'Colossus' was a British airborne operation to destroy the aqueduct at Tragino in southern Italy (10/11 February 1941).

Largely experimental, this undertaking was the first airborne operation undertaken by the British. The UK established its airborne arm on 22 June 1940 on the instruction of Prime Minister Winston Churchill, who had been greatly impressed by the success and daring of the airborne operations undertaken by the Germans in 'Weserübung' and 'Gelb', and now directed the War Office to look into the feasibility of establishing a 5,000-man airborne force in the shortest possible time. Although a training programme began almost immediately, a shortage of proper equipment and training facilities, as well as bureaucratic difficulties, meant that in the short term only a small number of volunteers could be trained as parachute troops. The first airborne unit to be formed was a re-trained commando unit, No. 2 Commando, which became No. 11 Special Air Service Battalion and comprised some 350 officers and other ranks by September 1940. The battalion finished its training in December 1940, and in February 1941 some 38 members of the battalion, known as X Troop, were selected to conduct an airborne operation intended to test the British airborne capability as well as the ability of the Royal Air Force to deliver such forces with the accuracy needed for effective military undertakings.

The target chosen for 'Colossus' was the aqueduct, near Calitri in southern Italy, which supplied fresh water to a large part of the local Italian population as well as several ports used by the Italian military, and thereby hamper efforts to supply the Italian forces in North Africa and Greece. The 38 British paratroopers were delivered by converted Armstrong Whitworth Whitley twin-engined medium bombers to the target on 10 February, but equipment failures and navigational errors meant that a significant portion of the required explosives, as well as a team of Royal Engineers, landed in the wrong area. Despite this setback the remaining members of the troop destroyed the aqueduct and withdrew from the area, but were all captured in short order by the Italians. An Italian translator was tortured and executed and one paratrooper managed to escape captivity, but the rest remained as prisoners of war. The aqueduct was rapidly repaired before local water reserves ran out, ensuring that the neither the ports nor the population were deprived of water. The operation was nonetheless a boost to the morale of the new British airborne arm, and the mission’s technical and operational lessons aided in the development of further airborne operations.

The British decision to follow the German lead and establish an airborne arm, based on glider-borne as well as parachute-landed troops, led eventually to the creation of two airborne divisions and a number of smaller units. In the short term, however, there were numerous problems to be overcome. These included the fact that there were very few gliders in the UK during 1940, and these were too light and small for military purposes, and also a shortage of aircraft suitable for the towing of gliders and the carriage of paratroopers. On 10 August, Churchill was informed that although 3,500 volunteers had been selected to train as airborne troops, only 500 could currently begin training for lack of adequate equipment and aircraft.

A training establishment for parachute troops was established at RAF Ringway near Manchester in June 1940 as the Central Landing Establishment, and the initial 500 volunteers began their training. The RAF provided a number of Whitley medium bombers for conversion into paratrooper transport aircraft. Specialised military gliders were also designed, starting with the General Aircraft Hotspur, but gliders were not used operationally by the British until 'Freshman' in 1942.

Organisational plans were also drafted, the War Office calling for two parachute brigades to be operational by 1943. However, the immediate development of the airborne arm, in terms of numbers of men and the formations which were to use them, was hampered by three problems. Firstly, in the light of the threat of the German 'Seelöwe' invasion in 1940, many War Office officials and senior army officers did not believe that sufficient men could be spared from the effort to rebuild the army after the Battle of France to create an effective airborne force. Many officials and officers also firmly believed that such a force would have only a nuisance value as raiders, and could not materially affect the course of the war in any useful way. Secondly, there were material problems: all three British armed forces, most especially the army, were expanding and rebuilding, and British industry had not yet been organised onto a war footing sufficient to support all three services as well as the fledgling airborne force. Thirdly, there was no single coherent organisational and operational doctrine about the manner in which the new airborne arm should be organised, or whether its should come under the command of the army or the RAF. In fact, inter-service rivalry between the War Office and Air Ministry was a major factor in delaying the expansion of the airborne arm.

