Sopwith F1 Camel Development

The Sopwith Camel F.1 was a direct development of Herbert Smith's Sopwith Pup and the two planes were not dissimilar in appearance, but this is where the similarity ended.
Unlike the elegant and docile handling Pup, the Camel was a high strung animal, difficult and dangerous to fly. Deadly in the hands of a novice, many a student was killed while learning to fly the Camel, but in the hands of a skilled pilot, able to take advantage of its temperamental flying characteristics, it was an extreme dog-fighter that could out maneuver any contemporary airplane with the possible exception of the Fokker Dr.I Triplane.

It was a British First World War single-seat biplane fighter introduced on the Western Front in 1917. Manufactured by Sopwith Aviation Company, it had a short-coupled fuselage, heavy, powerful rotary engine, and concentrated fire from twin synchronized machine guns.

Though difficult to handle, to an experienced pilot it provided unmatched maneuverability. A superlative fighter, the Camel was credited with shooting down 1,294 enemy aircraft, more than any other Allied fighter of the war. It also served as a ground-attack aircraft, especially near the end of the conflict, when it was outclassed in the air-to-air role by newer fighters.

The Camel's construction was based on the construction of its predecessor, the Sopwith Pup. Taking into account that a new larger and heavier engine would have to be mounted, Sopwith's chief designer Herbert Smith decided to make alterations to the previous design.
Some changes were made to the landing gear struts, the spacing of the wings and stabilizer were increased, and the fuselage acquired an extension to the cockpit's trailing edge which looked rather like a camel's hump. That 'hump' gave the plane its name - the Sopwith Camel. A remarkable detail of the plane's construction was its compactness: the pilot's seat, fuel tanks, machine guns and engine were all very compactly installed.

The Sopwith Camel Cockpit

The cockpit of the Camel was so small that the rear ends of the Vickers guns were alarmingly close to the pilot's face. Therefore some pilots had padding fitted to the guns. Basswood has been used for the panel.

The instruments are mounted on wooden rings, because the ammo boxes are very close against the back of the instrument panel.

Cockpit Instruments - Details

Compass - top center of panel sits the Creagh-Osborne Type 5/17 Air Compass.

Liquid compasses were adapted for aircraft. In 1909, Captain F.O. Creagh-Osborne, Superintendent of Compasses at the British Admiralty, introduced his Creagh-Osborne aircraft compass, which used a mixture of alcohol and distilled water to damp the compass card.

Operational Camels were finished in P.C.10, a pigmented coloring, sometimes described as Dark Khaki, that was basically mud-brown. This was normally applied to all upper and side surfaces; fabric under surfaces were clear doped. In Great Britain, the story began in 1913 with a series of experiments performed by the Royal Aircraft Factory, to discover the ideal pigmentation needed to protect aeroplane fabric from the damaging effects of the sun's ultraviolet rays.
The generic name used to describe the compounds was protective covering, or PC. A mixture offering the best compromise between protection and camouflage was adopted in April 1916; this was the so-called PC-10.

The first aircraft trials were performed by the British No.60 squadron in March of 1917, followed by a series of minor improvements to the plane's construction. The Sopwith Camel was delivered to fighter squadrons in May 1917. It was primarily used for destroying enemy aircraft and balloons, while from time to time it was also engaged in ground attack operations.
English journalists also called this plane a "Small bird of prey". Camel pilots mentioned the well-balanced plane controls, the good pilot's upward view and the high cruising speed. Due to the aircraft's unique balance, the plane could almost instantly change its heading: which made the Sopwith a dangerous opponent.

Construction of the Camel was of staggered wire braced wing bays with a straight upper wing and a very pronounced dihedral on the lower wing. The prototype upper wing panel was designed to be a single unit in order to simplify construction.

However, the production wing was three panels with an aft cutout between the spars and a center window for increased upper visibility, but the upper wing remained without dihedral-to compensate, the lower wing dihedral was doubled. Ailerons were fitted on both the upper and lower wings with the ailerons of a slightly greater span on the production models.

