Following on from Greg’s work on zone calls on 29 and 30 April, today saw another exercise in doing a shoot – directing artillery fire onto a target. That was evidently more successful than the two attempts at photography that followed: one was thwarted by engine trouble, and the other by the camera jamming.
Date: 4.5.18 Hour: 4.0 Machine type and No.: RE 6647 Passenger: – Time: 1 hr 20 m Height: 1500 Course: Shoot Remarks: Successful
Date: 4.5.18 Hour: 6.35 Machine type and No.: RE 6632 Passenger: – Time: 10 m Height: 1500 Course: Photos Remarks: Engine dud
Date: 4.5.18 Hour: 7.5 Machine type and No.: RE 5146 Passenger: – Time: 50 m Height: 2000 Course: Photos Remarks: Camera jambed
A Little More on Shoots
If zone calls are essentially about target acquisition for the artillery, then shoots are about target degradation and ideally destruction. In a shoot, the aircraft was again the artillery’s ‘eye in the sky’, to direct fire onto a target.
The corps squadrons of the Royal Air Force, and the Royal Flying Corps before them, worked with siege batteries of the Royal Garrison Artillery. Each battery might comprise four artillery pieces, for example 6″ or 8″ howitzers. The battery’s fire was directed from the air using ‘clockface’ radio signals in which the centre of an imaginary clockface was superimposed on the target and a number from 1 to 12 was used to indicate direction of a shell’s impact point from the target, with 12, 3, 6 and 9 representing north, east south and west respectively. The number was preceded by a letter code to indicate how far away the shell landed. The following diagram illustrates the numbers and letters:
A small complication was that the letter O was used instead of the number 12, in order to shorten messages.
The distance codes were:
- OK – Direct hit
- Y – 10 yards
- Z – 25 yards
- A – 50 yards
- B – 100 yards
- C – 200 yards
- D – 300 yards
- E – 400 yards
- F – 500 yards
So a near ideal sequence of signals for successive shells might be (in Morse code):
- C3 – shell landed 200 yards to the eastof the target
- A9 – shell landed 50 yards to the west
- OK – direct hit.
Ground-to-air signals from the battery to the aircraft were by means of ground strips.
For more, see:
For more on zone calls see: