From Roader's Digest: The SABRE Wiki
Who's working on this?
What's the process for putting up a new map?
- Find some maps! They're not as widespread as, say, New Popular maps (which you can buy for a quid in Oxfam) but close monitoring on eBay has thrown up some good deals. Some professional map dealers regularly have copies.
- Scan the maps. Most MOT maps will fit on an A1 scanner, but Ritchie333 has had surprisingly good results from taking four composite scans from an A3 scanner.
- Stitch the scans back together to make a complete map. Even if you've found an A1 scanner, you might still have to do this anyway, because quite a number of maps floating around are library copies that have been cut along the fold, which you'll have to remove by hand. Although this sounds like a slow and laborious process, it is doable, and it has the advantage of not having the scan distorting along the fold (which is flipping irritating). Ritchie333 uses GIMP to do this.
- Write the calibration file. This maps physical points on land to pixels on the scans. You need to do this to get all the maps to line up, and to display roads in the right place. See the technical notes at the bottom of the page. You can do this with Paint and Notepad, and it takes about 15 - 30 minutes.
- Generate the tiles and upload them to the maps server
Sheet List: England and Wales
Maps online are in bold title for 1922-23 revision, other revisions are also in bold if online.
Maps known to exist at a legal deposit library but not online are in italic.
Maps owned by a member of SABRE and available for use on SABRE Maps are marked by §
|Map Number||Map Name||Overlaps||Revisions||Notes|
|1||Jedburgh, Berwick upon Tweed and Alnwick||Scotland sheets 28, 32||1926-27, 1931-32||1926-27 - BL (dissected)|
|2||Carlisle||Scotland sheets 31, 32, 34||1928-29|
|3||Newcastle upon Tyne||1924-25 §||1924-25 - BL (dissected), Cambridge UL (unknown condition), Steven (excellent)|
|4||Isle of Man||Not issued as an MOT map|
|5||Lake District||1927-28||1927-28 BL|
|6||Middlesbrough, Richmond and Ripon||1927-28, 1936-37||1927-28 BL|
1936-37 - BL (dissected)
|7||Whitby and Scarborough||1926-27||1926-27 BL|
|8||Lancaster, Southport and Preston||9||1924-25, 1930-31|
|9||Harrogate, Leeds and Bradford||8||1924-25||1924-25 - BL and Cambridge UL (unknown condition)|
|10||York and Kingston upon Hull||1927-28, 1936-37||1927-28 BL|
|11||Carnarvon, Bangor and Colwyn Bay||1929-30||1929-30 - Cambridge UL (dissected)|
|12||Liverpool, Manchester and Chester||1924-25;, 1928-29, 1929-30, 1936-37||1924-25 - Steven |
|13||Sheffield||1924-25, 1929-30, 1936-37 §||1924-25 BL|
1936-37 - Steven
|14||Lincoln and Grimsby||1927-28, 1936-37||1927-28 BL|
|15||Barmouth and Aberystwyth||1927-28||1927-28 BL|
|16||Wrexham, Shrewsbury and Hanley||1926-27||1926-27 BL|
|17||Derby, Nottingham and Leicester||1924-25 §, 1928-29, 1936-37||1924-25 - BL, Steven |
|18||Peterborough and Boston||1926-27||1926-27 - BL, Cambridge UL (unknown condition), Steven (excellent)|
|19||Norwich and Great Yarmouth||1924-25, 1927-28 §, 1936-37||1924-25 BL|
1927-28 - BL and Cambridge UL (unknown condition)
1927-28 - Steven (dissected
|20||Pembroke and Fishguard||1924-25||1924-25 - Ritchie333|
|21||Brecon and Lampeter||1927-28||1927-28 BL|
|22||Worcester and Ludlow||1924-25 §, 1929-30||1924-25 - BL and Steven |
1929-30 - Cambridge UL (poor condition)
|23||Birmingham, Leamington and Northampton||1926-27, 1936-37||1926-27 BL|
|24||Bedford and Cambridge||1927-28, 1936-37||1927-28 BL and Ritchie333|
|25||Bury St Edmunds and Ipswich||1924-25, 1927-28, 1936-37||1924-25 - Cambridge UL (unknown condition)|
1927-28 - Ritchie333
|26||Swansea||1924-25, 1925-26||1924-25 - BL, Cambridge UL (unknown condition)|
|27||Gloucester, Monmouth and Newport||1926-27||1926-27 BL|
|28||Oxford and Swindon||1924-25 §, 1930-31||1924-25 BL and Steven (dissected)|
|29||North London, St Albans and Hertford||30, 34||1926-27||1926-27 BL|
|30||Colchester||29, 34||1927-28, 1936-37||1927-28 BL|
|31||Bideford, Ilfracombe and Tiverton||1927-28, 1936-37||1927-28 BL|
|32||Bristol and Cardiff||37||1926-27, 1936-37||1926-27 BL|
1936-37 - Cambridge UL
|33||Salisbury, Winchester and Reading||38||1927-28||1927-28 BL and M40|
|34||London||29, 30, 39||1925-26, 1927-28, 1936-37||1927-28 BL and Ritchie333|
|35||South West Cornwall and Scilly Isles||1927-28, 1930-31||1927-28 BL|
|36||Plymouth, Torquay and Exter||1927-28, 1930-31||1927-28 BL|
|37||Weymouth, Yeovil and Taunton||32||1927-28, 1930-31||1927-28 BL|
