Rudolf Kolster's role in developing technology student culture and engineer culture in Finland is undisputed. With him, a strong foundation of mathematics and natural sciences was built for what would become the culture of mechanical engineering.
In addition to his work as a teacher, Kolster was responsible for the inspection of steam engines and the training of steam engine operators in Finland together with Martin Wetzer.
In his capacity as an engineer, Kolster participated in many industrial development projects in the late 1800s. These included developing machinery at the industrial plants of Finlayson Co. and Serlachius, equipping the Student House in Helsinki with heaters and designing a mechanism for turning the telescope in the new Helsinki Observatory. At the end of the century, Kolster inaugurated a patent office together with his sons in Helsinki.
Kolster was the first of the Polytechnic Institute's teachers to receive a personal professorship. He was a practical engineer, not an administrator: While he did serve as the institute's deputy director during 1880–1883, the totality of his work cannot be contained in an archive of administrative decisions. Kolster was a cultivator of mechanical engineering.
The polytechnic student association commemorated the professor's sixtieth birthday with a stern-faced portrait in 1897. Rudolf Kolster passed away in 1901.