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Cake day: June 23rd, 2024

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  • Amateurs.

    The 1963 Černý Důl – Kunčice nad Labem aerial ropeway is over 8 km (5 mi) long, over 30 m high in places and carries 135 tons of limestone every hour from a quarry to the nearest train station. Its 120kW 3-phase synchronous motor requires power for a few minutes at the start and end of each day when most of the 800kg-capacity trolleys are empty, and spends most of the shift generating mains electricity and acting as a speed governor. Unlike the EV, it is fully autonomous most of the way, only 5 people are required to operate it. (Loading, unloading and timed dispatching is automatic, arriving/leaving carts just need to be checked; a safety latch has to be manually dis/engaged on trolleys passing the check.) The quarry will continue operation as long as it pays off, then the ropeway will be scrapped (projected 2033). A dude illegally rode the way up on it somewhat recently. He could have fallen to his death if he pulled the latch.













  • My point is, if you have a shared medium anyway, you can get rid of the MAU by having nodes manage the (virtual) token themselves, basically take limited-time turns based in some order like ascending MAC addresses. You could then wire the cable in any way you want with unlimited junctions, taps, whatever as long as you created a graph where all nodes are connected to each other. The entire point of a token ring is to manage a shared medium (that is, a single pair of wires, either UTP or coax, which can efficiently be wired along the shortest, possibly branching path) because if you have to use a direct connection from every endpoint to an MAU in a star topology, you could just have an Ethernet switch anyway.