Did Conkers Help to Win the First World War?

Royal Naval Cordite Factory (cooker house and concrete fermentation vessels)
Holton Heath, Dorset

Scheduled: 2001 (Royal Naval Cordite Factory)
Listed: 2000 (Cooker House)
Grade: II
NHLE entry: Listing details for the Royal Naval Cordite Factory and Listing details for the Cooker House

In the autumn of 1917, a call went out for children to collect horse chestnuts - popularly known as conkers - and acorns. Hundreds of tons were collected from playgrounds, gardens and local parks, as children responded to a notice pinned to their classroom walls: 'THIS COLLECTION IS INVALUABLE WAR WORK AND IS VERY URGENT. PLEASE ENCOURAGE IT.' But why was this huge effort so important in helping the Allies win the First World War?

'Destructive distillation'

Cordite is a member of a family of gaseous chemicals used to make smokeless explosives for the military. From the late 19th century it replaced black gunpowder as the main propellant for firearms and artillery, and during the First World War huge quantities of it were needed.

A vital ingredient in its manufacture was a solvent called acetone. Prior to 1915 this was mainly produced by causing wood to decompose at a high temperature through a controlled process called 'destructive distillation'. Although some acetone was produced in Britain, most was imported from countries like the United States. Low stocks became a crucial issue from 1914 onwards, and it was clear that an alternative domestic supply would be needed.

One substitute came through the science of biotechnology. Chaim Weizmann, a research chemist at the University of Manchester who would later become president of Israel, discovered a bacterium that could produce acetone from maize, which was full of starch. In April 1915 he was introduced to Winston Churchill, who ordered him to build a full-scale factory to manufacture maize-derived acetone. After the process was tested at a London pilot plant, the Royal Naval Cordite Factory at Holton Heath, Dorset was established.

Horse chestnuts and acorns

However, one security issue remained: German U-boats threatened the ships that carried the maize needed for the fermentation process. Therefore a new source of starch was required.

In the autumn of 1917 schoolchildren and Scouts were asked to collect horse chestnuts and acorns, specifically 'without the green husks'. It was never explained to them exactly why this national campaign was required but, for their efforts, children earned 7s 6d for every hundred weight (roughly 50kg) of conkers they handed in. Acetone was produced from this, though problems with shell removal made the wider use of conkers as a starch impractical.

A crucial time in British history

Remarkably, the cooker house, where the mash for fermentation was prepared, and the bases of the fermentation vessels survive today at Holton Heath. Both have been protected by listing (above-ground built protection) and scheduling (below-ground remains protection). The site, now owned by the Ministry of Defence, is closed.

The Royal Naval Cordite Factory's place on the National Heritage List for England commemorates not only the site's historical association with two of the 20th century's most influential politicians, but also an innovative industrial process that greatly aided the military at a crucial time in British history.