A machine that builds itself. Or how a crane is assembled using the same crane.

A tower crane doesn’t just "assemble itself" like magic. What you see in the video is the self-erecting system using a climbing frame. Here is the mechanical process: 1. Starting with external help First, the concrete base and the initial mast sections are assembled using a mobile crane. Once that crane reaches its limit, the real trick begins. 2. The climbing frame A steel structure (a cage) is installed around the mast, right beneath the slewing unit (the part that rotates, holding the cab, jib, and counterweight). This cage is equipped with powerful hydraulic cylinders. 3. Controlled disconnection The upper part of the crane is unbolted from the mast. That entire mass (tens of tons) is left hanging from the climbing frame. 4. The hydraulic "jump" The cylinders push upward. The cab, jib, and counterweight rise about 6 meters, leaving a perfect gap. The center of gravity must be positioned exactly over the mast; otherwise, the crane loses its balance. That’s why the trolley and jib are moved to maintain equilibrium. 5. The crane lifts itself Using its own hook, the crane picks up a new mast section (weighing several tons and standing 6 meters tall) from the ground and inserts it into the gap it just created. 6. Securing the section Workers (the ones in orange on the platforms) align the parts, insert giant pins, and tighten the bolts. Then, the hydraulics retract, and the weight shifts onto the new section. The crane has just grown taller. The cycle repeats as many times as necessary. This allows the crane to "grow" at the same pace as the building. It is precision engineering: hydraulics, geometry, and mass balance. A mistake of just a few millimeters, and everything goes to hell. That’s why it looks like science fiction, but it’s pure mechanics.

I haven't stopped feeling grateful since it happened. Some days are just worth savoring.