Aggressive patroling near Tobruk from April to October 1941

Aggressive patroling, mostly at night, was a feature of the Tobruk defense from April 1941 up until the Australians had left in late October 1941. Much of the work was done by Australians from the 9th Australian Division, but there were others as well. They included the Indians of the 18th Cavalry and the men of the King's Dragoon Guards. In mid-April, a German soldier's diary spoke of the stress and effect of attacks on the motorized infantry by night. They had taken losses and the attacks had a negative effect on morale. For example, in one night, six officers and 57 other men were captured.
Some thirteen Australian battalions were involved in defending Tobruk. They took losses as killed, wounded, and as prisoners. The German success in breaking into the perimeter resulted in 259 men being captured then, and later from the 2/24th Battalion of the 26th Brigade. The 2/23rd Battalion lost  as many as 79 men as prisoners. No other battalions lost prisoners as many as those. The 2/9th Battalion had suffered 205 men wounded. Both the 2/23rd and 2/24th Battalions had many men killed. The 2/23rd Battalion had 78 men killed while the 2/24th Battalion had 70 men killed.
In the vicinity of the Salient, when the enemy had penetrated the perimeter in a surprise attack, the area became one of the most dangerous areas of the fortress. Near the wire there was a chalk mound that they named Forbes Mound. In one incident on the night of 24-25 July 1941, six men were going after German machine gun and mortar crews. The Germans were moving in a truck to fight another Australian patrol. The Australians had been surprised to find German sangers close to the wire.
During the summer of 1941, there were no photographs from the air and the artillery depended on information gathered by patrols operating at night in enemy territory. There was a period when some successful patrols were made using carriers. In early May, a daylight raid was made with carriers. Despite being lightly armored, they were able to attack a working party and fight tanks and guns. They succeeded in returning without loss.
Because of the inshore squadron operations by the navy and the success of the anti-aircraft gunners, Tobruk was kept adequately supplied, so that there were not any extreme shortages of supplies or food. The anti-aircraft gunners had to deal with four types of air attacks. They would be hit by daytime dive bombing attacks against the harbor and installations. There were also daylight level-bombing attacks from higher altitude. The enemy would also bomb at night and would drop mines at night. Early in the siege, they would have large dive bombing raids. As the anti-aircraft defenses improved, the enemy moved to mostly night bombing raids.
Early in the defense of Tobruk, there were 16 mobile 3.7in anti-aircraft guns actually in use. There were other guns not yet available for use. There were also 40mm and 20mm Breda guns in use. They had as many as 42 of the captured Italian Breda guns. This is based on the account in Vol.III of the Australian Official History.