1/72 Caproni Ca.5, by Stephen Foster

The Caproni Ca 5 was designed in 1917 as a replacement for the earlier successful Ca 3 series of aircraft.The Ca 5 was slightly larger than its predecessor and the early versions were powered by Fiat A 12 engines developing between 200 and 300 horse power. Radiators were fitted in front of the engine on the booms, but in the nose of the fuselage for the middle engine which was in a pusher configuration. Three engines were used because of the nature of the terrain (most of the bombing raids had to pass over the Alps) and distances involved: a third engine gave both increased power and a better chance for the crew to return in the event of an engine malfunction. Later variants of the basic design were powered by Fiat, Isotta or Liberty engines which meant slight redesign of the nacelles, and in the case of the Liberty engined variants, the nose radiator was replaced by one mounted in front of the engine at the rear of the fuselage. Defensive armament consisted of a machine gun in the nose and one mounted on a platform above the engine in the fuselage and behind the top wing. Most of these machines were operated by the italian Air Force but a small number was also supplied to the American Air Service where they were deployed over the Western Front. Plans to build 1500 machines of this type in the US were cancelled when peace resumed in 1918. The type was used with some success as a bomber from late 1917 and through 1918 and after the war it continued in service with the Italian air force until the mid 1920's. At least one machine was fitted with floats and Liberty engines but this was not delivered until 1919 and so did not see wartime service. Some machines were converted to air ambulances in the post war period - they could carry two stretcher cases, one in each nacelle behind the engines, and up to 4 sitting cases in the fuselage: the fuel tanks were reduced in size to accommodate the seats. In terms of overall performance the design was a little disappointing as it suffered from constant engine problems. The fuselage engine was difficult to cool, and all of the engines tended to have a low reliability because of the poor quality control in the engine factories in Italy. Production was also hampered by the lack of skilled workers to make these complex aircraft in Italy at that time, but the type earned respect from its crews for its rugged qualities and powers of endurance which made them well suited to the conditions in which they had to operate.

The engines were made from 2 strips of 60 thou card sandwiching a strip of 20 thou card. This was then filed and sanded to shape. The cylinders were from 100 thou rod. Only the engine in the fuselage nacelle needs the magneto because these cannot be seen on the engines in the booms. The cam shaft was from 20 thou rod and the valve springs from short pieces of rod. The carburettor was from card and rod. The exhausts were 25 thou rod cut to length. The radiators were cut and shaped from 40 you card with the front and rear scribed to represent the radiator grilles. Remember in this scale much fine detail cannot be seen without a hand lens, so that the modeller needs to give an impression of what things look like rather than trying to replicate every fine detail.

The wings were made by laminating a strip of 30 thou card which had been bent in boiling water with a strip of 20 thou card laid over the top. The 30 thou strip was wide enough to extend to the rear spar, and then a strip of 20 thou card and 10 thou card was laid along the trailing edge of the 30 thou card. The edges of the card on the undersides was then sanded until a smooth aerofoil section was achieved and the trailing edge was as thin as possible. The leading edge was rounded off to give the correct profile. Ribs were 10 x 20 thou strip glued into place and then sanded to shape. Holes were drilled in the wings for the struts, and undercarriage and wing skids under the lower wing.

The booms were simple box structures with sides, top and bottom of 20 thou card. Strips were placed on the inside edges of the sides to provide support for the corners and help to get them square. Formers were also made from scrap card, three per boom, and the rear ends from 20 thou card. The curved lower surface of the booms was achieved by sliding the card between tweezers 3 - 5 times. The tops of the booms were moulded in the normal way from 30 thou card with filler used to fair in the rear ends. Two 30 x 40 thou strips were glued on to the top of the lower wing to hold the booms in place. The louvres on the sides of the booms were made from 10 x 20 thou strip cut to length and glued in place and when dry they were filed and sanded to shape.

The nacelle was moulded from 30 thou card. The interior consisted of a floor which I assume was an open frame so I used thin strip to make one each for the three cockpits, control panel with two sets of throttles, instrument panel, seats for the pilots and front and rear gunners, and control wheels. Fuel tanks were made from card bent to shape and the ends were simple blanks.Some interior framing was added from thin strip.The gun rings were made from 20 thou card which had been scribed with a pair of dividers. The radiator louvres on the nose were made from 10 x 20 thou strip as per the booms. The fronts of the nacelles were moulded from 30 thou card which were glued into place after the engines had been fitted into the nacelles.

Wheels were made from discs of 60 thou card.. First I scribed a circle of the correct diameter into the card with a pair of dividers. Then the card was cut into squares and finally rounded to shape with a file and sand paper using the scribed circles as a guide. One side of each disc was then filed to give a curved face. The tyres were made by bending 60 thou rod around a paintbrush handle and immersing it in boiling water for 10 seconds. I removed the rod and let it cool while still holding it under tension while it did so. Lengths of rod could then be cut to fit around each disc. By making the rod spiral smaller than the discs the rod sat tightly around the edges of the discs and could be held in place with liquid glue.

Having made all of the major components I could start assembly as per any kit. The booms and fuselage nacelles were assembled in the usual manner and the fuselage nacelle glued to the lower wing first. This needed careful alignment and a jig to support it while it dried out so they the horizontal centre line was at the correct angle to the wing surface. When this was complete one boom was added at a time to the lower wing, again using the drawing to help get the correct alignment. The engines were put into the booms using scrap plastic to provide the necessary supports. The moulded nacelle fronts and radiators completed the booms. The main struts were glued into the inside edges of the nacelles and allowed to set hard. The horizontal tail surface was glued to the rear of the booms.

COLORS & MARKINGS

Now the outer struts could be cemented to the lower wing and while these were still flexible the top wing could be lowered on to the struts and held in place with support while it dried out. This structure was not very strong but it allowed the addition of the remainder of the wing and nacelle struts and cabanas to be carefully inserted. The small radiators on the forward cabane struts were made from 30 thou card and the pipes from thin copper wire. The pipes on the fuselage sides were 30 thou rod. Next the ailerons, undercarriage legs and wing skids were fixed into place. The model was rigged using dark monofilament thread. Finally the rear gun position was made and glued into place, followed by the rudders which were held with thin pins of 5 amp fuse wire, the propellors, (also held with wire), and the wheels which have wire axles. The tail was rigged and the front bracing struts added. The last task was to add the drag wires from the nose to the leading edges of the wings.

CONCLUSIONS

There are occasions when I wish to add a model to my collection which is not available as a kit in any form. The Caproni Ca5 is an example of this. It was not a particularly important or successful aeroplane, but I found it to be of interest because of the exposed rear gunner position and I wanted to see if I could replicate that. It is also a multi-bay biplane which offers distinct challengers to the modeller. The camouflage pattern is also unusual and that too attracted my attention. Unfortunately there is little information available on this type published in English and researching the type took a long time. From a modelling view there were many processes which had to be used, so it was a good type to practice or refresh a number of different skills and made for an interesting project.

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PRICE:	$
DECALS:
REVIEWER:	Stephen Foster
NOTES:	Scratchbuilt.