Thick-Section Welding for US Shipbuilding: A Guide to the Technologies Closing the Gap

Thick-section welding means joining steel plate 15mm or thicker, usually in a single pass or a small number of passes. Ship hulls, bulkheads, and decks typically run 15 to 30mm or more. It’s a narrow technical category that just became a national priority: the US Navy’s FY27 budget request is roughly $65.8 billion, up about 46% from FY26’s $45 billion, and the Navy’s 2026 Shipbuilding Plan targets a 450-ship fleet by 2031, up from 291 battle-force ships today. The Department of Labor estimates the industry needs 200,000 to 250,000 additional workers over the next decade to build that fleet, and welding is named specifically as a critical-shortage occupation.

This is a guide to the technologies that answer that gap: what they are, where each one fits, and who builds them.

Why Thick-Section Welding Is Different From Standard Fabrication

Standard fabrication welding (thin sheet, light structural steel) tolerates a wide margin of error. Thick-section welding doesn’t.

At 15-30mm+, heat input has to be controlled carefully across the full weld depth, not just the surface. Too little penetration leaves an unfused root, a hidden defect that can propagate under cyclic loading long after the weld passes inspection. Too much heat causes distortion, and on a section this thick, distortion doesn’t stay local. A warped hull plate can throw an entire block assembly out of tolerance before it’s ever welded to the next section.

Multi-pass welding, the conventional answer to plate this thick, means stacking individual weld passes to fill a single joint. A 25mm butt weld done with conventional MIG or manual shielded-metal-arc might take 15 to 25 passes, each one adding heat, time, and a fresh chance for slag inclusions or porosity between layers. Run manual stick welding’s typical 5 inches-per-minute travel speed against that pass count, with a published 25% operating factor once electrode changes, slag chipping, and repositioning are counted, and one linear meter of 25mm seam works out to roughly 8 to 13 hours of shop time. A destroyer or amphibious-ship hull carries miles of seam at that thickness.

Deposition rate tells the same story from a different angle:

Every pass also needs its own inspection discipline. Classification-society and Navy rules require routine nondestructive testing on primary structural welds, most often radiographic and ultrasonic, and best practice on a multi-pass joint is to catch problems between passes rather than after the last one. A defect buried under pass 12 of 20 doesn’t surface until final inspection, and fixing it then means grinding back out through however many passes sit on top of it. On a ship with miles of weld seam at this thickness, that arithmetic compounds fast.

Conventional MIG, TIG, and manual shielded-metal-arc welding can all join thick plate. Shipyards have done it that way for decades, and multi-pass arc welding isn’t going away. What conventional processes can’t do is join thick plate fast enough to keep pace with a 450-ship production target on the current timeline. A process that replaces 15 or 20 stacked passes with one, or close to it, changes the economics of a hull weld from days to hours, and it changes the number of welders needed per linear meter of seam.

That’s what the technologies below have in common. Each one, in a different way, either penetrates deeper per pass or deposits metal faster than conventional arc welding. None of them replaces the welder. They change what one welder, or one welding cell, can get through in a shift.

The US Shipbuilding Demand Signal

The short version: policy, budget, and labor data all point the same direction, right now. None of it reads like a one-off announcement. It’s a stack of individually dated, individually funded actions that all land on the same conclusion.

Executive Order 14269, signed April 9, 2025, directed the White House to produce a Maritime Action Plan. That plan arrived February 13, 2026, built around rebuilding domestic shipbuilding capacity and workforce training. The Navy’s FY27 budget request followed in April 2026, and the Navy’s 2026 Shipbuilding Plan, released May 11, 2026, set the 450-ship-by-2031 target and called for growing distributed shipbuilding (work spread across smaller partner yards, not just the largest legacy shipbuilders) from 10% to 50% of production. The SHIPS for America Act and the Building Ships in America Act are both still pending in Congress as of this writing.

Why the US Shipbuilding Revival Is a Welding Capacity Problem covers the full policy and labor picture, including the Department of Labor’s worker-gap estimate and how shipyards are already responding. This piece stays focused on the technologies themselves.

Five Technology Families That Answer the Gap

None of these is a silver bullet. Each fits a different combination of plate thickness, production volume, and part geometry, and most shipyards will end up running more than one of them side by side rather than standardizing on a single process for every joint on the ship.

