In 1868 Korsman started trading firewood in Turku, but already in the following year he moved to a new line of business: Korsman bought a screw-propeller steamer named Ahkera and started liner shipping between Turku and Salo. In the 1870s he expanded from coastal shipping to liner shipping between Turku and Stockholm, and cargo shipping in the Baltic Sea. Korsman aimed to use the latest technology and to increase the capacity. In 1874 Korsman founded shipping companyÅngfartygsaktiebolaget Åbo to operate between Stockholm and Saint Petersburg by steamship Åbo, which was the largest steamship built in Finland until then. A company called Finska Transito-ångbåtsaktiebolaget had started winter season operation between Hanko and Stockholm in 1876 by 298-tonne S/S Express. Due to unprofitable summer season operation the company bankrupted in 1878. The state regarded a year-round operation to Sweden highly important, and sought for successor for the operation. Korsman saw the potential of steam shipping for wintertime operation, and rented the ship from the state which had confiscated it due to outstanding payments. He moved to Hanko and recruited captain August Alexander Granroth to master the ship. Express sailed weekly between Stockholm and Hanko between 15 November and 15 May. Out of total 303 journeys planned during 1878–1889, 242 were successful despite of difficult ice conditions at times. Korsman played with a high risk, because no a marine insurance company agreed giving an insurance to a such operation; on the other hand, the Grand Duchy and city of Stockholm supported him financially. During the 1880s the number of passengers grew and in addition to mail delivery, Korsman exported Finnish butter and paper to the Swedish and British market. Korsman and captain Granroth created the basis for the Finnish winter shipping, and Hanko became the centre of it. In 1889 the state organised a Danishicebreaker to ease manoeuvring in ice and in the following year the first state-owned icebreaker started in service. Korsman planned to grow his business and buy another ship alongside the Express which he had earlier purchased from the state, but gave up with the plan due to health reasons. He built a four-floor house in Helsinki, close to South Harbour in 1895.
Other businesses
Korsman was founder and manager of Vätti techno-chemical factory started in 1872. In 1874 he took part at founding engineering company Åbo Mekaniska Verkstads Ab and became its manager. During 1880–1890 Korsman was the manager of Hanko spa, which developed the most significant spa of Finland during his leadership.
Positions of trust
Korsman took part in many municipal positions of trust both in Turku and Hanko. He was chairman of Hanko town council in 1890–1891. During 1885–1889 Korsman participated in three committees which aimed developing the Finnish seafaring.
Personal life
In 1854 Korsman married Isabella Charlotta née Ramsell. The couple got 12 children in 1855–1875; ten of them lived until adulthood.