Excavator



The  is a giant mining machine. They appear in the campaign mission Vorkuta, the multiplayer map Radiation, and the Zombies level Moon. On the former two, they appear only in the background.

Moon
Three excavators appear in Moon, each with their own control panel in the starting room. When an Excavator activates, the players will be given multiple warnings - three well before the attack, one 60 seconds before, and another 30 seconds before it begins to breach. They will have to deactivate it by using the Hacker on its respective control panel. These panels are found in the starting room. If the players let it continue, the Excavator begins drilling into the base, blocking off one of the doors and making it harder to navigate. The Excavator will keep going until the end of the game unless the panel controlling it is hacked. When the Excavator breaches an area there will no longer be oxygen there. The Excavator must be allowed to breach Tunnel 6 for Richtofen's Grand Scheme.

Usually the first excavator activates around round 6-7, although it can be as early as round 4. The other excavators then activate in multiples of that round (or at least close to). For example, if the first excavator starts at round 6, then the second will activate at round 12 and the third at 18 (however, this isn't a guarantee. It can activate at round 10, the 12 is just an approximate).

The following excavators dig into the following areas on the map, seemingly randomly throughout the game:


 * Pi - Tunnel 6
 * Omicron - Tunnel 11
 * Epsilon - Biodome

Achievements
Ground Control (10G) - In Moon, prevent each excavator from breaching the base in one game.

One Giant Leap (5G) - In Moon, become trapped in the Receiving Area and free yourself through resurrection in co-op. (Requires Excavators Pi and Omicron to be blocking off the Receiving/Starting Area from the rest of the map.)

Trivia

 * There is no guarantee as to where an Excavator will breach. It can breach anywhere, including places the player hasn't opened yet. It can even attempt to breach the same place several times in a row. This can be frustrating for players going for the Ground Control achievement or trying to accomplish Richtofen's Grand Scheme.
 * Players may have problems getting back to the starting room to disable the excavators if two of the excavators are blocking their path back. To get around this a player must get the Hacker, teleport to area 51 and back again to hack the control panel. Another way of getting round this is to allow an Astronaut Zombie grab the player or jump through a Gersch Device to teleport them to an otherwise blocked off area. The astronauts will steal one of the player's perks in the process, so Gersch Devices are the preferred choice.