In addition to individual tanks whole companies of fresh men and machines came in and 5th Panzer Regiment of 21st Panzer Division which in February had had less than 70 panzers, had, by the end of April, been reinforced to a strength of 165, an establishment which the regiment had never had before nor would ever reach again. There was still a shortage of soft-skinned vehicles so that some units had only 60 of their official strength of 400 trucks. There were 12,000 men fewer than establishment for the whole of the Africa Corps, whose total strength, including supply troops for rear elements, was only 36,000 all ranks, the most acute shortage being in infantry.
Rommel then began to prepare the men of his command for the battle ahead. During May individual training gave place to company schemes and to collaboration with armour both by day and night. Special emphasis was laid on attacking prepared positions and permanent fortifications. Storm troop units were formed and these worked with combat engineers and tanks so that all-arm co-operation would be at a high peak of efficiency when the attack went in. By the end of May there were large-scale, divisional manoeuvres.
The 21st Panzer Division had been carrying out extensive patrol activity against severe British opposition and then the whole Africa Corps advanced into 'no man's land' at the south-eastern corner of Cyrenaica. This move fulfilled the purposes of thickening the battle line, of providing the maximum strength should 8th Army attack, and, lastly, of forming a firm jumping-off point for the panzers in the forthcoming battle. Officers were taken on secret reconnaissances to familiarise them with the terrain over which they would be fighting, forward fuel depots were, built up, and slowly, so as not to arouse suspicion, the number of shells fired was reduced to allow stocks to be gathered. On 12 May Rommel briefed the divisional commanders and then began the last minute preparations; traffic control points were established and the second echelon details sent back. To equip the fighting troops, orders were issued that all weapons, including those in training establishments and detachments, were to be handed in. The Africa Corps had girded itself for battle.
The 8th Army's defensive positions at Gazala stretched from the sea to Bir Hachim, a distance of some 45 miles and along the length of this very strong line defensive positions, known as boxes, had been laid out. These were usually sited on high or broken ground and capable of all round defence. They were intended mutually to be supporting and each of them had a strong garrison usually of brigade or equivalent establishment. To the west, that is the enemy side, lay extensive mine-fields of considerable depth and, in some areas, this sea of mines had been laid down on the eastern or 'friendly' side of the boxes.
To hold the forward, static defences Ritchie, 8th Army commander, put in 13 Corps. In the north, at Gazala, was 1st South African Division, then to the south 50th Infantry Division and 3000 men of 1st Free French Brigade holding the left flank box at Bir Hachim. This left wing was extended and strengthened by putting into a hastily prepared box, south-east of Bir Hachim. the newly arrived 3rd Indian Motor Brigade. At certain strategically important points along the southern flank and extending eastwards there were other boxes of which Knightsbridge, held by 22nd Guards Brigade, and El Adem were the most important. Behind the infantry boxes to give immediate support were 1st and 32nd Army Tank Brigades and behind this, located west and south of Tobruk, was the armoured mass of 8th Army, formed into 30 Corps. The 1st Armoured Division lay aside the Trigh Capuzzo and controlled the central sector while 7th Armoured Division was positioned farther south to deal with any threat from the direction of Bir Hachim.
The strengths of the two armies gave the British superiority. In armour there were 742 British tanks to 360 German and 210 Italian. In artillery there was a three to two superiority - 500 to 350 - a seven to five superiority in aircraft - 700 to 500 - and a larger number of men - 125,000 to 113,000.
The German commander-in-chief was faced with the choices of a frontal assault which would not only have robbed him of the element of surprise but would have allowed the mass of British armour to concentrate against him. The second alternative was to drive round the open flank at Bir Hachim and by a pincer operation from east and west of the Gazala position destroy 8th Army in the field. Rommel chose the second plan which had the advantages that the element of surprise would be maintained and that a successful assauh would divide the British Army in two and separate the infantry from its armour. The divisions holding the boxes in the Gazala position would not be able to release men to aid their comrades farther back because their whole attention would be needed to defend the western mine-fields. Neither could the Tobruk garrison spare forces and reduce its strength for then the town migh: fall to a coup de main.
Rommel's battle plan was for a diversionary attack to be mounted upon the northern, Gazala sector by X and XXI Italian Corps together with the non-motorised brigade of 90th Light Division. This force, known as CrüweL Group, would attack during the afternoon of 26 May and its aggressive moves were to hide the main thrust and to convince the British that the mass of German troops were on the northern sector. Instead, these would be concentrated in a second, mobile group. This would comprise the Africa Corps and the Italian XX (Motorised) Corps which, led by Rommel, would sweep round and behind the southern flank of 8th Army. Part of this group would strike northwards via Acroma and attain the coast thereby cutting off from the main of 8th Army the divisions in the Gazala sector. A pincer movement going in with the Crüwell Group from the west would then destroy the British and South African divisions.
Another part of the outflanking group would strike the British positions along the Gazala line in the back and to protect the flanks of this and the northern advance the motorised elements of 90th Light Division together with the reconnaissance battalions would drive eastwards towards El Adem and threaten Tobruk. [13]
The final preparations had been made. The routes forward had been marked with lamps, stores depots had been filled, a seven-day ration of food and water issued to all ranks, and, to aid in the deception plan, decoy convoys were sent out in the direction of Crüwell Group. The most difficult move in the opening stages of the operation would be the night drive by the outflanking force. This would be made over a vast distance and through unreconnoitred country by two Corps, neither of whom had even carried out such a manoeuvre at divisional level. Special measures were taken to ensure that distance and direction were maintained. The convoys were to move at exactly regulated speeds, 8 miles per hour in bright moonlight, on compass bearings which had been precisely worked out and the Luftwaffe was to drop flares throughout the night over the French held positions at Bir Hachim.
During the afternoon, with their movements hidden by the veil of a sandstorm, the divisions of the outflanking force moved to a point some 13 miles south-east of Rotondo Segnali there to rest and to refuel. At 17.00hrs on 26 May, the code 'Venice' was flashed; the battle for the Gazala line was on.
The attacks by Crüwell Group produced no reaction from the British. The Italian assault had been so weak and had been so well concealed by the khamsin that the 50th Division's boxes had not been aware that the attacks had taken place. At last light the fighting died down on the northern flank and Axis attention was directed southwards to where the outflanking group was marching through a brightly moqnlit light towards Bir Hachim. A short distance ahead of the main body were the advanced guards of 15th Panzer Division followed by the 'boxes' of the panzer regiment, the artillery and divisional headquarters, the motorised infantry, engineers, anti-tank, and other services. Between the two panzer blocks of 15th and 21st Divisions marched Corps headquarters. When it is considered that a panzer division's vehicles on the move covered an area of 11 square miles then it is possible to gain an idea of the impressive might of the Africa Corps and the Italian Corps as the divisions moved towards the British flank.