The Blast Furnace is a multiblock structure added by Railcraft. This structure is used to turn Iron into Steel. The Blast Furnace will only take Coal Coke and Charcoal as fuels, requiring 1 Coal Coke per ingot, and 4 Charcoal per ingot. To build the structure you require 34 Blast Furnace Bricks in a 3x3x4 with a hollow middle. You will know you built it correctly because it will show a window on the bottom-middle of each sides. When this furnace is active it will contain lava in the middle, so you should not break it while active. You cannot place 2 Blast Furnaces directly next to each other, you must have another block, or a gap in between the two.
