As a prodigious feat of engineering, the Acquedotto Pugliese had attracted a degree of international interest at the time of its construction, and a number of detailed articles were published, copies of which were sourced from the Institution of Civil Engineers, and the National Library of Wales. Much of the planning was based upon these, together with a few technical drawings, and a single pre-war photograph of the Tragino Aqueduct. Even so the information was far from complete, and most critically of all it was not known whether it had been made of masonry or reinforced concrete. Masonry was certainly the preferred material, as this would enable "X" Troop to cause considerable damage with the relatively small amount of explosive they could take with them; 2,100 lbs in total, which allowed for a generous reserve in the event of unforeseen complications and containers lost on the drop. 200 lbs was to be placed against each of the three central pillars to impose the maximum delay on the repair; the outer two could be made good relatively quickly, but the central one could not be tackled until these had been completed. If the aqueduct was found to be made of reinforced concrete, however, then such a demolition would not be possible as each pillar would require six times as much explosive, far more than could be brought to bear even if all of the containers were recovered. In this instance, "X" Troop were instructed to abandon the piers and demolish the waterway instead.
Operation Colossus presented a number of logistical difficulties and most revolved around the question of aircraft. Due to the range of the models available at the time, the raid could only sensibly be carried out from Malta. Occupying a dominant position in the central Mediterranean, the island was a vitally important base for the Royal Air Force and the Royal Navy, who used it to harass Mussolini's supply lines to North Africa, where his forces were currently being routed by the 8th Army. As a consequence of this, Malta was under siege, and would hold the unenviable distinction of being the most bombed place on Earth.
The only aircraft which had been converted to drop parachutists were the Whitleys at Ringway, but these were unsuitable as they had been stripped of not just their wireless communications but also their rear gun mountings, which were essential because, as one of the early planning reports noted, "the last two hours of a trip to Malta are in daylight and there is usually a fight." It was decided to acquire aircraft from elsewhere, with a mix of five Whitley Mk V's and four Bombays being proposed by a reluctant RAF, but as different types of aircraft would complicate the maintenance arrangements in an operation that was already complicated enough, it was decided to use eight Whitleys instead. Yet there were none in Malta at the time, and so these had to be borrowed from Bomber Command complete with their five-man crews; four each from 51 and 78 Squadrons.
As there were no Whitleys in Malta there were no mechanical spares either, and so to ensure that the aircraft remained serviceable, not only would they have to carry "X" Troop and all of their equipment which could not be acquired on the island, but they would also have to take a considerable range of spare parts and a skeleton team of RAF mechanics. This posed further problems because the distance to Malta was at the very limit of the Whitley's range, even with a following wind. In order to spread the weight, a Sunderland flying boat was drafted in to carry the maintenance crews and some of their heavy equipment, while "X" Troop and an array of lighter spares would go with the Whitleys. It was still not certain that they could make the distance, and so to be sure each aircraft had to perform an endurance flight to determine their precise fuel consumption.
"X" Troop would leave for Malta in February 1941, flying directly over Occupied France at night to minimise their chances of interception by enemy fighters. It would certainly be a dangerous flight, but if all went well the operation was scheduled to take place on the first suitable night between the 9th and 16th February. Meteorological information suggested a high likelihood of clear skies during this period, which, coupled with a favourable Moon, would make it relatively easy for the aircrews to locate the River Sele and follow its course towards the drop zone.
In the days before the operation took place it was planned to accustom the Italian air defences to the sound of British aircraft, with a few leaflet raids being carried out and bombs dropped on nearby railway junctions. The arrival of the Whitleys, therefore, would seem to herald nothing more than just another routine raid. To reinforce this impression, two of the eight aircraft involved would not carry any "X" Troop personnel but a heavy bomb load instead, whilst five of the remainder were equipped with a smaller one, and once the drop had been completed they would attack several nearby targets.
Due to the great distance and difficult terrain which lay between the aqueduct and the coast, it was highly likely that everyone would be taken prisoner, yet it was arranged for a submarine to be waiting at the mouth of the River Sele five days after the drop, returning four days later if it was known that others were still at large. To ensure that the men had sufficient energy levels to tackle the arduous terrain, a food company was approached to prepare a special ration pack, which included chocolate, raisins, hard-tack biscuits, and also pemmican; a greasy and barely edible concentrated meat extract which was a favourite of Polar expeditions. By consuming the same measure of two pounds per man each day, it was believed that this would be sufficient to keep them going for six days.