Petroleum Resin to Plastic Bar Chain

Lore & Background

On the scarred, iron-rich surface of this unnamed world, vast pools of viscous black liquid seep from fissures in the bedrock. The settlers who arrived in the crashed capsule found that this crude oil, when subjected to controlled thermal separation, yields lighter and heavier fractions that carry a peculiar amber resin. That resin—Petroleum—smells faintly of sulfur and warm stone, and it is the key to producing the rigid, pale bars that will become the skeleton of every pipe, every structural panel, and eventually every component in the factory. The process is deceptively simple in concept but punishing in execution. A single Oil Refinery must first crack the crude into its two fractions, then each fraction must be fed back through a second refining pass to coax out the Petroleum alongside the first batch of Plastic. Only then does the Chemical Plant step in, running the Petroleum through a polymerisation cycle that yields the final, uniform bars. Three distinct machine stages, two of them the same type, all linked by a web of pipes that must never clog, never leak, and never run dry. For the player, this chain marks the moment the factory stops being a handful of assemblers and starts becoming a system. The hum of the refineries, the slow amber pulse of Petroleum flowing through translucent pipes, the rhythmic clunk of Plastic Bars ejecting from the Chemical Plant's output slot—these become the ambient soundtrack of early progress, a reminder that every complex machine still rests on this humble, three-stage transformation of black rock-liquid into something you can hold.

In Their Own Story

The night shift was quiet except for the low thrum of the refineries. Kael pressed a gloved thumb against the warm pipe running along the refinery's flank and watched the amber glow of Petroleum pulse through the translucent tubing, slow and steady like a vein. Somewhere downstream, the Chemical Plant was chewing through its batch, and the soft *clink-clink-clink* of Plastic Bars dropping onto the output belt was the only music he needed. He'd built this line three weeks ago, back when the factory was two assemblers and a prayer. Now there were six refineries, four chemical plants, and a tangle of pipes that looked like the nervous system of some vast, slow creature. The oil wells were finite—each one a dark, glistening wound in the ground—and he'd already had to send a survey team to the eastern ridge to find more. But tonight, the bars were flowing, the belts were full, and the factory was alive. Kael peeled his glove off, wiped the oil residue on his trousers, and let himself lean against the refinery housing. It was warm. It was enough.

Reader's Guide

The full chain runs in four recipe stages across two machine types:

**Stage 1 – Crude Split:** Input: 1 Crude Oil. Output: 1 Light Oil + 1 Heavy Oil. Machine: Oil Refinery. This is the entry point; Crude Oil must be pumped from an Oil Well and piped in. **Stage 2 – Light Refine:** Input: 1 Light Oil. Output: 1 Petroleum + 1 Plastic Bar. Machine: Oil Refinery. Runs in parallel with Stage 3. **Stage 3 – Heavy Refine:** Input: 1 Heavy Oil. Output: 1 Petroleum + 1 Plastic Bar. Machine: Oil Refinery. **Stage 4 – Polymerise:** Input: 1 Petroleum. Output: 1 Plastic Bar. Machine: Chemical Plant. This is the step that gives the chain its name. **Optimal ratio:** For every 1 Crude Oil, you produce 2 Petroleum (one from each fraction) and 2 Plastic Bar directly, then the 2 Petroleum yield 2 more Plastic Bar—giving 4 Plastic Bar per 1 Crude Oil. Machine ratio is roughly 1 Refinery (Stage 1) : 2 Refineries (Stages 2+3) : 2 Chemical Plants (Stage 4), adjusted for real-world speed modifiers. **Bottleneck:** In the early game the Stage-1 Oil Refinery is the choke point because it feeds two parallel lines. As the factory grows and you add speed research, the Chemical Plant stage tends to become the limiting factor since it is a single-input, single-output process with no parallelism per machine. **Scaling:** The chain scales linearly with machine count but is constrained by the finite number of Oil Wells and the pipe network required to feed them. In large factories, dedicating an entire sector to petroleum processing—wells, pumps, refineries, chemical plants, and buffer storage—becomes standard practice to avoid pipeline starvation.

Did You Know?

• Plastic Bar is a prerequisite for crafting Pipes, which in turn are required to transport the very liquids that feed the petroleum chain—making it one of the few self-referential loops in the early game.
• Oil Wells are a finite surface resource; once depleted, they cannot be regenerated, so players must plan well placement carefully before committing to a large petroleum sector.
• The Petroleum intermediate is a liquid, meaning it must be moved through pipes rather than item belts, which adds a layer of logistical complexity not present in solid-item chains.
• The same Oil Refinery machine type handles three separate recipes in this chain, so a single physical building can be assigned to any of the three stages depending on which input pipe is connected.