The strip of land over which the 1942 Battle of El Alamein was to be fought was bounded to the north by the Mediterranean Sea, and to the south by the Qattara Depression, impassable to armor and wheeled vehicles (see map above). Operation Bertram was a misdirection plan employed by the British to deceive Erwin Rommel about British intentions regarding the direction of their upcoming attack. That was particularly important because Rommel faced fuel shortages which made redeployment of most of his troops, particularly the Italians, difficult or even impossible once fighting commenced. Wherever Rommel deployed his forces, that is where most of them would remain during the battle, so the British set out to convince him to deploy them in the wrong place.
The British planned to attack in the north, and to conceal that a specialist unit is known as the Camouflage, Development, and Training Centre (CDTC) was cobbled together from filmmakers, stage magicians, painters, sculptors, and architects, and tasked with flummoxing the enemy. The CDTC set out to hide the actual troop and materiel buildup in the north, make what buildup could not be concealed appear slower than it actually was, and convince the enemy that the main attack would fall upon the southern sector of the line and not the northern.
To that end, the British fed the Germans misinformation via turned spies, and borrowing from stage magic, built wood and canvass contraptions to fool German aerial reconnaissance by making concentrations of armor appear like trucks, and make transport trucks look like menacing concentrations of tanks. To misdirect about the buildup of supplies and munitions, the CDTC set up fake ammunition dumps, and with water being the most precious resource in the desert, whose concentration offered strong indicia of intent, built a 200-mile dummy water pipeline to the southern sector of the Alamein line.
The deception worked, and when the Battle of El Alamein commenced with a massive artillery bombardment on the night of October 23, 1942, the enemy commanders were surprised that the British Eighth Army’s main thrust came in the north, and not in the south as had been expected. As had been predicted, fuel shortages prevented the Axis from effectively redeploying troops from the southern sector to reinforce and meet the threat to the north. The battle ended in a complete British victory, and a retreat that culminated 6 months later in the complete surrender of all Axis forces in North Africa.