The success of Operation Colossus is difficult to classify because, while the objective of demolishing part of an important aqueduct had been achieved, the entire force had been lost, and its impact had fallen far short of the fanciful hope that it could severely impede Italy's military prospects in 1941. The aqueduct was repaired in just three days, and the reservoirs downstream were able to comfortably sustain the population with little disruption or limitation. The Italian press were naturally eager to portray the operation as a complete fiasco, declaring that the sad party of Britishers had been unable to carry out their mission and were quickly rounded up, however the Italian government recognised that they had been completely caught out and took the matter very seriously. Fearing that further raids of this nature would be made, guards were increased at identified strategic locations, and more rigorous air raid precautions were adopted which endured until Italy's surrender in September 1943.


In the immediate aftermath, the British at Malta had no idea whether the raid had been a success or failure. With all of the Martin Maryland's damaged by enemy bombing, it was not until the morning of the 12th February, 36 hours after the event, that one was able to fly over the aqueduct and take detailed photographs with a 20" lens. The results were disappointing as they were unable to show any evidence of damage to either the Tragino or Ginestra aqueducts; the effect of Paterson's demolitions probably being invisible from the air. It could only be concluded that "X" Troop had either been captured immediately on landing, or the aqueduct was found to have been constructed in a way which their equipment had no hope of damaging. The Italian press seemed to confirm the latter, but it was not until the last week of February that other reports began to drift in, first suggesting that the parachutists had damaged a bridge, and that Bari and Brindisi had been without water for several days due to an air raid, even though none had been carried out which could explain it, until at last an American journalist confirmed that the aqueduct had been blown up and had taken several days to repair.


From the point of view of the airborne troops, rather than becoming mired in trying to assess the raid as a tactical success or a strategic failure, it is perhaps more productive to think of Operation Colossus as a demonstration of what this fledgling force could achieve. Even with the very ad hoc preparations, it had proved that the Royal Air Force was capable of transporting parachutists to a distant objective and dropping them with a good degree of accuracy at night, albeit in very favourable conditions, and that these troops could retrieve their equipment and successfully carry out a substantial sabotage task.


Although much more could have been learned if "X" Troop had been dropped at an objective from which there was a good prospect of rescue, the raid nevertheless revealed a number of points which would lead to more effective operations in the future. As it was not until Lieutenant Deane-Drummond escaped in June 1942 that a clear picture emerged of what had taken place on the ground, many of these naturally revolved around aircraft, with improvements suggested for the training of the aircrews, their procedure on the run-in to the drop zone, and an overhaul of the container release mechanisms which had robbed the parachutists of 7 Thompson sub-machine guns and a sizeable proportion of their explosive.


The biggest recommendation, however, was the importance of thorough and up to date intelligence, as the information available during the preamble was very limited, resulting in a highly speculative plan. Much of which had been based on technical drawings and articles from engineering publications, yet it was not until Lieutenant Paterson got to work on the aqueduct with his chisel that it was realised that it had been made of reinforced concrete and not masonry. If this had been known at the outset then it is likely that the raid would have been abandoned altogether, as the comparatively small amount of explosive they could take was not sufficient to cause a severe delay to its repair. It was only in the hope of achieving this that "X" Troop had been committed to an operation from which they had little or no chance of escape, as their sacrifice would have been difficult to justify if the limited damage they could inflict would quickly be made good.


The only photograph of the aqueduct available to the planners was taken at the time of its construction, and it gave a good overall view of the structure but revealed little of the surrounding terrain. Attempts were made to obtain reconnaissance photographs, but in the event these only materialised on the eve of the operation, revealing buildings which had not seen before, others which were no longer there, and most alarmingly that there was not one but two aqueducts just 230 yards apart. This did not imperil the operation as the same waterway ran over both, and it was obvious enough that the larger Tragino aqueduct must be the objective, but it was an incredible oversight which demonstrates the lack of information.


The photographs gave no indication of any military presence in the area, but it was not until the first troops landed that this became certain. If the aqueduct had been guarded then the ensuing moments could have been very problematic; with aircraft overhead in an otherwise quiet valley and parachutes illuminated by the moonlight, they would surely have been seen and placed at a severe disadvantage, with their machine-guns somewhere amongst the supply containers and only their pistols and grenades to hand.


Operation Colossus may have been very far from perfect, but for a first attempt by a force that was barely six months old, pioneering an entirely new form of warfare, and dropping deep into enemy territory with a task which far exceeded the ambition of the first seaborne commando raids, it was nevertheless a remarkable start. At a time when Britain was isolated, surrounded by enemies and still threatened by invasion, it shocked the Italian government, and possibly also Hitler, to find that it was capable of taking the offensive in such an audacious manner.


The complete loss of "X" Troop had been anticipated and so this did not particularly detract from the sense of achievement felt by the 11th Special Air Service Battalion. From their point of view, the operation was a vindication of their efforts, and had demonstrated the feasibility and potential of the airborne movement to a sceptical military establishment. Before the year was out, this single experimental battalion had been radically expanded with the formation of the 1st Airborne Division.