Bomb Sight: Mapping the WW2 bomb census

The Bomb Sight project is mapping the London WW2 bomb census between 7/10/1940 and 06/06/1941. Previously available only by viewing in the Reading Room at The National Archives, Bomb Sight is making the maps available to citizen researchers, academics and students. They will be able to explore where the bombs fell and to discover memories and photographs from the period.

The project has scanned original 1940s bomb census maps , geo-referenced the maps and digitally captured the geographical locations of all the falling bombs recorded on the original map. The data has then been  integrated into 2 different types of applications  . .

Frequently Asked Questions

How did you select which data to map?

To develop a manageable set of data we had to select from a vast array of archive information. This blog post describes the process of narrowing the focus by selecting a time period, a region and a sub-set of maps.

The Bomb Sight is using the Bomb Census Maps as the primary data in the tools we are developing. The maps are part of an extensive array of material collected during the Bomb Census Survey 1940 to 1945, organised by the Ministry of Home Security. The records are held in The National Archive (TNA), and we are using the maps with a non-commercial education licence.


Due to the sheer volume of records, photos, documents and information collected during the Bomb Census Survey – the project had to carefully select data to prevent information overload which might mean we miss our completion deadlines. For this reason we spent some time before Christmas at the Archives with one of TNA’s map archivists Andrew Janes. The image shows a snapshot of the types of documents collected during the bomb census. The array of information had the purpose of providing the government with a complete picture of air raid patterns, types of weapon used and the damage caused (TNA, 2011).

How Did You Select a Time Period to Use?

To select a manageable data set we first decided to restrict the time period of the project to the period of the most intensive bombing known as The Blitz. The word ‘Blitz‘ is derived from the from the German term ‘Blitzkrieg’ (lightning war) and is associated with a period of continued aerial bombing by the Germans on Britain (Imperial War Museum, 2011). The Blitz started on the 7th September 1940 and continued until the spring of the following year. The maps in the archive do not completely align with the time period of the blitz so there is a slight mismatch but the reporting period we are investigating is between October 7th 1940 and June 1941 as this is the period in which data were collected.