PROJECT 54: THE NETHER TUNNELS
Somehow, I doubt this is a very interesting project. But it's something I'd been meaning to do for a while, and now seemed as good a time as any to do it. The railways through the Nether that are a short cut to the outer reaches of this world have never been consistent in their construction - recently I've started using Nether brick to lay the tracks on with redstone blocks for the powered rails, but that was far less of an option when the first few of these railways were built. Some of the tunnels were out in the open for pigmen to walk on if there was a cave high up near the Nether roof, where these are built. The plan here was to turn every tunnel into one completely built of Nether brick - roof, walls, track base - with occasional lighting where the powered tracks are.
It took 153 Minecraft days just to finish the tunnels; while this could fit into the time available between The Great Parrot Hunt and the 20-year mark (which would have been the logical thing to do, making it part of the Nether hub refurbishment), I had no way of knowing in advance I could finish it in time, which wasn't the case with securing all the villages, where at least I had target time for each one and could always tell if I was on schedule.