the filter bank trips. 17 August 2021 - The HVDC transmission line failed in the Weka Pass region, leading to conductors of the Pole 2 circuit falling across State Highway 7. Transpower issued a Grid Emergency Notice later in the day, advising that there was insufficient generation and transmission capacity to meet the forecast evening peak load in the North Island. Severe weather conditions delayed the repair and the return to service until 26 August. The original link Planning The initial vision for electricity transmission between the South and North Islands was developed by Bill Latta, the Chief Engineer of the State Hydroelectric Department. In 1950, he prepared a paper on the future of the North Island's electric power supply and he drew attention to the projected growth of the load and the limited potential for more hydroelectric generation development on the North Island. Latta's vision was to build more hydroelectric generating capacity in the South Island, where there was still significant opportunities for new schemes, and to transmit the power to the southern half of the North Island to meet the increasing demand. In 1951, the cable manufacturing company British Insulated Callender's Cables (BICC) advised the State Hydroelectric Department that a cable crossing of Cook Strait was possible, but difficult, since there was no precedent for installing power cables in such difficult marine conditions. The development of high power mercury arc valve converters in the 1950s led to the development of several HVDC transmission schemes in other countries. This demonstrated that a long distance, high power HVDC transmission scheme was feasible in principle. In 1956, the Government appointed BICC to undertake detailed investigations of the practicality and cost of a Cook Strait cable crossing. In December of that year, BICC reported that the project was "thoroughly practicable". In parallel with the technical investigations for cables underneath Cook Strait, the Minister responsible for the State Hydroelectric Department appointed a committee of key stakeholders to report on the options for power supply to New Zealand as a whole, not just the North Island. In 1957, the committee recommended that work commence on a large hydroelectric power station on the Waitaki River at Benmore, and that approval in principle should be given for linking the North and South Island's power systems. Recommendations were also received from the Swedish company ASEA (today part of the ABB Group), about the technical aspects of the