Marshal of Artillery Nikolai N. Voronov, the commander of the Red Army’s artillery, was sent as Stavka representative to the Don Front to help plan Operation Koltso (Ring), intended to begin on 10 January 1943. In order to reinforce Rokossovsky’s Don Front for Operation Koltso, Voronov brought in about 30,000 infantry replacements as well as a large number of artillery units as reinforcements. The 11th Artillery Division was assigned to the Don Front, adding over 300 guns/heavy mortars and 16 multiple rocket launchers to Rokossovsky’s arsenal. In addition, the Stavka sent 10 independent guards breakthrough tank regiments with 110 KV-1S heavy tanks and 21 Lend-Lease Churchill tanks to the Don Front to participate in Operation Koltso. However, Voronov planned Operation Koltso primarily as an artillery offensive, with infantry-armour shock groups only attacking once the German defences were thoroughly smashed. Don Front’s main effort would be made against the western side of the pocket with the 21st, 24th and 65th Armies, while the 57th and 65th Armies made a supporting attack against the southern side of the pocket. Voronov confidently expected that Koltso would collapse the pocket in just four days. Yet it is clear that the Stavka greatly underestimated the residual combat power of the 6.Armee and failed to provide Rokossovsky with enough resources to achieve a quick victory.
While building up to Operation Koltso, Rokossovsky’s Don Front limited themselves to mostly reconnaissance and raiding activity on 1–5 January, but on 6 January they began mounting a series of local attacks on the northern and western sides of the pocket. On 7 January, the Soviet 65th Army mounted a two rifle division attack against the German 44.Infanterie-Division on the western side of the pocket and succeeded in penetrating its defensive line (HKL) and inflicting significant casualties. In response, the VIII Armeekorps committed 24 tanks and a number of assault guns to contain the Soviet breakthrough, which exposed these units to concentrated Soviet artillery fire. Not only did the commitment of German armour fail to restore the former frontline in this sector, but it consumed fuel and ammunition for no gain. One of the cardinal rules of defence is not to commit one’s reserves prematurely, and Paulus had allowed a substantial part of his armour in the western sector of the pocket to be committed before the main Soviet offensive had even begun. The simple fact was that 6.Armee was trying to hold too much terrain with too few troops and the only logical solution was to withdraw into a tighter perimeter, but Hitler would not accept even modest tactical adjustments at this point of a losing battle.
At 0805 hours (local time) on 10 January 1943, Operation Koltso began with a massive 55-minute artillery barrage. Despite some cloud cover, visibility was fairly good and the Soviet artillery fire hammered the German frontline positions. In the 65th Army sector on the western side of the pocket Voronov was able to mass over 500 guns/howitzers and 450 multiple rocket launchers across a 12km-wide attack sector – the highest Soviet artillery density yet of the war. Once the artillery fire lifted, Soviet ground attack aircraft from the 16th Air Army (16 VA) strafed and bombed German positions to the rear of the HKL. Around 0900 hours, the shock groups of the 65th Army, comprised of five rifle divisions supported by the 91st Tank Brigade and six tank regiments (a total of 111 tanks) advanced against the still-smoking positions of the 44.Infanterie-Division. A squad of Soviet infantrymen was mounted on the back deck of each tank. The 65th Army had almost half of Rokossovsky’s armour, including about 60–70 KV-1S heavy tanks and 21 Churchill (Mk-IV) tanks in the 10th Guards Tank Regiment (10 GTR). The British-built Churchills were slower than the KV-1S but had slightly better armoured protection. On the flanks of the 65th Army, the 21st and 24th Armies launched smaller supporting attacks with a total of five rifle divisions and 27 tanks, intended to prevent the Germans from transferring units from these sectors to help the 44.Infanterie-Division. Clearly, the Red Army was learning how to mass combat power in a critical sector.
