Episode 5 of Season 2 picks up on the problem that closed Episode 4. The new smelting block has a flaw, and the commentary already has the fix in mind: space it out "to have coal run horizontally through here." Over about half an hour, Basket rebuilds the block with coal down the middle and long handed inserters, researches bigger power poles to run it, puts a turret line next to it, and then tears up the drills on the iron patch to lay them out again. When the video ends, the drills are back in rows and no research is running.
Coal down the middle
"We have a big bottleneck here." The inserters are grabbing from the wrong belt, so every other one comes out. The plan is to run coal through the middle of each column and reach it with long handed inserters. "They're a little slower, but I guess for the coal might not be too bad." Underground belts carry the coal under the rest.
The catch is power. "If I have long-arm inserters here, I need to power these somehow." Electric energy distribution 1 goes into research, and the commentary says the whole layout "relies on the better power lines that I'm about to get." The old furnaces keep running in the meantime, and a few repair kits get made along the way.
A viewer pointed out that better poles could go at the output side instead. "Oh, that's true." The commentary keeps the middle track anyway, "because maybe that's gonna be the output."
Bigger poles
Part of the block is set aside for steel, with a split in the belt to feed it. Steel and bricks from the chests turn into more steel furnaces, which leaves too little steel for the new poles. "Oh, we don't have very much steel, because I made it all into furnaces."
The research finishes. "Oh, we're ready for our bigger stuff." Medium electric poles go in down the columns: "that'll reach, awesome." With fast inserters at the top and the new poles in, the block starts putting out plates. Some steel turns up where none should be. "Where's all that steel coming from?" It turns out to be "a big stockpile" from before.
The columns go on up the belt, with the lanes swapped partway so coal stops below the steel section. "Ta-da!" For now that is "sort of the end of the line," and the commentary notes a bottleneck where it joins the main belt.
A wall of turrets
Next to the block, two assembling machines go in to make ammunition from the iron running past. Then comes "my wall of turrets," with gun turrets every other space, inserters to feed them and a stone wall in front. "This is an important area." Because iron already runs through here, "it's not like I have to transport it very far."
Rebuilding the drills
The old belts of coal through the ore patch no longer have a job. "If I had a deconstruction thing I would just highlight it and remove it. But I don't." So the drills come out by hand. "Our iron production will sort of halt for a little bit while we do it, but that's okay." A little later: "Oop, and I killed the power for up here." The new plan is "four lines at least" of drills with power down the middle, and warning icons sit over the drills while the rows go in.
Where it ends
Belts get rerouted so the output runs straight through, with a path left open in the middle. The last belt goes under and around, a pole goes in, and the commentary says, "There we go. Amazing." The video ends on the furnace columns at night. Electric energy distribution 1 is done and nothing new is being researched.