members are appointed by the Irish government. The acquisition was completed in December 2010 at a reported cost of £1.2bn. NIE Networks remains an autonomous organisation with its own board and management teams, and separate regulation via the Utility Regulator. Operations The company's transmission and distribution network consists of 45,000 kilometers of overhead lines and underground cables, 75,000 pole-mounted transformers and 258 major substations. As of 2018, NIE Networks transports power to over 840,000 business and domestic customers. Network monitoring and control NIE Networks operates the distribution network from a primary control centre based at Carn Industrial Estate, Craigavon, County Armagh. A secondary control centre in Ballymena, County Antrim, provides a disaster recovery facility. The primary control centre is staffed 24 hours a day, and adjoins the Customer Contact Centre and Dispatch room. The control centre staff can monitor the status of circuit breakers and other assets in both the 11 kV and 33 kV networks using SCADA. A detailed computer model is supplemented by a large wall-mounted mimic board which features LED indicators showing the status of key assets, and paper diagrams. Incident management NIE Networks has developed a set of procedures for dealing with major incidents, such as storms and snow, driven by the Boxing Day Storm of 1998, during which 162,000 customers were off-supply. At the company's office in Craigavon, a small incident management room sits in a constant state of readiness. Each week, the Duty Incident Manager meets with the other designated incident team members, in charge of resources, customer contact and network status, to perform a risk assessment of the week ahead. The risk assessment takes into account the weather forecast, provided by the Met Office, notable events happening throughout Northern Ireland, such as concerts or VIP visits, and any planned maintenance on the network, or services required for the normal operation of the system such as IT and telecoms. The team assess the risks and decide if any action should be taken to mitigate them. If any risk factor is deemed too high, such as a strong chance of high winds over 45kts, a pre-planned escalation can be scheduled for the day in question. At any time, if there are many concurrent faults, the control room staff can escalate to an Incident Level. During an incident escalation, the Duty Incident Manager and their team man the incident room continuously and co-ordinate operations between dispatch