{
  "type": "railcraft:rolling",
  "key": {
    "a": {
      "item": "railcraft:advanced_rail"
    },
    "b": {
      "item": "railcraft:standard_rail"
    },
    "c": {
      "item": "minecraft:redstone"
    }
  },
  "pattern": [
    "aca",
    "aba",
    "aca"
  ],
  "result": {
    "count": 8,
    "item": "railcraft:elevator_track"
  }
}