Deflection
From The Dreadnought Project
Deflection is an ambiguous term in many sources covering the World War I period, especially British ones owing to the twisted etymology of the word.
Be careful when contemporary British sources use the word "deflection", as it might mean either speed-across or gun deflection depending on the context.
| When a British source says... | ...it means |
|---|---|
| "Deflection" | (ambiguous) |
| "Gun Deflection" | Lateral Aim-off |
| "Sight Deflection" | Lateral Aim-off |
| "Dumaresq Deflection" | Speed-across |
Torpedo Control Usage
To make matters even worse, when "deflection" is spoken of in the sense of how to set a Torpedo Deflection Sight or similar device, they are generally speaking of the speed-across attributable to only the movement of the target vessel, discounting that attributable to movement of own ship. On this site, you may find that I employ my own term to make this distinction explicit: Torpedo Deflection.