This guide covers the deep-penetration and high-throughput processes shipyards are adopting or already running to close the single-pass gap. Established multi-pass processes, SMAW, GMAW, and flux-cored arc welding (FCAW), the actual workhorse on most shipyard floors today, remain in wide use and form the baseline this guide measures against. Friction stir welding and keyhole plasma arc welding are genuine single-pass processes used elsewhere in shipbuilding, but neither fits this guide’s 15-30mm+ steel hull-plate scope today, see the FAQ below for why.

Dynamic-Beam Laser Welding

A conventional fixed-beam laser drills a narrow, deep keyhole, but that keyhole becomes unstable at extreme depth. It collapses, traps gas, and leaves porosity behind once penetration reaches the process’s practical limit for a single pass. Dynamic-beam (also called coherent-beam-combined) laser welding fixes this by steering multiple laser beams in a rapidly shifting pattern instead of holding a single fixed spot. That widens and stabilizes the effective keyhole, letting the process punch through much thicker plate in one pass without a vacuum chamber.

Civan Lasers (Israel) is the vendor most associated with this approach and has demonstrated a 70mm single-pass atmospheric weld, well beyond what a conventional fixed-beam fiber laser can hold stable. Civan already has a US commercial presence. Its demonstration-lab partnerships with AMET in Rexburg, Idaho, and Photon Automation in Detroit, Michigan, are what Civan describes as the final phase of building out local sales and service infrastructure for the North American market. This is a technology category with real US access today.

Electron Beam Welding

Electron beam welding fires a focused beam of electrons at the workpiece inside a vacuum chamber. The vacuum eliminates atmospheric contamination and gas porosity, producing some of the deepest, cleanest, narrowest welds available for critical sections, with a heat-affected zone far smaller than an equivalent multi-pass arc weld. That narrow zone matters for fatigue life on a hull that will spend decades under cyclic loading from waves and vibration.

The tradeoff is the chamber itself. Part size is limited by what fits inside it, and pumping a chamber down to welding vacuum adds cycle time before the arc even strikes. That makes electron beam a strong fit for high-value, high-criticality sections, pressure vessel closures, submarine hull penetrations, and similar work, rather than a blanket replacement for general hull fabrication.

Three vendors anchor this category. pro-beam (Germany) runs pro-beam USA Inc., a dedicated sales and service office in Lombard, Illinois. PTR Strahltechnik / Steigerwald (Germany) has a sister company, PTR-Precision Technologies Inc. in Enfield, Connecticut, an active US manufacturing and service facility since 1989. FOCUS GmbH (Germany, now a business unit of the SPECS group) is a smaller specialist in this space. Its welding sales contact is still based in Germany, and it isn’t clear whether its US-based parent entity covers welding equipment specifically.

Hybrid Laser-Arc Welding

Hybrid laser-arc welding combines a laser beam with a conventional arc (typically MIG) in a single weld head, with the two heat sources working the same weld pool a few millimeters apart. The laser provides deep, narrow penetration. The arc trails behind it, filling the joint and bridging gaps the laser alone would struggle to close, since a laser keyhole tolerates almost no gap in the joint fit-up. That gap tolerance is the practical reason hybrid systems succeed where pure laser welding often can’t on real shipyard steel, which never arrives perfectly square. The combination handles 6 to 30mm plate in a single pass at production speed, and it’s already standard equipment on European shipyard floors.

Fronius (Austria), whose “LaserHybrid” product line is the best-known commercial system in this category, has run Fronius USA LLC since 2002 and today operates five US welding-technology sites, the Portage, Indiana headquarters plus welding labs in Michigan, Tennessee, Texas, and California. It’s already sold, serviced, and supported domestically by a 20-plus-year incumbent. Reis Robotics (Germany) also integrates hybrid laser-arc welding cells and states active US manufacturing operations on its own site today.

Narrow-Gap Submerged Arc Welding

Narrow-gap submerged arc welding (SAW) is the least glamorous of the five and the most load-bearing. It runs an arc under a blanket of granular flux inside a narrow joint preparation, typically 10 to 20mm wide regardless of how thick the plate is, and deposits metal at a high rate without the equipment cost of laser or electron beam systems. Narrowing the joint prep versus a conventional V-groove cuts the number of passes and the total filler metal needed to fill it, which is where most of the cost advantage comes from at extreme thickness. For sections 100mm and thicker, SAW is still the default.

