RimWorld Ground-Penetrating Scanner: Why It Sits Idle
PC 1.6 · Values for 1.6.4871 rev590 · Unmodded Core scanner · Updated September 28, 2026
The RimWorld ground-penetrating scanner finds new underground resource deposits on its map. A researcher operates the scanner; a miner uses a separate deep drill to extract the ore. Power alone does not advance the scan.
Build it for 150 steel, 4 components, and 1 advanced component, with Construction 8. It can find steel, plasteel, uranium, silver, gold, or jade. It cannot find components, and you cannot select a target mineral.
Watch on Open.Video · English audio
Why your ground-penetrating scanner is idle
A scanner stuck at 0% has a different problem from one that slowly reaches 2%. If the percentage never changes while you watch, check whether a pawn actually starts scanning. If it advances and then stops, watch where that pawn goes next.
The research bench usually gets the researcher first
Research benches and scanners share the Research work type. Within that work type, ordinary research takes priority over ground scanning when both jobs are available. Setting Research to priority 1 moves both ahead of lower-priority work; it does not make the scanner outrank the bench.
- For a quick check, select a capable colonist and try a manual order at the scanner. Any refusal can help identify a power, roof, access, or reservation problem.
- For sustained scanning, switch off a competing powered research bench, restrict that pawn’s access to the bench, or scan when no research job is available.
- For research and scanning together, provide another researcher after accounting for all available benches. An extra scanner without an extra operator does not create extra work time.
A manual order is useful for diagnosis, but it is not a permanent scanning schedule. The pawn can return to higher-priority work later. A spare unpowered simple research bench can also remain a competing job, so check more than the nearest hi-tech bench.
Check these requirements in order
- Remove every roof tile over the 3 × 3 building. One covered tile is enough to block operation. Check the roof overlay, including any overhead mountain.
- Restore power and repair breakdowns. The scanner draws 700 W when switched on, even while idle. A lit machine still needs a worker.
- Enable Research for a capable colonist. Intellectual influences Research Speed; Mining is for the drill. Vanilla mechs cannot do the scanning job.
- Allow access to the interaction spot. Check allowed areas, forbidden status, blocked routes, a reservation by another pawn, and fire on the building.
- Check the biome. Sea ice and orbit cannot run this scanner because they lack bedrock. Ice sheet is a different biome.
Keep the operator safe and reasonably comfortable outdoors. Food, rest, recreation, medical needs, and other work reduce time at the scanner. Do not treat a particular outdoor temperature quoted in an old guide as a universal scanner shutoff temperature.
How long does scanning take?
At 100% Research Speed, the game displays a 3-work-day random find interval and guarantees a find after 6 work-days of scanning. A work-day here means 60,000 game ticks: 24 hours of continuous work. It does not mean one ordinary colonist work shift.
The progress bar tracks work toward the guarantee. A random find can happen before 100%, and any find resets that scanner’s accumulated progress. An idle machine contributes nothing to the bar.
The displayed 3-day random interval is not the same as the average wait once the 6-day cap is included. With constant speed, that capped average is about 2.59 work-days at 100%. Use the guarantee to budget work; treat the average as a long-run expectation, never a promise for the next deposit.
Estimate one scanner’s waiting time
Enter the pawn’s Research Speed and the hours they actually spend operating the machine each day.
Changing operators, speed, or working hours changes the result. Walking time and breaks belong outside the scanning hours.
Does a second scanner make it faster?
With a second operator and another 700 W, a second scanner can roll for discoveries independently. Each building retains its own progress. Two equally fast scanners starting together still each need up to 6 work-days to reach their own guarantee; there is no shared 3-day guaranteed deadline. Moving one researcher between two machines splits that researcher’s work instead of doubling it.
What resources can it find?
Each successful scan selects one resource. The percentages below are the unmodded resource weights normalized across the six eligible resources. They describe the type of a discovery, not the chance of finding something on any given day.
| Resource | Weight | Share of discoveries |
|---|---|---|
 Steel | 4 | 53.33% |
 Plasteel | 1 | 13.33% |
 Uranium | 1 | 13.33% |
 Silver | 0.5 | 6.67% |
 Gold | 0.5 | 6.67% |
 Jade | 0.5 | 6.67% |
Steel is the most common result, but a run of other resources is possible. You cannot tune the scanner to steel or force plasteel by placing the machine near exposed plasteel. Its location does not select the mineral or confine discoveries to a circle around it.
No components, advanced components, chemfuel, or stone chunks are in this scanner’s pool. A deep drill can produce stone chunks when there is no underground resource within its working area. That is drill behavior, not a scanner discovery.
