Welsh coal quality does not remove the logistics problem

Welsh steam coal is treated as exceptionally good fuel for warships, but not automatically as the most expensive or highest-grade coal produced in Wales. Express railways could justify still more costly fuel, while naval stations had to balance quality against the cost and difficulty of shipping large tonnages worldwide. Ships on distant stations therefore burned the best suitable coal available locally or deliverable there, not invariably the finest Welsh supply. The discussion links that constraint to modern navies, whose fuel must also be effective at scale rather than the premium product used by aircraft or racing engines.