In the years leading up to the Second World War, the French authorities decided to transform Mers‑el‑Kebir, which is located close to Oran in Algeria, into a major naval base. Construction began in 1937 and intensified in 1939 as the need for a strategic port capable of accommodating large warships became increasingly urgent. The project involved extensive maritime engineering works, including the extension of the northern pier, the construction of a new eastern pier, and large‑scale dredging and rock removal to create breakwaters, quays, and protected harbor areas.

When war broke out in September 1939, these works were still in progress. And while conditions rapidly deteriorated, construction continued throughout 1940, 1941, and 1942. The companies involved, which included those working with Ackermans & van Haaren’s French subsidiary, faced severe shortages of fuel, cement, and mechanical parts. In addition, skilled labor became scarce as personnel were mobilized or reassigned, while financial uncertainty affected the execution of contracts. In particular, the supply of rock for breakwater construction was affected, with production dropping sharply and even coming to a complete halt for a period of time.

Nevertheless, dredging operations continued during these years. Crane vessels and barges were deployed in order to remove large volumes of rock and prepare the seabed for further construction. These operations were essential for stabilizing the breakwaters and creating sufficient depth for naval vessels. And even under constrained conditions, work progressed, albeit at a slower pace than originally planned.

The strategic importance of the site became evident early in the war. On July 3, 1940, Mers‑el‑Kebir was the scene of Operation Catapult, when British naval forces attacked the French fleet that was anchored in the harbor. A little over two years later, in November 1942, the Allied landings in North Africa turned the region into a key logistical hub. While ongoing works were temporarily disrupted, the infrastructure that was already in place, including quays and breakwaters, supported the buildup of Allied operations and continued to be developed afterward.

The construction of Mers‑el‑Kebir during the war years illustrates how maritime engineering can adapt to rapidly changing strategic needs. Even under extreme conditions, the continuation of dredging and port construction works directly contributed to the development of infrastructure that played a significant role in wartime logistics and long-term maritime capacity.