|38||Southampton, Portsmouth and Isle of Wight||33||1926-27, 1929-30||1926-27 BL|
|39||Brighton||34||1924-25, 1925-26 §, 1927-28||1924-25 BL|
1925-26 - Steven
1927-28 - M40 - scan is badly foxed
|40||Chatham, Margate and Hastings||1924-25, 1925-26, 1930-31||1924-25 - BL, Cambridge UL (unknown condition)|
Total maps : 108
Total scanned : 56
Sheet List : Scotland
|Map Number||Map Name||Overlaps||Revisions||Notes|
|1||Shetland Islands (north)|
|2||Shetland Islands (south)|
|3||Orkney Islands (north)||1930-31||Inset for Fair Isle|
|4||Orkney Islands (south)||1930-31|
|5||Lewis||1927-28, 1930-31||Inset for Flannan Islands|
|7||Wick and Thurso|
|8||Ullapool and Gairloch||11|
|9||Dornoch and Cromatry||13|
|10||North Uist||1927-28||1927-28 BL|
|13||Inverness and Nairn||9||1927-28|
|14||Elgin, Keith and Huntly|
|15||Aberdeen and Banff|
|16||Barra||1927-28, 1930-31||1927-28 BL|
|17||Mallaig and Tobermory|
|19||Ballater and Pitlochry||24|
|20||Forfar and Stonehaven||24|
|21||Oban and Iona|
|22||Oban and Killin|
|23||Dundee, Perth and Stirling||24|
|24||Montrose, Dundee and Kirkcaldy||19, 20, 23|
|26||Glasgow and Firth of Clyde||26|
|28||North Berwick and Kelso||England & Wales Sheet 1, 2||1927-28|
|29||Kintyre and Island of Arran||25, 26, 30|
|31||Moffat and Dumfries||34, England & Wales Sheet 2|
|32||Hawick, Jedburgh and Otterburn||England & Wales Sheet 1, 2|
|33||Wigtown and Stranraer||30||1927-28, 1930-31|
|34||Dumfries, Kirkcudbright and Cockermouth||31, England & Wales Sheet 2||1927-28, 1930-31|
Total maps : 50
Total scanned : 29
MOT maps predate the National Grid, and are derived off base maps that predate the Popular Edition which unified the whole of the UK under one projection system.
England and Wales
The English and Welsh maps use the Cassini (Delamere) projection. A handy page to convert between this, lat/lon and modern projections is here. This is defined in feet from an origin in Delamere Forest, Cheshire (where the A54 meets the A556) - approximately here.
Each map is broken up into 4x4 mile (ie: 21,120x21,120 feet) grid squares.
For English and Welsh maps, there are usually 13 1/2 west to east ("1" to "14" with 14 being half length, and 9 or 12 north to south ("A" to "J" or "M", "I" is not used). Most maps are "J" maps - the "M" maps include sheets 35 and 40. Sheet 40 is also narrower than most, with only 11 1/2 squares. The actual Delamere Forest origin is (according to my tape measure) 11/64 miles (907ft 6in) north and 9/128 miles (371ft 3in) west of the nearest grid square corner on sheet 12 (which is treated as the "false" origin for all other maps).
Most maps align exactly with each other, with only a few overlaps, the size of which is always a whole number of miles. The edges of the grid squares therefore generally line up with each other. The notable exceptions appear to be sheets 21, 31, 35 and 36, which have been aligned to fit as much land on the map without requiring an insert.
The Scottish maps use the Bonne (Scotland) projection, defined in feet from latitude 57.5, longitude -4, which happens to be about halfway between Inverness and Nairn here. This is (from measuring map scans) about 1042 feet east and 438 feet north of the nearest grid square.
Scottish maps appear to be all 12 squares by 9 squares, though the orientation can vary between portrait (9 across, 12 down) and landscape (12 across, 9 down). A couple of maps (eg: sheet 24) overlap substantially with others.
All maps also has markers and bars along the edges specifying a specific arc of longitude or latitude, at minute intervals (with 60 minutes to a degree), with every 5 minutes marked explicitly. Latitude is always positive, longitude is positive east of the Greenwich Meridian, or negative west of it. This is useful for testing the corner of the map is where you think it should be.
Format of calibration file
The first row contains a single entry, which is the map number. Subsequent rows contain three comma separated fields :
- A "grid reference". This consists of a letter (northing) followed by a number (easting) as seen on the map, and denotes the top left corner of that square. Because edges of the map frequently extend only to half squares, append "q" for a quarter length, "h" for half, or "t" for three quarters. The most common corners for the maps are A1, A14h, K1 and K14h.
- The x pixel that contains the top left corner of the square.
- The y pixel that contains the top left corner of the square.