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Combine Smart Barrier

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Smart Barrier plaza.jpg
Combine Smart Barrier
General information



Mechanic wall

Game information



The Combine Smart Barrier,[2] also known as the Combine Mobile Wall,[source?] or simply Combine Wall,[3][4] is a very large mechanical wall that uses powerful drive systems in tandem with heavy metal blocks to slowly expand outward and destroy existing structures in the way. Smart Barriers are seen surrounding the Citadel (where they make up the "City 17 Inner Wall"), certain areas of Nova Prospekt and City 17, notably on the Trainstation Plaza during Combine occupation of Earth and around the Overwatch Nexus.


Standard operation is to lift and force a set of blocks outward, before allowing them to drop, and then alternating with another set. During this procedure a metallic groaning is heard, presumably from the drive mechanisms. It is unknown whether the Combine are using this method to simply destroy existing structures, or whether to gather raw materials as well. Either way, they are also used as blockades, blocking off alleyways and even entire streets as necessary. Gordon Freeman narrowly escapes being crushed by Smart Barriers shortly before getting into the Nova Prospekt Depot.

Behind the scenes[edit]

  • As seen in the WC map pack and suggested by the Half-Life 2 leak sound files, the City 17 Inner Wall was originally to be stationary, much higher and made out of concrete. The Manhack Arcade was at some point to be located nearby, before being replaced by Captain Vance's Headquarters, where Gordon was to go look for Vance while Alyx was to be left hurt in the Skyscraper.[5][6]
  • An early version, only existing as concept art, was made of cubes.[3]
  • An early prototype version, featured in the WC map pack as a brush, was named "Sensor Gate". It can be found in the WC map pack maps sensor_gate_004, combine_gallery_002 or d1_garage_01. It is always accompanied by an early Combine Watchtower (Watchtowers are often seen near Smart Barriers, but also Barricades), often featuring a Metrocop inside. By default in open state, it shuts itself when the player approaches it, also reacting to a nearby presence with its "sensors", much like the final version.





List of appearances[edit]

Main games[edit]