Other formations in Tobruk were: 32nd Army Tank Brigade with about sixty serviceable infantry tanks, mostly Valentines with a few Matilda IIs; the 201st Guards Motor Brigade with three infantry battalions, only one of which was actually a Guards unit and the 11th Indian Infantry Brigade with three battalions, one of which was a Gurkha unit and one was the experienced Queen's Own Cameron Highlanders; also attached to the brigade was a composite infantry battalion made up from various units in the 1st South African Division known as Beergroup. The Indian brigade was deployed to the east and south of the perimeter. Between these formations were three regiments of field artillery and two of medium artillery, the latter possessing sixteen 4.5-inch medium guns and sixteen 155 mm M1918 howitzers between them. In the various anti-tank batteries in Tobruk there were fifteen new 6-pounders, thirty two of the older and less effective 2-pounders and eight Bofors 37 mm anti-tank guns. The total number of anti-aircraft guns was eighteen 3.7-inch heavy and a regiment of light guns. The garrison was large in sheer numbers, but it included around 8,000 support troops and around 2,000 non-combatant labourers. The perimeter was long, and the coastline added another . Each infantry battalion had to defend a frontage of about on average and each anti-tank gun would have had to defend on average a frontage of if they had been spread evenly across the perimeter. Although many non-essential troops had been evacuated, there remained a number of administrative units under the command of a brigadier. Unnecessary shipping had also been evacuated but some small coastal vessels and a shore-based Naval Establishment were retained. The fighter aircraft of 40 Squadron SAAF had been withdrawn from the airfield within the perimeter but a forward air control unit, known as a "tentacle", remained. The combat squadrons of the DAF had been compelled to move to airfields at Sidi Barrani, which put Tobruk beyond the range of all their fighters with the exception of No. 250 Squadron RAF, which operated Curtiss Kittyhawks, able to carry drop tanks. Owing to the earlier decision not to allow Tobruk to endure another siege, little work had been done to maintain or repair its defences since its relief. In many places, the trenches and the anti-tank ditch had collapsed or filled with drifting sand and part of the ditch had been filled in to allow the British armour to deploy during the December 1941 breakout.