While General Lavarack had been commander of Cyrenaica Command, he found out through a visiting staff officer on 11 April 1941 from General Headquarters that Wavell had other plans in the works. Wavell intended to include what had been Cyrenaica Command into a new Western Desert Command. He affirmed the plan to defend Tobruk for two months. After that, he intended to go on the offensive against the Germans and Italians. General Lavarack replied with a request to get the rest of the 7th Australian Division in Tobruk to aid the defense.
Late on 10 April, General Lavarack put the 1st RTR under the control of General Morshead, but that did not amount to much since he would not be allowed to use the 1st RTR without General Lavarack's approval. 11 April 1941 was good Friday. The sandstorm that had been blowing on 10 April, earlier in the day had gradually stopped. 11 April proved to be better weather, as it was clear. Only a week had passed since the 9th Australian Division had been in contact with the Germans near Benghazi. The Australians defending the perimeter at Tobruk now had a good view of the situation. There would be the defenders on a perimeter in Tobruk, with a band of unoccupied land, with a surrounding German-Italian static line, rather World War One-like.
The Tobruk perimeter was at an elevation of 400 to 500 feet. The land was very arid. Every day, as the sun warmed the land and air, you would get a mirage effect. The only deviation was if there were clouds or dust storm. The mirages affected artillery, since guns could only be ranged by sight early or late in the day. Both sides were effected by the mirages and both Axis and British artillery would fire early and late in the day.
A system of perimeter posts were constructed. The outer line of posts were about 750 yards apart. There was a backing line that were about 500 yards apart. There was also an anti-tank ditch, but it was only partial. The uncompleted parts had concertina wire that did not seem to be very effective. This is baed on the account in Vol.III of the Australian Official History.