Their oldest son, Geldolph Adriaan Kessler, also worked for the Royal Dutch before he left to help form and run the Hoogovens, the Dutch steel company.
In 1918, the steel producer Koninklijke Hoogovens was established in Velsen-Noord along the North Sea Canal.
Amsterdam went over to gas from Hoogovens in IJmuiden, so the production of coal gas from the Factory decreased.