O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Friedrichshafen FF 60
   Powered with, four 160 h.p. Mercedes D III engines, the FF 60 was a giant experimental triplane, built during 1918, and carried a crew of four. Intended for long-range patrol duties, a defensive armament of three to four Parabellum machine-guns was carried.

J.Herris Friedrichshafen Aircraft of WWI (A Centennial Perspective on Great War Airplanes 21)

Friedrichshafen FF60

   Friedrichshafen's FF60 was the most unusual floatplane the company built, being a large triplane intended to be seaworthy to Sea State 4. The FF60 had four 170 hp Mercedes D.IIIa engines and was designed for long-range maritime reconnaissance. Despite its unusual configuration, its structure was the conventional wire-braced wood covered by fabric construction used by Friedrichshafen for all of its aircraft.
   The FF60 carried a crew of four. Defensive armament of this large aircraft consisted of three flexible Parabellum machine guns, and it could carry 1,000 kg of bombs.
   Three FF60 aircraft, Marine Numbers 3301-3303, were ordered although as far as is known, only one FF60, likely MN 3301, was finished. Completed just as the war ended, the first flight of the FF60 was in November 1918.

Friedrichshafen FF60 Specifications
Engine: 4x170 hp Mercedes D.IIIa
Wing: Span Upper 27.00 m
Area 235.0 m2
General: Height 8.25 m
Empty Weight 4,875 kg
Loaded Weight 7,342 kg
Maximum Speed: 140 km/h