Captain of Industry developer MaFi Games has detailed Update 4.3, which is due "in a few weeks". In Captain's Diary #57, published on 21 October 2026, Captain Marek describes the update's headline feature, full support for mixed materials, along with factory overlays, radiation-shielded train wagons, new train statistics and a web server built into the game. Players who want to try it early are told to watch the experimental branch.
Mixed Materials Everywhere
Trucks and excavators could already carry mixed loads, but storages, conveyor belts and trains could not. That meant every mine needed an ore sorting plant, plus separate storage for rock, dirt and ore. "So yes, we made you sort rock from dirt just to dump them both into the ocean," Marek writes.
In Update 4.3, mixed mined materials can be stored, moved on conveyor belts and loaded onto trains. A factory can now run one central sorting facility, and terraforming gets faster because unsorted material can be dumped without sorting it first. Ore sorting plants gain conveyor input ports and can send materials they aren't set up to sort straight to an output, and mine towers can be assigned mixed-material storages.
The same system fixes how recyclables work. They used to be tracked in one global register, so recyclables from Maintenance I production, which uses only iron, could return copper and glass scrap just because a research lab elsewhere was consuming copper and glass. Now every recyclable remembers what it was made of, which makes local waste sorting plants for only some scrap types possible. Settlements also respect the recycling ratio now, so they will produce fewer recyclables than before.
Overlays for Spotting Problems
To help players find issues in large factories, Update 4.3 adds overlays that gray out the game view and color only the buildings of interest. It launches with eight, covering productivity, pollution (including radiation and landfill), building priority, electricity and computing, workers, maintenance and product flow. The overlay system is open to mods, and the pollution overlay finally makes radiation visible.
A separate overlay colors train tracks by their maximum speed. Steep 25% tracks now have an 80 km/h speed limit, the same as medium R22 turns, while shallower 12% slopes still have no limit.
Safer Trains for Radioactive Cargo
Players had no good way to move radioactive materials over long distances, so MaFi built a new class of radiation-shielded train wagons and stations. They can store and carry any radioactive cargo without causing radiation pollution, and they are part of the base game. Each wagon holds 240 units and takes about twice as long to load. The developers also improved how radiation is tracked, so the game can now detect and fix radiation that "leaks" through miscounted products, whether the cause is a bug or a mod.
Statistics for Train Networks
Every train and train line gets an activity graph showing how much time it spends idle, working, refueling or not working, by month and by year. A second statistic shows travel efficiency: not traveling, accelerating or braking, traveling at full speed, limited by the track speed limit, or blocked by other trains. In a healthy network, trains spend most of their time accelerating, braking or at full speed, and as little as possible limited or blocked. Marek says the feature was partly inspired by YouTuber Charles Circle Gaming, who optimized a large train network with player ringgeest11.
A Web Server Inside the Game
The console command web_api_start now starts a web server that runs locally on the player's computer and cannot be reached from the internet. Code in the game or in mods can answer requests at a URL with HTML, JSON or binary data, and a demo dashboard can change the game speed and fetch screenshots from a browser. MaFi sees modders using the browser as a second screen for dashboards, alerts and notes. Developer Matt has already prototyped a live, zoomable minimap with moving vehicles. For now, the officially supported features are the demo dashboard and screenshot retrieval.
Smaller Changes
- Products at the ends of conveyor belts no longer pop in and out of existence, and connectors are about 25% faster to simulate
- Changelogs are machine-translated into all 20 supported languages, and mods can now include their own translations
- A new first-launch screen picks the language and the monitor and window mode, and the language can be changed from the main menu without a restart, with British English now available
- A rewritten sound system groups similar sounds so more variety can be heard, and adds ocean, forest and terrain collapse sounds
- Work on making the simulation fully deterministic makes bugs easier to reproduce, is the basis for a replay system in development, and brings multiplayer closer
