The Cannon Pioneers

[Tony Williams]

For those of you interested in this subject, there is an illustrated article on my website here: http://www.quarry.nildram.co.uk/cannon_pioneers.htm

[centurion]

Some additional info for your article

The Vickers Crayford whilst a conventional gun utilised a propellant that burnt slightly slower than the conventional filling. This resulted in a slower build up of pressure in the breech allowing it to be of simpler and lighter construction. This mixture was not entirely satisfactory (and may have been the cause of the hang fires) sometimes not all the propellant was consumed in the initial firing leaving a burning residue to exhaust backwards when the breech was opened and the cartridge extracted. This problem was not evident when ground firings were made but was all too obvious to gunners of those FB2s fitted with the weapon as the air pressure from the aircrafts forward motion caused a stream of air down the barrel that would blow the burning material back and over the gunner. Crews involved in the development trials of this weapon could be easily distinguished by pained expressions and a complete lack of facial hair.

A significant number of aircraft were designed (and built) to take the Davis. These included the ADC Scout of 1915 and the Blackburn Triplane of 1916 respectively. Both were designed by the same person and very similar in concept being single seat triplanes with pusher engines and propellers mounted behind the pilot. The tail assemblies were mounted on a spindly looking framework attached to the upper and bottom wings. The nacelle for the pilot and engine was, unlike most pusher aircraft, mounted high up on the top wing, presumably to maximise the chances of the pilot being killed if the aircraft should nose over on landing! This was encouraged in the ADC design by a tall main undercarriage with the wheels extremely close together. Maintaining the engine on both aircraft would have been awkward for the ground staff and the airman who swung the propeller to start the engine must have had an interesting time as he would have needed to do this from a stepladder (and probably been blown off it by the prop wash). Both nacelles had long deep noses to house the Davis gun, these must have greatly impeded the pilot’s forward view. It seems probable that both aircraft were designed without their designer being aware of the full characteristics of the Davis gun. If fitted in the Sparrow the breach would have been between the pilot’s legs, giving full scope for the effects of the escape of fire and smoke, whilst in both aircraft the only direction in which the counterweight could be fired would be through the propeller with a high probability that this would be smashed. In fact neither aircraft was fitted with its intended armament and both never proceeded past the prototype stage.

The RE8 in the Middle East used a 'lash up' mounting the Davis gun on the outside of the fuselage where it could be loaded by the observer. It fired downwards at 45 degrees. At least one successful attack was made on Turkish positions. This is the only instance of a Davis being used in action

The second Pemberton Billing Machine was actually a Supermarine aircraft (PB had relinquished controll of the company as there was a conflict of interest with his activities as an MP). It was apparently called the Nighthawk although I believe its crew replaced night with another word that rihymed with night. A junior member of the design team was R J Mitchell later much better known for the Supermarine Schnieder Trophy racers and , of course, the Spitfire.

I have more if anyone's interested.

[BlackSeptember1918]

A very interesting article Tony . I learnt a fair bit reading that . Thank you .