Centennial Perspective
German Seaplane Fighters of WWI

J.Herris - German Seaplane Fighters of WWI /Centennial Perspective/ (2)

Felixstowe No.4305 burns. The Brandenburgs earned their reputation as "The Hornets of Zeebrugge."
Christiansen had confirmed the following victories over seven of the large America flying boats, all in 1918. Curtiss H.12B N4338, 15 February 1918. Curtiss H.8 8677, 24 April. Curtiss H.12, 25 April. Felixstowe F.2A N5433, 4 June. N5433 had landed and was taxing towards shore when set on fire. Felixstowe F.2A N4297 and N4540, both on 4 July 1917. N4297 was forced down but not lost and N4540 was only shot up. Felixstowe F.2A N4305, 31 July. Some of these victories were shared. He also had ships that were sunk or captured in his total score.
Albatros W4

   Albatros, the largest German aircraft manufacturer, responded to the Navy's request with the W4, a seaplane development of their Albatros D.I fighter that was being built at the same time. Both the W4 and D.I were powered by the 160 hp Mercedes D.III engine. Due to its floats, the W4 was heavier than the D.I and needed larger wings for more lift. The horizontal tail was larger to compensate for the larger wings, and flight testing of the prototype revealed tail heaviness. Changing the amount of stagger solved the problem and happily also improved climb rate and top speed. The prototype and initial production W4s had ear radiators and a single machine gun. The harsh operating environment caused considerable problems with the wood floats and a number of different designs had to be tried both for strength and seaworthiness. Repairs and water-proofing the leading edge and spars of the lower wings were also required after water damage, including delamination of the spars, was discovered. Starting with the second W4 production batch, two machine guns were fitted.
   The arrival of summer weather revealed problems with the ear radiators, which had to be replaced with a new design. Starting with the fifth production batch (1484-1503), airfoil radiators were fitted to reduce drag. To improve maneuverability the last two production batches were fitted with ailerons on all four wings.
   By the time the final production batch was built, the Brandenburg W12 two-seat floatplane fighter had proved it was more effective in combat than single-seater floatplane fighters and the final production batch of W4s was delivered directly to storage. Eight W4s were traded to the Austro-Hungarian Navy in July 1918 in return for Austro-Daimler V-12 engines to power Staaken R-planes. Designated E5 to E12 in Austro-Hungarian service, these saw no combat. By August 1918 only four W4s were on combat duty on the North Sea and another five were on combat duty in Turkey.
   A total of 118 W4 fighters were built in a series of production batches summarized in the table above.

Albatros W4 Production Summary
Marine Number Qty Notes
747, 785-786 3 Prototypes; 1 gun, ear radiators
902-911 10 1 gun, ear radiators
948-967 20 2 guns, ear radiators
1107-1116 10 2 guns, ear radiators
1302-1326 25 2 guns, ear radiators
1484-1503 20 2 guns, airfoil radiator, 4 ailerons
1504-1513 10 2 guns, airfoil radiator, 4 ailerons
1719-1738 20 As 1504-1513; delivered directly to storage.
The prototype Albatros W4 Marine #747 as built with stained wood fuselage and clear-doped linen flying surfaces. After it was assigned to Zeebrugge it was partly over-painted in camouflage colors.
Albatros W4 Marine #911 after tactical markings were added. Close inspection of available photos shows the circular markings were in three colors, thought to be the German national colors, and were applied to the top of the rear fuselage in addition to the sides. This fighter was flown by Lt.s.Z. Schulz, who downed three aircraft while flying it.
Albatros W4 Marine #1512 was the next to last W4 built in the next to last production batch. It represented the final W4 production configuration with two guns, an airfoil radiator, and ailerons on all four wings for better maneuverability, and was finished in standard naval late-war camouflage.
Albatros W4 Marine #964 of the second production batch.
When the German Navy requested single-seat floatplane fighters for station defense, Albatros responded with their W4, which was based on their D.I fighter and used the same 160 hp Mercedes D.III engine. The W4 had larger wings to support the extra weight of the floats.
Albatros W.4 Marine #965 outside its hangar. The dent in the spinner appears to match the two photos opposite.
This view of wrecked Albatros W4 Marine #958 of the second production batch being recovered from the water shows the three-color naval hexagonal camouflage fabric used on later production aircraft. The printed fabric was used on all upper surfaces. Printing the color on the fabric during manufacture saved time, labor, the weight of paint, and the paint itself.
Albatros W8

   The Albatros company, largest aircraft manufacturer in WWI Germany, offered the Albatros W8 for the Navy's two-seat fighter. Although similar in concept to the Brandenburg W12, its tail design obstructed more of the gunner's field of fire and it used an experimental engine that reached production too late to power aircraft at the front; only three were built.
The first prototype Albatros W8 was a handsome, well-streamlined two-seat fighter powered by a V-8 that was not yet in mass production. However, the flat radiator under the wing somewhat spoiled the overall streamlining.
FF33L - Fighter Forerunner

   The main purpose of fighter aircraft is to attack enemy aircraft. Some early fighters like the Vickers Gunbus and SPAD pulpit fighters had a gunner with flexible gun and no gun for the pilot, but the fighter soon evolved and a fixed gun for the pilot became essential. Thus to be included in this work, a fixed gun for the pilot was a requirement, and the C2MG variant of the Friedrichshafen FF33L qualifies. Of the 145 production FF33Ls, 60 were the C2MG category with fixed gun for the pilot; the other 85 were category CHFT with wireless transmitter and receiver and a flexible gun for the observer, but no gun for the pilot. An additional 40 of the C2MG version of the FF33L were ordered but not built and the order was cancelled in December 1918.
   The FF33 series was built in greater numbers, 491, than any other German naval aircraft and perhaps any WWI floatplane. The early FF33A and FF33B were unarmed reconnaissance seaplanes built in small numbers. The main early production aircraft was the FF33E, also an unarmed reconnaissance floatplane. The FF33H was an armed development of the FF33E with a flexible gun for the observer and smaller span for better maneuverability. The FF33J was a replacement for the FF33E and the FF33S was a trainer.
   The FF33L, the final version of the large FF33 family, was designed for use as an escort and patrol fighter and its C2MG variant was the first German seaplane to mount a fixed gun for the pilot. The FF33L was developed from the FF33H and was somewhat smaller and more streamlined than earlier FF33 floatplanes to increase speed and maneuverability compared to its general-purpose ancestors. For a seaplane of the time the FF33L had good maneuverability and handling and fair speed, and it was an effective escort for its unarmed reconnaissance companions over the North Sea and Baltic.
   While its offensive capabilities were modest, the C2MG valiant of the FF33L was the transitional design to the floatplane fighter and showed the need for more effective aircraft like the faster, more maneuverable Brandenburg W12 that truly warranted being called fighters through their enhanced offensive combat capability.

FF33L Production Orders
Marine Numbers Category Qty Delivery Dates
932-941 C2MG 10 Jan.-Feb./1917
1001-1010 CHFT 10 Mar.-July/1917
1085-1094 CHFT 10 Apr.-June/1917
1117-1126 C2MG 10 Apr.-June/1917
1158-1177 CHFT 20 Apr.-June/1917
1234-1278 CHFT 45 May-Oct./1917
1279-1288 C2MG 10 June/1917
1577-1596 C2MG 20 Aug.-Sep/1917.
3144-3153 C2MG 10 Late 1918
3154-3193 C2MG 40 Cancelled 12/18
Marine #3144 had an experimental tail design.