The fuselage had a rounded top conventional wire braced wooden frame, typical of the period. Aluminum panels covered the first bay behind the engine, and plywood was installed to the end of the cockpit, with the remainder of the fuselage covered in fabric.

With the engine, guns, pilot, cockpit and fuel all concentrated in a length of seven feet, this became one of the main contributing factors of the Camel's excellent maneuverability. For the pilot, a small windscreen was fitted behind the guns. The landing gear had short steel tube vees with a split axle, with rather large wheels.

This images shows the construction of the underside of the fuselage with the control cables running from the control stick (center) and rudder peddal (lower left). Also visible is the rear engine mounting bracket and the air induction elbow and tube.

Another view of the fuselage underside, showing the control stick tube axle and the aileron lever.

The typical combat scenario for the Camel pilot was a dogfight at low and mid altitudes, where the Camel had the advantage in steep turns. Veterans used to say "Once you become a Camel pilot, you will fly it forever".

Besides British pilots, this plane was also piloted by four American squadrons of the US Air Service, and by some Belgian pilots.
The Sopwith Camel took part in battles over both the Western and the Eastern fronts; in Mesopotamia, Egypt, Palestine, Macedonia and Italy.

"A great number of trainee pilots had been killed learning to fly this machine, as its tricks took some learning, although they were really simple to overcome. Its main trouble was that owing to its very small wingspan, and its purposely unstable characteristics, coupled with the gyroscopic effect of a rotating engine and propeller, it flipped into a spin very easily at low speeds. Consequently, in landing and taking off, a tremendous number of fatal accidents occurred, and a general feeling of dislike for the machine was prevalent. It really had people frightened."

Arthur Cobby

Throttle Quadrant

The throttle quadrant assembly contains the Throttle lever, the Mixture control lever and the Fuel filter.
As shown in the animation, mixture control is provided by the mixture control lever which operates the regulator plunger through the control bell-crank.
The regulator plunger contains the regulator needle, allowing for fine adjustment of petrol flow through the regulator. The petrol passes through a fine #30 mesh filter at the bottom of the body. The tapered needle position determines the amount of petrol that will be supplied from the selected petrol tank through the output connection pipe to the carburetor.

The Sopwith F1 Camel F6314

AID stamps found on the airframe fuselage and original woodwork during restoration in 1960 suggest this or October 1918 as the date of manufacture, the latter being more likely, based on probable contract date. The original log book, now lost, gave the manufacturer as Boulton and Paul Ltd of Norwich. This company built 1,575 of the 5,490 Camels constructed.
The original serial number is unclear.
In 1935 the then owner D C Mason wrote to 'Popular Flying' stating that on the lower wings the painted-over traces of roundels and the serial `F6314' could be discerned.

The pressurized Main tank, mounted behind the pilot's seat, had a capacity of 113.5 liters. Together with the Gravity tank the total fuel capacity was 168 liters.

The wood and fabric construction lacked any protection for the the fuel tanks. Like nearly all WW1 aircraft, this also made the Camel susceptibe to fire.

In parallel with the work of the central factory, the plane was also assembled by a number of other companies such as Ruston Proctor Co, Portholme Aerodrome Ltd, Boulton & Paul Ltd, British Caudron Co. Ltd, Clayton & Shuttleworth Ltd, Hooper & Co. Ltd and others.

In total, about 5490 Camels were built.

An agile, highly maneuverable biplane. The Sopwith F.1 Camel accounted for more aerial victories than any other Allied aircraft during World War I. Credited with destroying 1,294 enemy aircraft, it was called the Camel due to the humped fairing over its twin machine guns. Much like a real camel, this aircraft could turn and bite you.
Noted for its tendency to kill inexperienced flyers, many pilots feared its vicious spin characteristics. Until sufficient speed was developed during takeoff, Camel pilots maintained right rudder to counteract the torque the rotary engine. Failure to do so often resulted in a ground loop with the Camel crashing on its starboard wingtip. During World War I, 413 pilots died in combat and 385 pilots died from non-combat related causes while flying the Sopwith Camel.

