moving the armies up only at night, and camouflaging them by day on the open, treeless steppes. Strategic deception included increasing military activity far away, near Moscow. At the sites of the planned attack, elaborate disinformation was fed to the enemy. Defence lines were built to deceive German tactical reconnaissance. Civilians within of the front were evacuated, and trenches were dug around the villages for Luftwaffe reconnaissance to see. Conversely, along the uninvolved Voronezh Front, bridging equipment and boats were prepared to suggest an offensive there. The five real bridges that were built for the attack were masked by the construction of seventeen false bridges over the River Don. To the south of Stalingrad, for the southern arm of the pincer movement, 160,000 men with 550 guns, 430 tanks and 14,000 trucks were ferried across the much larger River Volga, which was beginning to freeze over with dangerous ice floes, entirely at night. Overall, Stavka succeeded in moving a million men, 1000 tanks, 14,000 guns and 1400 aircraft into position without alerting their enemy. Despite the correct appreciation by German air reconnaissance of a major build-up of forces on the River Don, the commander of the 6th Army, Friedrich Paulus took no action. He was caught completely by surprise, failing either to prepare his armour as a mobile reserve with fuel and ammunition, or to move it on the day of the attack. The historian David Glantz considered that the concealment of the scale of the offensive was the Red Army's "greatest feat". Battle of Kursk, 1943 Deception was put into practice on a large scale in the 1943 Battle of Kursk, especially on the Red Army's Steppe Front commanded by Ivan Konev. This was a deception for a defensive battle, as Hitler was planning to attack the Kursk salient in a pincer movement. The Soviet forces were moved into position at night and carefully concealed, as were the extensively prepared defences-in-depth, with multiple lines of defence, minefields, and as many as 200 anti-tank guns per mile. Soviet defences were quickly built up using deception techniques to conceal the flow of men and equipment. This was accompanied by a whole suite of deception measures including feint attacks, false troop and logistics concentrations, radio deception, false airfields and false rumours. In mid-June 1943 German army high command (OKH) had estimated 1500 Soviet tanks in the Kursk salient, against the true figure