FF33L Specifications
Engine 150 hp Benz Bz.III
Span 13.3 m
Length 8.825 m
Wing Area 40.54 sq. m.
Empty Wt. 916 kg
Gross Wt. 1,373 kg
Max Speed 136 km/h
Climb to 1,000 m 8 minutes
Friedrichshafen FF33E Marine #841 Wolfchen was the most famous German floatplane. Seen here after its return to Germany and after being restored to a dramatic finish it never wore on operations, Wolfchen was the reconniassance carried into the Indian Ocean and back by the German merchant raider Wolf, the most successful of all Germany's raiders in WWI. Wolfchen played a key role in Wolf's success. During the voyage Wolfchen was covered in plain, unmarked fabric, and at one point was recovered by captured silk fabric after its original fabric wore out. The FF33E was a reliable maid of all work among German floatplanes and served for most of the war, but only Wolfchen became famous.
Friedrichshafen FF33L Marine Number 1009 is at the far right with FF33L Marine Number 1239 in front of it on the ramp.
FF33L C2MG #1123 at left and a companion FF33L, possibly C2MG #1124, at right, are ready for their next mission from Angernsee in 1917. The FF33L was smaller and more streamlined than earlier FF33 variants, giving it better speed and maneuverability. That, coupled with its fixed gun for the pilot, enabled it to undertake more aggressive missions than its antecedents, making it the transition stage to a true floatplane fighter.
Friedrichshafen FF33L floatplanes lined up on the Mole at Zeebrugge. German seaplanes from Zeebrugge frequently engaged seaplanes and landplanes of the Royal Naval Air Service. Landplanes normally had the advantage in these combats because they were not encumbered with floats, but a number of landplanes were downed by floatplanes.
Friedrichshafen FF33L floatplanes from Zeebrugge on patrol over the North Sea sight a Dutch schooner.
One of the Friedrichshafen FF33L floatplanes lands near the Dutch schooner to check it for contraband. German seaplanes captured or sunk a number of vessels like this that they found carrying contraband.
Friedrichshafen FF43

   Friedrichshafen was the largest supplier of seaplanes to the German Navy, and its products were noted for being robust and having good seakeeping qualities. The Friedrichshafen FF43, Marine #749, was an original seaplane fighter design powered by a 160 hp Mercedes D.III that first flew on 30 September 1916 but remained a single prototype. Mounting two
machine guns, it had a maximum speed of 163 km/h. This was slightly faster than the contemporary Albatros W4 that was selected for production, so the FF43 must have had other shortcomings, and one source notes that it had a poor rate of climb, which is probably why it was not selected for a production order.
Friedrichshafen FF48

   Friedrichshafen, who produced more seaplanes than any other German company during the war, built their FF48 to the same requirement as the W19. The FF48 had good speed and climb for such a large floatplane but may have lacked the necessary maneuverability, and only three were built, indicating it had no significant advantages over the W19. Certainly it required more wire bracing than the W19 and did not have the look of a fighter.
The Friedrichshafen FF48 was a larger aircraft in the class of the W19 and like the W19 was powered by the 240 hp Maybach Mb.IVa.
Friedrichshafen FF63

   Friedrichshafen, who manufactured more seaplanes than any other German company, produced a competitor to the Brandenburg monoplanes, the FF63. The engine was the 200 hp Benz Bz.IV; virtually no other technical data on the type survives, and even its Marine Number is not known.
   The FF63 was not as innovative in its structural design as the Brandenburg monoplanes and only a single FF63 was built. The radiator above the engine was surely fitted to expedite early flight testing; this installation produced far too much drag for a production aircraft and also obstructed vision.
Powered by the 200 hp Benz Bz.IV, the Friedrichshafen FF63 appears to be a fair design that just does not match the innovative structural design of the W29 and W33 that were its competitors. The additional bracing struts above the wing and the struts above the fuselage added weight and drag that the Brandenburg monoplanes avoided. The tail gave the gunner a good field of fire, but again the Brandenburg designs had a better field of file.
Only one Friedrichshafen FF63 was built. The radiator mounted above the engine was surely to expedite flight testing and would certainly have been replaced by an installation of lower drag had it gone into production.
Ursinus Floatplane Fighter

   The most innovative single-seat floatplane fighter prototype built was the Ursinus, which had retractable floats for higher speed through reduced drag. To improve maneuverability the engine was located on the center of gravity and drove the propeller via an extension shaft. The floats were retracted by a manual crank. During trials there were problems with the propeller extension shaft and float retraction mechanism. The prototype was destroyed before it could achieve its estimated top speed of 200 km/h. Its Marine Number was 782.
The Ursinus floatplane fighter Marine Number 782 seen from the side with floats extended. The cockpit was well aft because the engine was set back to the center of gravity and drove the propeller via an extension shaft.
The Ursinus U.1 floatplane fighter was unique in having retractable floats, a significant innovation for its time. To improve maneuverability the 150 hp Benz Bz.III engine was located on the center of gravity. Technical difficulties with the extended drive shaft to the propeller and the float retraction mechanism limited the design to a single prototype.
Friedrichshafen FF33L Marine Number 1009 is at the far right with FF33L Marine Number 1239 in front of it on the ramp.
Brandenburg CC

   The Brandenburg CC shared the star-strut wing design of the Brandenburg KDW. The star-strut design was stronger but slightly heavier than conventional bracing and eliminated the need for external bracing wires. The prototype and German production CC aircraft were powered by a 150 hp Benz Bz.III. The prototype had a single fixed gun for the pilot; production aircraft mounted two fixed guns and a frontal radiator. Like later KDW fighters that shared the star-strut bracing, additional interplane struts to stiffen the wingtips for improved aileron response were added to some CC fighters.
Although it was placed in production, with 35 built in addition to the prototype, German pilots did not consider the Type CC suitable for flying in Northern Europe, perhaps because as a flying boat it did not keep the pilot as far out of the cold water as floatplanes did. The Type CC did not serve very long in the German Navy and the aircraft were soon placed in storage.
   However, Camillo Castiglione, head of the Austro-Hungarian branch of Brandenburg and for whom the Type CC was named, was aware that the Austro-Hungarian Navy needed a fighter, and Castiglione gave them a Type CC powered by a 185 hp Austro-Daimler engine that was assigned serial number A.12. This aircraft was presented to naval ace Gottfried Banfield, CO of the Trieste Naval Air Station, who stated that it was the best single-seat naval fighter so far. The Austro-Hungarian Navy then purchased a dozen more Type CC aircraft, serials A.13 - A.24. These aircraft were supposed to be powered by 185 hp Hiero engines, although engine shortages meant the first four used the 160 hp Hiero.
   A second batch of two dozen aircraft, A.25 - A.48, to be powered by the 200 Hiero, was soon ordered. From A.31 on the aircraft featured a number of improvements, most notably mounting two fixed Schwarzlose machine guns and using an airfoil radiator instead of the previous car-type radiator. During production the fuselage was also lengthened for better directional stability. During the triplane craze one aircraft, A.45, was tested with a third wing mounted between the existing wings; climb was slightly improved but the additional weight and drag made it noticeably slower. The CC served successfully in the warmer waters of the Adriatic until replaced by the improved W.18.

