How Kemppi Supports Defence Shipyard Welding from Steel to Aluminium

Demand for defence industry shipbuilding is developing rapidly. As naval development programmes expand across the Nordics and wider Europe, shipyards are facing growing pressure to increase productivity with strict quality, traceability and compliance requirements.

According to SIPRI, global military expenditure reached $2.44 trillion in 2023, with Europe seeing one of the sharpest rises in defence spending in decades. Modern naval vessels are becoming more complex, combining high-strength steels, marine aluminium, varying material thicknesses, and confined structures that place increasing demands on welding operations.

Welding quality directly affects structural integrity, distortion control, production timelines, and rework. Long seams, positional welds, changing environments, and large hull sections make repeatability increasingly important, especially when multiple vessels are simultaneously under construction.

For Nordic shipyards, the environment adds another layer of difficulty. Welding often takes place in sub-zero ambient temperatures, outdoor staging areas and confined compartments, with long cable runs and rapidly changing work locations. In some circumstances, welding power systems may also need to operate using electrical power generators during temporary infrastructure setups, dockside repairs, or situations where stable grid power is unavailable.

Kemppi design and manufacture welding solutions that specifically meet shipbuilding needs, offering portable, compact and system class equipment that resolve the many alternative and complex needs for shipbuilders. Kemppi X5P FastMig for example is developed for demanding industrial welding environments where stable arc performance, controlled heat input, repeatability and parameter validation are critical. X5 FastMig combines alternative MIG/MAG process options, including pulse and double-pulse capability, WISE and MAX arc optimisation processes, alternative robust wire feeding system options, and compatibility with long cable setups for reach & access, plus the ability to run from generated power supplies.

Generations of customer experience and feedback have shaped Kemppi welding solution development. Examples include Meyer Turku shipyard and Turula Engineering, combining welding gun, portable and system class equipment, including use of X5P FastMig with its digital WPS and WeldEye capability, plus Leimet’s AX MIG Welder pilot in robotic welding production.

We spoke to John Frost, Product Manager at Kemppi, who explains some of the key welding challenges facing modern defence shipyards and how the X5P is designed to support them.

Reducing process variability

“In marine fabrication, one of the biggest challenges and risks is parameter and process variability, leading to quality issues,” says Frost. “Inconsistent equipment setting can lead to welding defects, penetration issues and/or excessive heat input, impacting product quality, increased rework, welding cost elevation and impacts on downstream production.”

Kemppi X5P FASTMIG is designed to regulate welding quality. Digital WPS integration option helps regulate welding quality, including controlled heat input across long seams and positional welding. Performance tools such as WiseFusion, WiseSteel, Max Cool, Max Speed and Max position support usability, productivity and repeatable weld quality, particularly in changing welding conditions and multi-operator shift working.

Welding high-strength steel and marine aluminium

Military vessel fabrication often involves both thick black steel structures and lightweight marine aluminium applications.

“With aluminium, heat control and transfer stability become critical because of the material’s conductivity and inherent oxide layer,” Frost explains. “With steel, the focus is maintaining defined parameter specification across variable material sections and joint types.”

The X5P FastMig supports reliable and repeatable welding quality through integrated digital control, offering customers wide ranging synergic welding programs, that help standardise parameter control across different materials, operators and work areas.

Why shipyard hardware matters

Shipyards present practical challenges beyond the weld itself. Confined space and small compartmental areas, long distance, outdoor work areas, and constantly changing setups at distance from the welding power source, present unique challenges for welding management.

Kemppi offer alternative wire feeding solutions and cabinet sizes meeting reach and access challenges. For example, X5 Wire Feeder HD200 AP and APC are designed for demanding industrial MIG/MAG welding including robust, impact absorbing structures, while the Kemppi SuperSnake intermediate wire feeder extends reliable wire feeding distances up to 30 metres from the main feeder cabinet. This allows the power source to remain outside confined workspaces, while still reaching challenging weld locations and offering excellent operational mobility.

Managing unstable power conditions

Large shipyard environments rarely provide fixed production conditions. Cable lengths, staging areas, and work locations can change throughout vessel construction.

“Welding quality comes from measured values, aligning WPS parameters with real arc conditions, even when setups change,” says Frost. “The X5P FastMig includes welding cable calibration feature (without an additional voltage-sensing cable), ensuring welding parameters and measured values compensate for electrical resistance changes across long cable runs and welding circuit loops.”

Generator-powered compatibility can also become important in temporary production zones, dockside repairs, or environments where stable grid power is unavailable.

Process control and repeatability

As defence shipbuilding becomes more industrialised, shipyards are placing greater emphasis on process control, repeatability, and welding traceability.

Customers are increasingly demanding visibility into welding quality and documentation, particularly as stronger steels become more common across both military and commercial vessels.

At the same time, shipyards across Europe continue facing skilled labour shortages, making process guidance, stored parameters, and consistent welding behaviour increasingly valuable for maintaining quality across teams and shifts.

“The challenge today is not simply achieving weld quality once,” Frost says. “It’s maintaining repeatable quality across changing environments, operators, and production stages while keeping productivity and compliance under control.”