And the cost of sustaining the R1 is not affordable (read post 1310 - why do I bother???). The R1 is being replaced on COST grounds. It is not about whether or not it would be feasible to keep it going in engineering terms, but how much that would COST.......
Watch my lips, cost, cost, cost.......
No doubt our political lords and masters may also be glad to see the backs of 'Nimrod' on other grounds, but that is beside the point......!!