The one factor which most reduced the combat readiness of the units in the west was the increasing shortage of fuel supplies. Allied bombing of the German fuel industry had had far-reaching consequences: training programmes had had to be curtailed, depots reduced in size and number, and transport in general slowed down. In many cases the Germans now had to make do with bicycles and horse transport.
The manpower state in the German camp was also gradually wearing thin. The huge losses, particularly in the east, increasingly forced Hitler and his followers to use foreign workers in the factories in order to release German workers for the Army. At the end of November 1943 the Army High Command initiated a so-called “combing out” drive to round up all surplus manpower from all walks of life for service at the front. C-in-C West even formed a special staff for this purpose in February 1944 under the command of a general. The result was pitiful. Despite the severest penalties for evasion, by April only 6,500 soldiers had been enlisted in the west (according to Jodi the available manpower in the region was 1,870,000, together with 310,000 in Norway and 170,000 in Denmark). Yet in Paris alone at this time there were 50,000 Germans engaged in innumerable occupations.
This abortive effort demonstrated once more how complicated and involved the command structure in the west had become. Nobody could even judge any more whether an organization had too many or too few personnel. It is little wonder therefore that the manpower needs of von Rundstedt s divisions underwent little improvement. In the SS divisions, more than 50 percent of the troops were often under 20 years of age, while the “static” divisions were made up with many over-age soldiers. The manpower shortage was considerably exacerbated by the Allied bombing of important transport and armaments centers in the occupied west. The Germans were forced to devote an ever-increasing number of men to repairing the damage caused. So far as the equipment of his units was concerned, von Rundstedts divisions did not always receive the most up-to-date equipment from the factories, and often had to make do with obsolete, captured equipment to make up the numbers. This often tried the technical know-how of the operators and severely complicated supply requirements.
The flying units of Luftflotte 3 and IX Air Corps had to contend with similar problems. At the end of May 1944, Luftflotte 3 had just over 900 aircraft on inventory, of which only 650 were operational (with a further 145 aircraft in Norway). The IX Air Corps, whose bombers had carried out sporadic attacks on British embarkation ports in the weeks before the landing, albeit without causing significant damage, reported only 100 combat-ready aircraft by the end of May. In the event of an invasion the Germans planned to transfer approximately 1,000 aircraft to the west from all parts of occupied Europe. Even with this number - should the transfer actually to take place — the Germans would still find themselves in a hopelessly inferior position. Although the Minister for Armaments, Albert Speer, had again succeeded in considerably increasing aircraft production in 1944, this output far outstripped the availability of pilots. It was for this reason for example that in May 1944, out of a total of 2,155 aircraft losses by the Luftwaffe, 847 were accidents not involving enemy action.
The Navy in the west also faced a similar sorry outlook. After most of the large surface units had been brought back to harbor in Norway or Germany, only 3 destroyers, 5 torpedo boats, 34 motor gunboats, 163 minehunters and 34 U-boats were left in the west. Due to the weakness of the Luftwaffe even these units were unable to venture outside the antiaircraft protection of their harbors during daylight hours.
Yet Doenitz ordered these warships to be employed regardless of potential losses. According to the Grand-Admiral, they had only one job in the event of a landing: “Attack and sink.” At the end of March 1944, Doenitz proposed using the U-boats in a style reminiscent of the Japanese kamikaze mentality: “The U-boat which causes losses to the enemy during a landing has fulfilled its ultimate aim and justified its existence, even if it remains there.” As it turned out, most of the U-boats intended for this purpose never had the opportunity, for Doenitz had ordered them back out into the mid-Atlantic at the end of May, when the threat of an invasion seemed to have receded.
The only effective weapon remaining to the Navy in the west to combat a landing seemed to be the use of mines. Naval Group West wanted to mine the whole sea around the Isle of Wight with the aid of the Luftwaffe. The latter however refused to have anything to do with this plan, leaving the Navy with the sole remaining option of laying so called “lightning barrages” along the coast at the last minute. In order for this to be feasible however, the enemy approach across the Ghannel would have to be detected in good time. The head of Naval Group West, Adm. Krancke, hoped to be able to do this with his few remaining patrol boats which patrolled the coastline, weather permitting, each night.