Brandenburg CC Production
Marine Numbers Qty Notes
946 1 Prototype, 1 gun, frontal radiator
1137 - 1146 10 Two guns, airfoil radiator
1327 - 1351 25 Two guns, airfoil radiator

Specifications For Flying Boat Fighters
Type Brandenburg CC (German) Brandenburg CC (Austro-Hungarian) Brandenburg CC (Austro-Hungarian) Brandenburg W18 (Austro-Hungarian)
Engine 150 hp Benz Bz.III 185 hp Austro-Daimler 200 hp Hiero 230 hp Hiero
Span 9.50 m 9.3 m 9.3 m 10.7 m
Length 8.50 m 7.65 m 7.65 m 8.64 m
Wt. Empty 709 kg 716 kg 800 kg 812 kg
Wt. Loaded 989 kg 1,030 kg 1,030 kg 1,092 kg
Max. Speed 155 km/h 170 km/h 180 km/h 180 km/h
Climb to 1,000 m 5.5 min. 5 min. 4 min. 5 min.
Climb to 2,000 m 8.5 min. 11.2 min. - 11.2 min.
Climb to 3,000 m 23 min. - 16 min. 23.4 min.
Armament 1-2 guns 1 gun 1-2 guns 2 guns
These four photos of the Brandenburg CC prototype show the early configuration of a single gun and frontal radiator for its 150 hp Benz Bz.III engine. The wood hull is stained and the flying surfaces are clear-doped linen.
The Brandenburg CC was a successful flying boat fighter, but German crews preferred floatplanes in the chill waters in which they operated and the CC did not long remain in German service. In the warmer waters of the Adriatic it was a great success operating with the Austro-Hungarian Navy. The CC used the star-struts of the KDW; this model mounts one machine gun. Power for the German CC was the 150 hp Benz Bz.III.
Brandenburg CC #1114 was from the first production batch. It carries two guns, has an airfoil radiator, and a streamlined engine cowling.
Brandenburg CC from the first production batch, probably #1144, displays its clean lines, it carries two guns, has an airfoil radiator, and a streamlined engine cowling with propeller spinner.
Like the KDW, later (post-July 1917) production Brandenburg CC fighters were fitted with additional interplane struts to stiffen the upper wing for improved aileron effectiveness. Two guns and an airfoil radiator are fitted.
Brandenburg KDW

   The Brandenburg KDW [Kampf Doppeldecker Wasser - literally 'combat biplane water') was developed from the earlier Brandenburg KD (Kampf Doppeldecker) landplane fighter. The Brandenburg KD was designed in Germany in 1916 and went into production for the Luftfahrtruppe, the Austro-Hungarian air service, as the Brandenburg D.I fighter.
   The Brandenburg KD, or D.I, was basically a conventional, wire-braced wooden design of the time except for one notably different feature, the interplane struts. The metal interplane struts, streamlined by laminated wood fairings, were designed as a set of four triangles that met at their apex, giving a unique star appearance. The star-strut design was very strong and eliminated the need for the drag-producing bracing wires featured by contemporary designs. The resulting Brandenburg KD was a strong, fast fighter. Unfortunately, its single machine gun was mounted in a streamlined housing above the wing, making it impossible for the pilot to clear jams during flight. Worse, the KD lacked both maneuverability and stability, and was prone to stalling and spinning with little provocation.
   The German Navy's need for a seaplane station defense fighter led to development of the Brandenburg KDW, a straight-forward conversion of the KD to a floatplane fighter. Floats replaced the wheels and both the wing span and area were increased to provide additional lift to compensate for the extra weight of the floats. Fortunately, a synchronized machine gun was mounted on the starboard side of the fuselage instead of the clumsy, over-wing mounting used by the KD. Initially the gun was mounted too far forward to be reached by the pilot in case of a jam during flight, but this was rectified with the first production series. The final production series was intended to mount two guns adjacent to the cockpit where the pilot could reach them in flight, but some machines carried only one gun.
   The three prototype aircraft had the 150 hp Benz Bz.III engine with car-type, frontal radiator. Aircraft of the second production series had the 150 hp Benz Bz.III (if intended for the Baltic) or the 160 hp Mercedes D.III engine with radiator in the starboard side of the upper wing (if intended for Flanders or the North Sea). All aircraft of the first, third, and fourth production series had the 160 hp Maybach Mb.III engine with radiator in the starboard side of the upper wing. In the summer of 1917 early production aircraft were refitted with additional small interplane struts bracing the upper wing to increase torsional stiffness of the longer span wing, thereby improving aileron response. From the third production batch these struts were installed during production.
   Based so closely on the KD, the KDW inherited its performance and flying qualities. These included structural strength and good speed for a floatplane fighter, although the additional weight and drag of the floats and longer wings necessarily reduced speed and climb given that engine power was essentially the same. Less happily, the KDW also inherited the poor stability and flying qualities of the KD. A number of changes to the vertical tail surfaces were made during production in an attempt to improve these, but without notable success. As a result, the KDW was able to engage reconnaissance seaplanes and similar targets with a reasonable chance of success, but was at a distinct disadvantage in combat with contemporary landplane fighters. The KDW's most significant operational success was when the first example, Marine Number 748, downed Russian Ilya Mouromets IM-6, a four-engine reconnaissance-bomber, one of only three downed in air-to-air combat during the war.
   The KDW was delivered in small batches from September 1916 to February 1918. Only about 2,365 aircraft were produced for the German navy during the war, so the 58 KDW aircraft produced represented a reasonable success. However, the competing Albatros W4, the floatplane conversion of the successful Albatros D.I fighter, was produced in twice the numbers of the KDW, 118 being delivered from September 1916 to December 1917. Although the KDW with 160 hp Mercedes D.III had a slight speed advantage over the Albatros W.4, the KDW with the 150 hp Benz was slower. Furthermore, the W.4 had better climb rate and maneuverability, better visibility from the cockpit, and, perhaps most important, much better flying characteristics. Both types served on the Flanders front, the North Sea, and in the Baltic. Eventually the KDW succumbed to the same poor flying qualities and cockpit vision problems as its landplane predecessor, the D.I.

KDW Production
Marine Number Qty Notes
748, 783, 784 3 Prototypes. 1 gun, 150 hp Benz Bz.III engine. Completed September 1916.
912-921 10 1 gun, 160 hp Maybach Mb.III engine. Series completed February 1917.
1067-1076 10 1 gun, either 160 hp Mercedes D.III engine (aircraft destined for the Western Front) or 150 hp Benz Bz.III engine (aircraft destined for the Baltic). Series completed in March and April 1917.
1380-1394 15 1 gun, 160 hp Maybach Mb.III engine. Series completed in summer 1917.
1554-1573 20 1 or 2 guns, 160 hp Maybach Mb.III engine. Series delivered between October 1917 and February 1918.
The prototype KDW Marine #748, as confirmed by the fairings over the apex of the struts. The Marine Number has not yet been applied.
The KDW prototype before armament was fitted. No Marine Number is visible and the frontal, car-type radiator and overall aerodynamic cleanliness of the design are prominent.
Marine Number 783, the second KDW prototype, showing its frontal radiator. The machine gun is far forward, out of the pilot's reach in case of jams. The wing structure is evident through the fabric. The Balkenkreuz on the wings appear to be painted over white backgrounds. Although it is difficult to see in this view, there is no fixed fin above the fuselage.
Side view of Marine Number 912, the first production KDW, shows the machine gun has been moved back to enable the pilot to reach it in flight to clear jams. This change was made on the basis of early combat reports on #748.
An early Brandenburg KDW (no vertical fin above the fuselage) is launched as the pilot enters the cockpit. The engine appears to be a Benz due to the exhaust stack.
This appears to be another photo of the KDW above, and provides an interesting view of the star struts augmented with the auxiliary bracing struts. This arrangement was strong and eliminated the need for drag-producing bracing wires, but was heavier than conventional wing bracing. The additional weight and drag of the auxiliary bracing struts basically eliminated the advantages of the star-strut design, and later designs returned to conventional wing struts.
Marine Number 1562 of the final KDW production batch displays the additional interplane struts and shows off the three-color hexagonal camouflage fabric used on the upper surfaces of German naval aircraft late in the war. The machine guns have been moved up in front of the pilot for better access.
Essentially a float-equipped version of the Ernst Heinkel-designed Hansa-Brandenburg KD/D I of early 1916, with added outboard wing bracing, the first of the navy's 58 Hansa-Brandenburg KDWs was completed in September 1916. Typically, no less than three different engine types were fitted to the KDW, the initial 150hp Benz Bz III to the 13 aircraft, followed by the 160hp Mercedes D III in the next 10, while the last 35 machines received the 160hp Maybach Mb III. In the first 23 of these single seat fighters only one 7.92mm Spandau was fitted, whereas the last 35 mounted twin Spandaus. Top level speed was 106mph for the later fighters and range was cited as 310 miles. From a pilot's viewpoint, the KDW was not highly thought of, having virtually none existent visibility directly forward.
Lt. d.RMi Fritz Hammer, flying the KDW prototype, Marine Number 748, from the German naval air station at Angernsee, downs a Russian four-engine Sikorski Il'ya Mouromets reconnaissance-bomber on 23 September 1916. Sikorski IM-6 crash-landed at its base with 293 bullet holes and three of its four crewmen wounded. This was one of only three air-to-air victories scored over these tough bombers during the war.
Brandenburg W.11

