'Wirbelwind' was a German plan by Generalfeldmarschall Günther von Kluge’s Heeresgruppe 'Mitte' for an offensive by Generaloberst Gotthard Heinrici’s 4^th Army and Generaloberst Rudolf Schmidt’s 2^nd Panzerarmee to pinch off the Soviet salient in the region of Sukhinichi in the German-occupied western USSR (11/24 August 1942).

In the summer of 1942 the Soviet leadership, confident in its belief that the Germans would, sooner or later, seek the military decision on the Eastern Front along the axis to Moscow, in no way considered the front’s central sector to be of secondary importance despite the German launch of the major 'Blau I', 'Blau II' and 'Blau III' offensives (otherwise 'Braunschweig' , 'Clausewitz' and 'Dampfhammer') farther to the south. General Georgi K. Zhukov, who had been one of the primary architects of the USSR’s survival in the summer of 1941 as the Germans struck toward Moscow in 'Barbarossa', therefore remained commander of the West Front. The fronts opposite von Kluge’s Heeresgruppe 'Mitte', namely General Polkovnik Ivan S. Konev’s Kalinin Front, Zhukov’s West Front, and the two right-wing armies of General Leytenant Konstantin K. Rokossovsky’s Bryansk Front, possessed 140 divisions to the German formation’s 70 divisions, and the Stavka also had four combined-arms armies as well as General Leytenant Prokofi L. Romanenko’s 3^rd Tank Army and General Major Aleksandr I. Liziakov’s (from 27 July General Leytenant Pavel S. Rybalko’s) 5^th Tank Army as reserves in the Moscow area.

The Soviets maintained their adherence to the strategy of active defence on the Moscow axis, and on 16 July, four days after the offensive in the area to the north of Orel against Schmidt’s 2^nd Panzerarmee had been brought to a halt, the Stavka instructed Zhukov and Konev to prepare their West Front and Kalinin Front to ready an offensive in the area of Rzhev and Sychevka area. The objectives of this 'Rzhev-Sychevka Offensive Operation' (30 July/23 August) were to be the driving of the German forces back to the Volga and Vazuza rivers, and the liberation of Rzhev and Zubtsov.

With the end of 'Seydlitz' (iii) on 12 July, Heeresgruppe 'Mitte' was prepared to settle into an essentially defensive role for the summer. By their elimination of the most critical dangers to the army group’s rear, 'Hannover I', 'Hannover II' and 'Seydlitz' (iii) had made the army group once more an almost credible threat to Moscow and, consequently, something more than a current passive bystander in the war, but nevertheless offensive action was out of the question at least until a partial reorganisation and considerable reinforcement of the formation had been completed in August. The army group’s armies at this time had three operations in the early planning stages as 'Derfflinger', 'Orkan' (i) and 'Wirbelwind'. An evolution from the earlier 'Brückenschlag', 'Derfflinger' was to be an offensive by Generaloberst Walter Model’s 9^th Army, currently under the temporary command of Generaloberst Heinrich-Gottfried von Vietinghoff-Scheel, toward Ostashkov from the area of the front to the north of Rzhev. As suggested by their names, 'Orkan' (i) and 'Wirbelwind' were related operations to be undertaken by Heinrici’s 4^th Army and Schmidt’s 2^nd Panzerarmee against the Sukhinichi salient. In 'Orkan' (i) the two armies, striking from the north and the south, were to obliterate the entire salient and carry the front forward to Belev, Kaluga and Yukhnov, while 'Wirbelwind' was to be a considerably less ambitious alternative to 'Orkan' (i) designed merely to pinch off the western one-third of the salient and establish a new front line some miles to the east of Sukhinichi. Although 'Orkan' (i) could have been markedly more effective than 'Wirbelwind', through the reopening the south-western approaches to Moscow via Yukhnov and Kaluga, in the middle of July there was almost no chance of its implementation, unless there was a sudden Soviet collapse, as Heeresgruppe 'Mitte' lacked the strength in men and matériel to undertake so large an effort.

Whether or not 'Derfflinger' could be executed was also moot, for much of the strength needed for it would have to be diverted from 'Wirbelwind', which had a higher priority. 'Derfflinger' could not be attempted until September, however, and this would place it dangerously close to the effective end of the summer campaigning season.

