Complex sentence: Christen Christensen took over "Rødsverven" in 1868 and bought the other yards one by one, and he started "Sandefjord Flytedokker A/S" in 1884.
Split into simpler sentences: Christen Christensen took over "Rødsverven" in 1868 and bought the other yards one by one. He started "Sandefjord Flytedokker A/S" in 1884.