| Ivar Knudsen | |
| Birth Date: | 1 April 1861 |
| Birth Place: | Følle, Denmark |
| Death Place: | Mumbai, British Indian Empire |
| Occupation: | Engineer |
Ivar Peter Bagger Knudsen (1 April 1861 – 23 March 1920) was a Danish engineer. As the director of Burmeister & Wain (B&W), Knudsen led the development of the, the biggest, most advanced diesel-powered vessel of its time.
Knudsen was born to Jens Elsbert Knudsen (1826–1901), a manager of a grocery firm, and Julie Vilhelmine Rønberg (1828–88). He was the brother of military physician Morten Knudsen and the women's rights activist Olga Knudsen. He trained to be a mechanic in Aarhus and worked in this profession until 1882 when he went to Copenhagen to study at the Technical University of Denmark. After finishing his studies in 1887 he was involved in the design of the fortifications of Copenhagen. He then worked as a mechanical engineer for the electric utility of Copenhagen.
In 1895 he joined B&W as chief mechanical engineer. He was promoted to Director of the engine department in 1897 where he started a comprehensive modernization. Knudsen realised the potential of the diesel engine as ship propulsion and traveled to Germany to meet Rudolf Diesel who was testing the new engines at MAN AG in Augsburg. Consequently B&W obtained the patent rights on the Diesel engine for Denmark. The following years saw numerous tests and improvements, eventually resulting in an efficient and reliable machine. In 1908 Knudsen became the head of both the machine factory in Christianshavn and the shipyard in Refshaleøen.
Hans Niels Andersen, founder of the East Asiatic Company, saw that diesel powered ships would mean a leap forward for the shipping industry, and in December 1910 placed an order with B&W for a large oceangoing motor ship, the .
The first voyage in February 1912, with Andersen and Knudsen on board, was from Copenhagen to Bangkok via London and Antwerp. The ship was received with great interest and many people visited the Selandia including the First Lord of the Admiralty, Winston Churchill, and other high ranking naval officers.
Selandia had two sister ships, the and the ; finishing their sea trials in June 1912, and July 1912, respectively. The Fionia was met with similar interest in Germany during Kiel Week, where visitors included German Emperor Wilhelm II and Albert Ballin, director of the Hamburg America Line.
Knudsen resigned from the yard's daily management in April 1919, joining the company's board as an advisor.
Knudsen is one of the men seen in Peder Severin Krøyer's monumental 1904 oil-on-canvas group portrait painting Men of Industry. He died "mysteriously" from food poisoning while on a trip to India on 23 March 1920. He is buried in Hellerup Cemetery. His grave has been removed.[1] A large memorial stone was unveiled in Følle in 1932.[2]