He was appointed assistant in the government of the Gold Coast by royal decree of 18 November 1845.
After working in Elmina Castle for five years, he was appointed commandant of Fort Orange at Dutch Sekondi.
When he returned to the coast in August, he was appointed to the offices of bookkeeper, public prosecutor, government secretary and cashier, which made him second in command.
A month later, government commissioner Willem George Frederik Derx arrived on the Gold Coast, charged by the Dutch government to resume the recruitment of soldiers for the Netherlands East Indies Army.
Runckel was honourably discharged from service in December 1857 on medical grounds, as he suffered from splenomegaly and facial nerve paralysis.