Paper Model Airplanes

Hansa Brandenburg, WWI Monoplane W.29

Ernst Heinkel designed the W.29 for the Brandenburg factory in 1918. Used on the North Sea, its most famous pilot was Oberleutenant Christiensen. It was later built in Denmark and served several countries in modified forms almost until WW II.

..An entirely new type of seaplane was evolved by Heinkel during the last months of 1917: a two-seater low wing monoplane, the W.29. The first batch, Nos. 2201 2206, were ordered in December and reached the operational units in the following spring and summer; they had 195 h.p. Benz engines with frontal radiators.

Six exhaust stubs discharged above and to port of the exposed cylinder heads. Ventilation louvers were provided in the metal side panels which enclosed the bulk of the engine.

HANSA-BRANDENBURG W.29 AND W.33

The thick, broad-chord wings, of wood and fabric construction, had blunt tips and horn-balanced ailerons, and were rigged with several degrees of dihedral. The fuselage closely resembled that of the W.12, but the tail-plane was neater, with a rounded leading-edge: the elevators were horn-balanced and of unequal chord. Hinged to the vertical knife-edge of the fuselage was the rudder, with a large horn balance on its lower end and a straight trailing-edge its upper end extended above the top of the tail-plane.

Similar floats to those of the W.12 were fitted, and additional N-shaped bracing struts connected them to the under surface of the wings. The armament consisted of twin synchronized Spandau guns fixed on each side of the curved top decking in front of the pilot's cockpit,and a Parabellum gun on a ring mounting for the observer.

The new monoplane was an immediate success, and the further batches 2287-2300, 2501-2536 and 2564-2583 were ordered in April and May 1918. These aircraft had 150 h.p. Benz engines: the final batch of W.29s, Nos. 25842589, had Benz Illas of 185 h.p.

The Brandenburg monoplanes augmented the WI2 and W19s already operating from the seaplane bases at Zeebrugge, Ostend, Borkum and Nordeney. Their top speed of 110 m.p.h. and excellent maneuverability made them dangerous adversaries for the opposing Short sea planes and Curtiss and Felixstowe flying boats. They also preyed on naval vessels: on July 6th, 1918, the British sub marine C25 was surprised on the surface by a formation of Brandenburgs led by Christiansen. In a short time the submarine's motors had been put out of action, and many of the crew, including the CO., had become casualties. Eventually the C25 was towed into Harwich, leaking 'like a sieve'. The damage was all done by machine-gun fire, for the submarine was old, and the thin plating of its hull was not bullet proof.

An enlarged and more powerful version of the W.29). the W.33, was ordered in April 1918. It had the 260 h.p Mercedes engine, with six unusually long exhaust stubs which discharged above and to starboard of the nose. The tail-plane was squarer in shape. Nos. 2538-2563 are known to have been built, and there was certainly at least one later batch, for No. 2670 was surrendered to the British. This aircraft had a 240 h.p. Maybach engine.

The Hansa-Brandenburg monoplanes influenced German seaplane design quite considerably: several copies appeared in 1918, such as the Friedrichshafen FF 63. the Dornier Cs-I. the Junkers J.11, and the L.F.G. Roland ME 8. After the war a version of the W.29 was.used by Denmark, while a licence for the manufacture of the W.33 was obtained by Finland.

It has been suggested that Oberleutnant Christiansen, commander of the important German Naval air base at Zeebrugge, played a part in urging the development of the W.29: certainly he was invited to fly the prototype, and he may have been allowed to take it back with him to Zeebrugge in February 1918 for operational use. Heinkel's development of the W.29 took the logical form of a monoplane version of the successful W.12, retaining the Benz engine in a shorter but basically similar fuselage. The slightly tapered single wings were increased in span and chord to give a total area almost equal to that of the biplane, and the tailplane was also altered slightly.

The first W.29 model to be built could really be regarded as a fighter, being a fast and very manoeuvrable aircraft with twin forward-firing guns and a Parabellum gun in the rear cockpit. It was powered by a 195hp Bz.IIIb. The first six W.29s were to this pattern, as were a further four ordered later in 1918, although there is some doubt whether this second batch was completed. Between these two orders came four other batches totaling seventy aircraft. The first twenty had the standard Bz.III, and radio equipment instead of one of the front guns. A second similar batch of twenty may not all have been delivered. The remaining thirty W.29s, with Bz.IIIs, had two front guns and no radio.

