Project Zveno

In the early 1930's, a Russian aviation pioneer called Vladimir Sergeevich Vakhmistrov finally went ahead and built that most elusive of aircraft, the airborne aircraft carrier. Lots of people had dreamt of airborne carriers before (and since), but no one else has ever actually made one, at least not one that actually worked! Vakhmistrov not only made one, he made several, and some of these even fought in action against the Germans in World War Two, and despite their age and eccentric design were not unsuccessful.

So what exactly is an airborne aircraft carrier? In this case, its a huge four engined Tupolev TB1 bomber, with two, three, or even five fighters strapped to it or later, as Vakhmistrov developed his idea, a Tupolev TB3 bomber mothership with the parasite fighters being either Tupolev I-4's or later, the popular Polikarpov I-16's.

The whole project was called 'Zveno', which means 'Chain link' and you can see on the images just how unweildy this idea was. It gained enough initial support in the Soviet Union however (where no small amount of crazy aircraft designs were eagerly pursued) to develop beyond several variations, eventually culminating in the Zveno-SPB series which saw action in Stalingrad in 1942. The fighters were by then outdated so instead of being interceptors they were used as dive bombers. The advantage for the I-16s was clear. By themselves they had a maximum take off payload of 100kg but strapped to a Zveno-SPB they could carry two FAB-250 high explosive bombs and increase their combat range by 80%. Each Zveno-SPB could carry three parasite planes which would deliver their bombs to the target then act as ordinary fighters there after.

The most successful attack by the SPB squadron came in 1941, when repeated attacks with conventional bombers had failed, three SPB's were deployed to destroy the King Carol bridge of the River Danube over which passed the important Pliesti-Constanta oil pipeline. Two attacks were required, and the fighters carried external fuel tanks to give them additional range. The bridge and the pipeline were severed and the missions were a success. German Field-Marshal, Erich von Manstein would later write in his memoirs that the final loss of Stalingrad hinged on the Russians bombing the bridges over the Danube and Dniepr rivers in August 1941. Shortly there after the squadron was expanded to five motherships and fifteen fighters, but eventually the spare parts for the big TB3's became too hard to manufacture and like all such eccentricities the Zveno project met the implacable application of practicality and was abandoned.

Looking back on this project, its hard to imagine it as high tech. Even without the handicap of hindsight it appears to have been a particularly low tech, yet effective approach to the idea of the airborne aircraft carrier. It could be that the lack of any stylistic approach was a hall mark of Russian engineering, later Soviet aviation projects also have this same blatent disregard for aesthetics, but when one considers the beauty of the USS Akron airborne aircraft carrier and compare it to the Zveno, one must conclude that, in this instance, the uglier of the two designs was by far the most effective.

Modelling the Zveno