Konev was ready to start the 'Rzhev-Sychevka Offensive Operation' on 30 July, when he had General Major Dmitri D. Lelyushenko’s 30^th Army and General Major Vasili I. Shvetsov’s 29^th Army positioned to the north and north-east of Rzhev, but Zhukov, whose West Front was to play the main part while he himself co-ordinate the operations of both fronts after the start of the offensive, required another five more days. The West Front had General Major Vitali S. Polenov’s 31^st Army and General Leytenant Maks A. Reiter’s 20^th Army in the line and two tank corps, two guards cavalry corps and five cavalry divisions in position to follow. Each of the armies also had a mobile group of three tank brigades. The 31^st Army was to sweep to the south of the Volga toward Zubtsov, where it would be in position to threaten Rzhev from the south-east. The 20^th Army would advance to the south-west toward the Vazuza river and Sychevka.

The 9^th Army became aware of the increase in the strength of the Soviet forces facing it during the last week of July: it identified several new divisions in the 30^th Army and several more in the 31^st Army. As the West Front had already completed several similar, but apparently pointless regroupments on other parts of its front, however, the 9^th Army suspected that the Soviet moves were little more than deceptive posturings akin to the German 'Kreml'.

As the area was deluged with heavy rain, at 06.00 on 30 July a one-hour Soviet artillery barrage, accompanied by air attacks, was followed by the 30^th Army’s assault on the 9^th Army's front along the Volga river bridgehead due north of Rzhev. By the fall of darkness, the 30^th Army had broken open some 4 miles (6.5 km) of the front and penetrated about 2 miles (3.25 km) to the rear, in the process overrunning artillery positions. For the next four days, the Germans held tight to the shoulders and flanks of the Soviet breakthrough, so preventing the attack from penetrating more deeply as as the Germans braced themselves also for an attack from the east past Zubtsov toward Rzhev, which now seemed inevitable. The distances were short, in the north less than 10 miles (15 km) and in the east 25 miles (40 km), but the danger was considerable. Should the Soviets take Rzhev, Heeresgruppe 'Mitte' would lose the anchor of its northern flank, and with it every chance of closing the gap to Generalfeldmarschall Georg von Küchler’s Heeresgruppe 'Nord' and most, if not all, of its essential nature as a major threat to Moscow.

During the morning of 4 August, the 31^st Army surged with great speed and momentum first into and then over Generalleutnant Heinrich Recke’s 161^st Division on an 8-mile (12.75-km) sector to the east of Zubtsov. By the fall of night, the only evidence of the original front was the occasional light of flares over bypassed German strongpoints. During the day the 9^th Army had received two more shocks: the attack through the gap in the east was directed not only toward Zubtsov but also to the south-west in the direction of Sychevka, and General Leytenant Vladimir V. Kurasov’s 4^th Shock Army appeared to be readying itself for action in the area to the west of Bely. Thus it became clear to von Vietinghoff-Scheel, to von Kluge on his return from leave during the afternoon of 4 August, and to Adolf Hitler that the 9^th Army, which had no reserves, could not hold Rzhev or the 175-mile (280-km) northward loop of its front unless it received swift and substantial reinforcement. There was help to be had, though, and Hitler was more than usually quick to give it. This meant the dismemberment of the force which the 4^th Army was assembling for 'Wirbelwind', but more important for Hitler at this time was the need to prevent the Soviets from winning a high-profile battle for Rzhev. Thus Hitler released Generalleutnant Walter Krüger’s (between 8 August and 21 October Oberst Oswin Grolig’s) 1^st Panzerdivision, Generalleutnant Hans-Karl Freiherr von Esebeck’s (between 10 and 28 August Oberst Vollrath Lübbe’s) 2^nd Panzerdivision, Generalleutnant Gustav Fehn’s 5^th Panzerdivision, Generalleutnant Paul Völckers’s 78^th Division and Generalleutnant Johannes Friessner’s 102^nd Division, and instructed von Kluge to see that the Panzer divisions were used only for a concentrated counterattack from the south across the mouth of the West Front’s breakthrough.

The German front held to the north of Rzhev and at Zubtsov on 5 and 6 August, but fell apart in the south-west, thereby opening a wide axis to Sychevka. To take advantage of the latter, Zhukov revised his plan, and on 6 August secured approval from the Stavka to stop the 29^th Army, which in fact had made no progress, and to leave Rzhev to the 30^th and 31^st Armies. At the same time, he relocated the primary weight of the Soviet operation to the south, committing his reserve armour and cavalry (the VI and VIII Tank Corps and the II and VIII Guards Cavalry Corps) together with the 20^th Army. Not originally one of the Soviet objectives, Sychevka now became the first target as the 20^th Army’s mobile group, comprising the VI and VIII Tank Corps and the II Guards Cavalry Corps, advanced on it.

