After completing telegraph operator training at the Royal Telegraph Administration in 1866, Julia Hammar is hired by SJ as a telegraph operator in 1967. She begins as a temporary employee, but is granted a permanent position later that same year. She holds this position until her death in 1890.

The profession of telegraph operator was one of the government jobs in the field of communications that was opened up to women in the 1860s. The railway was already employing women as gatekeepers and level crossing guards at that time.