After completing middle school in 1899, he received training in Germany and at Newcastle upon Tyne, followed by trade college in Kristiania (now Oslo).

He would later assume control of large part of his father's and his father-in-law's extensive businesses following their deaths during the 1920s.

[4][5] Endurance, the ship that became famous after Sir Ernest Shackleton's failed Imperial Trans-Antarctic Expedition of 1914, was originally built for Christensen, who intended to use her for Arctic cruises for tourists to hunt polar bears.

From the seaplane brought on the 1936–1937 expedition, members took 2,200 oblique aerial photographs, covering 6,250 square miles (16,200 km2).

[9] During World War II, Christensen was Counsellor of Finance at The Royal Norwegian Embassy in Washington, DC and a member of the Nortraship Council.

After the War, the Thor Dahl Group, under the leadership of Christensen, regained its position as one of the leaders in the industry.

[10] Together with Otto Sverdrup and Oscar Wisting, Christensen initiated an expedition to recover another famous ship, the Fram.

The rotating bronze memorial statue is situated by the harbour at the end of Jernbanealleen in Sandefjord.

The frame around the front door shows Bible motifs designed by Finn Henrik Bodvin.