One of the M271 casemates for a 170mm SKL/40 gun of MKB York near Amfreville on the coast west of Cherbourg. (NARA)
This is the third casemate of MKB Hamburg, 9./MAA.260, in Fermanville east of Cherbourg armed with a Krupp 240mm SKL/40. The battery commander, Oberleutnant Rudi Gelbhaar, was awarded the Knight’s Cross in June 1944 for the battery’s engagements with Allied warships. (NARA)
Operation Astonia: Festung Le Havre
While the US Army was dealing with the fortified ports in Brittany, Montgomery’s 21st Army Group was advancing northward toward upper Normandy, the Picardy coast and, eventually, the Pas-de-Calais. The honor of taking Dieppe was given to the Canadian 2nd Division and the city fell without a major fight on September 1. The second major port in Normandy, Le Havre, was invested by the British I Corps starting on September 3. To soften up the defenses before the ground attack, the Royal Navy monitor HMS Erebus began bombardment along the coast on September 5, but was forced to withdraw by the heavy concentration of coastal artillery west of the city. These positions included the only heavy gun battery in the city, a 380mm turreted gun from the French warship Jean-Bart located at Clos de Ronces and supported by the Goldbrunner battery of 3./HKAR.1254 with three 170mm K18 guns, two of which were in H688 casemates. Besides these batteries, there were several other batteries in the immediate vicinity that took part in some of the subsequent engagements. The Erebus returned on September 8, but was again forced back by heavy gunfire from the German coastal batteries. Prior to the start of I Corps’ main attack, Operation Astonia, on September 10, the Erebus returned but was accompanied by the battleship HMS Warspite, which demolished the offending batteries with its 15in. guns. The two ships then conducted a six-hour bombardment against other coastal fortifications and defenses. The battle for Le Havre by two infantry divisions supported by the specialized armor of the 79th Armoured Division lasted only two days in no small measure due to the demoralization of the isolated garrison.
The 105mm Unterseeboot Torpedoboot Flak L/45 was a U-boat deck gun adapted to coastal defense and is seen here with 3./MAA.260 in one of two casemates located at the end of the pier at the Gare Maritime in Cherbourg. (NARA)
Some bunkers were camouflaged to blend into their surroundings like this observation bunker along the seawall in Le Havre. (NARA)
This is Bruno, one of three gun casemates of MKB Friedrich August of 2./MAA.240 in La Trésorerie, armed with a massive 305mm SKL/50 gun. It was captured by the Canadian North Shore Regiment during Operation Wellhit. (NAC PA-174409 Donald Grant)
Operation Wellhit: Festung Boulogne
While Operation Astonia was under way, Canadian forces had begun to probe the outer defenses of both Boulogne and Calais. The Canadian 3rd Infantry Division was assigned Operation Wellhit, the assault against Boulogne and the associated German fortifications in the neighboring hills. In light of the experiences at Le Havre, the specialized armor of the 79th Armoured Division was also used to support the Canadians, especially Churchill Crocodile flamethrower tanks and Churchill AVRE (Armoured Vehicle Royal Engineer) fitted with heavy petards. Festung Boulogne had three major concentrations of fortifications: a trio of coastal batteries near Pointe de la Crèche on the coast north of the city, a set of defensive bunkers and a gun battery from 4./AR.147 on Mont Lambert on the main road into the city from the east, and a series of coastal guns and bunkers on the heights to the south of the port around Le Portel. Besides the defenses of the city itself, Operation Wellhit also contained a subsidiary attack on German positions around La Trésorerie overlooking the city to the northeast, which contained the substantial naval battery of Batterie Friedrich August of MAA.240 with three 305mm SKL/50 guns in massive casemates. Operation Wellhit began on September 17, including an attack by the North Shore Regiment on La Trésorerie and two brigades assaulting toward Mont Lambert. Mont Lambert was not overcome until September 18 after engineers had blasted the final bunkers with explosive charges. The gun casemates of Batterie Friedrich August were stubbornly defended by nearby Flak positions armed with 20mm cannon, but the position was finally overwhelmed on the second day of fighting using PIAT anti-tank launchers and grenades. The Canadians fought into the city and captured the old citadel, but then were faced with the problem of clearing the numerous bunkers on the heights south of the city around Le Portel. These positions had been a constant source of fire through the fighting, with one battery of Flak guns alone having fired some 2,000 rounds in the three days of fighting. This position was finally overwhelmed but fighting for the other bunkers on the high ground continued through September 22 when the garrison finally surrendered. Canadian troops had begun to attack the bunker complexes of La Crèche but the garrison surrendered before a full-scale attack was launched.
This is one of four M272 casemates of MKB Vasouy, 9./MAA.266, opposite Le Havre which was armed with a 150mm Tbts.KL/45. (Author’s collection)
Operation Wellhit led to the capture of about 10,000 German troops at a cost of about 600 Canadian casualties through the use of proven combined tank–infantry tactics that succeeded in the face of a significant number of bunkers and heavy gun emplacements. The capture of the port took six days instead of the planned two days, but the operation involved only about a third the troops used at Le Havre. The Churchill Crocodile flamethrower tanks proved to be especially useful and an after-action report recorded that most German bunkers surrendered at the first sign of a flamethrower tank. The AVRE tanks were not particularly effective as their petard launcher, although powerful, could not penetrate the 2m reinforced concrete of the bunkers, and this weapon was no more effective than any other tank gun in penetrating the embrasures and armored doors of the fortifications, if anything being shorter-ranged and less accurate. The aerial bombardment that preceded the attack was not effective in suppressing the bunkers and hindered tank operations in Boulogne due to the craters and rubble. In subsequent operations, such as Calais, the emphasis was shifted to the use of fragmentation bombs to limit the cratering. The fighting demonstrated the limitations of the Atlantic Wall fortifications since the vast majority of defenses were oriented seaward. The heavy gun casemates limited the arc of fire of the guns and, as a result, most batteries were unable to take part in the fighting. The few batteries that did have suitable orientations, such as the dual-role Flak batteries designed for enfilade fire along the port, were responsible for the majority of Canadian casualties.
Operation Undergo: Festung Calais
Although consideration was given to simply bypassing Calais in favor of devoting the troop strength to the clearing of the Scheldt estuary leading to Antwerp, in late September Montgomery was convinced to deal with Calais due to the havoc that its strong gun positions could cause to Allied shipping in the Channel. On the night of September 9/10, the Regina Rifles took the fortified port town of Wissant and overran the bunkers on Mont Coupole, which offered excellent observation of the Cap Gris-Nez and Calais region.