Episode 15 picks up with "a couple changes since the last episode" already made off camera and "Press T to start a new research" in the research box. It doubles as a live stream, so some of the talk is aimed at viewers. Over the hour Basket opens a new iron mine with turrets around it, sorts out a jam in the furnace rows, and starts a new plan: one long main belt running north, with assembling machines along it that put ammo, gears, copper cable and circuits onto belts. When the video ends the first rows are built, power and defense are still being patched, and Electric energy distribution 2 is researching.
More iron, and guards for it
The opening tour finds congestion. Steel plates were "messing everything up," so for now they are being pulled off the main belt, and a fight breaks out at the edge of the base before the tour is done. Basket drops a turret there, tests how underground belts sit next to a chest, and decides the base needs more iron: "I feel like I actually need more iron in the process."
The map shows a big iron patch to the north. Before mining it, Basket rings it with gun turrets ("I just really don't want all my stuff to be destroyed"), then packs electric mining drills across the patch and runs power poles down the middle. The commentary is not sure about the spacing: "maybe actually building them directly next to each other isn't the best." Night falls while a belt goes in to carry the ore back toward the base.
Untangling the furnaces
The extra iron meets a bottleneck where several belts merge into one. Basket crafts more fast transport belts, upgrades the stretch where they join, and reroutes the lines so one belt is the main feed. The furnace rows are the next problem. Some furnaces sit idle because "the output's too slow," and filter inserters set to allow steel are grabbing iron meant for elsewhere. Basket rebuilds a row so both belts run straight down, resets the filter inserters to iron and steel, and finds one spot still on a slow belt. "There was one spot where I didn't have a faster thing, so we're good now." The backup starts to clear.
Research picks up again too. Electric engine goes in, finishes a few minutes later, and Flight follows.
Biters at the solar field
Basket clears trees to the north and loops a belt so copper rides one side and iron the other. Then an attack hits the solar panels. "There's a bunch of bad guys that decided to avoid all of my defenses," the commentary says, "and then they came in the side." More turrets go in, filled with ammo by hand, which is the part Basket wants to stop doing: "right now I have to go manually grab it all."
The main belt and the first assemblers
The new plan is a long main belt going north, with a dedicated belt beside it for each resource, spaced so turrets fit between them. Filter inserters move steel onto one side of the new belt. Flight finishes and Sulfur processing goes in. Ammo production moves up the line: a small block of assembling machines pulls iron off the main belt, and the ammo travels around and under the belts to the other side of the steel belt. Gun turrets go along that line with inserters pointed into them, "so that these turrets that will be defending this thing I'm making will be automatically populated with ammo."
Three assemblers for gears come next, then three for copper cable, each pair of rows feeding one side of a new belt. Sulfur processing finishes, and Electric energy distribution 2 starts. The underground belts surprise Basket by passing under another tunnel: "You can. That seems crazy." Last come three assemblers for circuits, fed iron and cable by filter inserters, dropping the chips onto the inside of another belt. "So now the inside belt of this is now green microchips."
Where it ends
The commentary sums up the idea: keep the belts full, add a new row of assemblers wherever something is needed, and maybe put a buffer chest at the end. "There might be bottlenecks, but for now I think this works pretty well." A turret maker is talked through but not built, and the episode ends over the new rows at night, with Electric energy distribution 2 still researching and the hope that "these turrets can defend this area, because the bad guys are real bad."