On 26 April 1941, the airborne force which the UK currently possessed was displayed to Churchill, who was informed that although some 800 parachute troops had been trained, their deployment was severely limited by the lack of suitable transport aircraft. The primary airborne unit in existence by this time was No. 11 Special Air Service Battalion. When this began it conversion from the commando role to the airborne role in June 1940, it had a strength of some 500 men, but this figure had been reduced to 342 men (21 officers and 321 other ranks) by September 1940: despite the fact that they had already rigorous training, many of the commandos failed their airborne training by refusing to make a parachute drop. One senior RAF officer at the Central Landing Establishment believed that many who refused were affected by a combination of inexperience and the fear that their parachutes would not open when they jumped. On 21 November 1940 No. 2 Commando was officially redesignated as No. 11 Special Air Service Battalion and reorganized with a battalion headquarters, one parachute wing and one glider wing. By 17 December the battalion had officially completed its parachute training, including taking part in a number of demonstrations for military observers, and was considered to be ready for active duty.

There were still only very limited airborne resources available to the British army by mid-1941. The only unit operationally available was No. 11 Special Air Service Battalion, there were very few transport aircraft suitable for employment in the airborne role, there were few RAF crews with experience of parachute droppings and none at all with operational experience, and there were no overseas facilities able to provide for airborne operations. Even so, it had been decided that and airborne operation would have to be carried out for two reasons: firstly, a successful raid would demonstrate to the rest of the world that the UK was still a power with which to be reckoned and, secondly, a raid would test the fighting ability of the sole battalion and its equipment and also the capability of the RAF to deliver paratroopers in an accurate and timely fashion.

The target chosen for the operation was the aqueduct over the Tragino river in the Campania province of southern Italy near Calitri. This aqueduct provided most of the fresh water needed by the province of Apulia, which had a civilian population of about two million persons and included the strategically important port and naval base of Taranto. The aqueduct was far enough from the coast that a seaborne raiding party could in all probability not reach it, and was believed to be too sturdily constructed for destruction by aerial bombing. Almost be default, therefore, an airborne raid was seen to be the ideal way to destroy the aqueduct.

A force of seven officers and 31 other ranks was selected from the battalion and designated X Troop, which was commanded by Major T. A. G. Pritchard. Three Italian-speaking interpreters attached to the troop for the operation were Squadron Leader Lucky, Rifleman Nasri and Fortunato Picchi, the last a civilian waiter at the Savoy Hotel. Training for the operation began in January 1941 and lasted for six weeks, which was the time needed for six Whitley bombers to be converted to drop paratroopers. A full-scale model of the aqueduct was built early in February to allow the men to practice their attack, and during training one enlisted man was killed when he parachuted into an ice-covered pond and drowned before he could be rescued.

The operational plan called for six Whitley aircraft of No. 91 Squadron to transport X Troop from Malta to the target area on 10 February as another two bombers carried out a diversionary raid in the railway marshalling yards at Foggia, some 60 miles (100 km) to the north of the aqueduct. The aircraft were to drop the paratroopers at 21.30, and after landing, regrouping and destroying the aqueduct the paratroopers were to march some 50 miles (80 km) to the coast, where the submarine Triumph would collect them during the night of 15 February from the mouth of the Sele river.

On 7 February X Troop boarded the Whitley aircraft and were flown 1,600 miles (2575 km) to Malta without incident despite the fact that much of the journey had to be made over German-occupied France. In Malta the paratroopers were briefed with aerial reconnaissance photographs of the objective taken by aircraft of the Photographic Reconnaissance Unit. The photographs revealed that there were in fact two aqueducts in the area, one large and the other small. After a brief discussion it was decided that it was to be the larger of the two aqueducts which would be attacked.

