This class was the most advanced of non-rigid airships when they came into service in 1917. They were designed to carry out long-term maritime and anti-submarine patrol missions and convoy escort duties. The crew consisted of 10 men distributed in two work shifts of 5 because some of these patrols lasted more than 24 hours. The record was a 101 hours mine-hunting patrol conducted in February 1919, during which it traveled more than 6,000 km!These airships carried a complete communications system. It was composed by a wireless telegraph equipment and the installation of Aldis lamps along with an international maritime signal flags to communicate with ships in high seas. Electricity on board was provided by two dynamos and batteries that powered the lights, telephones and other equipment.The first units of the class were somewhat problematic with the arrangement of the engines. NS-1, NS-2 and NS-3 were lost within a few months of their entry into service, so the next to be manufactured received several improvements and modifications. The change of engines and control cabins resulted in higher speed, lower air resistance and lower weight. Nevertheless, it was the greater reliability and ease of operation wich converted them probably in the best non-rigid airship class put into service.North Sea class conducted numerous missions during WWI and when the war ended there were still six airships in service. In July 1919, the NS-11 was lost in fatal accident and since then only the NS-7 and NS-8 remained, which would retire three months later. To their credit, there are several records, both of flight altitude, as well as the longest flight. However, their battle’s honours were not as bright as those of the Coastal class.
