Quality on the high seas Blohm+Voss relies on welding technology from Fronius for shipbuilding

The Port of Hamburg is a world-famous landmark of the Hanseatic city, as well as its gateway to the world. It is also home to Blohm+Voss, which has been a cornerstone of Hamburg since it was founded in 1877. The company has shaped the appearance of the docks south of the Elbe tunnel from St. Pauli and continues to do so today – from the venerable administration buildings and huge cranes to the enormous workshops and docks, which regularly house the largest passenger and cargo ships in the world.

In 2016, Lürssen, a family-run business from Bremen, took over Blohm+Voss, which currently employs over 600 people. The company not only specializes in shipbuilding but also repairs, refits and maintenance – everything from yachts and merchant ships to giant international cruise liners. “Around 25 to 30 ships come to our docks each year,” explains Herbert Lembcke, welding engineer at Blohm+Voss.

Time in dock costs money

The largest dock is around 350 meters in length, making it large enough to accommodate the cruise liners that arrive for maintenance and repairs: “The time pressure is particularly high,” describes Lembcke. “Each day that a vessel spends on dry land costs the shipowner a huge amount of money. Yachts can stay docked for longer, but cruise ships often have to be up and running again within a few days.” Operations in the shipyard are therefore meticulously planned.

Welding is a fundamental part of ship repair and so welders have around 700 different power sources at their disposal: “We primarily deal with steel applications but also with aluminum and other metals in all material thicknesses,” explains Lembcke. “The majority of work is performed manually, as the procedures are often too specialist to make automation worthwhile.”

Strict verification for welding processes

Flux-cored wire welding is by far the most commonly used welding process at Blohm+Voss, but the ship construction specialists also use electrode, submerged arc, and TIG welding. “The robustness of the joint is always the most important factor,” stresses Lembcke. “It is vital that the weld seams are thick and are able to hold - everything else is secondary.” Since the safety of the crew and passengers is of the upmost importance on ships, all work is rigorously checked. In the case of the weld seams on underwater sections of the outer hull, these checks are conducted partly with the help of vacuum or ultrasound tools. “We are also liable for the basic verification of the devices and processes that are used – both our welding certifications and the entire shipyard are audited every three years,” explains the welding engineer.

Work on tanks, supporting constructions, interior fixtures, rudders, and propellers is also commonplace, which makes for the most diverse welding challenges: “Sometimes these can involve very thick materials of up to 100 millimeters or more that have to be joined,” explains Lembcke. “Besides that, we frequently encounter restricted spaces and high temperatures. Our employees must also weld under tough conditions at times.” To prevent exposure to welding fumes, the welders wear helmets with a built-in air filtration system. “On top of that, we also have tight time pressures to contend with. For this reason, we need welding systems that are effective, safe, and error-free.”

The perfect welding system for every task

Fronius is an important partner when purchasing new equipment. “Fronius has a very good reputation as a premium manufacturer that is able to accommodate our strict quality requirements,” says Lembcke. Meanwhile Blohm+Voss uses numerous TransSteel 5000 models and several devices from the TPS/i range. The TransSteel is preferably used in assembly and has been especially designed for welding steel. The power source is loaded with special characteristics that optimize the properties when joining steel. “We are extremely impressed by the high process reliability and seam quality,” says Lembcke. “The portable wirefeeder is easy to remove and easy to carry into difficult to access places. Furthermore, the device is extremely robust and particularly suitable for use in harsh environments,” finds the welding engineer. “This is also important because our employees are not exactly gentle with their equipment.”

Blohm+Voss relies on the TPS/i devices in the workshop and when repairing yachts, as their wide array of functions make them suitable for a variety of tasks, such as welding aluminum, which is an important material for external and internal fixtures. “The high processor performance allows us to precisely control the welding processes and to achieve even better results,” reports Lembcke. With the TPS/i, Blohm+Voss is able to work on vessels where the appearance of the weld seam is very important, such as visible seams on yachts or inside cruise ships. “Our flexibility is limitless with this versatile welding system.”

Customized service is a priority

“We require a competent and flexible after-sales service as well as high product quality,” continues Lembcke. For example, Blohm+Voss made some special requests when purchasing these devices, which included making the plug out of aluminum instead of plastic and having special braided hoses, which are better able to withstand harsh environments. “Fronius dealt with each of our concerns quickly and without any fuss.” The experiences of the ship construction specialists also helps Fronius to develop new products, which is a win-win situation for both parties. “It is important to us that we can talk to our suppliers as equal partners,” confirms Lembcke. “And that is certainly the case here.”

Furthermore, Blohm+Voss is supported by a dedicated Fronius technician, who only works in the greater Hamburg area and can therefore be on site immediately if needed: “The quick response times help us to keep device failures to an absolute minimum, which in turn saves us a lot of money,” explains Lembcke. “I am happy that we have found a reliable, competent partner for welding technology in Fronius.”