At 18.30 on 10 February the Whitley aircraft took off from Malta, each carrying one officer and five other ranks of X Troop. The approach flight was uneventful, with clear weather and perfect visibility. The lead Whitley reached the drop zone, which was about 550 yards (505 m) from the aqueduct, at 21.42. All six men and their equipment containers landed within 275 yards (250 m) of the intended drop zone, as did the men from the next four aircraft. Two of the aircraft could not drop their containers, however, as their release mechanisms had been frozen. The sixth aeroplane could not find the drop zone and dropped its six men and containers two hours later in a valley 2 miles (3.2 km) from the aqueduct. These six men were the Royal Engineer team which was supposed to rig the aqueduct for demolition, and their Whitley had been carrying most of the explosives to be used in the operation.

Despite these losses, the troop gathered the remaining containers and took up positions around the aqueduct. Only at this point, however, was it discovered that the aqueduct’s piers were built of reinforced concrete and not brick, as had been expected, leading Pritchard to suspect that the remaining explosives might be insufficient to demolish the aqueduct. After closer inspection, Pritchard ordered that the majority of the explosives be placed around the western pier and the rest against its abutment, in the hope that this would cause enough damage to destroy the aqueduct. A small quantity of explosive was also placed under a nearby bridge over the Ginestra river.

The explosives were detonated at 00.30 on 11 February, and destroyed the western pier. This caused the aqueduct to crumble and effectively break in half, and the Ginestra bridge was also successfully destroyed. Leaving one man, who had broken his ankle as he landed, at a nearby farm, the rest of X Troop pulled our at 01.00, dividing into three groups and heading toward the coast. Each of the groups moved as speedily as it could, but all had been captured within a few hours of the aqueduct being demolished. The group commanded by Pritchard was spotted by a farmer who raised the alarm at a nearby village, whereupon a local carabinieri unit surrounded the group: heavily outnumbered and with little ammunition, Pritchard decided to surrender. The other three groups, including the six sappers who had landed 2 miles (3.2 km) from the objective, fared only slightly better. The two groups from the aqueduct were soon located by Italian soldiers and ambushed, and surrendered after brief firefights. The third group was found by civilians as it moved toward the coast ands, after trying unsuccessfully to bluff their way past by claiming to be German soldiers on a special field exercise, the men were captured by carabinieri. The military personnel were transported to Naples, but Picchi was handed over to Fascist paramilitary Blackshirts, who tortured and then executed him.

Even if any of the groups had managed to make their way to the coast and the rendezvous point, they would not have been collected by the appointed submarine. One of the two Whitley bombers flying the diversionary raid to Foggia had suffered engine trouble after bombing the marshalling yards, and the pilot radioed Malta to report that he was ditching in the mouth of the Sele river. Fearing that the message had been monitored by the Italians and that the submarine might therefore sail into a trap, senior officers decided not to send the boat to the rendezvous point.

The destruction of the aqueduct had only the most negligible effect on the Italian war effort, and did not create a serious interruption to the water supplies of Taranto and other ports. The operation did cause alarm in the Italian population, however, and caused the Italians to introduce stringent new air raid precautions.

Even so, lessons learned from an analysis of the operation provided the British with valuable operational and technical experience that helped shape future airborne operations. The undertaking had demonstrated the range and versatility of airborne troops, proved that these could indeed pose a threat to the Axis powers, and provided a useful fillip to the morale of the British military in general and the fledgling airborne arm in particular. In terms of technical experience, it was found that the containers used to drop equipment for the troop were manufactured from a soft-skinned material, which sagged during flight and could prevent the opening of weapons bay doors, so from this time on containers were constructed from metal to prevent this problem.

All but one of the surviving members of X Troop remained prisoners of war until they were repatriated after Italy’s surrender in September 1943. The single exception was Lieutenant Anthony Deane-Drummond, who had escaped after being captured and eventually returned to England in 1942, joining the newly formed 1^st Airborne Division.

When the British airborne arm was expanded, No. 11 Special Air Service Battalion was renamed as the 1^st Parachute Battalion, and eventually formed the nucleus of the 1^st Parachute Brigade when this was created in September 1941.