This is a modified version of the original 3-10-3 mega smelter that I made that only allows ore trains into a smelter that has a plate train waiting. It also has a prevention system that makes sure that you will not have a train no pathing on the way to deliver ore. You have to give the second station behind the true ore delivery station a name and add it to all your ore trains. You can have it wait for anything that you like as long as its there. You also have to put an item on each of the belt loops and set all the signals in the belts and combinators that were bluebelt to be the item of your choice.