Operation Bertram (1942) was the tactical element of the deception plan for the second battle of El Alamein, and focused on convincing the Germans both that the offensive wouldn't begin until some time in November and that the main attack would come on the southern end of the front line.
Operation Bertram was run by Lt Colonel Charles Richardson, a recently arrived member of the planning staff of the Eighth Army. Richardson was given two tasks – first to hide the buildup on the northern part of the Alamein line, and help convince Rommel that the main attack would come in the south, and second to convince Rommel that the attack wouldn't start until nearly November, two weeks after the genuine 'D-Day' of 23 October. The work was carried out by the Middle East Camoflage Department, commanded by Major Geoffrey Barkas. He had performed a similar role for General Auchinleck earlier in the year (Operation Sentinal), but Bertram would be on a much larger scale. Barkas was informed of the plan by Montgomery's chief of staff, de Guingand, on 17 September, and offered to create two dummy armoured brigades on the south front. Montgomery liked the idea, but wanted it to be on a bigger scale, and ordered them to create an entire fake armoured corps.
Operation Bertram thus had to achieve several different things. It had to hide the massive British buildup in the north, create the impression of a bigger buildup in the south, and indicate that preparations were two weeks less advanced than was the case.
The most difficult part of the plan was hiding the massive buildup in the north. X Corp's two armoured divisions were to move to an assembly area codenamed Martello, at El Imayid, around twenty miles east of the front. The field guns were to assemble at Cannibal 1, five mile east of the front, and then move further west to Cannibal 2 just before the start of the attack. A series of approach tracks needed to be bulldozed from the front to Martello.
The problem of the approach tracks was dealt with by having them completed in short patches, which didn't obviously lead from Martello to the front. The gaps were completed just before 'D-Day'.
A vast amount of store had to be concealed in the north – 3,000 tons at El Alamein station alone (600 tons of supplies, 2,000 tons of petrol and 420 tons of engineering supplies), and another 3,000 tons fifteen miles further east (again at El Imayid). A series of ingenious plans were used to hide these supplies. Much of the petrol was hidden in existing slit trenches, of which around 100 sections had been dug over time. Each trench was lined with a one-tank wide wall of petrol cans during the hours of darkness, making them slightly narrower. This difference wasn't visible from the air.
The food was hidden in plain site. Each night the supply trucks brought more supplies to the supply dumps. The food was stacked and then covered with the same sort of camoflague netting used to hide three on trucks. More food could be hidden under the fringes of the netting, or in soldier's tents. From the air this appeared to be a standard lorry park, and the illusion was completed by posting a unit of soldiers in the dump to operate vehicles and keep it working.
The 25-pounder field guns were hidden in a similar way – their limbers were backed up to the guns, and the combined parts were then covered by a canvas dummy truck. The wheels from the guns and limbers completed the illusion. The move from Cannibal 1 to Cannibal 2 was carried out overnight, and the cover was back in place before dawn.
The Martello area was filled with trucks (dummy and real) as quickly as possible. As each tank arrived it would replace one of these trucks, and would be hidden under a 'sunshield', a canvas canopy designed to look like a truck from the air. The Germans would inevitably spot this large assembly area, but wouldn't see any of the activity, and would hopefully dismiss it as a fairly dormant truck park.
Aound 400 dummy M3 Grant tanks and 1,750 dummy vehicles and guns had to be built for the false buildup in the south. This was supported by the creation of two high fake supply dumps just to the east of the false water pipe (see below). There was also one double-bluff. On 15 October a set of dummy gun batteries were set up east of the Munassib Depression. After a few days the camofluage was allowed to slip to make it clear that these were dummy guns. The Germans noticed this slip, but the dummy guns were then replaced with the real thing. During the battle one German armoured column was caught out by this trap.
The most famous attempt to deceive the Germans about the timing was the construction of a dummy water pipeline, running south from El Imayid on the coastal railway across the front, and then turning south-west to head towards the possible launching point for an attack in that area at Samaket Gaballa. The pace of progress would be set so that the pipeline would be completed ten days after D-Day. The Germans would be able to monitor the pace of progress, and see work on a series of dummy pumping stations, and from that work out when the pipeline would be completed. Work on the new pipeline began on 26 September. It was a very simple exercise. A short stretch of fake pipeline was made from crushed petrol cans. On the first night a stretch of trench was dug, and the false pipeline placed next to it. Each night after that the existing trench was filled in, a new section was dug, and the false pipework was moved alongside it. Three dummy pumping stations were built along the route of the pipeline.
Operation Bertram also covered the final advance of the British armour in the days immediately before the battle. The first move, from the training area to a staging area in the south was carried out in daylight, in the hope that the Germans would notice this and take it as evidence for an attack in that area. The tanks then moved into Martello on the night of 20-21 October (D-3), and were hidden under their sunscreens by dawn. Dummy tanks were then erected back at the original staging area, in the hope that the Germans would believe that the armour was still some way to the rear. A wireless deception unit then operated from the empty staging area, in a further attempt to keep the Germans guessing.
At the start of the battle a dummy amphibious landing was staged behind the northern end of the Axis line. This involved sonic deception, with the recording of battle sounds played from loudspeaksers on motor torpedo boats. The threat of an amphibious landing was real, and this appears to have distracted the Axis high command at the start of the battle, adding to the confusion caused by the artillery barrage, the absence of Rommel and the death of his deputy, General Stumme, of a heart attack right at the start of the battle.
Just how far the Germans were deceived is hard to tell. Rommel was away from the army, recovering from an illness, throughout October, and didn't rejoin his army until 25 October, two days into the battle, suggesting that the Germans hadn't expected an attack in late October. In addition Rommel's armour was split in half, with one German and one Italian armoured division in the north and the same in the south. This was unusual for Rommel, who preferred to mass his armour, and again suggests that the Axis high command didn't know where the Allied attack was coming from.
Operation Bertram, and its intelligence led sister Operation Treatment, were the first of a series of increasingly elaborate Allied deception plans. Similar operations were put in place to hide the invasion of Sicily, and most famously to try and prevent the Germans from reacting quickly after D-Day (Operation Fortitude).