The F6314 was one of a batch of 200 Camels, F6301-F6500, built by Boulton and Paul to contract 35a/1302/c.1293, ordered 18 June 1918, and delivered week ending 7 September 1918 - week ending 16 November 1918.

However, restoration by R G J Nash c.1936 discovered traces of the serial H?508 on the rudder. This does not match with any known Camel serial number, leaving F6314 as the most likely contender. There is however a further complication. Two different Camels carried the same serial number! This is explained in the Air-Britain Camel File (1993).

Front phantom view, showing the two .303 in (7.7 mm) Vickers machine guns which were mounted directly in front of the cockpit, firing forward through the propeller disc, synchronized by the interupter cam gear.

In appearance and design, the plane was not revolutionary. A biplane combining a distinct dihedral in the lower wing with a flat upper wing, it did have a distinctive "tapered gap." The fuselage was a wooden, box-like structure, covered with aluminum up front, plywood-covered around the cockpit, and then fabric-covered back to the tail.

The Rotherham air-pressure pump mounted on the right inner wing strut.
To limit possible damage to the wooden strut due to the pump's vibration, this section of the strut was reinforced with fabric tape.

The main fuel tank, together with the Gravity tank offered a total fuel capacity of 168 liters. The main fuels tank was pressurized by the air-pressure pump mounted on the engine or by the wind-driven Rotherham air-pressure pump.
However, before the engine was started, the hand fuel pump in the cockpit was used to pressurize the tank (2 - 2½ psi).

Rudder, Empennage and tail skid. Suspension was provided through the rubber bands connecting the tail skid to the stern post.
Note that the skid is steerable. The cables are connected to the rudder bar in the cockpit.

The Main tank, the Gravity tank and the Oil tank

The pilot could switch between the pressurized main- or the gravity tank by means of a fuel switch in the cockpit (left side of the pilot's seat.

With the fuel tanks located behind the pilot and well behind the CG with full tanks, the CG is at the aft of datum or 27% wing SMC (Standard Mean Chord). This caused the aircraft to be tricky to fly, but very maneuverable for a skilled pilot. While 413 Camel pilots were shot down in combat, 385 were lost in non-combat related situations, many due to the Camel's difficult handling.
When the fore-aft center of gravity is out of range, the aircraft may pitch uncontrollably down or up, and this tendency may exceed the control authority available to the pilot, causing a loss of control. Burning of fuel gradually produces a loss of weight and possibly a shift in the center of gravity.

The fuel system, showing the hand fuel pump and the three tanks. Note the fuel level indicator, a glass vertical tube, next to the throttle and mixture control handles in the center as well as the Rotherham pump on the top right.

Here a view in which the hand fuel pump and the tanks are clearly visible

Close view on the various parts that make up the fuel system. The fuel filter in front as well as the fuel indicator and fuel switch (main/gravity tank are clearly shown.

The Le Rhone Camels were fitted with a hydraulic Constantinesco interrupter gear, while the Clerget Camels had the percieved less efficient Sopwith-Kauper No. 3   mechanical synchronizing gear.

The Vickers gun was belt fed and had a higher rate of fire compared to the magazine fed Lewis gun, which required a magazine change every 97 rounds. The Camel's guns featured both left and right feed-blocks to improve ammunition feeding and ejection.

There are only seven authentic Sopwith Camels preserved.

