J.Herris Albatros Aircraft of WWI. Vol.3: Bombers, Seaplanes, J-types (A Centennial Perspective on Great War Airplanes 26)

Albatros WDD & W.1
  
  The Albatros WDD (Wasser Doppeldecker Doppelsitzer; water biplane two-seater) first flew in autumn 1913 and was the naval version of the Albatros biplanes that would be classified as B.I in army service. The WDD was a three-bay biplane with two main floats and a tail float. The first WDD was powered by a 100 hp Argus engine; later versions had the 125 hp Argus or contemporary Mercedes or Benz engines. Early aircraft used brow radiators, but later aircraft used side radiators for cooling.
After some success in the 1913 Bodensee Contest the Navy ordered additional aircraft. These became Marine Numbers 52-56.
MN Type Engine
52 Albatros Benz Bz.III
53 Albatros WDD Mercedes
54 Albatros WDD 200 Argus
55 Albatros WDD Mercedes
56 Albatros WDD Benz Bz.III
   Like many early aircraft, the WDD experienced running changes in production with little or no documentation about these changes surviving. These aircraft differed enough that had they been built later, at a time when designations were more formal and precise, they could have been given different designations. Changes in the vertical tail design and rear float were the most obvious of the changes made; other changes included the engine, radiators, and main floats.
   The WDD and W.1 are covered here in the same section because the W.1 designation was apparently applied retroactively to several developments of the Albatros WDD. Marine Number 52 is an example. Part of the WDD series noted above, it is shown as a W.1 in various references - painted with Marine Number 552, allegedly to deceive Allied intelligence. The other WDD's in the series also were painted with a '5' preceding their actual Marine Number.
   Marine Number 74 was another Albatros seaplane retroactively designated W.1, and others so redesignated are Marine Numbers 111, 221-230, 432, and 446.


Albatros Seaplane Specifications
Type W.1 W.2 W.3 W4 MN747 W4 (948-967) W.5 W.8
Engine 150 hp Benz Bz.III or 160 hp Mercedes D.III 150 hp Benz Bz.III 2x150 hp Benz Bz.III 160 hp Mercedes D.III 160 hp Mercedes D.III 2x150 hp Benz Bz.III 195 hp Benz Bz.IIIb
Span 14.3 m 10.0 m 22.7 m 9.50 m 9.50 m 22.7 m 11.46 m
Length 8.56 m 8.2 m 13.1 m 8.50 m 8.50 m 13.1 m 9.59 m
Wing Area 43.0 m2 31.4 m2 - 31.0 m2 - 100 m2 -
Empty Weight - 935 kg. - 709 kg 784 kg 2,263 kg -
Flying Weight - 1,215 kg - 989 kg 155 km/h 3,665 kg -
Maximum Speed - 176 km/h 133 km/h 155 km/h 160 km/h 133 km/h 150 km/h
Climb to 1,000m - - - - 5.5 min. 20.0 min. 6.5 min.
Climb to 2,000m - - - - 8.5 min. -
Climb to 3,000m - - - - 23 min. - 34 min.
Duration - - - - - 4 hours 3.5 hours
Guns None 1 gun 1 gun 1 gun 2 guns 1 gun 1-2 fixed guns + 1 flexible gun


Albatros W.1-W.8 Seaplane Production
Aircraft Number Built Marine Numbers
Albatros W.1 19 52-56, 74, 111, 221-230, 432, 446
Note: The early Albatros seaplanes are not clearly documented in the SVK tables. The Marine Numbers listed for the W.1 include those originally designated WDD (52-56 & 74) and those potentially W.1 (111, 221-230, 432, 446) with no type specified or specified as K.351 and K.361.

J.Davilla Italian Aviation in the First World War. Vol.2: Aircraft A-H (A Centennial Perspective on Great War Airplanes 74)

Albatros WDD

  In the fall of 1913 the Albatros firm flew the first of what was to become the German Navy version of their B Class military biplanes. The Type WDD (Wasser Doppeldecker Doppelsitzer), was powered originally with a 100hp Argus engine, but later versions had 125hp Argus, Mercedes or Benz power plants. Italy bought six WDDs from Germany in April 1914, two of which actually saw service based at the Venice Station. After the establishment of the Scuola di aviazione navale (Scuola di aviazione navale) in Venice, the school actually began its operation on February 1,1913, but but was officially inaugurated on April 25, St. Marco’s Day; it was for this reason the seaplane squadron was baptized “Squadriglia San Marco”.
  Federico Filippi in a World War One Aero article stated that it was the Zari firm that received orders to produce a copy of the WDD. He does show data (see below) that suggests the WDDs in Italian service had slightly different specifications, but, it is unclear if these were from the license-built copies or the one that was modified by Bresciano and Mirgala (see below). Filippi speculated that there were only two WDDs that came from Germany and that at least four were made by Enea Bossi in 1915 (although the original order was for six aircraft).
  At the declaration of war with Austria, two Albatros were in service at the Venice seaplane station, one piloted by tenente Giuseppe Miraglia the other by capitano del Genio Navale (Captain of Naval Engineers) ing. Luigi Bresciani.

