Operation Wet Pot

'Wet Pot' was an Allied series of unrealised plans for an amphibious landing on the Cotentin peninsula of German-occupied France (June/September 1944).

The plans were not needed as three infantry divisions of Major General J. Lawton Collins’s US VII Corps of Lieutenant General Omar N. Bradley’s US 1st Army had already taken the whole of the peninsula soon after the launch of 'Overlord'.

The Cotentin peninsula campaign, which lasted from 6 to 30 June 1944, was in fact the first major Allied advance after the D-Day landings of 'Neptune' (iii) to start 'Overlord', and ended with the seizure of Cherbourg, the port city was was regarded by the Allies as one of the most important early objectives of 'Overlord'. The capture of a major port was seen as an essential part of the build-up in France after D-Day, and the Allied seaborne assault had been extended westward to 'Utah' Beach, on the south-eastern corner of the Cotentin peninsula, specifically to facilitate an early advance on Cherbourg. The US landing on 'Utah' Beach came as a tactical and operational surprise to the Germans as they had flooded large areas of low-lying ground both behind 'Utah' Beach and along the Merderet river in the centre of the peninsula. Thus the coastal defences on 'Utah' Beach were among the weakest in Normandy.

Early in the morning of 6 June, Major General Matthew B. Ridgway’s US 82nd Airborne Division and Major General Maxwell D. Taylor’s US 101st Airborne Division dropped and landed by glider into the area between the coast and the Merderet river with the task of taking the western end of the causeways across the inundations behind the beaches, and of seizing and holding the line of the Merderet river. The landings did not take place as planned, however, and the US airborne soldiers instead found themselves scattered across the Cotentin peninsula in hundreds of small detachments, though eventually a number of larger groups coalesced and this made it possible for them to achieve their most important objectives, thereby making it possible for Major General Raymond O. Barton’s US 4th Division to advance inland from 'Utah' Beach. The scattered landings also caused a great deal of confusion behind the German lines, and prevented the commanders on the spot from mounting an effective counterattack on D-Day.

During the first few days after D-Day the US troops on the Cotentin peninsula could have been vulnerable to a major counterattack by German forces redeployed from Brittany, to the west of the Cotentin peninsula, but on 12 June the capture of Carentan closed the gap between the 'Utah' Beach and 'Omaha' Beach assault areas. Once again the confusion caused by the scattered airborne landings helped the Americans. Generaloberst Friedrich Dollman, commander of the 7th Army, did not learn that there had been a landing on the east coast of the Cotentin peninsula until a time late on D-Day, so the troops in Brittany received no movement order until nearly 23.00, were unable to start their movement only in the course of the following day’s morning, and then came under heavy and constant attack by Allied aircraft. More confusion resulted from the release of dummy paratroopers by a large force of US aircraft in the area to the west of St L. This convinced Generalfeldmarschall Erwin Rommel, the commander of Heeresgruppe 'B', that a second seaborne invasion was about to descend of the west coast of the Cotentin peninsula, and on 7 June he ordered all available reinforcements to move to that area, which lay well to the south-west of the real battlefield. This order was not rescinded until the morning of 8 June, by which time German communications were in chaos and the majority of the formations and units involved were out of touch.

This confusion probably saved the 82nd Airborne Division from defeat, for on the night of 6/7 June that division was under heavy pressure and might have been placed in a parlous situation had not reinforcements arrived from the UK during that night. Early on 7 June reinforcements arrived by glider and supplies were parachuted into the area, and at 10.00 contact was made with the leading units of the 4th Division arriving from 'Utah' Beach. Soon after that, gliderborne infantrymen were able to start the establishment of a line along the Merderet river, and then held that line against German attacks for the rest of the day. By the end of D+1 Collins’s US VII Corps had established a lodgement 9 miles (14.5 km) wide and 8 miles (13 km) deep, and by the morning of 9 June the 82nd and 101st Airborne Divisions had advanced to the west and south across the worst of the inundations. Further advance into the Cotentin peninsula was then impossible until the capture of Carentan, which the 101st Airborne Division took on 12 June.

By this date the Americans were winning the battle to enlarge their forces on the Cotentin peninsula. The Germans now had in the peninsula three complete divisions (Generalleutnant Eugen Knig’s 91st Division, Generalleutnant Heinz Hellmich’s 243rd Division and Generalleutnant Karl-Wilhelm von Schlieben’s 709th Division and one incomplete division of General Wilhelm Fahrmbacher’s LXXXIV Corps), although one had already lost 4,000 of its 10,555 men. In contrast the Americans had the original 4th Division and the now-reinforced 82nd and 101st Airborne Divisions, Major General Manton S. Eddy’s 9th Division and Brigadier General Jay W. MacKelvie’s 90th Division which had already landed and Major General Ira T. Wyche’s 79th Division which was crossing 'Utah' Beach. In addition these US forces had as their commander Collins, who was one of the few senior commanders who did not find the local bocage country restrictive as he had already led divisions in the still more restrictive conditions of Guadalcanal and New Guinea, and was also used to operating with limited armour and artillery support. Collins devised an effective tactic for fighting in the hedgerows of the bocage country. Aware that his opponents on the Cotentin peninsula had little or no potential for the planning or implementation of counterattacks, Collins advanced with his regiments in columns of battalions, each with a front of 1,000 yards (915 m). The leading battalion was relieved two or three times each day, so every part of the regiment was used, but none for too long.

