In 1892 he bought Sandefjord Mekaniske Verksted, merging it with his other ship yards to form Framnæs Mekaniske Værksted. The shipbuilding engineer Ole Wegger became its director and remained in that position for 47 years. Christensen then entered the whaling business as owner of the company "Shields & Værge", which ran most of the fishing in Finnmark. The company was bought at auction for a small price, undoubtedly because of the decline in the North Atlantic whaling stocks, which led to much of the whaling industry going bankrupt. Christensen, however, saw this as an opportunity, having remembered a pamphlet published in 1874 titled, "Report on the new whaling grounds of the southern seas" by Daniel and Jon Gray. Giving him the idea to send an expedition to Antarctica, in search of new sealing and whaling grounds. Something he would become well known for along with a young Carl Anton Larsen who was an officer aboard the barque "Freden", one of Christensen's ships.