   Following the KDW, Brandenburg constructed three other single-seat floatplane designs during the war. Like the final KDW production series, all were armed with two fixed, synchronized Spandau machine guns.
   The first design developed from the KDW was the Brandenburg W.11, an enlarged KDW powered by a 200 hp Benz Bz.IV engine. Span was enlarged slightly to 10.0 m, length to 8.2 m, and wing area to 31.4 sq. m. The additional power increased speed to 176 km/h (109 mph), but flight characteristics were not improved. With the increased power an increased climb rate would also be expected, but no data survive to confirm that. Only three aircraft, marine numbers 988-990, were built in late 1916 due to the marginal performance improvement over the KDW and the great success of the Brandenburg W12 two-seat fighter.
W11 Marine Number unknown; this type was a slightly enlarged KDW with two machine guns and the more powerful 200 hp Benz Bz.IV engine. Only three aircraft, marine numbers 988-990, were built in late 1916 due to the marginal improvement over the KDW. Of the three aircraft built, at least two, Marine Numbers 988 and 989, were assigned to Flandern 1 at Zeebrugge.
Brandenburg W16

   The W16 of 1916 was distinctly different from the KDW and was powered by an Oberursel U.III rotary engine of 160 hp. Span was the same as the KDW and due to the rotary engine it was much lighter. Flying characteristics likely were somewhat improved over the KDW, but speed was the same and above 1,000m climb was inferior. Like the W11, only three examples were built, Marine Numbers 1077-1079, because they were no improvement over the KDW, and there is no record the W16 flew on operations.
The W16 was an attempt to create a replacement for the KDW that had better maneuverability and handling qualities. It had a larger fixed fin to improve stability and the heavy star-strut arrangement was replaced with a new design that did not obstruct the pilot's view as much. Despite the same power and its much lighter weight than the KDW, it was no faster and its climb rate was actually lower above 1000m. The massive spinner was an attempt to minimize drag.
The W16 featured a different strut arrangement than the KDW to achieve better field of view for the pilot.
Brandenburg W12

   The Brandenburg W12 two-seat floatplane fighter was a breakthrough design. Despite being a two-seater using the same engines powering the smaller single-seaters it replaced, it had similar speed and greater range coupled with better maneuverability and flying characteristics!
   Its two-seat configuration also provided greatly improved air-to-air combat effectiveness from its combination of fixed and flexible armament, and the second crewman was able to assist the pilot with over-water navigation, a particular operational challenge in the days before electronic navigation aids. Furthermore, some W 12s carried wireless senders and receivers for the observer, something none of the single-seat fighters could do that was a tactical advantage. The W12 made all preceding single-seat seaplane fighters obsolete at a stroke.
   The key secret of its success was its innovative structural design that used its sturdy float bracing to also support the wings, eliminating the need for separate, drag-producing bracing wires, a key to its good speed. Furthermore, its innovative tail design gave the observer excellent visibility and field of fire. In addition, the observer and his gun ring were mounted high enough that he could fire forward over the upper wing, giving him an unexcelled field of fire and further enhancing combat effectiveness.
   Despite its general excellence, the basic design was subject to a great deal of fine tuning to improve stability, maneuverability, and sea handling. In fact, none of the Brandenburg two-seat fighters were ever able to handle sea states as rough as the robust Friedrichshafen reconnaissance floatplanes, and there were continual problems with float maintenance. Fuselage length was extended in later aircraft to improve longitudinal stability, and late production aircraft had ailerons on all four wings for improved maneuverability. The center section was also redesigned during production to improve the pilot's field of view and ease of egress in emergencies. Some 30 later aircraft were fitted with two fixed guns for the pilot, and some aircraft with only a single gun for the pilot were fitted with wireless.

Brandenburg W12 Production Orders
Order Date Marine Numbers Qty Class Engine Notes
15 Oct. 1916 1014-1016 3 C2MG Mercedes D.III 1014 was prototype, short fuselage
22 Nov. 1916 1011-1013 3 C2MG Mercedes D.III Short fuselage
5 Jan. 1917 1178-1187 10 C2MG Benz Bz.III 1185 had longer fuselage
13 Mar. 1917 1395-1414 20 C2MG Benz Bz.III Short fuselages; 1413 had four ailerons
10 Sep.1917 2000-2019 20 C2MG Benz Bz.III Long fuselages start with this series. Larger wing cut-out.
Oct. 1917 2023-2052 30 C3MG Benz Bz.IH Two fixed machine guns. 2027 destroyed during acceptance testing.
Oct. 1917 2093-2112 20 C2MG Mercedes D.III -
Oct. 1917 2113-2132 20 C3MG Mercedes D.III Two fixed machine guns
Nov. 1917 2217-2236 20 C2MGHFT Mercedes D.IIIa Wireless equipment fitted

Note: Of 146 W12 aircraft built, 116 aircraft had one fixed gun; 30 aircraft had two fixed guns.
Brandenburg W12 #1183 was the personal aircraft of Oblt.z.S. Friedrich Christiansen. Christiansen took command of the Naval Air Station at Zeebrugge in September 1917; his personal insignia was the initial of his last name in a diamond on a white stripe as shown. Otherwise the aircraft was finished according to the naval directive of April 1917.
Brandenburg W12 #1407 has had its original insignia over-painted to conform with the new insignia standardized on March 30, 1918. The single white stripe on the rear fuselage indicates assignment to a specific naval air station, possibly Borkum.
Brandenburg W12 #1409 was finished in the standard late-war naval camouflage with a personal insignia.
Brandenburg W12 Marine #1414 was the personal aircraft of Lt. Becht, Zeebrugge naval air station, December 1917. This short-fuselage aircraft is in standard camouflage with Becht's personal insignia of the white stripes with checkerboard.
Brandenburg W12 Marine #2002 is from the first series with the longer fuselage that improved stability. It is in standard camouflage with Bremen's coat of arms (white key on red) as a personal insignia. This aircraft has ailerons on all wings.
W12 Marine #1012, the second pre-production aircraft, is seen here in operational markings at Zeebrugge. As tabulated above, the pre-production aircraft were category C2MG and were powered by the 160 hp Mercedes D.III engine.
Oblt.z.S. Friedrich Christiansen downed British airship C27; that victory lead to his award of the Pour le Merite. He is shown here with his gunner, Vzfw. Wladika, in W12 #1183, the aircraft he used to destroy C27. W12 #1183 was accepted in September 1917 and served until destroyed in a bombing raid on the Zeebrugge Mole on May 10, 1918.
This photograph illustrates how the upper wing enclosed the pilot making it difficult if not impossible to get out in a hurry in the event of a accident at sea. The bulged surround for the observer's gun ring is well shown. There were at least two different types of gun ring supports used on the W.12. The proximity of the machine guns to the pilot allowed for jambs to be cleared. Later machines had the machine gun partially cowled.
W12s at their base at Zeebrugge. Oblt.z.S. Christiansen's #1183 is in the center.
Marine #2052, a Brandenburg W12 of the fourth production batch, has a nose radiator and ailerons on all wings, with upper and lower ailerons connected by an actuating strut. It also mounted two fixed machine guns for the pilot in addition to the observer's flexible gun, making it a category C3MG. The outer portion of the propeller leading edge was covered with metal to reduce erosion from water spray.
Disappointed with the operational limitations of its single-seat floatplane fighters, which could intercept opposing reconnaissance airplanes but could not undertake longer-range offensive operations or compete with land-based fighters, the German Navy requested two-seat floatplane fighters. The innovative Brandenburg W12 was a breakthrough two-seat floatplane fighter design. Its clever integration of float bracing struts nearly eliminated the need for drag-producing bracing wires. More important, the W12 had the speed and maneuverability of the similarly-powered single-seat floatplanes coupled with the great advantage of a gunner with flexible gun and longer range. The W12 fought very effectively over the North Sea against British flying boats on antisubmarine operations and made such an impact that it inspired all subsequent German floatplane fighter designs.
Army and Navy airmen and ground crew pose with MN 2108. The German Army assigned aircrew to the Navy to learn how to navigate over water, accounting for their presence in the photograph. There is a wealth of detail to be seen in this photograph. Note the personal insignia; the late narrow cross on the fuselage; the rack for flare cartridges under the gun ring; the bulged cockpit that was introduced to give the pilot more room; the rack on the upper wing center section, possibly as a guide for the gunner to avoid damaging his own machine; lack of a synchronised machine gun on the port side; and plumbing from the wing-mounted radiator of the Mercedes engine. The LVG gun ring was copied from the British Scarff-type ring.
The combat effectiveness of the new Brandenburg W12 two-seat fighter immediately rendered all other floatplane fighters obsolete. All subsequent production floatplane fighters were developed from the W12. Here a pair of W12 fighters escort a U-Boat into harbor on the Flanders coast.
Brandenburg W17

