob L. Devers Omar Bradley Jean de Lattre de Tassigny	Paul Hausser
Casualties and losses
17,220 3,540 killed	22,000 ~
German casualties do not include KIA, WIA, or those inflicted by U.S. Third Army. Allied casualties are for the U.S. Seventh Army (12,000) and French TF de Monsabert (887).

Operation Undertone, also called the Saar-Palatinate Offensive, was a major attack during World War II in March 1945. It was part of the Allied invasion of Germany. American and French armies worked together to push German forces out of an important area. This area was called the Saar-Palatinate region.

The goal was to clear German troops from the west bank of the Rhine River. This would allow the Allies to cross the Rhine and continue their advance into Germany. The operation was a big success. Allied forces reached the Rhine River in just 10 days. This victory helped complete the Allied push to the Rhine across all of Germany.

Planning the Attack

Allied leaders started planning this attack in February 1945. General Dwight D. Eisenhower, the top Allied commander, wanted two American army groups to work together. These were led by General Omar Bradley and General Jacob L. Devers. The plan was to clear the Saar-Palatinate region. It also aimed to create places to cross the Rhine River.

The main attack was to be made by the U.S. Seventh Army. This army would get extra divisions from the U.S. Third Army. The attack, named Operation Undertone, was approved by General Devers.

The Main Goals

The plan involved three army groups attacking side-by-side. They would stretch from Saarbrücken, Germany, to Hagenau, France. A French division would help clear a narrow strip along the Rhine. The Seventh Army's main effort was to push through the Kaiserslautern corridor.

General Eisenhower agreed with the plan. He stressed that the goal was not just to clear the Saar-Palatinate. It was also to set up bridgeheads over the Rhine River. These bridgeheads would be between Mainz and Mannheim. The U.S. Third Army would make smaller attacks. These would protect the main attack's left side.

General George S. Patton, who led the Third Army, also got approval for his plan. His army would cross the Moselle River near Koblenz. They would then sweep south along the Rhine's west bank. This would cut off German supply lines. It would also attack the Siegfried Line from behind. The Siegfried Line was a strong German defense system.

The commanders agreed on a new boundary between their armies. This allowed the Third Army to clear the northwest part of the Saar-Palatinate. They also decided that the Third and Seventh Army commanders could talk directly. This made things faster.

The Seventh Army faced the strong Siegfried Line. They planned a careful attack. It would start after many air bombings. Supplies had to be gathered, and units moved into place. This meant the attack could not begin before March 15.

The Attack Begins

General Jacob Devers

SS General Paul Hausser

On March 15, the U.S. Seventh Army launched its attack. They faced the German 1st Army. The attack stretched for about 110 kilometers (68 miles). It went from Saarlautern to the Rhine. The goal was to break through the Siegfried Line. If not, it would at least keep German troops busy. This would allow Patton's forces to attack them from behind.

The Seventh Army had a mix of experienced and new units. The VI Corps and three divisions (3rd, 36th, 45th) had fought in earlier battles. The XV Corps had fought across France. The XXI Corps was newer.

The big question was how hard the Germans would fight. Would they defend strongly or fall back to the Siegfried Line? Only the XXI Corps was close to the Siegfried Line. Other units were up to 32 kilometers (20 miles) away. The XV Corps faced a tough challenge at Bitche. This town was surrounded by French Maginot Line fortresses. The VI Corps had to cross the Moder River. One division also had to attack through the rugged Lower Vosges Mountains.

German Defenses

The Germans had two main corps and part of a third in the path of the American attack. Near Saarbrücken, the German LXXXV Corps faced the XXI Corps. Southeast of Saarbrücken, the XIII SS Corps had three divisions. Further along the line to the Rhine was the XC Corps. This corps had two volksgrenadier divisions and parts of a training division.

The Germans were worried about a breakthrough near the Wissembourg Gap. But the XIII SS Corps was actually stronger. It had more tanks and armored vehicles. So, the American main attack aimed at the stronger German units. However, by this point in the war, German divisions were not as strong as they used to be.

First Day of Fighting

The Seventh Army attacked before dawn on March 15. The Germans did not fight very hard in most places. Only in two areas was the resistance strong. One was on the left side, where the 63rd Infantry Division tried to go around Saarbrücken. They quickly hit the Siegfried Line, which explained the tough fight. The other tough spot was on the far right. Here, the 3rd Algerian Infantry Division faced an urban area and flat ground. This made it easy for German machine guns to fire.

