Editing Siegfried Line campaign (section)

===Logistics and supply===
{{main|American logistics in the Northern France campaign|British logistics in the Normandy campaign}}

Although the breakout from Normandy had taken longer than planned, the advances until September had far exceeded expectations. Bradley, for example, by September had four more divisions than planned and all of his forces were {{convert|150|mi|km}} ahead of their expected position. One effect was that insufficient supplies could be delivered to the various fronts to maintain the advance: demand had exceeded the expected needs.

[[Image:Omaha Mulberry Harbour.jpg|thumb|Mulberry 'A' off [[Omaha Beach]] was critical in the early days for Allied supplies.]]

Much war [[materiel]] still had to be brought ashore across the invasion beaches and through the one remaining [[Mulberry harbour]] (the other had been destroyed in an [[English Channel]] storm). Although small harbours, such as [[Isigny-sur-Mer|Isigny]], [[Port-en-Bessin-Huppain|Port-en-Bessin]], and [[Courcelles, Charente-Maritime|Courcelles]], were being used, the major forward ports such as [[Calais]], [[Boulogne-sur-Mer|Boulogne]], [[Dunkirk]] and [[Le Havre]] either remained in German hands as "fortresses" or had been systematically destroyed. The availability of Cherbourg had been valuable until the breakout, but then the shortage of transport to carry supplies to the rapidly advancing armies became the limiting factor.

Although fuel was successfully pumped from Britain to Normandy via the [[Operation Pluto|Pluto]] pipeline, this still had to reach the fronts, which were advancing faster than the pipelines could be extended.<ref>Ruppenthal, ''Logistic Support of the Armies'', Vol. I, pp. 501-502</ref>  The railways had been largely destroyed by Allied attacks and would take much effort to repair, so fleets of trucks were needed in the interim.<ref>Ruppenthal, ''Logistic Support of the Armies'', Vol. I, pp. 547–551</ref> In an attempt to address this acute shortage of transport, three newly arrived U.S. infantry divisions—the [[26th Infantry Division (United States)|26th]], [[95th Infantry Division (United States)|95th]], and [[104th Infantry Division (United States)|104th]]—were stripped of their trucks in order to haul supplies.<ref>Ruppenthal, ''Logistic Support of the Armies'', Vol. II, p. 170</ref> Advancing divisions of the U.S. 12th Army Group left all their heavy artillery and half their medium artillery west of the [[Seine]], freeing their trucks to move supplies for other units.<ref>Ruppenthal, ''Logistic Support of the Armies'', Vol. I, p. 487</ref>  Four British truck companies were loaned to the Americans.<ref>Ruppenthal, ''Logistic Support of the Armies'', Vol. I, p. 484</ref> Another 1,500 British trucks were found to have critical engine faults and were unusable, limiting assistance from that quarter.<ref>''Administrative History of the Operations of 21 Army Group'', p. 47</ref> The [[Red Ball Express]] was an attempt to expedite deliveries by truck but capacity was inadequate for the circumstances.<ref>Ruppenthal, ''Logistic Support of the Armies'', Vol. I, pp. 520</ref>

The 6th Army Group [[Operation Dragoon|advancing from southern France]] were supplied adequately from [[Toulon]] and [[Marseille]] because it had captured ports intact and the local railway system was less damaged. This source supplied about 25% of the Allied needs.

At this time the main Allied supply lines still ran back to Normandy, presenting serious logistical problems. The solution was to open the port of Antwerp. This major port had been captured at 90% intact on 4 September, but the occupation of Antwerp was not enough as the 21st Army Group failed to gain sea access by clearing the Scheldt estuary. So the port could not be used until 29 November after a protracted campaign by the [[First Canadian Army|Canadian First Army]]; initially the estuary was weakly held, but the [[15th Army (Wehrmacht)|German 15th Army]] was allowed to dig in there.

The delay in securing this area has been blamed on General Eisenhower as the 21st Army Group commander, Field Marshal Montgomery favored [[Operation Market-Garden]] and opening the French Channel ports over clearing the approaches to the port of Antwerp in the [[Battle of the Scheldt]]. However, even if the Scheldt Estuary had been secured immediately at the start of September, the port of Antwerp would not solve the supply crisis in that month, for the approaches had been mined by the Germans two months earlier, and when finally taken it took one month to clear it.<ref name=montys_men_384>{{cite book |title=Monty's Men |last=Buckley |first=John |year=2014 |publisher=Yale University Press |pages=384}}</ref>