   The Brandenburg W17 flying boat fighter was a development of the Type CC; the key difference was the use of a different wing cellule. The W17 had a smaller lower wing and the star-struts were replaced by slanted, parallel struts. One aircraft was tested by the German Navy and the other, A.49, was flown operationally by Oblt. Gottfried Banfield, the leading Austro-Hungarian naval ace, in late summer 1917, but no further production was undertaken. Mounting two fixed machine guns, the W17 was a transitional design between the production CC and the production W18.
Brandenburg W18

   The Brandenburg W18 flying boat fighter was a further development of the Type CC, this time using a more conventional wing cellule. One example, Marine #2138, was supplied to the German Navy, but with little German interest in flying boats only the single W18 was delivered.
   However, like the Type CC, the W18 was widely used by the Austro-Hungarian Navy. In December 1916 47 aircraft, serials A.50-A.96, were ordered. These mounted two fixed Schwarzlose machine guns and were powered by the 230 hp Hiero engine, although some aircraft were delivered with 200 hp Hiero engines due to shortages of the more powerful engine. The W18s were used for both station defense and for escorting bombing raids on Italian targets.
The German W18 had conventional wing struts, two guns, and the standard late-war German naval camouflage.
Produced in quantity for the Austro-Hungarian Navy, the Brandenburg W18 followed the CC into service.
The W18 had conventional wing struts, two guns, and the standard late-war German naval camouflage.
An Austro-Hungarian naval fighter pilot readies for his next mission in W18 A.50. Note the location of the machine gun along the top longeron.
This view of A.78. shows the red/white/red Austro-Hungarian markings under the upper wings and black outline to the iron cross insignia below the lower wings. Flying surfaces were clear-doped linen and the wood fuselage was stained. The old position of the serial shows as on the hull where it was scraped off.
W18 A.91 in Italian hands displays damage to the rear and bow of the hull. The windows on the fairing in front of the cockpit are visible.
Brandenburg W25

   The final Brandenburg single-seat floatplane fighter design was the W25, a development of the KDW with conventional wing bracing. The W25, with its revised wing bracing, ailerons on all four wings, and increased wing span and area, was clearly an attempt to improve on the maneuverability, flight characteristics, and field of view of the KDW. Weight
was reduced slightly due to replacement of the star struts, but with the same 150 hp Benz Bz.III engine and the larger wing with its greater drag, both speed and climb rate were actually less than the KDW. Due to its inferior performance compared to the KDW only a single aircraft, Marine Number 2258, was produced.
The final development of the KDW configuration was the W25. It has three-color naval hexagonal fabric on the upper surfaces; conventional interplane struts replaced the 'star-strut' arrangement of the KDW.
The Brandenburg W25 was the final attempt to improve the KDW by replacing the heavy star-struts with conventional wing bracing and installing ailerons on all four wings. It was not considered for production due to the great success of the two-seat Brandenburg W12. Power was a 150 hp Benz Bz.III.
Brandenburg W19

   Nearly identical to the W12 in configuration, the W19 was considerably enlarged to enable it to carry the greater fuel load needed for the longer range and endurance desired. Other than its larger size, the main visible difference was the W19 had two-bay interplane struts to support its larger wings instead of the single-bay struts of the smaller W12. Like late
production W12 aircraft, all W19 aircraft except the first prototype had ailerons on all four wingtips for enhanced maneuverability. With the exception of the first three W19 prototypes, which had a single fixed machine-gun for the pilot, all subsequent W19 production aircraft had two fixed machine guns.
   One early W19, Marine #2237 ordered in December 1917, had a flexible Becker 20mm cannon instead of a Parabellum for the observer. This seaplane apparently had an enlarged rudder and elevator, perhaps for greater stability with the cannon in the slipstream, although further details are lacking. After testing in April 1918, during which fifty rounds were rapid-fired with no installation problems, the only change requested was enlarging the observer's gun ring from 900mm to 1000mm diameter. After approval by front-line personnel, #2237 was send to the front for evaluation, where it was written off on 20 June. Apparently the evaluation was successful because in early June the Navy ordered the fourth W19 production series, Marine Numbers 2544-2563, armed with the Becker cannon. All 20 W 19s of this series were found at Warnemunde in December 1918 by the Allied Naval Armistice Commission, most still in their packing crates.
   Most W19 aircraft were powered by the 240 hp Maybach Mb.IVa, making the W19 much more powerful than the W12. This significant power increase compensated for its greater size and weight, making the W19 nearly as fast as the W12 while carrying more fuel, armament, and equipment. In April 1918 the first W19 arrived at Zeebrugge to supplement the W12 in the North Sea.

The W19 and the Maybach Mb.IVa

   All W19s used the Maybach Mb.IVa. W19s through the first three production batches were generally scheduled to receive the 240 hp Maybach Mb.IVa engine, but when struck off charge some individual airplanes had the high-compression 260 hp Maybach Mb.IVa engine. It is not known if the more powerful engine was installed during production or retrofitted after delivery. The fourth production series was scheduled to have the 260 hp Maybach Mb.IVa. On 12 August 1918 this series was allotted between Kofl F (North Sea) and Kofl Marinekorps (Flanders).
   Confusingly, both the Maybach 240 hp and 260 hp engines shared the designation Mb.IVa. The engine rated at 240 hp had cast iron pistons, produced a maximum of 245 hp, and weighed 400 kg. The engine rated at 260 hp had aluminum pistons, produced a maximum of 300 hp, and weighed 390 kg. Both engines had six cylinders of 165mm bore and 180mm stroke, providing 23.1 liters capacity and developed their rated power at 1,400 RPM. From these similarities it is apparent they were essentially the same engine with different pistons, power ratings, and compression ratios, but with little or nothing to distinguish between them externally.