Elsewhere, fights were short but sometimes fierce. There were many anti-personnel and anti-tank mines. German artillery fire was usually light. This was partly because Allied planes had been bombing German targets for days. Fighter-bombers and heavy bombers hit Siegfried Line forts. They also attacked industrial targets in cities like Zweibrücken and Kaiserslautern. The clear weather helped the planes hit many targets.

The XV Corps made good progress. The 45th Infantry Division crossed the Blies River quickly. They drove almost 5 kilometers (3 miles) beyond it. The 100th Infantry Division reached the edge of Bitche. They quickly took control of the fortified hills around the town.

The only strong German counterattack hit a battalion of the 3rd Division. This division was making the main push towards Zweibrücken. German infantry, supported by nine assault guns, attacked. They surrounded the American soldiers. But the Americans held their ground. Another battalion counterattacked. They destroyed several German vehicles and freed their trapped comrades.

The VI Corps also faced similar resistance. All four attacking divisions quickly crossed rivers like the Moder. The Germans were spread too thin to defend strongly everywhere. The 42nd Infantry Division attacked through the Lower Vosges Mountains. They avoided roads and villages. They used pack mules to carry supplies.

The 103rd Infantry Division faced a counterattack near Hagenau. They pulled back to better positions. In the 36th Infantry Division's area, Pfc. Silvestre S. Herrera showed great bravery. He charged a German strongpoint alone and took eight prisoners. Later, he stepped on a mine and lost both feet. But he kept firing, allowing his platoon to flank the enemy.

The 3rd Algerian Division crossed the Moder River. But they faced tough house-to-house fighting. Mines and two counterattacks added to their problems. By nightfall, no Algerian unit had advanced more than 1.6 kilometers (1 mile).

German Retreat

On the second day, March 16, it became clear the Germans were mostly delaying. They were not fighting to hold ground. This was especially true in the XV Corps area. All three attacking divisions gained more ground. Mines and strongpoints were the main problems. By nightfall, the 3rd and 45th Divisions were near the Siegfried Line. The 100th Division had also caught up.

Even though it looked like a retreat, the Germans planned to defend. German commanders wanted to pull back to the Siegfried Line earlier. But General Foertsch and General Hausser said no. The new German Commander-in-Chief West, Field Marshal Albert Kesselring, had orders from Hitler not to withdraw.

So, no formal order to retreat into the Siegfried Line came from the top. But starting on the night of March 16, German commanders simply did what was needed. They ordered their units to go into the Siegfried Line when American pressure became too strong. The next day, commanders facing the U.S. VI Corps did the same.

Breaking Through the Siegfried Line

As the U.S. Third Army pushed towards Kaiserslautern, the German 1st Army worried. They feared their troops in the Siegfried Line would be trapped. Once Kaiserslautern fell, the only way out was through the Palatinate Forest. This forest was thick and had only a few roads. American fighter pilots constantly attacked these roads, causing many wrecked vehicles.

On March 17, General Foertsch allowed his westernmost troops to withdraw. They would pull back in stages. They aimed to block the main highway through the Kaiserslautern Gap.

But the main threat to the Kaiserslautern Gap came from the northwest. Walker's XX Corps was pouring through. On March 20, the 10th Armored Division reached Kaiserslautern. This meant the German forces were now cut off from behind. Their only way out was through the Pfaelzer Forest.

As the Germans pulled back, they opened a path through the Siegfried Line. On March 19, the 63rd Division of the XXI Corps broke through near St. Ingbert. The American combat command then moved through this gap. They attacked the Siegfried Line defenders from behind.

The Germans knew the Americans would use this opening. So, on the night of March 19, they allowed more units to withdraw. On March 20, the 45th Division also broke through the Siegfried Line near Zweibrücken. The rest of the SS corps began to pull back that night. The 3rd Division's advance sped up.

The Forest Gauntlet

The German problem was getting their troops through the Pfaelzer Forest. They faced three big threats:

• The U.S. Seventh Army was following closely.
• The 10th Armored Division was at Kaiserslautern. It could swing south and cut off escape routes.
• American fighter-bombers were constantly attacking from the air.

The air attacks were the worst for the retreating Germans. They had to move day and night. This made them easy targets for planes. The main roads through the forest became clogged with wrecked vehicles. A lack of gasoline made things even worse.

