Guide to Engineering

From Colonial Marines Wiki

Tools of the Trade

Tool Function
Used for securing and unsecuring sentries, Also used to open panels on vendors and doors.
Used for cutting through walls and fixing sentries. Has 20 units of fuel inside.
Used for Opening unpowered doors and displacing girders so you can move them.
Used to rotate sentries, disassemble certain objects, unsecure and secure vendors and girders.
Cable coil
Used for fixing robotics and placing wire on the ground.
Used to hack doors and vendors, or for disarming mines.
Used for cutting cable coil on the ground, and for cutting wires and mending wires in doors.
Light Replacer
Used to replace lights quickly. Feed with glass to refill.
T-Ray Scanner.png
T-Ray Scanner
A terahertz-ray emitter and scanner used to detect underfloor objects such as cables and pipes.

The Basics

Power Duty

To setup power, you'll want to locate the geothermal generators Geothermal.png and assess the damage. Depending on the sprite, the generator will need different steps:

Geothermal Destroyed.png = Welder -> Wirecutters -> Wrench

Geothermal Broken.png = Wirecutters -> Wrench

Geothermal Damaged.png = Wrench

Note that you can also examine a geothermal generator to see what tool is required for the next step.

APC Maintenance

If the APC hasn't been blown up or destroyed during a gunfight always check the apcs wires by unscrewing the apc frame and click on the apc with your wirecutters, if the wires come up with a mend option, mend the wires with the wirecutters. (Click on mend while holding wirecutters in your active hand.) If someone blew up the apc or blasted it into another dimension follow the steps below.

So, someone decided to throw a grenade next to the APC or you just arrived to a broken APC and your SL has tasked you with fixing it whilst the squad holds off the incoming xeno tide. No need to panic as this section will get you to quickly repair that APC.

  1. First you'll want to whack off the cover; to do this just hit the APC with any sort of weapon, generally a combat knife is good for this.
  2. Take out the battery (Power cell) in the APC once the cover is off with an empty hand.
  3. Use a screwdriver on the APC.
  4. Use wirecutters on the APC.
  5. Use a crowbar on the APC.
  6. Build an APC frame from 2 metal sheets then click on the APC with the APC frame in hand.
  7. Use wires (Cable Coil) on the APC.
  8. Click on the APC with a power control module in hand.
  9. Use a screwdriver on the APC.
  10. Place a new battery (Power cell) in the APC. (Just click on the APC with the battery in hand.)
  11. Use a crowbar on the APC.
  12. Open up the APC pop up window once you've completed all previous steps and turn on the breaker.

SMES Setup

SMES units are used to store power, and then output it to the colony. If you setup power without setting the SMES units, power will not be stored and be wasted. There are two kinds of SMES units to be setup:

Shipside: While shipside, there will be a total of five SMES units to setup, with one optional one near requisitions, three on the lower floor and two on the upper floor. For the ship, you'll want to tinker with the settings to get the most optimal setup. One simple rule is to make sure the charge is higher than the output, and that all SMES units are equal. You'll want to use the power monitoring computers to see how much to allocate per SMES

Planetside: On the planet, the generators will provide enough power to be set to max charge and to less output. It won't need fine tuning like the Almayer's systems, as long as it's above 100,000 watts for output on each SMES.


Hacking sounds a lot harder than it actually is. To begin hacking a machine, follow these steps:

  1. Open its maintenance panel if possible with a screwdriver.
  2. If you have them on hand, you'll want to equip insulated gloves of some kind to protect against shock.
  3. You will need a multitool and/or wirecutter to manipulate the internal wires. Click on the machine to open the menu with your chosen tool (Multitool/Wirecutter) then cut/pulse each wire until you get the desired result. Memorize the wire which produced that outcome for future reference; the wire functions are listed below.


