on Malta was located right next to the only test benches. Lloyd himself said, "a few bombs on Kalafrana in the summer of 1941 would have ruined any hope of Malta ever operating an air force". Usually, the protection of air defences and naval assets on the island would have had priority. Certainly bringing in more supplies would have made greater strategic sense, before risking going on to the offensive and thus in turn risking the wrath of the enemy. But the period was an eventful one. In North Africa, the DAK was on the move and Rommel was pressing his army towards the Suez Canal and Alexandria in Egypt. RAF forces on Malta could not afford to sit idle; they could prevent Rommel's advance, or slow it down, by striking at his supply lines. Malta was the only place from where British strike aircraft could launch their attacks. Lloyd's bombers and a small flotilla of submarines were the only forces available to harass Rommel's supply lines into the autumn. Only then did the surface fleets return to Malta to support the offensive. Allied reinforcement With the exception of coal, fodder, kerosene and essential civilian supplies were such that a reserve of 8–15 months was built up. Operation Substance was particularly successful in July 1941. The supplies included spares and aircraft. Around 60 bombers and 120 Hurricanes were now available. Around 65,000 tons eventually reached Malta in July despite heavy damage inflicted by the Italian navy and air forces. No supplies were sent in August, but Operation Halberd in September 1941 brought in 85,000 tons of supplies, shipped by nine merchant vessels escorted by one aircraft carrier, five cruisers and 17 destroyers. One cargo ship, the Imperial Star was sunk, and the battleship was damaged by a torpedo. This convoy proved critical to saving Malta, as its supplies were deemed to be essential when the Germans returned in December. In mid-1941, new squadrons—No. 185 and No. 126—were formed and the defenders received the first cannon-armed Hurricane Mk IICs. Naval carriers flew in a total of 81 more fighters in April–May. By 12 May, there were 50 Hurricanes on the island. On 21 May, No. 249 Squadron RAF arrived, taking over from No. 261. 46 Squadron arrived in June, to be renumbered 126 Squadron. In May 1941, 47 Hurricanes were flown into the island. From May–December, the first Bristol Blenheim units