F1 Camels : B5747 Brussels Air Museum (Belgium) - F6314 Imperial War Museum, Hendon (UK) - B6291 Javier Arango Collection at Paso Robles, California(USA).
B7280 Polish Aviation Museum, Krakow (Poland) - N6254 Aerospace Education Center in Little Rock, Arkansas (USA).
2F1 Camels: N6812 Imperial War Museum, Lambeth (UK) - N8156 Canadian Aviation Museum, Rockcliffe (CAN).
Fortunately there are many replicas......

Companies that Produced the Sopwith Camel

Sopwith Aviation Company, - Ruston Proctor Co. (a tractor manufacturer that built over 1,000 Camels), - Portholme Aerodrome Ltd. (a short-lived company, located in Huntingdon, site of Portholme - site of many air shows in the early days of aviation), - Boulton & Paul Ltd. (a maker of prefabricated wooden buildings, including the huts for Scott's Antarctic expedition), - British Caudron Co. Ltd., - Clayton & Shuttleworth Ltd. (known for steam rollers and traction engines), - Hooper & Co. Ltd., - March, Jones & Cribb Ltd., - Nieuport & General Aircraft Ltd. , - Wm Beardmore & Co. Ltd. (a naval shipbuilder of Dalmuir, Glasgow), - Fairey Aviation Co. Ltd., and - Pegler & Co. Ltd..

Rotary Engines

The World War I rotary engines had a unique operating characteristic in which the engine crankcase and cylinders would rotate, while the crankshaft was stationary. The weight of the spinning engine mass created a gyroscopic effect, although the often-repeated tales about tricky aircraft handling due to the gyroscopic effects of rotating engines are exaggerated, it could flip into a spin very easily at low speeds. The induced torque effect into the airframe created a limitation for the rotary engines as aircraft grew in size requiring rpm above 1,400 and ever greater horsepower.

Sopwith F1 Camel in 3-D

I've started the project from the drawings (6 large sheets)  I ordered from Jim Kiger, Replicraft, who created the plans sets from the original factory drawing, construction and rigging materials.The next thing to do was to obtain the required Gauge tables for sheet metal, wires and information regarding the various materials used.
All parts were created in 3D and assembled into the various main structures e.g. fuselage, empennage, wings, under carriage, engine etc. In order to do this I had to consult the huge library of photo's that I collected. Creating parts and assemblies in 3-D is great, but you have to compare the results with the "real thing". All these rendered images have been generated from the "virtually" built Camel in 3-D, full scale.

This images hows how the Clerget 9B engine is mounted in the Sopwith Camel.

The Central support drum is secured against the Front Engine plate (D2019-4) by 16 bolts, washers and nuts.
The Rear Support flange, screwed onto the crank shaft of the engine, is bolted onto the Back engine plate (D2029) by 8 bolts, washers and nuts.

Vickers Machine Guns and Ammunition

It was the first British type to carry twin Vickers guns as standard equipment. The guns were synchronized to fire through the prop arc and the gun breeches were enclosed in a cowling which gave it the appearance of a hump and thereby gave the Camel its name.

The feed-block of the standard Vickers gun was on the right hand side, but towards the end of 1917, the Camel's guns featured both left and right feed-blocks to improve ammunition feeding and ejection.

This image shows the ammo cartridges and the feeding and ejection chutes.

In British service, the Vickers gun fired the standard .303 inch ammunition belts, which had to be hand-loaded into the ammo cartridges.

This image shows the ammo cartridges and the feeding and ejection chutes.

In British service, the Vickers gun fired the standard .303 inch ammunition belts, which had to be hand-loaded into the ammo cartridges.

Close views of the flying Camel.

Close views of the flying Camel.

The Sopwith Camel was credited with the destruction of approx. 1,300 enemy aircraft, making it the most successful Allied aircraft of WW1.
However, despite its successes as a fighter plane, the Camel saw her last days as a ground strike platform to which it performed this role particularly well.

There are only seven authentic Sopwith Camels preserved ....

Don't forget to watch the video of  The Last Flying Sopwith Camel Europe's only remaining (flying) Sopwith Camel which came to Stow Maries.