This huge mechanism at the Carrie Blast Furnaces National Historic Landmark in Pennsylvania lifted and dumped rail cars into huge hoppers ready to be fed into the blast furnace. Six months supply of Iron ore and limestone were stored on site since the barges bringing the feedstock to the plant could only operate for half the year. You can find a fascinating video describing the structure at https://youtu.be/wMR8a411v0c?si=wDXrbHKKdcVF9ouS.
For the technically inclined...