Egypt Red Belt Coordinate System (EPSG:22992)
Mar 10,2026

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Introduction

Egypt Red Belt coordinate system is a national projected coordinate system established in Egypt during the 20th century, forming part of the Old Egyptian National Coordinate System of 1907, together with the Egypt Blue Belt and Egypt Purple Belt. Based on the Helmert 1906 ellipsoid and employing the Transverse Mercator projection, this system was primarily used for engineering surveys and topographic mapping in the Nile Delta and along the Red Sea coast. Although modern GNSS applications are increasingly prevalent, the Red Belt system remains irreplaceable for processing historical Egyptian land records, Suez Canal infrastructure archives, and 20th‑century national topographic map series.

Coordinate System Composition

Egypt Red Belt (EPSG:22992) is a Transverse Mercator projection system based on the Egypt 1907 national datum, which itself uses the Helmert 1906 ellipsoid . Its defining parameters are tailored for its specific area of use: a central meridian at approximately 31° East (specifically 30.999999999999996°), a latitude of origin at 30° North, and a scale factor of 1.0 . Coordinates are expressed in meters using a false easting of 615,000 meters and a false northing of 810,000 meters . As its name implies, the system covers the "red" longitudinal zone of Egypt, officially designated for the area onshore between 29°E and 33°E, including the offshore Mediterranean east of 29°E and the offshore Gulf of Suez .

Pros

Zonal Accuracy for National Coverage: As one of three belt systems (Red, Blue, and Purple), it is specifically optimized to minimize distortion within its assigned longitudinal zone (29°E to 33°E), ensuring consistent accuracy for large-scale mapping across the Nile Delta, Nile Valley, and Gulf of Suez .
Standardization for Historical Engineering and Topographic Mapping: It served as an official standard for engineering survey and topographic mapping throughout much of the 20th century, creating a unified framework for major infrastructure and development projects within its zone .
Administrative and Legal Legacy: The system underpins a vast repository of historical cadastral records, land registration documents, and boundary demarcations, ensuring legal and technical continuity in property administration where historical records are the foundation.
Integration with Historical Datasets: It maintains compatibility with Egypt's other belt systems and the broader Egypt 1907 datum, facilitating the integration of historical maps, agricultural records, and resource surveys into modern GIS workflows.

Cons

Limited Zonal Applicability: Designed as a zone-specific system, its accuracy degrades rapidly outside its designated longitudinal strip (29°E to 33°E), necessitating a switch to the Blue Belt (west) or Purple Belt (east) for work elsewhere in the country .
Non-Geocentric Reference System: Based on the regional Helmert 1906 ellipsoid rather than a global geocentric reference like WGS84, its coordinates are inherently incompatible with modern GNSS (GPS) measurements and require transformation parameters .
Datum Transformation Requirements: Working with modern GPS or satellite data requires applying specific transformation parameters (e.g., towgs84=-130,110,-13 or -146.21,112.63,4.05) to convert between the Egypt 1907 datum and modern global systems, introducing potential complexity and error if not done correctly .
Belt System Complexity: The existence of multiple, adjacent belts (Red, Blue, Purple) creates a complex patchwork of coordinate systems, requiring users to correctly identify and apply the appropriate belt for their specific geographic area of interest .

Application Scenario

Egypt Red Belt is primarily employed in historical data management, cultural heritage preservation, and legacy system maintenance. It serves as the reference system for interpreting and georeferencing Egypt's historical topographic map series, colonial-era and mid-20th-century cadastral maps, and infrastructure plans for the Nile Delta, Nile Valley, and Suez Canal region. The coordinate system is indispensable for archaeologists and historians digitizing early 20th-century excavation records and site plans, as well as for engineers managing long-term infrastructure assets like irrigation networks and petroleum facilities in the Gulf of Suez, where original construction records were surveyed in this system . Additionally, it remains a necessary tool for integrating historical agricultural land records and water resource management documents into modern geospatial analyses.