Wires: Description:
The door bolts look down Means that the bolts are currently down, and you will be unable to open the door. Pulsing this wire will open or lower it.
The door bolt lights are off Indicates when bolts are up or down. Off means you won't be able to tell it's bolted
The test light is off The power wire. There are two of these. If the test light is off, you can crowbar it open. Cut and remend to turn it back on.
The AI control allowed light Allows control for the AI. Functionally useless in CM
The Check Wiring light No use.
The Check Timing Mechanism light How fast the door closes. If it's on, it will close instantly, crushing people under it.
The Shock Wire Determines if the door will shock people. No text to show it's on or off, shoots out sparks when activated. Cut and remend to stop the shocking.
Picture examples Description
Vendor 2.png

Example of a door that has been modified:

In the picture, it shows that the test light has been pulsed, turning it off and making it show you can crowbar your way through the door.


Example of an untouched door:

In the picture, it shows that the door has not been tampered with yet. You'll need the correct ID to open it, and you will not be able to crowbar it open.


Wires: Description:
Orange Light Electricity wire. If this is on, whenever the vendor is used it will shock the user. Cut and remend to stop the shocking.
Red Light Firing wire. If this this on, it will launch the contents of the vendor at nearby people.
Green Light Contraband wire. Turning this wire on means non-standard gear will be avaliable.
Purple Light Access wire. Turning this wire off changes it to a yellow light, making it so anyone can dispense the contacts.
Picture examples Description

Example of a vendor that has been modified:

In the picture, it shows that the contraband wire has been turned on, allowing for hidden goods to be displayed, and it shows that the access wire is now yellow, allowing anyone to use the vendor, regardless of ID

Vendor 1.png

Example of an untouched vendor:

In the picture, it shows that the vendor has not been tampered with yet. You'll need the correct ID to access it, and you will not be able to dispense hidden items from the vendor

FOB Defences

Defensive Equipment

Defensive Equipment: Description:
Sentry Gun
The Sentry Gun automatically tracks and fires upon any target that is wearing an ID not hooked up to the Almayer's systems. Via IFF, they are unable to hit friendly marines, allowing them to be safely placed behind marine laws as they lay down supressing fire. Comes with various options, such as 360 degree mode, burst fire, and the ability to take control of it. Has 300 bullets.

Additional Information (Construction and Other Functions):
How To Construct It:
  • Construct Turret Frame with Plasteel,
  • Wrench it,
  • Apply Cable,
  • Add Turret Piece,
  • Add Turret Sensor,
  • Apply Metal,
  • Weld it,
  • Add bigger battery if needed.
  • Click on the sentry with an empty hand to turn it on.


  • Use a welder to repair a damaged sentry.
  • If the sentry is knocked over click on it with an empty hand to right it.

Other Functions:

  • Rotate with wrench
  • Turn off the sentry then use a screwdriver on the sentry to unsecure it and thus make it movable.
M56D Mounted Smartgun
These engineer-only mounted smartguns are the heavy lifters of the Colonial Marines. The M56D can hold up to 700 tungsten rounds that cause high damage to the target upon hit due to their increased armour penetration. The tracking system of a standard smartgun is non-functional on the M56D. Note that this does not have IFF tracking built into it, so you will hit friendlies with it.

Additional Information (Construction and Other Functions):
How To Construct It:
  • Click on the mount once it's in your hand,
  • Wrench it,
  • Mount the Gun,
  • Screwdriver it,
  • Apply Ammo Drum.


  • Use a welder to repair it.


  • To toggle burst fire, ctrl-click the M56d before you man it, after this when you next hop on you'll use burst fire.

Other Functions:

  • Rotate with wrench
  • Deconstruct with screwdriver.
M20 mine box.png
M20 Mine Box
A secure box holding anti-personnel proximity mines. There are 4 M20 Claymore anti-personnel mines per mine box.

Additional Information (Deployment and Deactivation):
How To Deploy A Mine:
  • Take a M20 mine out of the box and keep it in your active hand,
  • Stand on top of the tile you want to place the mine on,
  • Face the tile you want the mine to detect enemies on,
  • Click on the mine in your active hand once you are facing the correct way,
  • After a few seconds you'll have the mine placed and armed on your tile.

Keep in mind that any mob that enters the mine's tile, or the tiles it's facing, living or dead, will cause the mine to detonate, unless they have an appropriate ID, an example being that the crew of the USS Almayer won't set off armed mines.

How To Deactivate Mines:

  • Use a multitool on the deployed mine.

