Sector D Administration

Sector D Administration is one of the seven main sectors of the Black Mesa Research Facility.

Administration Offices
Seen early in Half-Life, Sector D is mainly a large underground complex of Administration Offices where the bureaucratic aspects of Black Mesa's upkeep take place, along with some limited research.

High Security Storage Facility
The Administration Offices are built beneath a High Security Storage Facility, a large semi-subterranean warehouse made of interlocking Storage Areas located on the surface.

Silo D
The lower levels of Sector D also contain the Silo D where rocket engines are tested. The Silo D sector is made of three silos, also named "Prop Labs": Silo D-01 - Engine Testing, the red-coded and biggest silo where engines are tested and where three Tentacles can be found during the Black Mesa Incident, Silo D-02 - Power Facility, the green-coded silo used for Silo D-01's power, and Silo D-03 - Wind Tunnel, the yellow-coded silo containing a huge propeller, as well as the fuel and oxygen reserves provided for the Silo D-01 engines.

List of appearances

 * Half-Life
 * Half-Life: Blue Shift
 * Half-Life 2: Raising the Bar