Although the front of the 44.Infanterie-Division was smashed in fairly quickly and four depleted infantry battalions were overrun, the remaining Sturmgeschütz and anti-tank guns inflicted a fearsome toll on the attacking Soviet armour.{9} At the tactical level, the Red Army’s coordination between tanks and infantry was still fairly primitive and a platoon of three ex-Soviet 7.62cm PaK 36 (r) anti-tank guns from Panzerjäger-Abteilung 46 was able to pick off a number of the KV-1S tanks before the unit was overrun.{10} The other Soviet supporting attacks went fairly well. In the south, the 57th Army routed the Romanian 20th Infantry Division, causing the IV Armeekorps to recoil inward, abandoning 26 of its precious PaK guns.{11} In the Marinovka salient, Hauptmann Rudolf Haen’s 1./Pz.Abt. 103 from the 3.Infanterie-Division (mot.), supported by some 8.8cm flak guns, managed to shoot up virtually all of the 21st Army’s 18 tanks. However, by the end of the second day of the offensive, the XIV Panzerkorps’ 3. and 29.Infanterie-Division (mot.) were increasingly exposed in the Marinovka salient and Haen’s Panzer-Kompanie was isolated. Overall, Hube’s corps lost 30 of its 46 tanks and 11 of 18 PaK guns in the first 48 hours of the Soviet offensive.{12} In the northwest, the 24th Army’s attack forced Strecker’s XI Armeekorps to commit the last four assault guns from Sturmgeschütz-Abteilung 177 at the Kotluban rail station. These four assault guns knocked out four Soviet tanks before two of the StuG IIIs were destroyed by direct hits and a third suffered a mobility kill when struck on its final drive. Likewise, the 6.Armee succeeded in limiting the Soviet advance by committing its remaining AFVs and PaK guns, but this only prevented a complete collapse. Due to ferocious German resistance, the Don Front suffered 26,000 casualties in the first three days of Operation Koltso and 135 out of 264 tanks were knocked out.{13} The KV-1S heavy tanks performed particularly poorly, with nearly three-quarters disabled – a very disappointing combat debut. Nevertheless, the western side of the pocket was nearly smashed in and the decimated German units from the IV and VIII Armeekorps and XIV Panzerkorps were forced to retreat toward Stalingrad. While Soviet armour losses were heavy, the Germans had also lost over 60 tanks and assault guns in the opening phase of Operation Koltso.
By 15 January, the 6.Armee had contracted into a much tighter perimeter closer to Stalingrad, but was forced to hold the outlying areas around Pitomnik and Gumrak airfields. Yet since Hube’s XIV Panzerkorps was combat ineffective after five days of fighting, Paulus no longer had the means to defend the airfields. Almost all of the German tanks and assault guns were either knocked out or immobilized by lack of fuel, although Sturmgeschütz-Abteilung 243 still had two StuG IIIs defending Pitomnik and Sturmgeschütz-Abteilung 245 had a few at Gumrak. Hauptmann Haen from Panzer-Abteilung 103 had been badly wounded in action on 13 January but he was fortunate enough to be flown out on 15 January; those panzer crewmen still on their feet were turned into infantrymen.[3] Nearly one-third of 6.Armee’s personnel had become casualties in five days of fighting, leaving fewer than 20,000 combat troops to hold the shrinking perimeter. Rokossovsky had hoped to split the German pocket into several easily-digestible sub-groups, but instead the 65th Army’s attacks from the west and the 57th Army’s attacks from south merely herded the 6.Armee in closer to Stalingrad. With only about 100 tanks still in operation, Rokossovsky used his armour in small groups to help his infantry mop up various German Stützpunkte. In some sectors, Soviet infantry was advancing with only 2–3 tanks in support, but German defensive capabilities were sharply decreased due to starvation, frostbite and limited ammunition. German Pak guns continued to destroy Soviet tanks, but now they were literally down to their last few rounds.
3
Haen recovered and became the battalion commander of the rebuilt Panzer-Abteilung 103, which he led in the Italian Campaign. Remarkably, he survived the war but was shot in US captivity on the day after Germany’s surrender in 1945.