The Tunnel Bore - picture from Railcraft Wiki
The Tunnel Bore is a part of the Railcraft mod. When given a bore head, fuel, tracks, and gravel, the bore will dig through blocks, place rails, and place gravel to create a surface for rails if it comes across holes. Carts can be attached to the bore to ride with the bore, chest carts can be attached to the bore for the mined blocks to be stored, and anchor carts to keep the bore digging even when chunks aren't loaded.
The tunnel Bore will stop mining if water or lava is 2 blocks ahead of the bore. Although giving it gravel will make it fill in gaps, if the gap is too big it will stop without trying to fill it.
Crafting[]