Brandenburg W19 Production
Series Marine Numbers Qty Category Armament & Notes
Prototypes 1469-1471 3 C2MG 1 fixed, 1 flexible MG
Series 1 2207-2216 10 C3MG 2 fixed, 1 flexible MG
Series 2 2237 2238-2257 1 20 CK C3MG 2 fixed MG, 1 flexible 20mm cannon 2 fixed, 1 flexible MG
Series 3 2259-2275 2276-2278 2537 17 3 1 C2MGHTF CK C3MG 1 fixed, 1 flexible MG, wireless xmtr/rcvr 2 fixed MG, 1 flexible 20mm cannon 2 fixed, 1 flexible MG
Series 4 2544-2563 20 CK 2 fixed MG, 1 flexible 20mm cannon
Series 5 2683-2722 40 C3MG 2 fixed, 1 flexible MG

W19 Production Notes:
1. Marine Number #1469 was destroyed on its first flight in August 1917.
2. The engine for #1469 is not confirmed; #1470 & #1471 had the 240 hp Maybach Mb.IVa.
3. The engine for production series 1, 2, and 3 was usually the 240 hp Maybach Mb.IVa; some aircraft had the 260 hp Maybach Mb.IVa.
4. Marine Numbers 2208-2216 and 2237-2239 were accepted the second half of April/first half of May 1918.
5. Marine Number 2237, accepted in April 1918, was class CK; this was a test installation of the 20mm Becker in the W19.
6. Marine Number 2267, accepted in the second half of June 1918, had a 260 hp Maybach Mb.IVa.
7. The engine for production series 4 was the 260 hp Maybach Mb.IVa.
8. Completion of production series 5 is not confirmed, but #2687 and #2688 were handed over to Italy on 15 September 1920, so some aircraft of this series were produced.
9. A total of 115 W19s were ordered but it is not known if all of production series 5 were delivered. Production of at least 77 W19s is confirmed.
Front view, probably of Marine Number 2207, showing its over-wing radiator and twin forward-firing machine guns. The nearly vertical exhaust manifold is different that that of the aircraft in the other front view.
Race for Life. This striking painting by Steve Anderson depicts the action on August 11, 1918 when Brandenburg fighters attacked six British Motor Torpedo Boats (MTBs) operating against German minesweepers. Three of the MTBs were sunk and the remaining three were damaged so badly they beached themselves in neutral Holland to avoid sinking. Brandenburg W19 Marine #2249 shown here was one of the fighters that sank an MTB.
Brandenburg W27

   The W27 differed from the W12 primarily by its use of I-type interplane struts and a 195 hp Benz Bz.IIIb V-8 engine. These were class C3MG, so armament was two fixed Spandau machine guns for the pilot and one flexible Parabellum machine gun for the observer. Three aircraft, Marine Numbers 2201-2203, were built, but the engine was not in full production and the aircraft were used as trainers.

Brandenburg W32

   Yet another W12 derivative was the W32, which appears to have been a W27 fitted with a 175 hp Mercedes D.IIIa engine. Again three aircraft were apparently built; Marine Numbers 2282-2284. The first aircraft, #2282, was class C3MG; the other two were class C2MG HFT. Dimensions were the same as the W27 and the W32s were accepted about the end of June 1918. By this time the faster W29 and W33 monoplanes were in production and an improved W12 was unnecessary.
Brandenburg W 32
Brandenburg W29

   The W29 monoplane was based on the fuselage, engine, and floats of the W12 biplane. The sturdy struts bracing the floats did double duty bracing the wing, which had about the same area as both wings of the W12. The greatly reduced drag of the monoplane wing resulted in a notable speed increase with the same engines and payload. The increased speed of the W29 was welcomed because it made interception of the large Felixstowe flying boats easier, and the new monoplane set the standard for all future German wartime designs in its class.
   W29 production aircraft were powered by the 150 hp Benz Bz.III, 185 hp Benz Bz.IIIa, 175 hp Mercedes D.IIIa, or 185 hp BMW.IIIa, and had one or two fixed machine guns for the pilot (depending on the series) and one flexible gun for the observer. Elimination of the upper wing not only made the monoplanes faster, but stability was improved, as was the observer's field of fire and pilot's field of view.
   By naval standards the W29 was built in large numbers; 14 orders were submitted for a total of 239 aircraft, and 209 were built; the last batch of 30 ordered on 10 September 1918 was not completed due to the armistice.
Brandenburg W29 Production Orders
Order Date Marine Nos. Qty Category Engine Notes
17 Jan.1918 2204 1 C3MG 150 hp Benz Bz.III Type aircraft
17 Jan. 1918 2205 1 C2MG 185 hp BMW.IIIa
17 Jan. 1918 2206 1 C3MG 160 hp Mercedes D.III
13 Apr. 1918 2287-2300 14 C2MGHFT 150 hp Benz Bz.III 2287 was type aircraft
13 Apr. 1918 2501-2506 6 C2MGHFT 150 hp Benz Bz.III
13 Apr. 1918 2507-2536 30 C3MG 150 hp Benz Bz.III 2715 destroyed before accept.
25 May 1918 2564-2583 20 C2MGHFT 150 hp Benz Bz.III
30 May 1918 2584-2587 4 C3MG 185 hp Benz Bz.IIIa
30 May 1918 2588-2589 2 C2MGHFT 185 hp Benz Bz.IIIa
9 July 1918 2593-2642 50 C3MG 150 hp Benz Bz.III 2625 was C2MGHFT
9 July 1918 2643-2652 10 C3MG 185 hp BMW.IIIa
9 July 1918 2653-2682 30 C3MG 185 hp Benz Bz.IIIa
10 Sep. 1918 2730-2759 30 C3MG 185 hp Benz Bz.IIIa
10 Sep. 1918 2670-2789 30 C3MG 175 hp Mercedes D.IIIa None completed due to armistice
W29 #2516 was flown by Lt. A.R. Hasse and Kpt.Lt.d.R. Bertram from the naval air station at Borkum. It is finished in the standard late-war navy camouflage with reduced size crosses on the fuselage and rudder. The shield is a personal insignia, colors not confirmed.
W29 #2530 ANNIE with standard late-war naval camouflage and a personal insignia on the fuselage side.
Brandenburg W29 Marine #2532 displays the standard naval camouflage with the two white fuselage stripes indicating assignment to Norderney.
Mechanics work on the fixed pilot's guns on this W29.
Two W.29 floatplanes from Nordeney in flight. Note the lack of white outline to the underwing crosses. While the wing crosses are the late style the fuselage cross is still the interim type.
Two formations of Brandenburgs hunt over the North Sea. Brandenburgs often patrolled in formations of five aircraft; the trailing aircraft in the formation in the lower photo took the photo of the others.
Fighting seaplanes operated alone initially, but the emergence of Allied formations over the sea and the example provided by the fighter formation work in the German Army Air Service led to the establishment of the 'C-Staffeln' which operated in strengths of 3, 5 or 7 machines. These units did not confine themselves to pure aerial fighting but undertook reconnaissance work in all its forms. This is a C-Staffel of five Brandenburg W29 monoplanes from Borkum, identified by the white oblique band carried on the fuselage ahead of the tail unit.
A W29 attacks British Submarine C25 which was caught on the surface on 6 July 1918. Armed only with machine guns, the Brandenburgs penetrated the pressure hull, preventing the submarine from safely submerging. Their gunfire killed the captain and five crewmen and damaged the submarine so badly it was forced to return to port for repairs. For this action Oblt.z.S. Friedrich Christiansen was credited for a victory over C25.
W29 in Norwegian service postwar. The W29 and W33 enjoyed long, successful postwar careers in Nordic countries.
Race for Life. This striking painting by Steve Anderson depicts the action on August 11, 1918 when Brandenburg fighters attacked six British Motor Torpedo Boats (MTBs) operating against German minesweepers. Three of the MTBs were sunk and the remaining three were damaged so badly they beached themselves in neutral Holland to avoid sinking. Brandenburg W19 Marine #2249 shown here was one of the fighters that sank an MTB.
A pair of Brandenburg W29s sink a sloop carrying contraband to Holland.
Brandenburg W33, W34, & W37

