The Zeppelin Staaken R.VI of World War I was the largest bomber ever to strike Britain.

The name Zeppelin is usually associated with rigid lighter-than-air craft from the early 1900s through the 1930s, including the famous Graf Zeppelin and ill-fated Hindenburg. During World War I, the name was linked to giant airships employed by the Imperial German Navy to carry out nocturnal bombing missions against civilian targets in London. It’s largely forgotten that the Zeppelin firm also produced heavier-than-air craft—in fact, the largest and most technologically sophisticated airplanes to reach production during WWI. The Zeppelin Staaken R.VI was also the largest bomber ever to attack Britain, bigger than any used by the Luftwaffe for that purpose in World War II.

The story of Zeppelin’s foray into development of very large airplanes began in 1913, when Britain’s Daily Mail offered a £10,000 prize for the first airplane to fly across the Atlantic Ocean. German pilot Helmuth Hirth persuaded the head of the Robert Bosche Werke to finance the construction of a plane in which he could cross the Atlantic and continue on to the 1915 San Francisco World’s Fair. War put an end to Hirth’s plans, but the aircraft concept being developed for him attracted several German manufacturers to initiate designs along similar lines. After the appearance in 1915 of the Russian Sikorsky Ilya Muromets four-engine reconnaissance planes, with their long range and bombing capabilities, development proceeded in earnest, with bombing as the primary purpose.

A great number of Riesenflugzeuge (giant airplanes), also known as “R-planes,” were built by a surprising number of German companies, in a variety of configurations. All had multiple engines and were far larger than conventional twin-engine aircraft of the day. The R-planes’ extremely long range, combined with the limited reliability expected from engines of that period, meant the power plants had to be accessible for in-flight maintenance.

Not least among the Germans to become interested in R-planes was Ferdinand Graf von Zeppelin, head of Luftschiffbau Zeppelin GmbH. Until that time Zeppelin had built only airships, and had no experience in airplane construction. After Hirth’s giant transatlantic plane was canceled, however, Zeppelin persuaded Bosche to give the engineers who had been working on that project a leave of absence to begin work on a multiengine bomber for his firm instead. Since Zeppelin had no facilities for airplane construction, and given that his own works were fully occupied producing airships, in September 1914 Zeppelin and Bosche jointly funded a new company to build the giant planes, Versuchsbau GmbH at Gotha-Ost. VGO would build the first three of Zeppelin’s R-plane prototypes.

Aiming to locate its manufacturing facilities beyond the enemy’s reach, during 1916 the company established a new factory at Staaken, near Berlin, where all subsequent Zeppelin R-planes were developed. A total of 34 would be built during WWI, but just one variant, the R.VI, was put into series production. Of the 18 of those built, only six were actually manufactured at Staaken, the remainder built under license by Aviatik, Schütte-Lanz and Albatros.

Constructed mainly of wood and fabric, the Zeppelin Staaken R.VI was enormous by WWI standards, and would still be considered huge today. A biplane with a wingspan of 138 feet 5 inches and a length of 72 feet 6 inches, it weighed 25,500 pounds fully loaded, including a disposable load of 3,969 pounds. It had a top speed of 84 mph, took 35 minutes to climb to 9,843 feet and could stay in the air for seven to 10 hours, though its maximum range was only 497 miles.

The R.VI carried a crew of seven to nine, and included nose, dorsal and belly defensive gun positions. Some aircraft also had two additional gun positions atop the upper wings, manned by the engine mechanics. Unusual for an airplane of its day, the R.VI featured an enclosed cabin for the two pilots, navigator and radio operator, although the gun positions were exposed to the elements.

Unlike earlier Zeppelin R-planes, which mounted three or four engines between the wings and two in the nose, geared to drive a single propeller, the R.VI was simply powered by four—either 245-hp Maybach Mb IV or 260-hp Mercedes D IVa 6-cylinder, inline, water-cooled engines, installed in tandem nacelles between the wings, one as a tractor and one as a pusher. The R.VI’s engines were equipped with self-starters, another unusual feature for the time. Situated between the two engines in each nacelle was a cockpit for a mechanic, who climbed a ladder to reach his upper-wing gun position.

Two Riesenflugzeug Abteilingen (giantairplane detachments), Rfa 500 and Rfa 501, operated the Zeppelin R.VIs, first on the Eastern Front and then, beginning in September 1917, against Britain. On the Western Front, most R.VI bombing missions targeted London, though they were sometimes carried out against Paris and other French cities as well. The 60,000 pounds of ordnance they dropped on Britain included 2,204-pound bombs, the largest ever dropped operationally during WWI. One of those bombs struck the Chelsea Hospital.

Since all the missions were at night, it’s worth noting the means R.VI crews employed to navigate to and from targets. While the R-planes carried no electronic navigation equipment, they were equipped with telegraphic radio transceivers. The plane’s radio operator transmitted signals that were received by direction-finding stations in German-occupied territory, which in turn fixed the plane’s position and then radioed that information back to the operator. It was a clumsy and backhanded form of radio direction-finding, but it worked well enough to enable the R-plane crews to find their way to London and—usually—return.

As one might imagine with very large aircraft that lacked power-assisted controls, piloting the R.VI was physically demanding. Small wonder, then, that no fewer than eight of the 18 R.VIs are known to have crashed for reasons other than enemy action. Only three were confirmed as combat losses. One was felled over French lines by anti-aircraft fire on the night of June 1, 1918, becoming the first R.VI to be examined by the Allies. Another was shot down over Beugny, France, on the night of September 15-16, 1918, by a Sopwith Camel flown by Lieutenant Frank Broome of No. 151 Squadron, the Royal Air Force’s first night intruder unit—the only R.VI known to have been downed by an enemy aircraft. After the war, a third R.VI was shot down by Polish border troops during a clandestine diplomatic flight between the Ukraine and Germany in August 1919.

In its time, the R.VI was a magnificent achievement. Looking back, however, Germany’s ambitious R- plane program must be adjudged a failure. Considering the tactical and strategic results these enormous airplanes achieved against the investment it took to produce them, it seems likely Germany could have reaped a much greater benefit from building a larger number of normal-sized aircraft. Given the vast resources expended, in the long run the R-plane program benefited the Allied cause far more than it did Germany’s.

 

Originally published in the September 2014 issue of Aviation History. To subscribe, click here.