and assumed that General Paulus would agree to order his forces to escape the Stalingrad pocket. On 10 December, Manstein communicated to Paulus that the relief operation would commence in 24 hours. Order of Battle of 4. Panzer Armee (Dec 1942 – Jan 1943) Data from AxisHistory.Com 15. Lw. Feld-Division LVII Panzer Korps 17. Panzer-Division 23. Panzer-Division 5. SS-Panzer-Division "Wiking" (in transit until January) 16. Infanterie-Division (elements) Order of Battle for the XXXXVIII Panzer Korps (January 1st, 1943) Data from AxisHistory.Com 6. Panzer-Division 306. Infanterie-Division Gruppe Pfeiffer Soviet For the purpose of Operation Uranus, Soviet Marshal Georgy Zhukov deployed eleven Soviet armies. In an effort to bolster the offensive capabilities of the Stalingrad Front, over 420 tanks, 111,000 soldiers and 556 artillery guns were shipped over the Volga River in a period of three weeks. The Red Army and Red Air Force were able to amass over one million soldiers, 13,500 artillery guns, 890 tanks and 1,100 combat aircraft, organized into 66 rifle divisions, five tank corps, 14 tank brigades, a single mechanized brigade, a cavalry corps, and 127 artillery and mortar regiments. As the encirclement closed and the Soviets continued with secondary operations, the 51st Army was positioned on the edge of the outer encirclement with 34,000 men and 77 tanks. South of them was the 28th Army, with 44,000 soldiers, 40 tanks and 707 artillery guns and mortars. Concurrently, the Red Army began building its strength for Operation Saturn, in which it would aim to isolate and destroy German Army Group A in the Caucasus. German offensive On 12 December 1942, the LVII Panzer Corps of the Fourth Panzer Army began its north-eastward drive toward German forces trapped in the Stalingrad pocket. The 6th and 23rd Panzer Divisions made large gains, surprising the Red Army and threatening the rear of the 51st Army. The German drive was due to be spearheaded by the 503rd Heavy Tank Battalion of Tiger I tanks but the unit did not embark on its transport to the Eastern Front until 21 December 1942 and did not see battle until early January 1943, along the Manytsch River. At first, Winterstorm made rapid progress. Some units were able to travel up to on the first day. The Germans were aided by surprise, as Stavka had not expected the German offensive to begin so soon, while General Aleksandr Vasilevsky was unable to detach the 2nd Guards