NS has changed it's mind about a next generation destroyer platform after ceasing any development work last year, including the third phase of the Type 51, in favour of the Black Triangle programme. NS has now decided it will need conventional destroyers in future decades after all. The Isometric will finally reach the end of it's life in the mid-2130s, with the Mediterranean Sea, Freedom and Proxima Centauri fleets following later in the decade. All in all that is nearly fifty ships which will need to be replaced.
NS has begun the Destroyer Third Generation (D3G) design study (presumably the Starsystem and Isometrics are counted as being the same generation) which will feed into a design programme for a future destroyer by the end of the decade. NS has ruled out the new ships being a future development of the Type 51 due to the time gap.