von Kluge and von Vietinghoff-Scheel had no time to group the Panzer divisions for a counterattack, but instead had to commit them frontally along the Vazuza and Gzhat rivers, some 10 miles (16 km) to the west of Sychevka. Talking to Generalmajor Rudolf Schmundt, Hitler’s military adjutant, during the night of 6/7 August, von Vietinghoff-Scheel indicated that he might be able to create a counterattack if he could be provided, in addition to the understrength Panzer divisions already on their way to him, one fully equipped Panzer division, but the chance of this happening was remote, and in fact disappeared entirely during the following morning when the VIII Guards Cavalry Corps struck to the south off the flank of the 20^th Army. The reinforcements were perforce being committed to the expanding battle as soon as they arrived, and were immediately being engaged by waves of Soviet infantry, tanks and cavalry.

On 7 August the 9^th Army was on the defensive right along its front and on the verge of being overwhelmed. Once more, help was available, however. Three or four Panzer divisions and two infantry divisions could have been extracted from the 2^nd Panzerarmee's force for 'Wirbelwind'. During the day, von Kluge went to Hitler’s Eastern Front headquarters, the Wolfsschanze at Rastenburg, in order to secure a decision, and in fact received one which was totally different from that which he had wanted or expected. As Hitler saw it, the Soviet offensive on the southern flank had reached its final stage, and Soviet diversionary attacks could be expected at every point. These, such as that against the 9^th Army, Hitler averred, would have to be handled in the manner in which the Soviet 'Rzhev-Vyaz’ma Strategic Offensive Operation' of the previous winter had been, by holding fast in spite of occasional Soviet breakthroughs. The manner in which current operations should be fought, according to Hitler, was to get 'Wirbelwind' under way as rapidly as possible. After it was completed, the Panzer divisions could then be employed to solidify the position of the 9^th Army, which could then finish the summer campaign with 'Derfflinger'. When von Kluge returned to his headquarters at Smolensk, he brought with him Model, who had been recalled from convalescent leave, to resume command of the 9^th Army.

As the start date set in July for 'Wirbelwind' had been 7 August, the 2^nd Panzerarmee on the south-eastern flank of the planned operation was prepared to start almost immediately, but the situation of the 4^th Army, on the north-western flank of the operation, had changed completely, and Heinrici told von Kluge that he could not undertake an operation, which had been schemed on the basis of seven or eight divisions, with the mere two which were now all that were available to him. Yet Hitler’s order included the 4^th Army, and von Kluge therefore insisted on an advance of at least 10 miles (15 km) past its current front to Mosalsk.

This changed 'Wirbelwind' from a two-part thrust from south-east and north-west against the Soviet salient extending forward from Kaluga and Belev as far to the west as Kirov, and including Sukhinichi and Mosalsk, into little more than a one-part 'envelopment' and lengthened the distance which the 2^nd Panzerarmee was required to advance from about 40 to 65 miles (60 to 105 km). Schmidt, the commander of the 2^nd Panzerarmee, proposed to achieve this in two phases with a force of four Panzer and three infantry divisions. In the first phase, the Panzer divisions, starting in pairs from the eastern and western sides of a Soviet salient, some 18.5 miles (30 km) wide, in the front around Ulyanovo, were to advance through 15.5 miles (25 km) of heavily wooded terrain to the south of the Zhizdra River, and then converge on the river about 15.5 miles (25 km) to the south-south-east of Sukhinichi. In the second phase, to be undertaken across open terrain to the north of the river, the divisions were to press forward about 50 miles (80 km) to the north-west to Mosalsk, passing Sukhinichi on the way.

Delayed by two days of rain, 'Wirbelwind' started on 11 August, in continuing rain. Advancing from the south-east, Generalleutnant Hermann Balck’s 11^th Panzerdivision advanced 8 miles (13 km), about half the distance to the Zhizdra river, before being checked just short of Ulyanovo. The two Panzer divisions driving from the south-west covered only about 1 mile (1.5 km). The day brought two surprises: the Soviets had constructed fortifications at least all the way back to the river, and they were reacting with remarkable speed. Late in the afternoon of 11 August, German pilots flying support missions reported columns of trucks and tanks on all the roads leading into the operation’s area from the north and east. The tank corps which had been used in the Orel offensive during July, and which the 2^nd Panzerarmee believed had been redeployed out of the area, had in fact been refitting in the areas to the east of Belev and to the north of the Zhizdra river and were now rapidly committed to the battle. Moreover, in the trench lines weaving through the forest, the infantry was often fighting to the last man. One Panzer division managed to fight its way forward to the Zhizdra river in another two days and to establish a small bridgehead across the river on 14 August.

