In 1942, Franklin became an assistant research officer at the British Coal Utilisation Research Association, or BCURA.
BCURA was an industrial research association founded in 1938 to study the practical uses and efficient combustion of coal. During the Second World War, Franklin worked at its research site near Kingston upon Thames, investigating the physical structure and porosity of coal.
The work was scientifically important as well as practical. Franklin used physical chemistry and techniques related to X-ray analysis to study how coal’s structure affected its performance. Her research formed the basis of her Cambridge doctoral thesis, awarded in 1945, titled The Physical Chemistry of Solid Organic Colloids with Special Reference to Coal.
BCURA is often overshadowed by Franklin’s later DNA research, but coal research established her expertise in carbon materials and crystallographic analysis. That foundation helped prepare her for her later work on graphite, DNA, and viruses.