The destruction in the Pfaelzer Forest was terrible. Cities and towns near the Siegfried Line were in ruins. "Scarcely a man-made thing exists in our wake," wrote General Frederick. In Zweibrücken, only about 5,000 people remained. They were hiding in cellars. Fires burned everywhere.

As Germans tried to escape through the forest, they faced a fourth threat. Brooks's VI Corps had followed the German retreat from Alsace. On March 19, they began attacking the Siegfried Line near Wissembourg.

The French 3rd Algerian Division was supposed to stop at the German border. But General Jean de Lattre de Tassigny, the French First Army commander, wanted more. He wanted a zone along the Rhine inside Germany. This would give France a place to cross the river. General Devers agreed. The French pushed northward through the Bienwald forest. They fought through bunkers and trenches of the Siegfried Line.

The VI Corps' attack was focused on a smaller area. The German XC Corps had only a few weak divisions to defend against both Americans and French. So, a breakthrough was only a matter of time. But again, it was the U.S. Third Army's push from behind that truly broke the German defenses.

On March 20, the 10th Armored Division turned south into the Pfaelzer Forest. By nightfall, they were close to the main highway through the forest. Another column was nearing Neustadt. The 12th Armored Division was approaching the Rhine near Ludwigshafen. German escape routes were about to be cut off.

In desperation, the Luftwaffe sent about 300 planes to attack the Third Army. But it did little good. American anti-aircraft units shot down 25 German planes.

On March 20, the westernmost German units were ordered to fall back. On March 21, the 42nd Division launched a full attack on the Siegfried Line. They found little resistance. On March 22, a regiment of the 42nd cut the secondary highway through the forest. A column of the 10th Armored reached the Rhine flatlands at Landau. Any Germans left in the forest had to escape individually.

By nightfall on March 22, the Germans west of the Rhine had only hours left. The XC Corps still fought in the Siegfried Line pillboxes. But the defense was hopeless. The 14th Armored Division fought for Steinfeld. At Neustadt and Landau, German defenses collapsed. The 12th Armored Division drove south from Ludwigshafen towards Speyer.

To prevent the Allies from using them, the Germans blew up all Rhine bridges north of Ludwigshafen. Of the three remaining bridges upstream, one at Maximiliansau was destroyed on March 21. Another at Speyer was blown up on March 23.

The last bridge, at Germersheim, was used to evacuate vehicles and artillery. Still, no orders for a full withdrawal came from German high command. Finally, on March 23, permission came to cross the Rhine. Vehicles used the bridge at Germersheim. Foot soldiers used ferries south of the town.

Conclusion

On March 23, all U.S. VI Corps divisions broke through. But they only met German rear guards. They could not stop the German evacuation. The 12th and 14th Armored Divisions raced to the last Rhine bridge at Germersheim. But at 10:20 AM on March 24, the Germans blew it up. The formal German evacuation of the west bank ended that night. American units continued to clear out remaining German soldiers through March 25.

It's hard to know how many Germans escaped. But their losses were huge. The German 1st Army's chief of staff noted "Tremendous losses in both men and matériel." The U.S. Seventh Army estimated that the two German armies lost 75-80% of their infantry. The Seventh Army and its French units captured 22,000 Germans. The Third Army captured over 68,000. The Third Army estimated German losses at 113,000 men. The Third Army's casualties were 5,220, with 681 killed. The Seventh Army had about 12,000 casualties, with almost 1,000 killed.

The campaign was a great success. The German 1st Army, despite huge losses, managed a skillful delaying action. They faced overwhelming Allied strength on the ground and in the air. They avoided being completely surrounded. But to save their forces, the Germans had to give up the important industrial area around Saarbrücken. They also lost the easily defendable terrain of the Pfaelzer Forest.

Key Military Units

Here are some of the main military units involved in Operation Undertone:

United States Forces

• U.S. Third Army (Led by General George S. Patton)
  • VIII Corps
  • XII Corps
  • XX Corps
• U.S. Seventh Army (Led by Lt. General Alexander Patch)
  • XXI Corps
  • XV Corps
  • VI Corps
  • 3rd Algerian Infantry Division (French unit working with the U.S. Seventh Army)

German Forces

• German 7th Army (Led by General der Infanterie Hans Felber)
  • LXXXIX Korps
  • XIII Korps
  • LXXX Korps
• German 1st Army (Led by General der Infanterie Hermann Foertsch)
  • LXXXII Korps
  • LXXXV Korps
  • XIII SS Korps
  • XC Korps