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The government has released an interim report on the power outage across parts of the country on 9 August. Extracts from the section of the report on the impacts on essential services give an indication of the interconnectedness of power-dependent systems.

The Department for Business, Energy and Industrial Strategy has published a report titled ‘GB Power System Disruption – 9 August 2019‘ . It is an interim report by the Energy Emergencies Executive Committee. Extracts from the key parts detailing the impact on essential services can be found below and a summary at our Knowledge Hub.


‘The Department for Transport confirmed that rail commuters experienced significant disruption due to a safety mechanism built-in to all operational Class 700 and Class 717 Desiro City trains. This detected the drop in frequency on the electricity system which triggered 60 trains to shut down in order to protect the onboard systems and electronics.

While around half of the affected trains were restarted by their drivers, the rest required engineers to be dispatched, blocking tracks and causing huge disruption on lines into St Pancras International and King’s Cross. 371 services were cancelled and 873 delayed, despite these trains being unaffected by the power issues, and disrupting thousands of customers journeys.’


‘.. two hospitals were affected … with their back-up generation working as designed. Another hospital was affected by the fall in frequency/voltage excursion…’. ‘This was due to incorrect protection settings on the hospital’s own network, which resulted in the site switching over to back-up generation and one of its 11 generators failing to operate.’


‘Approximately 3,000 people experienced water supply disruptions due to booster water pumping stations failing to automatically switch over to back-up power supplies. Some of these customers would have experienced a temporary loss of running water in their homes, but others would have remained unaffected due to water storage in the system allowing running water to continue. The majority of customers were restored within 30 minutes.’


‘An oil refinery has confirmed to us that it was disconnected as a result of the site’s system which detected a drop in frequency and disconnected the plant to protect onsite equipment. The refinery operations team utilised the site’s emergency procedures and automated systems to safely shutdown portions of the plant however, due to the complexity of restarting large process units it took a few weeks to restore normal operations.’


‘”¦ two airports, one in the Midlands and one in the north of England, were impacted by the power disruption. One airport … had its own standby generation for its safety critical systems and power was restored via the distribution network after 17 minutes. The second airport … switched to back up power supplies without issue and was restored within a few minutes. A fault with its on site internal network meant that power to some services (check-in hall, central security search, hold baggage screening, and some telephony and comms systems) was delayed for up to 50 minutes.’


For further reading, please visit our Knowledge Hub.

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