On 12 and 13 June Collins attacked at the northern and western ends of his lodgement. On both days his troops entered the town of Montebourg, on the main road northward to Cherbourg, only to be repulsed, but in the south they crossed the Douve river 7 miles (11.25 km) to the west of St L and built a bridge over the river. This move convinced Rommel that Collins was about to launch an offensive to the south-west across the Cotentin peninsula, and early on 14 June he ordered all available troops to move to the Douve river front.

In fact Collins was planning to attack much farther to the north, toward St Sauveur le Vicomte. On 14 June the 9th Division and 82nd Division launched the attack, and in the following two days advanced 5 miles (8 km). On 15 June Dollman reported to Rommel that the German line on the Cotentin peninsula was like an archer’s bow at breaking-point, and during the morning of 16 June the bow snapped. The 82nd Division crossed the upper part of the Douve river at St Sauveur and the 9th Division crossed it at a point farther to the north. Thus the Germans had lost their last line of natural defence between the Americans and the west coast. On the following day the 9th Division advanced 6 miles (9.6 km), and by the end of the day the Americans could see the west coast of the Cotentin peninsula. As the 9th Division advanced to the west, Collins fed fresh troops into the line to defend their northern flank, and on the night of 17/18 June these troops fought off an accidental German counterattack.

This counterattack was a result of direct interference by Adolf Hitler. By 16 June the German forces on the Cotentin peninsula had been split into two Kampfgruppen: von Schlieben, with the 709th Division and part of Oberst Rudolf Bacherer’s 77th Division, was to defend the direct route to Cherbourg through Montebourg, while Hellmich, with the 91st Division and 243rd Division, was ordered to stop the Americans reaching the west coast and, if that failed, to prevent them breaking into Brittany. The US advance was now threatening to drive a wedge between the two Kampfgruppen. Dollman ordered von Schlieben to send the 77th Division to support Hellmich and to withdraw the rest of his troops into the fortress of Cherbourg. This was the only course of action that might had delayed the fall of Cherbourg, but Hitler intervened and refused to allow any troops to move back towards Cherbourg or to leave their current positions. Even when Rommel pointed out that this would allow the Americans to capture Cherbourg by advancing between the two battle groups Hitler refused to budge.

Early on 17 June Hitler had a change of heart and gave von Schlieben authorisation to make a fighting withdrawal under US pressure. Later on the same day Hitler almost reimposed his 'stand fast' order, and then in a rage drew a new line across the peninsula, from St Vaast la Hogue on the east coast, through Le Thiel to Vauville on the west coast. This line, some 30 miles (50 km) long, line was three times longer than the line which von Schlieben was already struggling to hold, and included large areas of no value whatsoever to the defence of Cherbourg. Worse still, von Schlieben would be allowed to retreat to this line only after fighting for as long as possible at Montebourg, and would have no time to organise the defence of the port.

While von Schlieben was struggling to hold Montebourg, Hellmich, reinforced by the 77th Division, attempted to move southward into a position from which he could block the US advance to the west coast, not realising that the Americans had already advanced to the west past his intended position. It was this movement which resulted in the accidental counterattack as Hellmich’s force encountered the northern flank of the advancing US forces. Most of Hellmich’s column was destroyed or dispersed, although 1,200 men did escape along the coast road. During the morning of 18 June that route was closed when the 9th Division reached Barneville, just inland of the little west-coast port of Carteret. The moment his men had reached the west coast, thereby severing the northern part of the Cotentin peninsula from the rest of France, Collins moved them into a new line facing to the north, with the 9th Division on the west coast, the 79th Division in the centre and the 4th Division toward the east coast. One of the reasons Collins was so successful in Normandy and the Cotentin was that he seldom wasted time, and at 03.00 on 19 June, while the Germans were still watching the west coast, his 4th Division advanced silently toward Montebourg. By the time the Germans appreciated the fact, their defensive line had been broken, the town was almost surrounded and von Schlieben’s forces were in full retreat. By the end of the day the Americans had reached Valognes on the road northward to Cherbourg, and by the evening of 20 June had arrived on Hitler’s 'last-stand' line.

The Cotentin peninsula campaign was thus about to become the battle of Cherbourg. On 21 June von Schlieben ignored a formal call for surrender, and on the following day the US attack got under way. The advance was slow but steady, and despite determined German resistance the US forces had taken control of the city by 26 June, when von Schlieben was captured. The Arsenal surrendered on the next day and the last naval fortresses on the mole on 29 June. The last resistance on the Cotentin peninsula, at Cap de la Hague on its north-western tip, ended at a time late on 30 June, and the Cotentin peninsula campaign was over.

However, the port of Cherbourg, which was the primary target of the whole campaign, had been comprehensively devastated by the Germans. Sunken ships and hundreds of contact mines blocked the harbour, while the port-side facilities had been damaged or destroyed. No maritime movement was possible for three weeks, and it was months before the port could be reopened.

Despite this, the capture of Cherbourg did have two important results. The Allies realised that the German-held ports in Brittany would probably be equally badly damaged should they be subjected to a comparable assault, so for the most part their garrisons were simply left to wither on the vine, not surrendering until the end of the war. In contrast the Germans realised that even their strongest fortresses could be captured relatively quickly by the Allies, meaning that they could not be used to limit the pace and extent of the Allied build-up on the continent.