The Junkyard Crane

The scrapyard at the edge of town buys everything: old cycles, dead fridges, bent gates, tin cans, broken plastic chairs, all of it, dumped in one enormous heap taller than the gate. But the yard only gets paid for the iron and steel. That's what the furnace across the river wants — clean metal, nothing else. So before anything can be sold, someone has to pull every scrap of iron out of that mountain and leave the plastic, the wood, and the rubber behind. Doing it by hand would take a week and shred your fingers. And here's the part that makes it impossible: a lot of the iron is buried, tangled, half-crushed inside other junk. You can't even see most of it. The old sorter, Rehman-chacha, doesn't touch the heap at all. He swings a fat steel drum on a chain out over the pile, and — you don't see him do anything — a great clump of nails, rods, and cans leaps up off the heap and sticks to the drum as if it were alive. He swings it over the iron cart, and the whole clump drops in one go. Plastic and wood? They don't budge. Not one piece. He never presses the drum down. He never uses a hook. The iron just comes to him when he wants it and lets go when he doesn't. The other kids think it's a trick magnet. But a plain magnet would never let go — once iron sticks to a fridge magnet, it stays stuck. Rehman-chacha's drum grabs a hundred kilos, then releases it on command, over and over, all day. There is a switch in his cab. That's the whole secret. A magnet you can switch on and off. Today, your team is going to build one.