A 40 mm gun on a container ship: that is the image released by Bae Systems Bofors to introduce Sea Tridon C, a weapon system housed in a standard shipping container that can also be temporarily installed on commercial vessels. Unveiled on 3 November 2026 at Euronaval in Paris-Villepinte, it is the containerised version of Sea Tridon, a weapon system combining the gun with an integrated electro-optical fire-control system, allowing it to operate independently at sea. Introducing the system, Bae Systems Bofors president Lena Gillström explained that maritime threats were evolving rapidly and required flexible solutions, allowing navies and maritime operators to choose the level of capability best suited to their needs.
The module makes it possible to arm vessels that have no ammunition magazines, explained Stefan Löfström, director of marketing and sales at Bae Systems Bofors. Rounds are stored beneath the gun mounting, inside the container itself, which is available in 10-foot and 20-foot versions. In the 10-foot version, the gun sits on a container housing a 60-round carousel, but Löfström recommends the 20-foot option, which can at least double ammunition capacity and provide space for command-and-control equipment. The container is built to withstand recoil and distribute the forces across the deck, which on a merchant vessel is not designed for such loads. Löfström added that the larger version also reduces structural stresses. Bae says the module can incorporate power and air-conditioning systems. The 3P ammunition is programmed immediately before firing and has six fuze settings, allowing a single ammunition family to engage aerial, surface and shore targets. The gun can fire 300 rounds per minute and, according to Bae, is effective at ranges of four to five kilometres. In trials, it reportedly brought down drones with as little as a single round. Its stated maximum range is 12,500 metres.
Bae is funding development and seeking its first customers. Löfström said there was no launch customer yet, but advanced talks were under way with several potential buyers, including navies interested in installing the armed containers on uncrewed vessels. The programme has so far focused on land-based trials, and the company intends to step up testing of the naval variant, including the containerised module, over the next twelve months. The idea of arming container ships with modular systems is not new. In February 2019, Mbda unveiled Spimm at Idex in Abu Dhabi, a module equipped with Mistral missiles to provide short-range defence for otherwise unarmed container ships in high-risk areas. Christophe Leduc, head of naval systems at Mbda, explained that a permanent system was expensive, required trained crews and was unnecessary most of the time.
Legally, there is no global rule governing weapons aboard civilian vessels: International Maritime Organization circulars provide guidance, flag states have the final say, and coastal and port states can impose stricter rules. However, these circulars concern private armed guards rather than the installation of naval guns. As early as 2012, the Imo acknowledged that carrying firearms aboard merchant ships was a complex legal issue on which member states held differing views. In their joint statement of 9 July 2025 on attacks in the Red Sea, Ics, Bimco, European Shipowners, Intercargo and Intertanko called on states to maintain robust support for the protection of shipping. In 2011, the Ics left the decision on whether to carry armed guards to shipowners, subject to approval by the flag state and insurers.
M.G.