   Just as the W19 was a larger, more powerful development of the W12 biplane for greater range and endurance, the Brandenburg W33 was a larger, more powerful development of the W29 monoplane. The larger size of the W33 enabled it to carry more fuel for a longer range and greater endurance, and its greater power made it as fast. The first three W33s were powered by the 260 hp Maybach Mb.IVa, but the 260 hp Mercedes D.IVa and 275-300 hp Basse & Selve BuS.IVa were also used.
   The Brandenburg W29 went into operational service in April/May 1918 and had an immediate impact on the fighting over the North Sea. The larger W33 followed in the late summer.
   Although only seven W33 aircraft were delivered during the war, they were ordered in three classes; the C3MG, armed with three machine guns, the C2MG HFT with a fixed gun, a flexible gun, and wireless (radio) equipment, and a CK class with two fixed machine guns and a flexible Becker 20mm cannon instead of a Parabellum machine gun for the observer.
   Like the earlier W12, W19, and W29, the W33 aircraft were used primarily from North Sea air stations where they performed armed reconnaissance missions and opposed the British flying boats that were performing anti-submarine patrols. The W33 was ordered in very limited numbers and may have been an interim step to the enlarged W34. Three W34 floatplanes in the C3MG class were also ordered and delivered but were too late to serve operationally before the armistice. Drawings show the W34 had an enlarged gun ring capable of mounting a 20mm Becker cannon. Work on the similar but even larger W37 was halted post armistice and these three aircraft were not completed. However, eleven W37 aircraft, powered by the 260 hp Maybach Mb.IV, were built in Germany post-war and shipped to Sweden for assembly as the Caspar S.I, and others were built in Sweden by the Heinkel company.
   Along with the smaller W29, the W33 enjoyed a long and successful postwar career in Norway and Finland. The W33 was produced under license in Finland from 1922-1925, 120 aircraft being built. The 220 hp Benz Bz.IV was not available so 300 hp Fiat A-12bis engines were purchased from France. The first 57 aircraft built had provision for a fixed Vickers gun for the pilot, but these were not fitted to aircraft in service. The observer had a pair of Lewis guns on a flexible gun ring. Known as the IVL A.22 in Finnish service, the type served until 1936. License production of the W33 was also undertaken in Norway, 24 aircraft being delivered during 1920-1929 and serving until 1935. Most Norwegian W33s used the 260 hp Mercedes D.IVa engine.
Brandenburg W33, W34, & W37 Production Orders
Order Date Type Marine Nos. Qty Category Engine
24 Apr. 1918 W33 2538-2540 3 C3MG 260 hp Mercedes D.Iva
24 Apr. 1918 W33 2541 1 C2MG HFT 260 hp Maybach Mb.Iva
24 Apr. 1918 W33 2542 1 C3MG 275-300 hp BuS.Iva
24 Apr. 1918 W33 2543 1 CK 275-300 hp BuS.Iva
24 Apr. 1918 W33 2726 1 C3MG 260 hp Mercedes D.Iva
29 Aug. 1918 W34 2727-2729 3 C3MG 275-300 hp BuS.Iva
24 Aug. 1918 W37 2723-2725 3 CHFT 220 hp Benz Bz.IV
The W33 was known as the IVL A.22 in Finnish service, this example survives in the Finnish aviation museum.
Front view of Marine #2538, the first Brandenburg W33, shows its streamlined lines. The wing was complex and presented a manufacturing challenge to the Finns when they undertook license production; a lot of technology transfer took place in 1922 between Germany and Finland.
The W3 3 was an enlarged development of the W29 powered by the 260 hp Mercedes D.IVa or similar engines and designed for greater range and endurance. Photographed at Warnemunde on 30 August 1918, these views of W33 Marine #2538 shows the very clean lines of the W33 despite its size. It was finished in the standard late-war naval camouflage.
Junkers CLS.I

   A more serious competitor was the all-metal Junkers with factory designation J11, military designation CLS.I, a floatplane development of the Junkers CL.I two-seat fighter. A fixed fin was added to compensate for the side area of the floats in front of the center of gravity, but insufficient stability required modifications that continued even after the war, when the type was modified for civil use. The all-metal structure resisted the maritime environment better than did wood structures like those of the Brandenburgs, but the type was too late for wartime service.
Marine #7501 was a floatplane adaption of the all-metal Junkers CL.I two-seat fighter. The CL.I landplane had no fixed fin, but one was required on the CLS.I due to the destabilizing effect of the floats. The CLS.I tail surfaces underwent extensive modifications to achieve good flying characteristics, but the type arrived too late for wartime service.
K.W. (Wilhelmshafen) No.945

   The Naval Shipyard at Wilhelmshafen built a small number of prototype seaplanes, none of which were produced in quantity. One prototype built there was the K.W. No.945, a two-seat naval fighter clearly inspired by the Brandenburg W12. It was powered by a 150 hp Benz Bz.III engine, a powerplant used by many Brandenburg W12s. Other than its engine, few details survive.
K.W. (Wilhelmshafen) No.945

   The Naval Shipyard at Wilhelmshafen built a small number of prototype seaplanes, none of which were produced in quantity. One prototype built there was the K.W. No.945, a two-seat naval fighter clearly inspired by the Brandenburg W12. It was powered by a 150 hp Benz Bz.III engine, a powerplant used by many Brandenburg W12s. Other than its engine, few details survive.
The KW Type 945 was a two-seat floatplane fighter category C2MG, designated 'W9' by the Kaiserliche Werften.
The sole prototype of the K.W. (Wilhelmshafen) No.945 (150 h.p. Benz Bz III) built was clearly inspired by the Brandenburg W12, but lacked the qualities to gain a production order.
Roland W

   The Roland W, Marine #750, was derived from the operational Roland C.II two-seater. Like the C.II, the W was powered by a 160 hp Mercedes D.III and mounted a single fixed machine gun, but other details are not known and no production was undertaken.
   The Roland C.II was more noted for its speed than its good handling qualities, and it is likely the similar Roland W did not excel in handling either, with the result the production order went to the more docile and maneuverable Rumpler 6B1.
The Roland W photographed at the SVK Warnemunde.
Except for its ear radiators, the Roland W was nicely streamlined, it used the Wickelrumpf technology of fuselage construction, narrow ribbons of wood wrapped around a mold and glued into a strong, light-weight shell that was streamlined and resistant to combat damage. Wickelrumpf was pioneered by L.F.G. and later used successfully by Pfalz.
L.T.G. FD1
   The Luft Torpedo Gesellschaft, Johannisthal, normally designed aerial torpedoes. Nevertheless, L.T.G. built Marine #1299 and delivered it to Warnemunde, were it was destroyed during load testing. Three re-designed aircraft were ordered, and the first two were delivered to the SVK in July 1918. The type was still being tested when the war ended. The engine was listed as a 150 hp Benz Bz.III. However, the hand (direction of rotation) of the propeller is opposite to normal German engines, including the Benz, indicating the engine must have been geared, but details are not known.
Marine number 1299 was the first prototype of the FD 1 floatplane fighter. Power was provided by a 150 hp Benz Bz.III engine driving the propeller through a Loeb reduction gear, accounting for the propeller rotating in opposite direction to that of the engine.
Three FD1 prototypes, Marine #1299-1301, were ordered. Marine #1299 shown here was destroyed during static load testing. Problems noted during testing resulted in an order for three redesigned versions, at least two of which were delivered to the SVK, but no production resulted.
Rumpler 6B1 & 6B2

   The Rumpler 6B1 (known to the Navy as the Rumpler ED) was derived from the successful Rumpler C.I two-seat reconnaissance aircraft. The weight of the floats was compensated for by elimination of the observer and his equipment, and the upper wing was moved forward to compensate for the forward shift in center of gravity. Like the Rumpler C.I and Albatros W4, the 6B1 was powered by a 160 hp Mercedes D.III. The 6B1 retained the C.I's single fixed gun for the pilot. The prototype, Marine #751, was delivered to the seaplane testing command on 7 July 1916. After testing it was accepted on 10 August, and the first production batch of ten fighters was ordered on 14 August, followed by a further batch of 25 fighters.

