TNT Duper (Rail Duplicator)

The classic coral-fan TNT duper for Java Edition only (it relies on Java piston behaviour, and Paper servers switch it off). It hangs in a glass and stone-brick chamber on top of a tower over a water pool, with a platform, a stair, chests with hoppers, a rail spur and lanterns. The machine follows the common documented design: two L-shaped sets of three slime blocks, a stone brick wall with the TNT under it, a dead coral fan on the side of the lowest slime block, a detector rail on the slime next to the wall, and a sticky piston against the top slime block, worked by a lever through the front window. The last step is yours: put a minecart on the detector rail (the pictures don't show it). Then flip the lever once to prime it. That first push moves only the upper slime blocks forward, so the slime under the rail ends up over the TNT. After that, keep flipping the lever: the machine rocks back and forth and drops lit TNT through the hole in the floor into the water, where it explodes without breaking any blocks. The TNT block itself stays put, so it never runs out. Leave the air around the machine and the hole under it exactly as the guide shows.

Difficulty

hard

Steps

11

Blocks

542

Time

~27 min

Size

13×11×10

Version

java 1.21