ABSTRACT
Air is supplied to the service tunnel from ventilation buildings at Shakespeare Cliff and Sangatte. At the English side the fan buildings are connected to the service tunnel by a shaft. There are two fans, each rated at 88m3 Is at a pressure of 2.9kPa. Each of the fans can do the full duty so that there is 100% standby capacity. This enables the ventilation to be maintained if one fan fails and also routine maintenance can be carried out on one fan whilst the other continues to operate.