It was perhaps reasonable for Hitler to have expected that 'Wirbelwind' would have worried the Soviets sufficiently for them to switch their focus away from the rest of the front held by Heeresgruppe 'Mitte', but this was not the case. With all of his original forces for the 'Rzhev-Sychevka Offensive Operation' committed by 9 August, Zhukov now put the right flank of General Polkovnik Yakov T. Cherevichenko’s 5^th Army, the southern neighbour of Reiter’s 20^th Army, into movement to the east of Karmanovo. Four days later, the 30^th Army’s armour was ranging into the forest 3.25 miles (5 km) to the north-east of Rzhev, and on 13 August a surprise attack by General Leytenant Mikhail S. Khozin’s 33^rd Army broke through the right flank of Generaloberst Georg-Hans Reinhardt’s 3^rd Panzerarmee on the Vorya river along the axis toward Vyaz’ma. After that, all of von Kluge’s armies except Heinrici’s 4^th Army were embroiled in desperate combat, and the 4^th Army was in some respects worse off than the others: it had to give an infantry division to the 3^rd Panzerarmee on 13 August, after having sent a reinforced regiment to the 9^th Army two days earlier. What was left of the 4^th Army's force for 'Wirbelwind' had disappeared, and each of its divisions was now attempting to hold a sector of the front between 9.25 and 15.5 miles (15 to 25 km): the 4^th Army's front was therefore little more than a picket line.

The only bright spot for Heeresgruppe 'Mitte' was on the 9^th Army's western front, where the 4^th Shock Army had not managed to achieve anything of significance.

von Kluge spent 14 August and the headquarters of the 2^nd Panzerarmee, where he sought to enthuse divisional commanders but privately coming to the decision that the prospects for 'Wirbelwind' were too s’mall to be worth the risks of losing Rzhev or allowing the Soviets to work their way deep into the 3^rd Panzerarmee. von Kluge later informed General Franz Halder, chief of the Oberkommando des Heeres’s general staff, that Heeresgruppe 'Mitte' had no further reserves, and that 'Wirbelwind' must be brought to an end so that reinforcements could be send to the 9^th Army and the 3^rd Panzerarmee. Knowing the type of furious reaction this was likely to elicit from Hitler, Halder resisted the notion of bringing 'Wirbelwind' to an early end, but at his late situation conference managed to persuaded Hitler to provide von Kluge with another two divisions, Generalmajor Curt Souchay’s 72^nd Division and Generalleutnant Walter Hörnlein’s Infanteriedivision 'Grossdeutschland' (mot.). The former, which had been earmarked for the Leningrad area with Generalfeldmarschall Erich von Manstein’s 11^th Army, was moving out of Crimea, and the latter was at Rostov-na-Donu awaiting movement to the west, but neither could start toward Smolensk in less than a week, and because of the logistical situation on the railways both could not be there before the first week of September. Once again, von Kluge had reserves, but they were 700 miles (1125 km) to the south of the area in which they were so desperately needed.

Two days later, Model presented von Kluge with something little short of an ultimatum: the defeat of the 9^th Army could be staved off only by the receipt of three additional divisions, and that failing this the army group would have to take responsibility for what happened next and generate detailed orders about the further prosecution of the battle. This was the psychological turning point for the German operations of the summer of 1942. von Kluge needed to persuade 9^th Army that it was not teetering on the edge of defeat, and the 9^th Army needed to believe that this actually was the case. von Kluge achieved this by offering Model the 72^nd Division and the prospect of another division, which Model assumed to be the Infanteriedivision 'Grossdeutschland' (mot.). The first train carrying the leading elements of the 72^nd Division's men and equipment was scheduled to reach Smolensk on 17 August, but the movement of an entire division required 30 or more trains. Moreover, it was Hitler rather than von Kluge who controlled the Infanteriedivision 'Grossdeutschland' (mot.), and Hitler intended that this formation be used in 'Wirbelwind'.

By the third week of August, Heeresgruppe 'Mitte' was wholly committed in three battles in which matériel was the decisive factor. The 9^th Army had suffered more than 20,000 casualties by 17 August. The 3^rd Panzerarmee was involved in trench fighting along the Vorya river. In the Zhizdra river bridgehead, the 2^nd Panzerarmee's armour was rendered effectively immobile by the presence of dense Soviet minefields. Thus the ends of 9^th Army's position were being reduced to the east of Rzhev and around Karmanovo. On 22 August Hitler finally appreciated the need to bring 'Wirbelwind' to an end and, removing two Panzer divisions to work with the Infanteriedivision 'Grossdeutschland' (mot.) in a new but smaller 'Wirbelwind Klein' to the north-east of Kirov. Before he was able to extract these divisions, however, the 2^nd Panzerarmee came under great pressure from Soviet counterattacks which compelled it to abandon its Zhizdra river bridgehead on 24 August.

