EPSG systems

EPSG:9741 EOS21 Grid

Projected system (Transverse Mercator) in use: UK - Tweedmouth to Aberdeen. The full definition below, and conversion in one click.

EPSG publishes no simple transformation to WGS 84 for this datum: conversion works on the ellipsoid alone and can be off by tens of metres.

System record
CodeEPSG:9741
NameEOS21 Grid
TypeProjected system — Transverse Mercator
Area of use UK - Tweedmouth to Aberdeen
United Kingdom (UK) - on or related to the complex of rail routes in the East of Scotland, incorporating the route from Tweedbank through the Borders to Edinburgh; the line from Edinburgh to Aberdeen; routes via Kirkaldy and Cowdenbeath; and routes via Leuchars and Perth to Dundee.
Bounds W -3,56° · S 55,55° · E -1,94° · N 57,21°
Countries United Kingdom
DatumEOS21 Intermediate Reference Frame
Ellipsoid GRS 1980 a = 6378137 m · 1/f = 298.257222101
Base geographic system EPSG:9739 — EOS21-IRF
Unit metre (E east, N north)
Transformation to WGS 84 No simple transformation published (ellipsoid alone)
ScopeEngineering survey and topographic mapping for railway applications.

Projection parameters

ParameterValueUnit
Latitude of natural origin56.35degree
Longitude of natural origin-2.75degree
Scale factor at natural origin1unity
False easting74996.927metre
False northing133508.35metre

proj4 definition

+proj=tmerc +lat_0=56.35 +lon_0=-2.75 +k=1 +x_0=74996.927 +y_0=133508.35 +ellps=GRS80 +units=m +no_defs

Paste it into QGIS, proj4js, PostGIS (spatial_ref_sys) or GDAL. +towgs84 carries the EPSG transformation to WGS 84; the official code stays EPSG:9741.

WKT (ESRI format, the .prj content)

PROJCS["EOS21_Grid",GEOGCS["GCS_EOS21-IRF",DATUM["EOS21_Intermediate_Reference_Frame",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",74996.927],PARAMETER["False_Northing",133508.35],PARAMETER["Central_Meridian",-2.75],PARAMETER["Scale_Factor",1.0],PARAMETER["Latitude_Of_Origin",56.35],UNIT["Meter",1.0]]

All systems — United Kingdom

Source: EPSG registry v11.022 (IOGP), through the PROJ database. Always check a code on epsg.org before contractual work.