before anyone says it... no to downloading RailCraft.
all i'd like if a chain that i can use to make 1 minecart "follow" the other for industrial and storage uses. these could be used to specify the led train cart and the secondary train cart, and then could be chained in a line of like 12 carts to make either a cargo train for transporting supplies or players like a Subway System.
maybe have the recipe 3 Refined Iron in a vertical line.