Factorio Megabase Transition Guide - From Starter Base to 1,000 SPM

I rebuilt my factory three times trying to reach 1,000 SPM. The first attempt: slapped beaconed assemblers onto my existing main bus. The bus collapsed under the throughput. Second attempt: built a train network without train limits. Deadlocks everywhere. Third attempt: planned modular outposts with circuit-controlled trains. It worked. Here's the playbook I wish I'd had.

When to Start the Transition

The signal: Your main bus has 4 belts of iron and 4 belts of copper, and you need more. Instead of adding belt 5 and 6 (which requires rebuilding the entire bus), lay down your first train loop.

The rule: The starter base stays. It produces construction materials (mall items), modules, and fuel. The megabase produces only science. If the starter base breaks, your megabase stops expanding, but the megabase doesn't need to produce everything - only science.

The Megabase Design Philosophy

A megabase is a collection of modules (independent production cells) connected by trains.

Module template:

• Receives raw materials via train (iron ore, copper ore, coal)
• Produces one intermediate (iron plates, green circuits, steel)
• Loads output back onto trains
• Has local roboport coverage for construction
• Is beaconed with 8 or 12 beacons per building
• Has solar/accumulator blueprint for power independence

Step 1: The Rail Network

The rail network is the spine of your megabase. Build it first, even before any module.

Rail blueprint essentials:

• 2 lanes per direction (4 tracks total in the middle section)
• Roundabouts at every rail intersection
• Train limits on every station (disable the old stacker-based system)
• Railyard with refueling (refuel at depot, not at stations)
• Grid pattern: each chunk (32x32) gets one rail segment

Intersection design: Use a 4-lane roundabout for main intersections. Compact "T" junctions for branch lines. No intersection should cross tracks - use bridges (elevated rails in 2.0) to separate crossing paths.

Train limits (the 2.0 revolution):

Instead of building stackers, use the train limit feature:

Station signal: Enable/disable based on chest contents
Train limit: Set to 1 for small stations, 2-3 for large stations

• When a station has enough materials for one train load, limit = 1
• When almost empty or full, limit = 0 or higher
• Trains automatically target stations with available slots

This eliminates deadlocks and removes the need for stackers. The railyard provides fuel and a default stop for idle trains.

Step 2: Smelting Module (Your First Cell)

Build this first because everything else consumes plates.

Input: 4 train wagons of iron ore per minute (2,000 ore/wagon, 8k total) Output: 4 wagons of iron plates

Layout (beaconed):

• 48 electric furnaces with 8 speed module 3 beacons each
• 3 rows of 16 furnaces, alternating with beacon rows
• Input ore belt runs the length of the cell
• Output plates belt runs to train loaders
• 4 stack inserters per chest for full-blue-belt loading

Power: 16 MW per smelting module plus 10 MW for beacons = ~26 MW per cell Size: 50x100 tiles

Build 2 of these (iron + copper), then a steel module (same pattern, but feeds iron plates instead of ore).

Step 3: Green Circuit Module

Green circuits are consumed at a shocking rate. A 1,000 SPM base needs roughly 70 full blue belts of green circuits.

Layout consideration: Don't belt green circuits across the base. Build green circuit modules near each consuming module (red circuits, science). Better yet: build a central green circuit plant and use trains.

1,000 SPM green circuit module:

• 256 assembling machine 3s with 8 beacons each
• 8 blue belts of copper plates input
• 4 blue belts of iron plates input
• 12 blue belts of green circuits output
• Dedicated smelting cells feeding copper and iron directly

Step 4: Oil Processing Module

Megabase oil needs to scale massively. The beaconed refinery is the key.

Layout per cell:

• 16 refineries with advanced oil processing
• 12 heavy->light crackers
• 24 light->petroleum crackers
• 6 plastic chemical plants with 12 beacons each
• 2 sulfur plants
• 4 sulfuric acid plants

Fluid handling: Use underground pipes for the main fluid bus. Each row of refineries outputs its assigned fraction (heavy, light, petroleum) into separate pipe networks. Cracking circuits use tank levels to trigger:

Heavy->light: enable when heavy oil tank > 10k
Light->petroleum: enable when light oil tank > 10k AND petroleum < 20k

This prevents refinery stall from overfilled tanks.

Step 5: Science Modules

Build each science as a separate train-fed module. The pattern is universal:

1. Trains bring plates, circuits, and fluids to a drop-off station
2. A beaconed assembler array produces the science pack
3. A single belt or chest buffers the output
4. A train picks up the finished science and takes it to the lab complex

Lab complex:

• 100-200 labs with productivity modules
• 9-12 labs linked via chain inserters
• 1 beacon per 2 labs (alternating pattern)
• All 7 science types (including Space Age sciences) belted in
• Research productivity and mining productivity are the highest ROI techs

Common Megabase Mistakes

Building too close to the starter base. You run out of room to expand modules. Leave 4-6 rail segments between the starter base and your first megabase cell.

Over-building the rail network. A 4-track main line is plenty for 1,000 SPM. Single-track branch lines to each module. Don't build 8-lane highways.

Neglecting module production. Modules (speed 3, productivity 3) cost more resources than the entire megabase infrastructure. Start module production before building the first smelting cell. You need roughly 2,000 module 3s for a 1,000 SPM base.

Forgetting landfill. Megabases eat map space. Automate landfill production in your starter base before transition. You'll fill 50+ tiles per module.

No solar blueprint. If you use nuclear power, build a reactor blueprint you can stamp. Solar is better for UPS but requires blueprint stamps. Have either ready before you need it.

The 1,000 SPM Milestone

Your first 1,000 SPM base is a rite of passage. Here's what it requires:

The first time you check the production screen and see "1,000 SPM" with all assemblers running, the rebuilds are worth it.

Bottom Line

The megabase transition is the biggest structural change in Factorio. Build the rail network first, then smelting, then circuits, then science. Use train limits instead of stackers. Keep the starter base for mall and modules. Accept that you'll rebuild modules 2-3 times before they flow right. Each rebuild teaches you something.

Numbers to remember:

• Start transition at 60 SPM
• Starter base stays - it makes modules and mall items
• Modules first, rails second, science last
• Train limits > stackers in Factorio 2.0
• 1,000 SPM needs 70 belts of green circuits

Previous: Main Bus Guide Related: Nuclear Power Guide | Beacon Module Guide | Basic Rail Network

Community Verification & Resources

• Reddit -- Transitioning to Megabase - community discussion on scaling strategies
• Forum -- Step-by-Step Megabase - technical discussion from Factorio forums
• YouTube -- Megabase Tutorial Series - visual guides for modular base design
• FactorioLab Planner - SPM-to-input calculator for megabase planning