A 1930s U-2

In the early 1930s, Great Britain’s independent Royal Air Force still had as its main mission policing the British Empire, while its original raison d’être, as a strategic bombing force, remained mainly theoretical.

The RAF was so committed to this mission that as late as 1934 it issued a call for a new general purpose biplane for the role of, among other things, strategic bombing, even though it was clear the monoplane was the aircraft of the future.
The Vickers Aircraft Corporation offered a biplane but at the same time also presented a private venture monoplane for the mission. The monoplane’s performance was so superior that it was ordered into production and dubbed the Wellesley.

In fact, despite the modest requirements, the Wellesley was a most innovative aircraft, both in appearance and under the skin. It was quite awkward looking – a large, low wing, single engine monoplane with a U-2 like high aspect wing (that is, long and thin) with a length/width ratio of 9-to-1, which gave it a service ceiling of more than 33,000 feet (very high for the time). It was modestly powered by a 950 horsepower radial engine, had manually retractable landing gear and the crew of two had separate canopies, with the rear crew member serving as the radio operator/navigator and manning the single .303 defensive machine gun.

The Wellesley’s most unusual feature was under its skin. The aircraft had been designed by the British aeronautical engineer Barnes Wallis, who was to later design a whole series of unique bombs, including those used by the “Dam Busters” (more of this later).

Wallace had originally been an airship designer and decided to build the Wellesley’s fuselage based on the metal lattice framework he had used for his airship.
Wallace called the design “geodesic” and he expected that the frame, which would be fabric covered, would be both light and very strong.

Ironically, this basic framework design used by Wallace was first used in the controversial late 1700s design of U.S. Navy frigates by Joshua Humphreys, who used 12 diagonal riders to provide structural strength for the hull. The design proved so strong it allowed U.S. Navy frigates to dominate English frigates in the War of 1812.

The problem with the geodesic fuselage, at least initially, was it could not have bomb bay doors because it was feared such doors would weaken the lattice work of the fuselage. This was awkward, since the Wellesley was expected to operate as a bomber and had to be overcome by mounting a flat bomb dispenser under each wing. While the Wellesley could carry up to 2,000 pounds of bombs, the dispenser could not fit a bomb larger than 100 pounds.

The RAF received its first Wellesley in April 1937, but by then the German Luftwaffe was being equipped with modern fighters and it was clear the Wellesley would be inadequate for European combat missions. Nevertheless, it equipped six RAF Bomber Command squadrons until the RAF could re-equip them with more modern aircraft in 1939.

The Wellesley did find a role as a reconnaissance aircraft, where its long, thin wings made it ideal for long range, high altitude missions. With large external fuel tanks in palace of the bomb dispensers and an additional crew member, three Wellesleys flew non-stop more than  7,000 miles from Egypt to Australia, a record that lasted until late 1945.

When World War II began, the obsolete Wellesleys were moved out of harm’s way to Egypt. When Italy declared war on England in June 1940, the Wellesleys began a series of raids against Italian bases in East Africa. But when Italian fighters arrived, even thought they were old CR. 42 biplanes, the Wellesleys were so vulnerable they were withdrawn from bombing missions. They then reverted to long range, high altitude reconnaissance missions where their  high service ceiling made in invulnerable to Italian interceptors until it was removed from service in 1942.

The Wellesley proved that Wallace’s geodesic fuselage was viable, and he incorporated it into the Wellington bomber, which was a mainstay of the RAF bombing operations through 1943 as well as antisubmarine operations.

The Wellington proved to be highly resistant to battle damage, as Wallace had predicted, but in the end the geodesic fuselage was too labor intensive for mass production and, after a failed follow-on the Wellington, the method was dropped.

(For questions or comments, contact Dr. Michel at arshall.michel@ramstein.af.mil.)