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A heavy mechanoid built for mining in treacherous locations. While intended for excavation, the tunneler's gigantic power claws and ultra-thick armor makes it a dangerous force in combat.

Base Stats

Market Value
1200 Silver


Armor - Sharp
Armor - Blunt
Armor - Heat

Pawn Stats

Move Speed
1.9 c/s
Health Scale
Body Size
210 kg
Pack Capacity
122.5 kg
Carrying Capacity
263 kg
Filth Rate
Comfortable Temp Range
-100 °C – 250 °C (-148 °F – 482 °F)

Melee Combat

Attack 1
left power claw
22 dmg (Scratch)
33% AP
2.9 second cooldown
Attack 2
right power claw
22 dmg (Scratch)
33% AP
2.9 second cooldown
Average DPS


Crafted At
Large mech gestator
Required Research
Standard mechtech
Resources to make
Steel 150 + Plasteel 75 + Component 4 + Standard subcore 1

A tunneler is a mechanoid added by the Biotech DLC.


As mechanoids, every tunneler is immune to fire, Flame and Heat damage, and temperature extremes, despite having Comfortable Temperatures defined. They have 100% Toxic Resistance and Toxic Environment Resistance, making them immune to toxic buildup, rot stink and other toxic effects. They do not need to eat, rest, and have no mood. They will be stunned by EMP attacks for a time proportional to the EMP damage inflicted and will "adapt" and rendered immune to further EMP strikes for 2,200 ticks (36.67 secs).

Tunnelers do not seem to spawn in regular mech raids, crashed ship parts, or mech clustersContent added by the Royalty DLC.[Verify] However, they appear as part of certain war queen and apocriton summon groups.


In combat, tunnelers use blunt melee attacks. They have an innate smokepop pack ability, but this has a cooldown of 15 days.

Tunnelers have the highest armor values of any mechanoid in the game, with +5% more Sharp and Blunt armor than the war queen. However, with a health scale of 1.52, it doesn't have the hit point pool of the larger mechs. They have an innate shield, which is equivalent to a shield belt, just with 250 HP. This is higher than even a legendary quality shield belt.

Uniquely, tunnelers are staggered by any ranged projectile that hits it - regardless of its stopping power. Instead of the usual 95 ticks (1.58 secs) stagger time, tunnelers are slowed for 120 ticks (2 secs) per hit, though tunnelers move slightly faster than a "usual" stagger. This stagger is caused even if the bullet hits the shield, or if the bullet's damage is negated entirely by armor.

As an ally[edit]

Tunnelers are a heavy mechanoid, and require Standard Mechtech to create. They are created from a large mech gestator with Steel 150 Steel, Plasteel 75 Plasteel, Component 4 Components, Standard subcore 1 Standard subcore, taking up 3 bandwidth from a mechanitor. Then, they must gestate for 4 gestation cycles to be made. Once made, they recharge in a large mech recharger (50% power/day), creating 15 wastepacks whenever the recharger's waste is filled up. When killed, friendly tunnelers can be resurrected for the cost of Steel 75 steel, so long as the corpse is extant.


Tunnelers will do tasks associated with the Mining tab, though are unable to use deep drills. They cannot be manually controlled, except when drafted for combat. They have an effective Mining skill of 10, but with a Global Work Speed of 150%.

For reference, every other labor mechanoid has a Global Work Speed of 50%. As control sublinks and the Mechanoid Labor preceptContent added by the Ideology DLC both act as additive offsets to work speed, the tunneler receives a relatively smaller boost. For example, a cleansweeper could go from 50% to 70% work speed - a ×140% increase. A tunneler would go from 150% to 170%, which is only a ×113.3% increase.


Tunnelers are useful for mass mining operations, whether it is expanding out your mountain base or mining mineral lumps found using a long-range mineral scanner. Mechanoids are not subject to illness or mental breaks, and only recharge for 2 days out of every 12.

Work Speed[edit]

The following table summarizes the work speed effects of operating within the influence of a mech booster and having control sublinks installed by the Mechanitor. All values are for 50%+ lighting conditions.