Three W.29s were built by Ufag before the Armistice, for the Austro-Hunganan Navy, but were not delivered. The W.29 entered German Naval service from about April 1918. serving alongside the W. 12 and W. 19 and often undertaking combined missions with the W. 19. Like the earlier Brandenburgs, they were treated with healthy respect by Allied submarines, surface vessels, flying-boats and airships. Most of their successes were achieved by concentrated fire-power, but some W.29s carried a small bomb load.

Twenty-six were apparently ordered, but it seems that only six were completed before the Annistice. The first three had two front guns and 260hp Maybach engines: the next two had single front guns and 300hp Basse und Selve engines, but were later refitted with Maybachs. The last of the six (presumably Maybach-powered) had one front gun and a 20mm Becker cannon in the rear cockpit.

A later and still larger version, the W.34 (300hp Fiat), was too late for war service, but some were purchased by the Finnish and Latvian Air Forces after the war. Some W.33s and W.29s were also acquired post-war by the Finnish and Royal Danish Air Forces respectively. Not only were the Brandenburg monoplane floatplane's first-class combat machines in themselves, but their general characteristics were also reflected in a number of prototypes from other manufacturers late in 1918.

The Brandenburg W 12 was created as a direct result of a request from the Reich's Marine Amt (German Admiralty) for a two-seat seaplane capable of carrying out offensive operations as well as other tasks normally undertaken by such machines. What emerged was a two-seat fighter biplane which, after numerous alterations and improvements, proved to be a remarkably manoeuvrable aeroplane of considerably advanced design for the period. To fully appreciate this it is necessary to compare its clean-cut profile with the collection of multi strutted excessively-wired large seaplanes characterized by the Short family and the Fairey's etc. and the miscellany of small flying boats seen over the Franco-Belgian littoral, the Baltic and the Adriatic. However, the RNAS did have the large Curtiss and Felixstowe flying boats which were powerful and capable of long range operations as well as being heavily armed.

The Brandenburgs were to come as something of a shock even to their crews when they first appeared. The HansaBrandenburgische Flugzeugwerke A.G. of Briest on the Havel river was just one company in a consortium created by the Austrian Industrialist, Camillo Castiglione. Other companies in the fold included the UFAG and Phoenix firms. The Chief Technical Director of the Brandenburg company was Ernst Heinkel who was perhaps a trifle prone to imply that he alone was responsible for the successful Brandenburg marine aircraft. However, certain design features of the W.12 were undoubtedly influenced by developments in the other branches of the CC empire, especially Phoenix. Indeed, the family resemblance between the W. 12 and the excellent Phoenix C. I ( 121 series) is obvious.

Although only 146 W.12s were produced the seaplane was subjected to a large number of tests and investigations leading to a continuous program of improvements and alterations during the various production batches. The major changes are listed below with notes, but to illustrate the problems one might consider the difficulties with the floats. Like wooden floats (and hulls) everywhere, they leaked, especially at the junctions of the float with the struts. Additionally, wooden floats absorbed moisture even when coated with layers of tough marine varnish and enamels.

Later, a thin bituminous paint was applied but the problem was never completely solved until metal floats became available late in the war. Some late production W.12s may have had aluminum bottoms fitted to their floats. Despite all the problems the W. 12 had a strong airframe and, apart from a pair of stagger (aka incidence) wires between the inter plane struts, the cellule was wire free. The formidable struts between floats and lower wings provided more than adequate strength. The deep fuselage made up for the lack of a fin and the inverted position of the rudder permitted a superb field of fire for the observer with his Parabellum on a ring mount. With its remarkable handling qualities and armament the W. 12 was a formidable fighting machine.

Designation & Production List

Another obvious difference was in the engine and radiator, the Benz engine W. 12s having the frontal radiator whilst the Mercedes had the upper wing mounted type. There were also at least three types of exhaust fitted, the Benz exhausting to port and the Mercedes to starboard. The longer fuselage meant that the stern/rudder post was shorter and in consequence, the rudder was also shorter but wider. From 2001 (it seems) onwards, the stabilizer (tailplane) was of a more angular shape.

