Episode 14 of Season 2 is a live stream, and it picks up the Rail chain signal that closed Episode 13. Basket places a few on the rail grid to see what they do. After that the tank goes south against the enemy bases, a new cell for solar panels goes into the grid, and a defended block goes up on the northern edge. When the video ends, the chain signals still have no job, and the new block is short on inserters.
A tour of the grid
The stream opens with a catch-up. Each walled square of the grid is its own logistic network, built from templates: a roundabout, a straightaway, and in the middle a solar field or a smelting block. One square takes iron and makes "iron sticks," and one train's "entire purpose is to get sticks, store sticks, and then bring it to wherever I tell it to go," which for now means a square that makes lamps.
Traffic jams still happen. The commentary lists what the intersections have taught so far: no signals inside a crossing, so only one train can be in it, and an extra signal at a small cut-over, so a train going straight is not held by one turning.
Testing the rail chain signal
The description on screen reads "Reads the next signals in the path to allow better control of the trains." The first one goes on a track the stick train uses. The commentary watches it turn red, then blue, and works it out from the trains: one stops at the chain signal when the path it wants past the next signal is busy, while a train headed another way rolls straight through. "So it's able to see kind of ahead of time the road I want to go is it actually available."
To test it, the green chip train gets sent by hand to the lamp drop-off. It stops where a regular signal would have let it move forward. "I don't know exactly how to use that yet." The chain signals come out, and regular ones go back in.
Tank runs to the south
The map shows enemy bases crowding the southern edge, and they have to go before the grid can grow there. The tank gets loaded, and the routine is drive-bys: shoot with the machine gun, swing back to the wall where the turrets help and the robots repair the tank, then go again. Cannon shells handle the biggest enemies, which the machine gun cannot kill, but "the cannon shell takes plastic to make, so I typically run out."
The rule, learned the hard way: "If I stop moving, ever, they surround me." Trying to run over too many enemies at once leaves the tank stuck twice, and once it comes close to blowing up with all its shells inside. After many passes several nests and one of the big enemies go down. "Yes! Took it out!"
A solar panel cell
Back in the grid, an old square gets cleared for a construction template that makes solar panels from steel, green chips and copper. The robots tear out the old parts first. Then the inserters get set to the new items, and one back belt in the template turns out to run the wrong way, a fix saved for later. The new stop is "SolarPanelMatDropoff," and the green chip, copper and steel trains each get it added to their schedules.
The first green chip train arrives empty and needs a pickup stop added ahead of the drop-off. Once chips arrive, "the little gears in the buildings are moving," and finished panels land in a chest for the robots to place around the grid. The commentary adds that trains stopping inside these cells cause jams, and a future playthrough might put construction on a side track instead.
A new block in the north
On the way north, on foot because the car cannot drive through trees, the commentary shows a deep coal storage area where trains drop off leftover coal. Near the edge, trees come down and the grid template goes in: walls and track first, then the defense module on the outer sides. Chests in the module request ammunition for the turrets. Enemies nearby get angry, and the commentary expects some back and forth until the turrets have ammunition. Two small turret extensions, fed from a chest by belt, go along the wall so it can creep forward.
Where it ends
"That's gonna be the end of the stream." The commentary says research has slowed, and the next plan is cells for each kind of science. The new block is still going up, and the robots are short on inserters, so some get handed over. The research box shows Inserter capacity bonus 6 from start to finish, and the idea of express lanes using chain signals stays an idea.