We have a comprehensive collection of Ordnance Survey maps, as well as Ordnance Survey of Northern Ireland (OSNI) and Ordnance Survey of Ireland Maps (OSI).
About the collection
Our most frequently consulted items are the large-scale plans, which began to be published in the mid-19th century as the 25 and 6 inches to the mile County Series (c.1:2500 and 1:10,560), and town plans at larger scales. They show the landscape in great detail. All pre-World War II 1:2500 editions are now available on microfiche. These are organised by county then sheet number. For a comprehensive guide go to:
- Guide to large scale Ordnance Survey maps of Great Britain
- Guide to large scale Ordnance Survey maps of Ireland
- List of 25” County editions for England and Wales, excluding London
- List of 6”, 25” and 5' London editions with index maps
Since World War II, the modern equivalent of county series mapping has been the National Grid series at scales of 1:10,560/1:10,000 for rural and moorland areas, 1:2,500 and 1:1250 for urban areas (c.6 inches to 1 mile, c.25 inches to 1 mile and c.50 inches to 1 mile). The National Grid is a single grid system covering Great Britain. From c.1946 until about 1980 the maps were produced on paper sheets; between 1980 and until 1999 the maps were supplied on microfiche. Since 1997 Ordnance Survey has supplied the Legal Deposit Libraries with digital mapping, namely LandLine® and then Ordnance Survey MasterMap ® data.To determine the grid reference for the map you require use the county indexes available in the Maps Reading Room or go to the 'Get-a map' service on the the Ordnance Survey website. Type in a placename or postcode and a 2-letter, 6-digit grid reference will display eg. TQ 324412. To get a 1:2500 sheet number remove the 3rd and 6th digits, e.g. TQ3241.
Small Scale (2” to the mile, 1” to the mile or 1:50,000) Ordnance SurveyThe first small-scale maps are the Ordnance Surveyors Drawings between 1789 and 1840. They are generally made at 2” to the mile and cover England and Wales as far north as a line from Preston to Hull. They were followed by the 1” to the mile survey which later became the 1:50,000 series, on national grid lines. A comprehensive guide is available at Small Scale OS Maps.
What is available online?
What is available in our Reading Rooms?
Ordnance Survey Resources for Environmental Site ResearchersSite researchers into the incidence of contaminated land etc. are very welcome to visit the Maps Reading Room. Resources available include a comprehensive collection of large-scale Ordnance Survey plans for Great Britain and Ireland dating back to the mid-19th century. This includes post World War II National Grid paper sheets until the 1980s, microfilm aperture cards from the 1980s until 1997 and a digital data terminal from 1997 onwards. Large-scale OS plans are also available for Northern Ireland and Eire.
The Maps Reading Room has a rapid copy service tailored to the needs of site researchers. For Ordnance Survey maps in copyright, i.e. published less than 50 years ago, one A4 from each tile or sheet can be supplied without permission from the Ordnance Survey. Up to 50 copies can be produced within 45 minutes. A4 sheets from microfiche or film of pre-WWII large-scale county Series maps and National Grid sheets on aperture cards can be obtained instantly from self-service reader-printers. There is no restriction on the quantity of A4 sheets for Ordnance Survey maps published more than 50 years ago. We regret that printouts from digital data are not available to commercial users owing to copyright restrictions.
What is available in other organisations?
More information is available form the following websites:
- Ordnance Survey (Great Britain)
- Ordnance Survey of Northern Ireland
- Ordnance Survey of Ireland
- Charles Close Society - a society dedicated to the study of OS mapping
- Old-maps 19th century, 25” and 6” OS maps. Place name search to 1:50,000
- David Archer Maps Map dealer specialising in old OS maps.
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