Rumpler 6B2

   The Rumpler 6B1 was followed in production by the improved 6B2 that had the ability to mount two machine guns. The 6B2 also had refined aerodynamics derived from later production Rumpler C.IV aircraft that gave it greater speed; specifically the spinner was replaced by a rounded nose. Three production batches totaling 50 aircraft were ordered in early 1917. However, production was slow; the first aircraft were delivered a full ten months after being ordered, and only about half were fitted with two guns, the others mounting a single gun. Production data and other information about use suggest that by the time the 6B2 was ready, the Navy strongly preferred two-seat seaplane fighters, reducing the urgency for the 6B2 and other single-seat fighters. The 6B2 therefore saw limited operational service and was mostly used for training. Four 6B2 aircraft were sold to the Austro-Hungarian Navy, which assigned them serial numbers E1-E4.

Rumpler 6B1 & 6B2 Production
Marine Numbers Qty Notes
751, 787-788 3 Prototypes, C.I tailplane
890-899 10 First 6B1 production, C.IV tailplane
1037-1061 25 Second 6B1 production
1062-1066 5 6B2 pre-production
1188-1207 20 First 6B2 production
1434-1458 25 Second 6B2 production
The prototype Rumpler 6B1 after armament was fitted, which was a single machine gun on the port side with 750 rounds of ammunition.
The prototype Rumpler 6B1 while at the SVK in Warnemunde.The light color does not contrast well with the sky background, which was good for air-to-air camouflage and bad for photography. Power was provided by a 160 hp Mercedes D.III engine. The first three prototypes had the C.I horizontal stabilizers with straight leading edges; production aircraft had the C.IV tailplane with curved leading edges.
Rumpler 6B1 Marine #899 after successful launch. The curved tailplane applied to production aircraft is clearly visible. The standard late-war, three-color lozenge fabric does not appear to have been used on this aircraft; instead, the upper surfaces of the wings appear to be sprayed in two colors. On 15 May 1917 #899 was stationed at Borkum on the Flanders coast for operations over the North Sea.
Rumpler 6B1 Marine #1045 photographed in flight. This fighter was stationed at Borkum on September 13, 1917, where these photos were probably taken.
Rumpler 6B1 Marine #1045 of the last 6B1 production batch shows its propeller spinner and streamlined nose in this air-to-air photograph. Production 6B1 aircraft had the Rumpler C.IV's curved horizontal tailplane. Surprisingly, the 6B1 was more effective on operations than either the Albatros W4 or KDW. Pilots liked its excellent handling qualities and its performance was competitive despite being derived from a two-seat reconnaissance airplane.
Rumpler 6B1 W4 Marine #1051 shows its dark coloring and operational markings. The 6B1 and 6B2 had good performance despite their size and had far better handling qualities than the KDW.
This Rumpler 6B1 has been repainted in the late, straight-sided national insignia specified by the Navy on March 30, 1918. It is being readied for a training flight at Putzig naval air station.
Rumpler 6B1 W4 Marine #1189 was from the first 6B2 production batch. Its lack of propeller spinner was due to research to improve the Rumpler C.IV series that showed a streamlined nose without spinner had less drag. This made the 6B2 14 km/h faster than the similarly-powered 6B1, a significant improvement for such an apparently minor change. Here is is shown on its beaching gear at Seeflugstation Puntisella on July 9, 1918, in Austro-Hungarian service.
Rumpler continued development of the 6B1 into the 6B2, which had some modifications based on Rumpler's development of their C.IV reconnaissance plane, including deletion of the spinner, which actually reduced drag and made the airplane faster. Designed to carry two guns instead of the one fitted to the 6B1, about half the production aircraft had only one gun. Both the 6B1 and 6B2 used the 160 hp Mercedes D.III engine. The 6B2 saw limited service because, by the time it was in production, the Brandenburg W12 two-seat floatplane fighter had proven to be a tremendous success on operations and was strongly preferred.
Rumpler 6B2
Rumpler 6B2
Sablatnig SF3

   Sablatnig, a small firm that specialized in seaplanes, produced two two-seat floatplane fighter designs. First was the SF3, a sturdy-looking aircraft powered by a 220 hp Benz Bz.IV. The drag of the streamlined fuselage was more than compensated for by its multitude of struts and bracing wires, and it remained a single prototype.

Sablatnig SF7

   The SF7, powered by a 240 hp Maybach Mb.IVa, was the second Sablatnig design for a two-seat naval fighter. It had good speed but despite that only three, Marine Numbers 1475-1477, were built.
The SF7 was a massive aircraft, looking more like a typical reconnaissance floatplane than a two-seat fighter. It probably lacked maneuverability competitive with that of the W19. Marine #1475 was the first of three prototypes.
Sablatnig SF4 Biplane & Triplane

   Designed as a single-seat floatplane fighter, the SF4 was unique in that it was built in both biplane and triplane versions. Both were powered by a 150 hp Benz Bz.III and carried one fixed, forward-firing Spandau machine gun. The biplane, Marine #900, was tested first, and while speed was competitive, it had the lowest climb rate of all the singleseat floatplane fighter competitors. Worse, its maneuverability was poor due to its large wingspan and, despite its multitude of bracing wires, its structure was insufficiently robust; wing vibration was excessive in even a shallow dive. To improve the climb rate a triplane version, Marine #901, was built; like the biplane it was not competitive.
   Company founder Josef Sablatnig was a trained mechanical engineer and a well-known pioneer pilot, so it is especially disappointing that he was unable to design an airframe that was at once light, strong, and streamlined. Although nose entry was streamlined, the wing structure created a lot of drag due to extensive bracing wires, and despite that the wing structure was weak.
Elegant appearance belied the poor manoeuvrability displayed by the SF 4 biplane.
The SF4 biplane prototype is photographed in the snow; the broad interplane struts may have helped streamlining but obstructed the pilot's field of view to the sides.
The SF4 triplane carried Marine #901 and had ailerons on all wings. Little information is available on the triplane SF4, but it was not selected for production.
Zeppelin-Lindau (Dornier) Cs.I

   Another serious competitor for two-seat floatplane fighter production was the Zeppelin-Lindau (Dornier) Cs.I monoplane powered by a 195 hp Benz V-8. This aircraft was also all metal except for fabric-covered wing and tail surfaces. The drag-producing box radiators mounted on the fuselage sides for testing undoubtedly resulted in lower speed than the design was potentially capable of, but were likely an expedient to speed up flight testing. The single Cs.I flown, Marine #8502, had not completed testing when the war ended.
The all-metal Zeppelin-Lindau (Dornier) CS.I was the second German all-metal floatplane fighter design to fly during the war. It is seen here during testing with the spinner removed and the original drag-producing ear radiators.
Clearly inspired by the Brandenburg monoplanes, the all-metal Dornier Cs.I takes off on a test flight. Ear radiators are fitted to expedite testing, but a nose radiator was soon fitted for lower drag. Powered by a 195 hp Benz Bz.IIIb V-8 engine, it had a maximum speed of 150 kmh (94 mph) and was armed with a fixed gun for the pilot and a flexible gun for the observer. Three examples were built but it was too late for service.
The ZWL Cs.I number 8502 with ear radiators and spinner on a compass platform. The bracing wires and box radiators on the fuselage side produced too much drag for the design to fulfill its designed performance despite its 195 hp Benz V-8 engine.
Lt. d.RMi Fritz Hammer, flying the KDW prototype, Marine Number 748, from the German naval air station at Angernsee, downs a Russian four-engine Sikorski Il'ya Mouromets reconnaissance-bomber on 23 September 1916. Sikorski IM-6 crash-landed at its base with 293 bullet holes and three of its four crewmen wounded. This was one of only three air-to-air victories scored over these tough bombers during the war.