In 1951 Andersson & Callenberg El AB was founded in Uddevalla, Sweden. The founding fathers, Olle Andersson and Hugo Callenberg, captured the Uddevalla Shipyard as their principle customer and, at the same time, worked up clientele outside the marine market. Andersson & Callenberg grew large during the golden years of the Swedish shipyard industry. When the domestic market collapsed in the late 70’s and early 80’s, the company turned to the foreign market.

In the early 80’s Callenberg Engineering Inc in Miami, USA and Callenberg Engineering in Uddevalla, Sweden were established, and within a few years’ time operations in installation and service of marine electrical systems were in full swing.

In 1999 the Callenberg Group established a presence in Asia with its service and sales-company Callenberg Engineering Pte Ltd.

In 2003 the Callenberg Group acquired two Scandinavian companies and renamed them Semco Callenberg Marine A/S and AC Marine AS. Both companies, which were founded during the first half of the 20th century, are highly competitive and they have long experience of their fields of operation. Through these acquisitions, the Group was further strengthened within its areas of expertise.

In September, 2007 Wilhelmsen Maritime Services acquired the Callenberg Group AB, forming the basis of a new business area, Wilhelmsen Marine Engineering.

Today, Wilhelmsen Marine Engineering is one of the largest independent providers of marine EL & automation, and HVAC systems in Scandinavia.