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D-Day: American

Operation Cobra
24 July to 4 August 1944


Since the initial landings on D-Day American forces in the west of Normandy had been fighting their way through hellish bocage country. Each bocage-lined field was another battle, to be taken against fierce German opposition, before moving on to the next for more of the same. Wheeled and half-track vehicles were forced into the narrow country lanes, where they were vulnerable to ambush, and tanks ran the risk of exposing their vulnerable belly armour every time they attempted to cross these horrendous stone reinforced hedgerows. Getting across the bocage was a task in itself.

The more this went on the more time the Germans had to organise themselves, even in spite the best efforts of the Allied Air Forces who made German troop movements during the day all but impossible. 

The Allies desired to utilise their advantage in mobile warfare. The bocage country, and the creeping stale mate it had caused, voided many of the advantages in numbers, tactical air power, armour, mechanised infantry and logistics. They needed to breakout of the bocage country and into the open country to the south where these advantages could be brought to bear.

Operation Cobra, to be launched initially on 18 July, was the plan that would at long last open a decisive gap in the German lines. 

US Infantry and tanks head to the front
Operation Cobra
Crossing the bocage General Bradley, commanding the US First Army, had worked out a strategy that included aerial saturation bombing over a limited area to briefly destroy defences and the resulting breach would be taken and pushed through by the infantry divisions of the US VII Corps. The US VIII and XIX Corps to prevent the Germans moving reinforcements to the breach would then carry out diversionary attacks. After some debate at his headquarters, Bradley amended his initial phase three objective from merely seizing the Cotentin peninsula and cutting off the Germans there, to heading further south and potentially heading for Brittany and the Atlantic ports there. The target area he chose for the start of Operation Cobra lay between the villages of La Chapelle-Enjuger and Hébécrevon, a few kilometres north of the main road between Saint-Lô and Coutances.

Operation Cobra Begins
24 – 27 July 1944

Initial plans called for the operation to begin on 18 July. Due to poor weather the start was delayed until 24 July. On 24 July visibility for aircraft still proved poor so the start was delayed again until the next day. Unfortunately some bomber squadrons weren’t called back and made their runs on the target areas. Poor visibility, smoke drift, and the close proximity of the assault troops to the target area lead to many of the bombs falling on the US troops.

The following day the attack went ahead, but unfortunately some bombers were off target once again and further casualties were inflicted on the waiting assault troops. However, for three hours, 1500 B-17 and B-24 bombers pummelled the target zone, supported by medium bombers and fighter-bombers. Despite the casualties caused by the off target bombing most of the lead American units were able to carry out their attacks on time.

The Germans proved to be much worse off. The Panzer Lehr division was reduced to a third of its fighting strength and other units in the target area had faired little better.

The initial movement of the attacking US infantry was cautious, over a month of bocage fighting had left them weary, but as they broke through the weak German opposition the advance sped up. Fierce fighting continued throughout the 25 July, as efforts were made to open up a passage for the armoured vehicles. For the operation the tanks had been fitted with Cullin Prong hedgerow cutters.

Operation Cobra
A .50cal machine-gun sets up in the bocage

These had been highly secret until the opening of Operation Cobra and now the new devices allowed the tanks to rip their way through the bocage with ease.

On 26 July VII Corps advanced ten kilometres, taking Saint-Gilles, then Canisy, after crossing the Coutances-Saint-Lô road. Gaps started to appear in the German front line and the defence finally collapsed the next day. The first day’s advance made 4000 yards and on 26 July they made a further 8000 yards. 

The Breakout
27 July – 4 August 1944

On 26 July the breakthrough Armored divisions were released and were soon sweeping south and westwards. Marigny, Lessay and Périers were taken that day.

General Wood’s 4th Armored Division liberated Coutances, a major road junction beyond the German lines, on 28 July.

Entire German units were encircled in places like the Roncey Pocket, while others units simply collapsed under the pressure of the advancing Armored divisions. The fighting since 6 June had be hard on the German forces as well and the concentrated assault on their lines was simply too much for many of these shaken and demoralized German troops.

US infantry take cover in the bocage
The advance continues

Thousands were captured, disarmed and, more often than not, left where they were, as there was no time or spare troops to escort them to the rear. The 8th Korps commander, Von Choltitz, attempted establish new lines of defence, but these line were quickly over run before sufficient troops could be positioned to meet the offensive. Nothing seemed able to stop the American drive.

On 30 July, the American 6th Armored Division crossed the Bréhal and passed Granville without stopping. The 4th Armored Division, still leading the advance, captured Avranches the same evening, cutting off the Cotentin peninsula. 

Operation Cobra

The next day the division succeeded in securing a vital bridgehead over the Sélune at the Pontaubault Bridge. The Americans had arrived in Brittany.

Meanwhile in eastern Normandy the Canadian Corps attacked, pinning potential German reinforcements down and no allowing them to be moved to face the Americans in the west.

In less than a week US 1st Army troops had broken through German lines and penetrated sixty kilometres and taken 18,000 prisoners.

Travelling the bocage
Sherman with Cullens Prongs

The stalemate had come to an end and the war of attrition of the bocage had suddenly and dramatically been replaced by a war of movement. 

The success of the operation was so great that on 4 August Montgomery, overall Allied ground commander, ordered a major change to the follow up operation plan. Most of the newly formed US 3rd Army, under Patton, was sent east rather than into Brittany. General Courtney Hodges’ 1st Army also attacked east. Bradley now commanded the newly activated 12th Army Group in overall commander of both American armies. In the British and Canadian sectors the Commonwealth forces continued to push east and south. The encirclement of the German forces in Normandy had begun and would ultimately climax at Falaise.

17. SS-Panzergrenadierdivision StuG IVs

By 25 August all four Allied armies were on the Seine and the Campaign for Normandy had been won. 

US Forces deployed for Operation Cobra 

VII Corps (initial breakthrough force) General J. Lawton Collins

4th Infantry Division
9th Infantry Division
30th Infantry Division

Exploitation forces

1st Infantry Division (temporarily motorised in trucks)
2nd Armoured Division
3rd Armoured Division

VIII Corps (flank exploitation) General Troy Middleton

8th Infantry Division
70th Infantry Division
83rd Infantry Division
90th Infantry Division


4th Armoured Division

Last Updated On Wednesday, October 16, 2019 by Wayne at Battlefront