The Soviets believed that the 'Rzhev-Sychevka Offensive Operation' had ended on 23 August, and on 26 August Zhukov departed.

Between 24 and 30 August, the 3^rd Panzerarmee destroyed a Soviet breakthrough across the Vorya river, and its front then stabilised. By the end of the month, the 2^nd Panzerarmee's front to the south of the Zhizdra river had also stabilised to the extent that Hitler could begin to consider the removal of one Panzer division from it. The Kalinin Front and West Front were in fact as close to Rzhev and Sychevka as they were going to get in this campaign.

As a match of comparative endurance capabilities, however, the Soviet offensive was not in fact over. On 1 September, von Kluge again travelled to Hitler’s headquarters, on this occasion to report what Model had told him the day before, that the 9^th Army had reached the point at which the collapse of its front wad imminent. The army’s casualties were were now in the order of 42,000 men and the casualty rate rate was almost 2,000 men per day. Even so, Hitler refused even to consider a shortening of the front as this would necessitate the loss of Rzhev. He also refused to release the Infanteriedivision 'Grossdeutschland' (mot.), which was assembling at Sychevka on the grounds that this formation was a 'guards division' to be used only for short periods in time of crisis, but was prepared to redeploy Generalleutnant Friedrich Zickwolff’s 95^th Division to the north from the Voronezh area in about two weeks and remove Oberst Erwin Jollasse’s 9^th Panzerdivision from the 2^nd Panzerarmee. Meanwhile, Hitler concluded, the 9^th Army would have to shift for itself.

For a short time it seemed that the Soviets were weakening. The 9^th Army recorded little activity on 6, 7, and 8 September, the first such period of quietude since 30 July. The situation changed once more on 9 September, however, as the 30^th Army fell on the Volga river bridgehead around Rzhev, and the 31^st Army broke open 6.25 miles (10 km) of the front in the area to the west of Zubtsov. The 31^st Army, in particular, attacked so aggressively that Model suspected that Zhukov had returned. After several telephone exchanges, in the afternoon Hitler allowed the deployment of the Infanteriedivision 'Grossdeutschland' (mot.) between Rzhev and Zubtsov, and during the evening gave command of the division to Model with instructions that it was to be used purely for offensive purposes in a counterattack.

At 04.00 on the following day, the 31^st Army began an artillery barrage which continued right through the day. The Infanteriedivision 'Grossdeutschland' (mot.) began its counterattack 90 minutes later and ran straight into a Soviet infantry attack with potent air support. The 9^th Army then received a string of negative reports: a regimental commander wounded, the tank battalion commander wounded, and many tanks lost. Experienced in the hit-and-run tactics of the Blitzkrieg concept, the formation seemed to be on the verge of destroying itself in an attempt to advance across a small distance of woodland and swamp. One day later, the division was in so confused a situation that Model put it temporarily under the commander of the neighbouring 72^nd Division in the hope of establishing what was happening. Some hours later Model was able to discover the situation of the supposed elite formation: all but five of the division’s 40 tanks were out of commission; the troops were suffering the effects of confusion rather than casualties; and the counterattack was a total failure.

On 13 September, Model persuaded Hitler to let him have the 9^th Panzerdivision and 95^th Division fore another attempt as soon as they had become available. It seemed as if the situation round Rzhev was balanced very delicately, by on 15 September the balance shifted toward the 9^th Army. In the course of the morning, the 31^st Army gathered itself and struck the 72^nd Division with a powerful concentration of armour and infantry. In the course of the afternoon, the 430^th Regiment the IV Tank Corps, which was the core of the Soviet attack, eliminated some 35 of its tanks, and closed the gap in the German line. Three days of rain followed, an in this time the 31^st Army, 30^th Army and 4^th Shock Army appeared to be readying themselves for another onslaught. When the rain ended, however, it was only the 31^st Army with renewed the attack, an then only without the commitment of the earlier assault. The Soviet artillery and air support subsided 22 September, and two days later the Soviet infantry started to break contact.

Heeresgruppe 'Mitte' had held its own through the summer campaigning season, although only by the narrowest of margins.