Transport Drones (Continued)

A ground-based logistics system for Factorio 2.0. Transport drones haul items and fluids between depots connected by road networks - a flexible alternative to belts and trains for mid-to-late game logistics.

This is a full rewrite of Klonan's Transport Drones for Factorio 2.0, with major new features: quality scaling, priority routing, channel segregation, supply thresholds, load balancing, blueprint persistence, circuit network overhaul, bot integration, Factorissimo 3 cross-surface support, and more.

Graphics by Bubbles from the Factorio discord.

How it works

1. Build roads to connect your production areas.
2. Place depots on the road network: supply depots offer items, request depots collect them.
3. Insert transport drones into depots. Drones autonomously pick up items from supply depots and deliver them to request depots.
4. Fuel the network with fuel depots - drones consume fuel proportional to travel distance.

Depot types

Supply depot

Makes its inventory available to the road network. Other depots dispatch drones to collect from it.
- Quality scaling: 80 / 100 / 125 / 175 / 250 inventory slots.
- Optional logistics bot access (passive provider) with the Transport Logistics research.
- Supply threshold: reserves items below a set count, only offering excess to the network.

Request depot

Dispatches drones to collect a selected item from supply depots. The number of drones controls throughput - more drones means more concurrent deliveries.
- Quality scaling: 5 / 6 / 7 / 8 / 10 drone slots.
- Max storage cap, ignore capacity research, and full stack only toggles for fine-tuned control.
- Supports both items and fluids (connect pipes to the output side for fluids).

Buffer depot

Acts as both a request and supply depot. Ideal for collecting resources from distant outposts and redistributing them locally.
- Quality scaling: 5 / 6 / 7 / 8 / 10 drone slots.
- Optional logistics bot access (buffer chest).

Fuel depot

Delivers fuel to all depots on the road network. Fuel type is configurable (petroleum gas by default).
- Quality scaling: 5 / 6 / 7 / 8 / 10 drone slots.

Fluid depot

Makes fluid available to the road network. Connect it to pipes - request depots can request fluids just like items.

Active depot

A push-based supplier for mixed item output. Automatically offers whatever items it contains to the network without needing a recipe - ideal for assembler outputs with multiple products.
- Fluid mode toggle: switch between pushing items (from chest) and pushing fluids (from south pipe). The entity swaps to a furnace variant that auto-detects the piped fluid.
- Confirmation dialog warns before switching when contents would be lost.
- Can be disabled via startup setting.

Storage depot

A passive warehouse for the drone transport network. Accepts overflow from active depots and serves items back when requested.
- Prioritized over supply depots at equal score (preferred sink for excess items).
- Shows zero-count items in the road network GUI so you can see what was stored even when depleted.
- Can be disabled via startup setting.

Drone dispatcher

Holds transport drones and distributes them to other depots on the road network.
- Drone request slider: each depot can request a specific number of drones from the dispatcher.
- Priority-based distribution: higher-priority dispatchers distribute drones first.
- Return slots: locked inventory slots collect excess drones when a depot's slider is reduced. Drones are returned automatically.
- Can be disabled via startup setting.

All depot settings - recipe, drones, priority, channel, threshold, and toggles - are configured in a single unified Transport Drones panel that opens when clicking any depot.

Roads

• Road - Standard tile. Walking speed bonus: 1.5x.
• Fast Road - Upgraded tile. Walking speed bonus: 2.0x. Drones are ~33% faster on fast roads.

Any connected road tiles form a road network. Disconnected road areas are separate networks.

Diagonal crossing prevention (enabled by default) stops drones from connecting road networks diagonally through non-road corners.

Roads can also be placed on space platform foundations (Space Age).

Quality support

Depot quality scales inventory size:
- Supply inventory: 80 / 100 / 125 / 175 / 250 slots (Normal to Legendary)
- Drone slots: 5 / 6 / 7 / 8 / 10 (Normal to Legendary)

Drone quality scales performance:
- Speed bonus: +15% / +30% / +50% / +80% (Uncommon to Legendary)
- Fuel savings: 10% / 20% / 30% / 45% (Uncommon to Legendary)

Any quality drone can be used in any quality depot. Drones are stored in a separate drone inventory that supports logistics robot delivery for automated restocking. Higher-quality drones are dispatched first (legendary before epic, etc.).