Large-volume manufacturers of narrow-gap SAW equipment exist globally, including KeyGree (China), a large exporter shipping to more than 30 countries. KeyGree has no formal, managed US sales channel that public information confirms, though it’s a category example worth naming for completeness rather than a specific recommendation. Domestic and other allied-nation SAW equipment builders also serve this category. The point of naming KeyGree here is category coverage.

Electroslag and Electrogas Welding

Electroslag welding (ESW) and electrogas welding (EGW) are built specifically for long, vertical seams, exactly the geometry of a ship hull plate joint. ESW maintains a molten slag bath between the plates that carries the welding current and shields the weld pool. EGW substitutes a shielding gas for the slag bath and works a comparatively thinner range. Both complete a joint in a single pass regardless of thickness, ESW handles roughly 25 to 300mm, EGW roughly 12 to 100mm, which is why both show up specifically in shipbuilding and storage-tank engineering literature rather than general fabrication.

ESW and EGW differ from the other five in one important way: they’ve been standard shipyard equipment, in the US and internationally, for decades. Their inclusion here reflects a second path to closing the gap, running equipment shipyards already have at full capacity, alongside adopting the newer processes above. Equipment for both processes is manufactured globally, including by established Asian and domestic suppliers, without the same single-vendor spotlight the newer technologies above carry.

The Qualification Clock Behind Every Technology Choice

Owning one of the five technologies above doesn’t put it on a real hull. Every welding procedure used on Navy work has to clear NAVSEA S9074-AQ-GIB-010/248, the standard governing welding and brazing procedure and performance qualification, before it touches production steel. That means coupon welds, destructive testing, radiographic review, and formal sign-off. Industry commentary on the standard puts the full approval process at several months to a few years, depending on the number of revisions and welder qualifications a yard is pursuing. Commercial and Jones Act yards answer to a classification society instead, most often ABS, running a parallel qualification regime with its own named test coupons for plate, pipe, and fillet welds.

Established arc processes get a shortcut here that beam-based processes don’t have yet. AWS and NAVSEA jointly publish Standard Welding Procedure Specifications, the B2.1 series, pre-qualified procedures for shielded-metal-arc and GTAW on carbon steel plate that a yard can adopt without running its own qualification testing from scratch. As far as public documentation shows, no equivalent pre-qualified specification exists yet for dynamic-beam laser, hybrid laser-arc, or electron beam welding on hull steel. NAVSEA is actively building toward closing that gap: a current qualification-framework project with the Edison Welding Institute is producing test data intended to help NAVSEA develop procedures for beam-based processes, though it’s scoped to additive manufacturing rather than hull-plate fusion welding specifically.

Until that framework matures, every yard adopting a beam-based process still has to run its own procedure through the months-to-years qualification process before a single production weld counts toward a ship. That qualification queue is what actually sets the pace at which any of the five technologies above can scale onto real Navy or commercial hull programs.

What This Means for US Yards

The framing matters here. This is a story about rising demand.

Several of the technology families above already have an established US commercial presence: Fronius’s hybrid laser-arc systems, pro-beam and PTR/Steigerwald’s electron beam equipment, and Civan’s dynamic-beam lasers are all sold, serviced, or demonstrated domestically today. The real opportunity for US yards is adopting and scaling what’s already accessible, paired with the workforce to run it and the qualification work to certify it.

That pairing is the constraint once a process clears qualification. The Department of Labor’s $13.8 million workforce-training award in January 2026 and Hanwha’s collaborative-robot welding rollout at Philly Shipyard both treat technology and training as a single investment. Neither treats new equipment as a substitute for skilled operators. A cell running dynamic-beam laser or electron beam welding still needs a trained programmer to set parameters, a welder or technician to monitor the process, and an inspector qualified to sign off on a weld that a machine, not a person, actually made.

A yard evaluating any of the five technologies above should weigh the same set of factors before committing capital.

Additive manufacturing is a related, sometimes competing option for some large thick-section parts. Plasma arc additive manufacturing builds up structural geometry from wire feedstock rather than joining two existing plates, and for certain part geometries it’s a genuine alternative to conventional welding.