Wings Fortunately, apart from the prototypes, these did not vary in span or chord throughout. However, other changes were made during the production runs. The cabane (an old term which came to mean what were later called the center-section struts) in its original form was a pair of inverted Vee struts, and awkward for the pilot, especially combined with the original very small cutout above his head.

Starting with the series 2000 - 2001 this was replaced by the more open strut system as seen in the drawing. In addition, a larger cut-out was installed on 1404, and eventually an even larger one was adopted in the series 2000 - 2019. Some earlier W. 12s may have had the increased cut-out installed at service stations.

Ailerons were originally fitted to the upper wing but to improve handling they were later added to the lower wing panels after testing on No. 1413. They were generally adopted as standard. The ailerons of the W.12 had a distinct 'washout', a common design feature of very many German aircraft of WW I. For those not familiar with this old term, it merely means that the aero foil section at the trailing edge near the wing tips flattens out giving it a turned up appearance.

Photographed from certain angles, the wing form looks tapered, an illusion which has led some draftsmen to falsely represent wing shapes in plan form.

Armament The pilot was provided with a fixed synchronized machine gun on the starboard flank, mounted externally on brackets with the ammunition belt fed through curved trunking into the right side of the breech. In later models the gun breech was contained within the fuselage panel. However, heat from the engine passing back near the ammunition feed was not liked by some pilots. Due to the diversity in this area it is important to check with photos. On later W. 12s starting with the 2113-2023-2052 and 2113- 2132 series, twin guns were fitted. The guns themselves were IMG 08s not LMG 08/lSs as so often portrayed.

The German Navy had its own supply arrangement with the Spandau Arsenal and all W. 12s and indeed the subsequent W.29 and later monoplane series also mounted these guns, recognizable by their slightly fatter jackets and rectangular breech cases. The observer was equipped with a Parabellum M14 machine gun and later the narrow jacketed M14/17 (see author's feature on the Hannover Cl series in SAMI Vol 4 Iss 4 April 1998). The weapon appeared on two distinct types of mount; the photographs illustrate these clearly. Both types were also used on subsequent Brandenburg seaplanes.

Contemporary documentation (and researchers have uncovered some), does not contain precise detail of colors, no color chips, no Methuen codes, merely general descriptions such as light blue','grayish brown' etc. From such meager ingredients some have managed to prepare a multi course banquet. It is true that in recent times a fragment of naval hexagonal fabric has turned up which appears to be authentic. Unfortunately, as it has never been doped or varnished, it was obviously never used on the surfaces of an aircraft. As such, it gives only a slight indication (bearing in mind fading), of the true color of the treated fabric covering the wings of an operational aircraft.

The crux of all this rests on documents dated March 28th 1917 which specified that upper-surfaces of wings, floats and tail surfaces were to be covered in the three colored hexagonal printed fabric. The colors are merely specified as gray brown, gray blue and gray violet'. This regulation also specified the color that was to be applied to the sides of fuselages, floats etc. It was light blue-gray', no precision, only general terms. There are further unhelpful fragments such as comments by British officers inspecting German naval seaplanes using the term 'slate gray' to describe this color. As slate varies in color depending on the quarry from which it came this again lacks precision. Slate can vary from a greenish-gray (like dark sea-gray) to a bluish-violet shade. If anyone tells you that your model has the wrong color camouflage, ask them to prove it.

There is one specific aspect worth noting and which is illustrated in one of the photographs with this feature, the care with which the printed fabric was applied. This is particularly true with the Brandenburg seaplanes but not necessarily true of other types. Just like a competent paper-hanger care was taken to match up the pattern when applying the various lengths. Another point of note is that on photographs, even very sharp ones, it is very difficult to discern the rib tapes on the upper wing surfaces. They existed of course, but the only explanation can be that the tapes were cut from the same stock and carefully applied so that the pattern coincided with the fabric beneath.

There is one other small matter concerning finish. A study of photographs shows that the interior of the pilot's cockpit at least, of many Brandenburg aircraft, from the KD Scout onwards was painted white.

The W. 12 was in service at the time that the order changing the national insignia from the eiserne kreuz (iron cross, a term commonly used by German airmen) to the simple balkenkreuz (bar cross) was issued in March 1918. This led to the many variations in cross sizes and proportions on large numbers of aircraft up until November 1918.