Sight Lines for Seated Spectators

The Guide to Safety at Sports Grounds, United Kingdom, provides a detailed explanation as follows:

Sightlines

The term “sightline” refers to the ability of a spectator to see a predetermined focal point ( on the pitch or area of activity) over the top of the head of the spectators immediately in front. The better the sightline, the more likely it is that spectators will remain seated during the event. Ensuring adequate sightlines is therefore an important part of providing safe seated accommodation.

The quality of a sightline is often expressed as a C value. Diagram 12.1 below shows how C values are calculated. The recommended C value for spectators varies according to the sport, as does the choice of focal point.

For example: it is important for spectators at football or rugby matches to be able to see the nearest touchline, so this should form the focal point. However, a focal point further in-field may be acceptable for viewing cricket.

Because of the complex nature of sightline calculations in individual circumstances it is therefore recommended that management seeks professional advice from competent persons of the appropriate skill, and with experience of designing spectator accommodation for the sport (or sports) to be staged.

The point of focus is often a point of conjecture, however EN13200-1:2003 states the following points of focus in millimetres above the finished floor level or ground level: