| R.IV | |
|---|---|
 | |
| General information | |
| Type | Heavy bomber |
| National origin | Germany |
| Manufacturer | Zeppelin-Staaken |
| Primary user | Imperial German Army Air Service |
| Number built | 1 |
| History | |
| First flight | 16 August 1916 |
| Developed from | Zeppelin-Staaken VGO.I Zeppelin-Staaken VGO.II Zeppelin-Staaken VGO.III |
TheZeppelin-Staaken R.IV was a heavy bomber built in Germany in 1916 and which saw service during World War I, briefly on theEastern Front and then more extensively on theWestern Front until the end of the war. Built to the Imperial German Army'sRiesenflugzeuge ("giant aircraft") specification, it was the first such design by Zeppelin-Staaken to receive the "R" designation.[1]
The R.IV was based on its VGO.I, VGO.II, and VGO.III predecessors.[2][3] It shared their wing design, albeit with the dihedral on the lower wing reduced from 3° to 1.5°.[4] Its biplane tail unit was similar to that of the VGO.II and VGO.III, but was raised so that the lower of the two horizontal stabilisers was mounted on top of the fuselage instead of beneath it.[4][3]
Overall, it was a four-bay, equal-span biplane with slightly negative wing stagger.[5] Of mostly conventional configuration it diverged most noticeably from the designs of the day not only by its size, but by its biplane horizontal stabilisers, its two fins, and its tricycle undercarriage.[6] Its two pilots sat in an open cockpit.[7]
It adopted the innovative coupled-engine design of the VGO.III, which featured pairs of engines combined by gearboxes and clutches.[2][3] One pair, in the nose, drove a tractor propeller, and two pairs in nacelles in the interplane gaps drove pusher propellers.[2][3] The power of each pair was combined by a gearbox and clutch to turn a single propeller, meaning that if one of the pair failed, it could be disengaged so that the surviving engine could continue to provide power.[8][9]
The fuselage included a bomb bay large enough to carry a 1,000-kilogram (2,200 lb) bomb.[5] As defensive armament, the R.IV carried two machine guns in the fuselage, one firing upward and the other downward, plus a machine gun in the front of each engine nacelle.[4] It also featured gunners' platforms on the top wing, above the engine nacelles.[3][4] These were accessible in flight via a ladder and offered a 360° field of fire around the aircraft.[3][4]
Like its predecessors, construction of the R.IV began at Versuchsbau Gotha-Ost (VGO), a division ofGothaer Waggonfabrik, in February 1916.[2][3] However, during that year, production of airships by the Zeppelin company was relocated fromFriedrichshafen toStaaken to distance the construction facilities from the increasing reach of strategic bombing by the Allies.[10][3] Its first flight was made on 16 August 1916.[3] VGO personnel had begun to transfer to Staaken on 15 June,[10] and by the time the R.IV had completed its test flights, the migration was complete.[2] The aircraft was given theIdflieg serial R.12/15.[2][3]
The R.IV was accepted by theImperial German Army Air Service on 5 May 1917,[11][12] and on 12 June was assiged toRfa 500 (Riesenflugzeugabteilung, "giant aeroplane unit") atAuce.[11][12] There, it participated in raids onValmiera (28/29 June) andSaaremaa (8/9 July).[11]
In late July, the aircraft was redeployed toRfa 501 nearGhent.[11][12] From there, until the end of the war, the R.IV dropped 25,000 kilograms (55,000 lb) of bombs on London,Chelmsford,Thames Estuary,Calais,Morville,Boulogne,Étaples,Le Havre,Gravelines,Deauville, andDoullens.[11] During a raid on London on the night of 16/17 February 1918, the R.IV survived a collision with aballoon apron stretched between theWoolwich Works and theWest India Docks with only very minor damage.[13][11]
The R.IV survived the war and was publicly displayed inKassel and other German cities in 1919.[11]
Data from Kroschel & Stützer 1994, p.151, and as noted
General characteristics
Performance
Armament