Supply and Overlord
By June ( July?) the Allied were 30% behind in planned port capacity. In August 207 ships sat waiting to be unloaded but there was nowhere to go. Cargo ships began to be used as floating warehouses. In the fall of 1944 American divisions arriving in France were forced to sit idle because there was no way to support them.
1944 Americans in Brest
Jonathan Gawne
http://www.militaria.com/brittany/bob.html