Control Sublinks Work Speed Mech Boosted
0 150% 225%
1 156% 231%
2 162% 237%
3 168% 243%
4 174% 249%
5 180% 255%
6 186% 261%

A colonist's work speed is based on their Mining Speed stat. At about skill 13, a normal colonist with no traits or health conditions will mine as fast as a tunneler operating without a Mech Booster or Sublink bonus. A similar colonist at skill 18 mines roughly 97% as fast a mech-boosted Tunneler with no Sublink bonuses. Installing a Drill arm allows a Skill 5 pawn to mine faster than an unboosted Tunneler.[Mining Specialist?]

Mining Yield[edit]

Tunnelers appear to have no special modifiers to Mining Yield, meaning that they function identically to a Skill 10 Colonist for this purpose. Higher skilled colonists will extract more material, but the increase isn't very large until very high skill levels. For comparison, a healthy, level 20 human miner has the maximum possible mining yield of 113% compared to the 102% of the tunneler. For maximum resources, leave ores for higher skill colonists, if present, to mine. However, it may be more useful to get a place dug out now then to get a little more ore.

Conversely, a lower mining yield will slightly lower the amount of stone chunks that have to be hauled out of a mountain base. The difference is too small to notice, either way.

As an ally in combat[edit]

Tunnelers are incredibly slow, with middling DPS and a decent durability. They have 152% the health of a human, armor slightly worse than normal recon armor, and an innate shield better than a legendary shield belt. While they won't deal as much damage compared to a dedicated melee pawn, nor able to run or lock down enemies like a scyther, tunnelers can draw enemy fire. This lets other combatants focus on dealing damage.

Tunnelers face competition from scythers, a melee-focused mech also unlocked from Standard mechtech. Tunnelers don't have a scyther's speed, and consume +1 bandwidth. However, they are significantly more durable, with significantly more armor, slightly higher health, and the aforementioned shield. The tunneler's base true DPS of 7.59 (4.71 after Melee Hit Chance) seems low at only 75.9% of the 10 (6.2 after Melee Hit Chance) of the scyther. However, tunnelers use Blunt damage. Blunt attacks usually face far less armor than a scyther's Sharp blades.

  • Against a normal flak vest, the tunneler faces almost no DPS loss at all, while the scyther's DPS is more than halved.
  • Against centipedes, the scyther is reduced to 70% of their DPS, while the tunneler's AP totally negates their blunt armor.

So, while the scyther still has superior DPS against most enemies, their damage output is far closer than it first appears. Blunt damage's superior damage propagation and overkill mechanics further help narrow the gap against enemies with health scales comparable to humans. If durability is completely irrelevant, such as when using Skip psycast Content added by the Royalty DLC mobbing tactics, then scythers are superior due to their lower bandwidth cost.

Centipedes have 288% the health scale and thus HP of the tunneler, slightly worse armor (Sharp: 72% Blunt: 22%), and no shield belt. They also have 86% of the base true melee DPS, cost 1 more bandwidth, and are unlocked at High mechtech. For the sole purpose of tanking against melee enemies, the centipede is almost always better[Verify] if they can be afforded. Their ranged weaponry also makes the centipede more flexible. However, lower melee DPS and lack of shield can be determental against mixed-range enemies. When a centipede is tied up in melee, unable to fire while being fired at, it will be worse (or at least, not much better) than a tunneler.


Specify body type when known.

Body part Health
Head 38
Skull 38
Brain 15
Nose 15
Neck 38
Jaw 30
Eye [1]
(left, right)
(left, right)
Body 60
(left, right)
(left, right)
Liver[2] 30
Heart[2] 23
Spine[2] 38
Stomach[2] 30
(left, right, fore, hind)
(left, right, fore, hind)
  1. Located inside of Head.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Located inside of Body.


Version history[edit]

  • Biotech DLC Release - Added
  • Somewhere between Release and 1.4.3641 - Power claw attack changed from Blunt to Scratch.
  • 1.4.3531 - Increased armor values from 40/20/200 to 80/40/200