Fortifications of the Trade

Image Name Material Needed Function
WoodenBarricade.png Wood Barricade Wood Used for a hasty defence against aliens. Mostly seen prespawned.
Metal Barricade.png Metal Barricade Metal Used for areas that will be under constant attack. Can be repaired with a blow torch.
Sandbag Full.png Sandbags Sandbags Used for making directional defences, multiple can be applied to a tile. Needs to be filled up with empty sandbags and an entrenching tool. 25 in a filled stack.
Plasteel barricade.png Plasteel Barricade Plasteel Used to allow passage by closing it, and providing heavy protection. Can be repaired with a blow torch
Barbed Wire.png Barbed Wire Metal Used to make barricades and sandbags stronger, and making it so they can't be ran or climbed over. Also damages any thing that attacks it.
Wall.png Wall Metal Used to fully block off an area.

FOB Construction Quick Tips

Barricade Placement

Barricade Placement Description

This is an example of what not to do when constructing a defensive position.

In the picture on the left you'll see that the xenomorphs are able to hit the barricade without being shot due to it's forward position and as such the xeno will be able to break through and kill that marine with ease.


This is an example of what you should do when constructing a defensive position.

To rectify the above barricade placement errors you'll want to move the barricades back one tile like the photo on the left. By moving the barricades back this will allow you to shoot xenomorphs who are attacking them.

Barbed Wire

Barbed Wire.png Barbed wire is a string of sharp metal that will harm and prevent xenos from pouncing over barricades once attached. It also gives a small health boost to the barricade itself.

Barbed Wire Tactics Description
In the picture you'll see that the engineer was killed due to the xeno being able to pounce over the barricade.

Due to the engineer placing barbed wire onto the barricades the xenomorph was unable to jump over.

FOB Space

How To: Fob Space Description

This is an example of what not to do when constructing a defensive position.

In the picture you'll see that the FOB has very little space for the marines to move around in which will lead to:

  • Friendly fire.
  • Shuffling of positions.
  • Preventing wounded marines from entering.
  • Hindering the movement of supplies.

This is an example of what you should do when constructing a defensive position.

In the picture you'll see that the FOB has ample space to move which means:

  • The reduction of friendly fire.
  • Less shuffling of positions.
  • Ease of access for wounded traffic.
  • Free movement of supplies.

Fixing Breaches in Defences

Fixing Defensive Breaches Description
Bad breaches.png

This is an example of what not to do when attempting to fix a breach in the defensive line with hostiles nearby.

In the picture you'll see that this is a highly dangerous and ineffective way to fix the breach in a defensive line if hostiles are nearby. This will let you get slashed up by an alien running up willy nilly, and will give you less time to react if multiple xenos decide to push the defensive line.


This is an example of what to do when attempting to fix a breach in the defensive line with hostiles nearby.

In the picture you'll see that it shows the optimal way of repairing a breach in your defences if xenos are nearby.

To perform this fixing manoeuvre, you'll want to:

  • Build a barricade a few tiles back,
  • Screwdriver the freshly built barricade,
  • Wrench it, to allow it to be moved,
  • Pull the barricade (Ctrl + Click or open up the right click menu) and then pull it to the tile below you (By clicking on the tile), and then finally the breached tile as demonstrated in the photo.

This will force the xenomorphs to run into the FOB to attack you, and put themselves at risk of death due to being in the FOB. This method takes much more time than the above one, however, the safety gained from doing it is worth it's weight in attachments ten times over. If there are no hostiles at all, building it in the normal manner is perfectly acceptable.

Misc. FOB tips

Fob Tips Description

In the picture you'll see that it demostrates that windows, even if reinforced, are not an acceptable replacement for a line of all-american steel barricades.
Windows as a defence:

  • Provide no firing lines
  • Are Weak

In summary, avoid using them as a defence.


Barricades will end up damaged due to the ravages of war and incompetence, and if it isn't horribly damaged, you'll be able to use a blowtorch on it to repair it. This works on metal and plasteel barricades.Note that if a barricade is too damaged you will be unable to fix it.

Each time you repair a barricade it will consume one unit of welder fuel.

FOB Guides

[WIP] Useful engineering 101 by Challenger on 22 Jul 2017