If I remember correctly, the first doped fibre manufacturing, or maybe the first fibre manufacturing, used an old peening drop tower (https://en.wikipedia.org/w

If I remember correctly, the first doped fibre manufacturing, or maybe the first fibre manufacturing, used an old peening drop tower (https://en.wikipedia.org/wiki/Shot_tower https://en.wikipedia.org/wiki/Shot_tower) for the gravity feed. I guess they are called "drawing towers" now.