G.Haddow, P.Grosz The German Giants (Putnam)

Daimler R.I and R.II

   In the summer of 1915 the Daimler-Motoren-Gesellschaft A.G., manufacturers of the famous Mercedes engine, formed an aircraft construction division with hangars located at the airfield in Sindelfingen. In August they began construction of a four-engined bomber that was almost identical to the Union G.T. Daimler, having made the decision to begin aircraft production, had chosen the Union-design as its first product.
   The Daimler R.I, as the Union-design was now called, was constructed under the direction of Baurat Rittberger and Ing. Karl Schopper (both formerly with Union) at the rather primitive and make-shift facilities at Sindelfingen. Most of the R.I and R.II parts were built by the Stuttgart firm of Schiedmayer and taken to Sindelfingen for assembly. The R.I fuselage was more robust than its predecessors, and the troublesome inverted engines were replaced by the reliable 160 h.p. Mercedes D.III engine. The R.I first flew in late 1915 at Sindelfingen. While engine problems had been eliminated, the airframe had to be strengthened more than once. At least three different wing assemblies were flight-tested between 1915 and 1917. A second R.I was constructed with a larger tail to improve directional control.
   Idflieg was interested in the R.I, initially as an experimental type, later as a trainer for G-type bomber crews. Although the performance and flight characteristics of the Daimler R.I were not very promising, the aircraft were test flown until the middle of 1917. In November 1917 one G.I (as the R.I was now designated) was transferred to Idflieg.
   Two examples of an improved version, the Daimler R.II, were constructed in the spring of 1916. (According to the Sindelfingen city archive and latest researches at the Daimler-Benz Archiv, a total of six R.II aircraft were built. Two were taken by Idflieg and four were crated in boxes for reasons unknown.) Outwardly more robust in appearance, the R.II was almost an exact duplicate of the R.I. The overall dimensions were similar, only the weight was slightly increased. A major change was the finely shaped nacelles, mounted between the wings and supported in the centre by a streamlined pylon. Both R.II bombers were taken over by Idflieg and remained on flight status until the middle of 1917 at Sindelfingen.
   In 1916 the R.I and R.II were redesignated G.I and G.II, since they belonged to the same category as the four-engined Union G.I Albatros G.I and SSW-Forssman R-types: large in size, but engines not serviceable in flight. Records in the Daimler-Benz archives show that the R.I (G.I) and two R.II (G.II) bombers were numbered 478/15, 450/15 and 451/15 respectively. These numbers do not fit the R-plane numbering sequence, or the 1915 G-type sequence.


SPECIFICATIONS

Type: Daimler R.I
   Manufacturer: Daimler-Motoren-Gesellschaft A.G., Sindelfingen
   Engines: Four 160 h.p. Mercedes D.III engine
   Dimensions:
   Span, 21•08 m. (69 ft. 2 in.)
   Length, 18•35 m. (60 ft. 2 1/2 in.)
   Height, 3•80 m. (12 ft. 6 in.)
   Areas: Wings, 73•62 sq. m. (792 sq. ft.)
   Weights:
   Empty, 2512 kg. (5538 lb.)
   Loaded, 3630 kg. (8003 lb.)
   Wing Loading: 49•3 kg./sq. m. (10,1 lb./sq. ft.)
   Performance, Maximum Speed, 120 km.h. (74,6 m.p.h.)
   Cruising Speed, 114 km.h. (70'8 m.p.h.)
   Climb,
   1000 m. (3281 ft.) in 16•8 mins.
   1500 m. (4921 ft.) in 26•9 mins.
   Ceiling, 3000 m. (9843 ft.)

Type: Daimler R.I (second version)
   Manufacturer: Daimler-Motoren-Gesellschaft A.G., Sindelfingen
   Engines: Four 160 h.p. Mercedes D.III engines
   Dimensions: Span, 21,15 m. (69 ft. 4 in.)
   Length, 18•20 m. (59 ft. 8 1/2 in.)
   Height, 3•75 m. (12 ft. 3 1/2 in.)
   Areas: Wings, 70•60 sq. m. (760 sq. ft.)
   Weights:
   Empty, 2510 kg. (5534 lb.)
   Loaded, 3700 kg. (8157 lb.)
   Wing Loading: 52-4 kg./sq. m. (10'7 lb./sq. ft.)
   Performance: Maximum Speed, 119 km.h. (73,9 m.p.h.)
   Cruising Speed, 114 km.h. (70'8 m.p.h.)
   Climb,
   1000 m. (3281 ft.) in 17•0 mins.
   1500 m. (4921 ft.) in 28•0 min.
   Ceiling, 3000 m. (9843 ft.)

Type: Daimler R.II
   Manufacturer: Daimler-Motoren-Gesellschaft A.G., Sindelfingen
   Engines: Four 160 h.p. Mercedes D.III engines
   Dimensions: Span, 21 •26 m. (69 ft. 9 in.)
   Length, 18-40 m. (60 ft. 4 in.)
   Height, 3•80 m. (12 ft. 6 in.)
   Areas: Wings, 74•80 sq. m. (805 sq. ft.)
   Weights:
   Empty, 2540 kg. (5600 lb.)
   Loaded, 3680 kg. (8113 lb.)
   Wing Loading: 49•3 kg.jsq. m. (10,1 lb./sq. ft.)
   Performance: Maximum Speed, 123 km.h. (76-4 m.p.h.)
   Cruising Speed, 120 km.h. (74'6 m.p.h.)
   Climb,
   1000 m. (3281 ft.) in 15•2 mins.
   1500 m. (4921 ft.) in 25•0 mins.
   Ceiling, 3000 m. (9843 ft.)