Technical

  In June 1915 the original 100-hp Mercedes engine, was replaced by Ing. Bresciani and Mirgala who fitted a new 150 hp Isotta-Fraschini V.4 engine. They also modified the fuselage to carry this larger engine and added enlarged fuel tanks. To maintain the center of gravity the crew seating was rearranged.
  The engine was partly enclosed by a metal cowling, which left the entire upper part of the engine protruding into the airstream. This arrangement caused significant drag.
  Immediately behind the engine was the observer’s seat, under which the fuel tank was located; the pilot’s seat was behind that fuel tank. To ensure visibility of the sea and ground there was a cutout in the lower wing, immediately behind the rear wing spar.
  A small auxiliary fuel tank was also placed underneath the bottom of the upper wing, between the interplane struts.
  A camera for reconnaissance missions was carried in the cockpit.
  The main floats had the following dimensions:
   Length 3.40 m; width 0.80; distance between the floats 3.00 m; volume of the floats was 1,500 cubic meters.
  The arrangement on the float support struts was different from the Albatos-supplied machines. On these the support struts formed an ‘M’-shape which connected to two horizontal pipes to which the floats were attached by bungie chords. The middle point of these tubes was fitted with ahinge to allow the small rotations of the floats possible.
  The tail float was located the end of the fuselage, but was found to cause the aircraft to remain tilted backwards (about 15° at rest).

Operations

  The new engine increased the maximum speed of the aircraft from 90 to 105 km/h and the ceiling from 2,000 to 3,000 m. he maximum flight altitude was about 2000 meters with the Mercedes engine and over 3000 m with the Isotta Fraschini.
  A contemporary evaluation of the type is given in Magaldi’s Gli Idrovolanti in Italia pages 90 to 91:
   The maneuverability was excellent, the behavior in air and in water safe, the robustness remarkable; nor have these qualities diminished with the transformation undergone for the change of engine. Both before and after this, the aircraft... descended into rough sea, and this without suffering any inconvenience.
  In a long period of service they never had (complaints) about flight accidents or serious equipment failures.
  These aircraft could also now carry a radio or bombs.
  The first operation of a modified WDD took place in July 1915 when a reconnaissance of the Pola naval base was performed by commander Miraglia.
  The military use of the surviving two WDDs was limited to short-range reconnaissance and light bombing raids until the end of 1915.
  One of the last aerial accidents in 1915 took a heavy toll; on 23 December tenente di vascello Giuseppe Miraglia was killed in a flight accident on 23 December; he had played a critical role in establishing the seaplane base at Venice and led the Albatros WDDs stationed there on several reconnaissance missions to Pola, the last one on 18 December.
  The French established a CAM (Centre d’aviation maritime = Naval Aviation Station) Venise (Venice) in June 1915, and their FBAs were to replace the Albatros floatplanes in their daily flights over Pola. However, the FBA B’s 100-hp engines limited their radios of action to 30 miles, so the WDDs continued their patrols until retired at the end of 1915.

Albatros WDD two-seat floatplane with one 100-hp Mercedes engine
  Wingspan 15.10 m (16.3 m data quoted by Filippi); length 9.10 m; height 3.80 m; wing area 52 sq m (50 sq m)
  Empty weight 930 kg (1,130) kg; loaded weight 1,200 kg; payload 270 kg
  Maximum speed 90 km/h; range 400 km (250 km) (ceiling 2,000 m)

Albatros WDD two-seat floatplane with 150-hp Isotta-Fraschini V.4 engine
  (Only changes from the standard WDD are noted below)
  Empty weight 1,140 kg; loaded weight 1,480 kg; payload 340 kg
  Maximum speed 105 km/h; range 500 km (250 km); (ceiling 3,000 m)

Журнал Flight

Flight, October 9, 1914.

AIRCRAFT "MADE IN GERMANY"
WHICH MAY BE EMPLOYED AGAINST THE ALLIES.

7. The Albatros Tractor Seaplane
   is practically identical with the land machines, with the exception of course that floats are fitted. These, which are of the non-stepped type, are sprung from the chassis struts by rubber shock absorbers which are enclosed in streamlined casings, partly to reduce head resistance and partly in order to protect them against the effect of salt water. The body, which is of rectangular section, is covered with three-ply wood in the same manner as the land machines flown by Thelen at Hendon some time ago. The seats are arranged in tandem, the pilot sitting at the rear, from where he obtains a good view in a downward direction further enhanced by leaving the inner portion of the trailing edge of the lower plane uncovered. In front of him, and protected by a mica wind-screen, is the passenger, situated immediately behind the 160 h.p. Mercedes engine, which is mounted in the nose of the body. Long exhaust pipes carry the exhaust gases away over the side of the body. The weight of the tail planes is taken when the machine is at rest by a peculiarly shaped float mounted underneath the rear portion of the body. The wheels shown in the illustration do not form part of the chassis, but are part of a transport trolley attached to the floats by strong steel straps.