to break the Soviet encirclement of Stalingrad, codenamed Operation Winter Storm (). Manstein believed that—due to the inability of the Luftwaffe to supply the Stalingrad pocket—it was becoming more important to relieve them "at the earliest possible date". On 28 November, Manstein sent Hitler a detailed report on Army Group Don's situation, including the strength of the 6th Army and an assessment of the ammunition for German artillery inside the city. The dire strategic situation made Manstein doubt whether the relief operation could afford to wait to receive all units earmarked for the offensive. Stavka postponed Operation Saturn until 16 December, as Soviet forces struggled to clear German defenders from the lower Chir River. The Red Army's offensive in the area commenced on 30 November, involving around 50,000 soldiers, which forced Manstein to use the 48th Panzer Corps to hold the area. The 5th Tank Army was reinforced by the new 5th Shock Army, drawn from existing formations of the South-Western and Stalingrad Fronts; the 5th Tank Army totaled nearly 71,000 men, 252 tanks and 814 guns. The Soviet offensive succeeded in tying down the 48th Panzer Corps, originally chosen to lead one of the main attacks on the Soviet encirclement. The Soviets were forewarned of the impending German assault when they discovered the 6th Panzer Division unloading at the town of Morozovsk and held back several armies from the attack on the lower Chir River to prepare for a possible breakout attempt by German forces inside Stalingrad. Comparison of forces German The relief operation was originally scheduled to include the LVII Panzer Corps of the 4th Panzer Army, under the command of General Friedrich Kirchner, including the 6th and 23rd Panzer Divisions, and Army Detachment Hollidt, consisting of three infantry divisions and two armored divisions (11th and 22nd Panzer Divisions). In total, it was expected that four panzer divisions, four infantry divisions and three Luftwaffe Field Divisions were to take part in Operation Winter Storm. They would be tasked with temporarily opening a passage to the 6th Army. The Luftwaffe field divisions—formed of non-combat soldiers, headquarters staffs and unit-less Luftwaffe and Heer personnel—were poorly trained and lacked seasoned officers and enlisted soldiers, as well as sufficient anti-tank and artillery guns. Many of the personnel promised for the relief effort never arrived, partly due to the poor transportation service to the front, while some units originally chosen to be transferred