Buying & Consuming Coal or Iron

When you need coal, take it free from the closest connected, unflipped Coal Mine — owned by anyone — measured in fewest Link tiles away; only buy from the Coal Market if nothing connected has coal left, and only if you also have a connection to a Merchant. Iron works the same way but never needs a connection at all — any unflipped Iron Works anywhere gives free iron, and the Iron Market needs no Merchant connection either. If two Coal Mines are equally close, you choose; if one runs out, use the next closest. Spent coal, iron and beer go back to the General Supply.