Deposit shape and drill output are separate from these selection odds. Terrain can cut down the usable patch. For extraction, placement radius, and yields, use the deep drill setup and yield planner.
Research and build requirements
- Complete Microelectronics and build a hi-tech research bench.
- Research Deep drilling: 1,000 base research points, requiring the hi-tech bench.
- Research Ground-penetrating scanner: another 1,000 base points, also requiring the hi-tech bench. Neither of these two projects requires a multi-analyzer.
- Build the scanner from Architect → Misc. Supply 150 steel, 4 components, and 1 advanced component, with a builder at Construction 8.
- Power it and assign the researcher. Leave the entire footprint unroofed and the interaction spot reachable.
Those research values are base costs; research penalties and your colony’s research speed affect how long the projects take. Fabrication is not a prerequisite for the scanner: an advanced component obtained by trading or another source can pay its construction cost.
The building requires terrain that supports Heavy structures. Its footprint is 3 × 3. It cannot be uninstalled and carried to a new location, so choose a convenient operating spot before building. A deep drill can be relocated later as you work through deposits.
Ground scanner vs long-range scanner vs orbital scanner
| Scanner | What you get | Best reason to use it |
|---|---|---|
| Ground-penetrating | Random buried mineral on the current map; deep drill required | Ongoing home-map resources without a caravan |
| Long-range mineral | A selected mineral, including components, at an off-map site | You need a specific resource and can manage the trip |
| Orbital (Odyssey) | Space sites discovered through the orbital scanning system | Exploring orbital sites; it is a different system from buried ore scanning |
The ground scanner is a strong choice for repeated steel supply once your colony can spare a researcher and a miner. It is less dependable when a project urgently needs one specific resource. The long-range alternative adds travel, possible threats, mining time, and return hauling, but lets you choose your target.
For immediate shortages, see other steel sources, how to get components, and plasteel options. Neither scanner turns a shortage into instant stockpile resources.
Where the scanner works, and where ore appears
The machine’s position and the deposit’s position are separate
Keep the scanner near a convenient, safe route for its operator. It searches the map, so moving it toward a mountain does not aim the next result there. Deposits can occur beneath ordinary buildings, floors, or mountains; reachability and excavation still matter when you decide where to drill.
New discoveries generate resource patches rather than reveal a fixed, pre-existing underground supply. In PC 1.6.4871, tiles that still contain underground resources are excluded from new placement. Keep using and exhausting useful deposits; the scanner does not overwrite their remaining ore.
Sea ice, orbit, and bridges
Sea ice and orbit lack the bedrock required for operation. Clearing roofs or adding power does not fix that. A map with bedrock can still contain unsuitable individual tiles where deposits cannot generate.
A regular bridge does not provide the Heavy support needed to place the scanner. Odyssey heavy bridges do provide Heavy support, but that does not make every tile beneath them eligible for ore. In this version, deposit placement rejects impassable water underneath a bridge, checks for Light support for the drill, and excludes already-occupied resource cells. A bridge over shallow water is therefore a different case from one over impassable deep water.
Use solid ground for a predictable scanner setup. Treat blanket advice that ore always or never appears beneath every kind of bridge as too broad for PC 1.6.4871.
Once you find a patch
Select a powered ground scanner to see the underground resource overlay, then inspect the new patch. Place a deep drill so its working radius overlaps the resource, connect power, and assign Mining work. A scanner does not need to sit beside that drill.
If the drill only makes chunks, check the underground patch rather than surface rock. The deposit may be outside its radius or already exhausted. Relocate the drill and confirm the resource under its working area. Deep-drilling infestations belong to operating drills; scanning itself does not trigger that mechanic. See the deep drill instructions before committing miners to a distant patch.
Quick questions
Can it scan under an overhead mountain?
No. A roof over any part of the scanner blocks operation. A deposit may appear beneath a mountain elsewhere, but the scanner itself must remain unroofed.
Why did progress reset before 100%?
A random discovery can happen early. Every discovery resets that scanner’s progress toward the next guaranteed find. Check the discovery letter and resource overlay.
Does Mining skill speed up the scanner?
No. Scanning uses the operator’s Research Speed. Mining and deep-drilling performance matter later, at the drill.
Can I use this on console or with scanner mods?
This page covers PC 1.6.4871. Console runs a separate version branch. Mods that allow roofs, add deep resources, change biomes, or choose minerals can change the requirements and odds.
Further reading: RimWorld Wiki: ground-penetrating scanner · PC 1.6.4518 patch history. Version-specific values above apply to PC 1.6.4871.