Priority system

Every depot has a priority slider (0-100, default 50):
- Supply/fuel depots: higher priority = collected from first, even if farther away.
- Request/buffer depots: higher priority = claims scarce supply first.

Priority can be overridden via circuit network using signal [P].

Load balancing

Two runtime settings fine-tune supply selection:
- Load balance threshold (default: 20) - when greater than 0, supply depots with similar scores are treated as equivalent and one is chosen randomly, spreading load across nearby depots.
- Priority weight (default: 0) - replaces the absolute priority system with a weighted bias, making priority a soft preference that can be outweighed by distance.

Supply threshold

Supplier depots (supply, buffer, fluid, mining) can set a supply threshold - items below this count are reserved and not offered to the network. Only excess above the threshold is available for drones to collect.

• Set in the depot panel or via circuit writer using signal [T].
• Useful for keeping a minimum buffer in supply depots before serving requests.

Channel segregation

LTN-style bitmask channels let you run multiple independent logistics networks on the same physical roads.

• Default: -1 (all channels - everything interacts).
• Assign channels like 1, 2, 4, 8... to segregate traffic.
• Depots only interact when their channels share at least one bit (bitwise AND != 0).
• Fuel depots respect channels - they only fuel depots on matching channels.
• Overridable via circuit network using signal [C].

Circuit network integration

Three circuit entities, unlocked by the Transport Depot Circuits research:

Depot reader

Reads the contents of the attached depot as circuit signals. Works on all depot types (supply, request, buffer, fuel, fluid, active, storage, mining, dispatcher).

Three modes:
1. Network total - total supply across the entire road network.
2. Depot local - only the attached depot's contents.
3. Network minus local - network total excluding the attached depot (prevents feedback loops).

Additional signals (configurable via toggles):
- [D] - drone count
- Active drone count
- Fuel level
- Used stacks / max stacks
- Max capacity ([M])
- Stack size

Depot writer

Controls the attached depot via circuit signals:
- Set Filter mode: force the depot's recipe via circuit signal. Supports Anything/Everything virtual signals. The highest-count item signal wins when multiple are present.
- Enable/disable condition: enable or disable a depot based on signal comparison (signal vs constant, or signal vs signal). Disabled depots show a visual status indicator.
- Override priority, channel, and supply threshold via signals [P], [C], [T].
- Override request count: if the signal matches the requested item with condition =, the depot uses that value as its target.
- Custom GUI with live signal value display (auto-refreshes every 0.5s).

Road network reader

Set one or more item signals in its slots - it continuously outputs the total supply of each item across the entire road network. Useful for enabling/disabling production based on network stock levels.

Compatible depots are highlighted when placing circuit entities.

Blueprint support

Blueprints fully preserve:
- Requested item recipe
- Per-quality drone counts (logistics request proxy created automatically)
- Priority, channel, storage limit, supply threshold, and all toggle settings
- Active depot fluid mode

Paste a blueprint and logistics bots will deliver the correct drones automatically.

Logistics bot integration

With the Transport Logistics research:
- Supply depots can become passive providers - bots take items out.
- Buffer depots can become buffer chests - bots distribute items locally.

Toggle per-depot in the depot panel. Preserved in blueprints.

Road network GUI

Press Ctrl+T (or use the toolbar shortcut) to open the road network overview:

• Surface/planet selector to filter depots by world (Factorissimo factory surfaces resolve to their parent planet).
• Item filter and channel filter in the title bar to narrow results.
• Contents tab: all items across the network with supply/request progress bars and capacity labels.
• Depot tabs (Supply, Mining, Active, Storage, Dispatcher, Fuel, Request, Buffer): minimap + structured depot info panel side by side.
• Item names with capacity progress bars.
• Inline priority sliders (edit in real-time).
• Editable channel fields.
• Drone progress bars with per-quality breakdown.
• Circuit override indicators when priority, channel, or threshold are set by signals.
• Writer status dot (green = enabled, red = disabled).
• Click minimap buttons to teleport directly to any depot.
• Tabs auto-hide when no depots of that type are present.

Factorissimo 3 integration

Road networks bridge across Factorissimo 3 factory building surfaces. Place road tiles at both sides of a factory door to connect inside and outside networks. Drones automatically teleport through factory entrances.

