The Siemens-Schuckert R.VIII was a mammoth biplane aircraft design intended as a heavy bomber for the German Air Service during World War 1 (1914-1918). Work began as early as 1916 but progress proved slow and only one airframe was wholly complete by the end of the war - a second example lay partially finished. For its time, the R.VIII was the largest complete aircraft anywhere in the world. The first prototype actually entered ground trials in early 1919 but was undone in by a gearbox failure as well as the restrictions imposed on German war-making capabilities through the Treaty of Versailles. No more work on the type was done.
As completed, the R.VIII showcased a crew of at least eight to manage piloting, engine repairs, and defensive machine gun positions. Its length was 70 feet, 10 inches with a wingspan of 157 feet, 6 inches, and height of 24 feet, 3 inches. Empty weight was listed at 23,100lbs with a gross weight in the vicinity of 35,000lbs. Power was through 6 x Basse und Selve BuS.IVa 6-cylinder, water-cooled, inline piston engines developing 300 horsepower each. The engines were arranged in a unique formation with two as "puller" units and the remaining four as "pusher" units. The actual powerplants resided within the fuselage so as to provide easier access for the in-flight mechanics to which drive shafts managed the externally-mounted propeller units. Performance estimates included a maximum speed of 78 miles per hour with a range of 560 miles and a service ceiling of 13,125 feet.
It can be assumed that, as a military bomber, the R.VIII would have been outfitted with a network of machine guns for local defense. Machine guns were have been perched at the nose, on the dorsal spine aft of the upper wing unit, over the upper wing unit, and at a rear ventral position. Its actual bombload remained unknown though, for its size and deep fuselage, it would have packed quite a load when compared to the largest German Air Service bombers of the war.
Externally, the aircraft managed a typical configuration of the time utilizing a wide-spanning biplane wing arrangement made up of an upper and lower wing mainplane. At least six bays were used in the wing structure that featured parallel struts and applicable cabling for support and controlling. The fuselage was of a deep-hulled design and the tail sported a three-vertical-finned biplane wing. As with other aircraft of the period, its undercarriage was wheeled and not retractable. The tail was supported by its own wheel unit.