But how do the Olympic fencing helmets work? Basically the fencing system in use consists of a simple open-closed circuit that detects a charge from the opponent’s weapon. When hit is detected, the signal is sent wirelessly to the scorekeeper station, which in turn indicates the hit. The lights on the futuristic helmets actually display the same information that has been shown on the scorer’s desk for years.
Variations exist on the scoring mechanism depending on the weapon used, since different weapons (foil, saber, etc.) will score in different areas of the body. The helmet display also helps the referee make quicker scoring calls, potentially critical in a tight match, as well as allowing the duelers to know when a hit has been scored without diverting attention from the action.
In order to better explain the helmet’s lights, it is necessary to briefly discuss electric fencing scoring. The explanation refers to foil use, but the method is similar for other weapons.
In electric scoring, a dueler most be a wearing a metallic vest, known as a lame, and use an electric foil (or other applicable weapon). The lame is worn over the jacket, and this covers the target area. The foil parts of note are the bell guard that protects the hand, the piste, and the blade itself.
The foil has button on the end with three wires. These wires attach to the target lame, power, and return. The bell guard and piste are electrically grounded. The button is a normally closed switch that is opened when .1 lb of force depresses it.
When the foil touches something, then one of the scenarios take place below:
- if the foil touches opponent’s piste or bell guard then there is no effect and play continues
- if the foil touches the target, then colored lights indicate a valid hit
- if the foil touches a non-metal part of the opponent, then a white light indicates an off-target hit
- if a foil touches a non-metal part of the opponent before touching the target lame within 1/20 of a second, then both lights light up indicating an off-target hit. No points are awarded.
When lights go off, play is stopped until the director can sort out the action. Is is not uncommon for both players to have lights at the same time, so the player with right of way is awarded points. In the case that both duelers make valid touches at the same time there are no points awarded.