• Cross-surface distance estimation: depot scoring accounts for travel distance through factory portals, preferring closer factories.
• Visual indicators: "Road connected" / "Road disconnected" floating text appears when factory portals activate or deactivate.
• Road network GUI minimap navigates to the correct surface when clicking a depot inside a factory.

Mining Drones integration

Works with Klonan's Mining Drones and Mining Drones Remastered. Mining depots automatically connect to the transport drone road network when placed adjacent to road tiles - mined resources become available to transport drones with no extra setup. Roads placed after the depot trigger auto-connection too.

Migrating from other Transport Drones forks

Switching from the Meglinge Fork or any other Transport Drones fork? Load your existing save - a "Recover unregistered depots" button appears automatically when orphaned depot entities are detected.

Click it to open a confirmation dialog explaining what will be preserved and what will be lost:

The migration adopts all depot entities, preserves recipes, items, fuel, and circuit connections. Active drones on the road and drones stored as recipe ingredients are lost - you'll need to re-add drones to your depots after conversion.

Spoilable items

Spoil timers are preserved through drone transport. Items like nutrients and biter eggs maintain their freshness - no spoilage reset on delivery.

Third-party road compatibility

Built-in support for road tiles from:
- Asphalt Roads (AsphaltRoadsPatched)
- Dectorio (gravel, wood floor, concrete grid)
- PyIndustry (all py-tiles)

Custom tiles from any mod can be whitelisted via the Road tile whitelist startup setting (comma-separated Lua patterns or @subgroup matches).

Other mods can also register tiles programmatically by setting is_road_tile = true on their item prototype.

Technology tree

Engine
  +-- Transport System (unlocks roads, supply/request/fuel depots, drones, dispatcher)
        |-- Fast Road
        |-- Transport Fluids (requires Fluid Handling) -> Fluid depot
        |-- Transport Buffering -> Buffer depot
        |   +-- Transport Active Supply -> Active depot, Storage depot
        |-- Transport Logistics (requires Logistic Robotics) -> Bot toggle
        |-- Transport Depot Circuits (requires Circuit Network) -> Reader, Writer, Network Reader
        |-- Transport Drone Speed 1-4 (+15% each)
        |   +-- Speed 5+ (infinite research, +15% per level)
        +-- Transport Drone Capacity 1-5 (+1 stack each)

Configuration

Startup settings:
- Fuel type (petroleum gas, water, steam, crude oil, light/heavy oil, sulfuric acid, lubricant)
- Fuel per drone and fuel consumption per meter
- Drone fluid capacity
- Drone pollution per second
- Drone sound volume (0-100%, default 80%)
- Fluid depot storage capacity (default 25,000)
- Request depot fluid output capacity (default 25,000)
- Road tile whitelist (third-party mod compatibility)
- Diagonal corner-cutting prevention
- Space platform roads (default: enabled)
- Enable/disable drone dispatcher, active depot, storage depot (all default: enabled)

Runtime settings:
- Depot update interval (default 60 ticks - lower = more responsive, higher = better UPS)
- Load balance threshold (default 20 - randomize among similarly-scored supply depots)
- Priority weight (default 0 - blend priority with distance instead of absolute priority)
- Max dispatches per depot per tick (default 100)
- Redispatch interval (default 10 ticks)
- Active depot overfill percent (default 25%)
- Pathfinder tuning (max steps, max work, path cache)

Remote interface

The mod exposes a "transport_drones" remote interface with 25+ functions for mod-to-mod integration:
- Query networks, depots, and drones
- Read/write priority, channel, storage limit, bot access, capacity bonus, full-stack-only
- Diagnostics and debugging tools
- Force depot updates and bucket recalculation

Usage: remote.call("transport_drones", "<function_name>", ...)

See the source code for full API documentation.

Localization

Fully translated in 9 languages: English, French, German, Spanish, Russian, Japanese, Korean, Chinese (Simplified), Polish.

Credits

• Original mod: Klonan - Transport Drones (Factorio 1.1)
• Graphics: Bubbles (Factorio Discord)
• Factorio 2.0 port: Shadoxa
• Mod tutorial: Nilaus on YouTube