About the data
This is a proof of concept for a larger map of the London Blitz. Its main source is the London Fire Brigade's log of every incident it attended in the first raid of the Blitz, on Saturday 7 and Sunday 8 September 1940.
The log
The log has 843 entries. Each gives the time, the address as the firemen wrote it, the type of bomb, and a short note on the damage. Dimensions in the notes are in feet. The types are: IB, incendiary bomb; EB, explosive bomb; COB, crude oil bomb.
The Guardian Datablog published the log in full, and it has circulated as a public spreadsheet since. We show the addresses and notes exactly as recorded, spelling mistakes and all. Only the bomb types are grouped, so that variants such as “EB & IB” and “IB and EB” count as one.
The log's times run from 00:08 to 23:59 but carry no date. We read it as one raid rather than one calendar day: the entries from 16:14 onwards are the Saturday afternoon and evening, and those after midnight are the early hours of Sunday 8 September, while the night raid went on. A local historian reading the same records places the Catford bombs at 00:18 and 00:20 in the early hours of Sunday (Running Past).
The timeline runs from 16:00 on the Saturday to 06:00 on the Sunday, an hour and a half after the all clear. 10 entries logged later on the Sunday, fires and unexploded bombs found during the day, are left off the map. A few entries between the all clear and 06:00 are flagged in the details as possibly found after the raid.
One set of times has been corrected. Twelve entries for Woolwich Arsenal, where 49 men were killed, are logged at 14:55. Read literally that would be the Sunday afternoon, long after the raid; other accounts put the attack on the Arsenal at about 17:15 on the Saturday, in the afternoon raid. We show them at 17:15 on the Saturday, and each one says it was logged at 14:55.
The course of the raid
The diamonds on the timeline mark these moments, taken from published accounts rather than from the log.
| Time | What happened | Source |
|---|---|---|
| 16:43 | Sirens. Air-raid sirens sound across London. | London Museum |
| 17:00 | First bombs. The first bombs fall, on the oil tanks at Thameshaven; Woolwich Arsenal is hit at about 17:15. | Battle of Britain timeline |
| 18:30 | All clear. The all clear sounds between the two raids. | London Museum |
| 20:00 | Night raid. The second raid begins: over 300 more bombers. | London Museum |
| 04:30 | All clear. The last raiders turn for home. The night raid has lasted over eight hours. | London Museum |
Placing it on the map
The log has addresses, not coordinates. The coordinates come from Enrico Spinielli's 2012 project theblitz, which geocoded the same 843 rows with OpenStreetMap's Nominatim and Google's geocoder, and placed some by hand from a 1908 map. We fixed the rows that repo had stored with latitude and longitude swapped, and placed by hand the ones it had matched to a street of the same name outside London.
| Placement | Entries | On the map |
|---|---|---|
| On the street named in the log | 682 | Solid dot |
| On the district only | 127 | Hollow ring |
| By hand from a 1908 map (street gone) | 14 | Solid dot |
| By hand, fixing a wrong match | 9 | Solid dot |
| Could not be placed | 1 | Not shown |
No point marks the exact building. Where several entries share one address or one district, they are spread in a small spiral so each can be clicked. London's streets have changed a great deal since 1940, and some of the matches will be wrong. The list of entries worth checking by hand is kept with the source files.
Credits
- Incident log: London Fire Brigade records, published by the Guardian Datablog.
- Geocoding: Enrico Spinielli, github.com/espinielli/theblitz.
- Base map: drawn from © OpenStreetMap contributors (ODbL), via the Geofabrik Greater London extract, and hosted with the site. It shows London's streets today, not in 1940: the Surrey Commercial Docks, for example, have mostly been filled in since.
- Course of the raid: London Museum, “Black Saturday: the first day of the Blitz”; Battle of Britain Historical Timeline, 7 September 1940.
- Further reading: Peter Stansky, The First Day of the Blitz (Yale University Press, 2007).
This is a non-commercial, educational project.