An inner cordon will be established to control the immediate scene of operations. The cordon must take into account the specific factors associated with working at height, such as:
- Almost any object falling from height may cause injury. Personal protective equipment (PPE) should be worn inside the cordon but may not be enough to protect personnel from injury.
- The wind can have a dramatic effect on how far objects travel: for example, a karabiner with a sling attached will travel a considerable distance because the sling acts like a sail in the wind. Even with no wind, some objects will naturally plane away from a structure.
- The height at which work is taking place can have an impact on how dropped objects behave, particularly if the wind is involved and if objects strike the structure on the way down, causing them to bounce outwards.
- There is a risk that equipment may be tampered with, for example, anchors could be vulnerable if set up and then left unattended.
A range of issues must therefore be taken into account when deciding on an appropriate cordon. The unique situation and circumstances of each incident will inform the incident commander's judgment about the size of a cordon and whether the minimum cordons recommended should be increased.
The location and environmental conditions such as wind at the incident will need to be considered when establishing an effective cordon around a work at height incident, as these factors could affect the movement of an unsecured item falling from height. The type and shape of structure can also have an effect on the way that items may fall, for example very tall buildings can create specific wind conditions that can make items move laterally further than may be expected.
See National Operational Guidance: Incident command.