Germany

International Maritime Research GmbH & Co. KG

The AZ Project is aimed at researching new methodologies for fairing hulls and cladding superstructures. The brainchild of Kay-Johannes Wrede, coating expert and founder of <a data-gid="gid://syiq/Company/2988" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Wrede Consulting GmbH (Company)">Wrede Consulting</a> in Hamburg, his theories are being put into practice on a 30-metre motor yacht in build in Bremerhaven.Beyond the fried fish outlets that line the seafront in Bremerhaven, a half-built yacht sits in a modest construction shed next to <a data-gid="gid://syiq/Company/3779" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Dörries Yachts (Company)">Dörries Yachts</a>. The classic two-decker with a canoe stern designed by <a data-gid="gid://syiq/Company/11" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="De Vries Lentsch (Company)">De Vries Lentsch</a> is effectively a floating laboratory initiated by <a data-gid="gid://syiq/Company/6207" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="International Maritime Research GmbH & Co. KG (Company)">International Maritime Research (IMR)</a>, a sister company of <a data-gid="gid://syiq/Company/2988" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Wrede Consulting GmbH (Company)">Wrede Consulting</a>, and funded in part by the German government. The yacht’s deckhouse is still a network of steel frames and carbon modules, but the hull is complete and has been faired, although the two sides use visibly different coatings – for reasons that will become apparent.<img src="https://photo-assets.superyachttimes.com/photo/320899/image/large-803a1b12086f1e5bfd2cee375cd9147c.jpg" data-gid="gid://syiq/Photo/320899">The AZ Project was started three years ago by a consortium of international companies under the guidance of <a data-gid="gid://syiq/Company/6207" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="International Maritime Research GmbH & Co. KG (Company)">IMR</a> and <a data-gid="gid://syiq/Company/2988" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Wrede Consulting GmbH (Company)">Wrede Consulting</a> in a supervisory role as a full-scale R&amp;D project comprising two areas of research: to test new methodologies for filling and fairing, and to develop a modular process for cladding the steel structure of a superstructure with composite sandwich panels.&nbsp;Traditional production of the final surfaces on metal yachts requires several labour-intensive steps. Correcting pronounced defects such as welding distortions or the connection with functional elements like doors, windows and hatches with filler compound is time-consuming, heavyweight and costly. Part of the research program was to resolve these issues with a composite fairing solution for hulls.“Fairing the metal hulls of superyachts requires a lot of filler, many tons in some cases,” says Kay-Johannes Wrede, founder of Wrede Consulting. “The thicker the filler the more sensitive it is to temperature fluctuations and flexing, leading to cracking and flaking, We wanted to save weight, reduce the time-consuming filler work, and achieve better thermal insulation of the hull to save energy costs. Our proposal is to use a foam core laminated with GRP in a modular, industrialised manufacturing process.”&nbsp;Like many good ideas, the concept is not new. Going back over 20 years, Fagerdala Marine Systems, a division of Fagerdala World Foams in Sweden, developed a coating system based on the application of a foam composite structure on the aluminium hull of a yacht (see sidebar). The system proposed by Wrede, however, benefits from advances in engineering and technology over the past two decades to increase manufacturing accuracy and efficiency. &nbsp;&nbsp;A giant jigsawAfter laser scanning the bare hull to create a 3D model, a new surface is CNC milled from foam panels that are pre-laminated with fibreglass on the outside. These panels are then glued onto the existing structure like a giant jigsaw puzzle to create a robust and very stiff ‘skin’. The 3D model exactly measures every deflection, imperfection and weld seam in the hull so the foam panels fit flush with the metal plates to provide a ready-made faired finish. Only a minimal amount of fine filler is required on top to provide a perfect exterior finish.<img src="https://photo-assets.superyachttimes.com/photo/320902/image/large-44da2f081ba7f5f520b0339bce1d849d.jpg" data-gid="gid://syiq/Photo/320902">“This sandwich construction offers several advantages,” says Enno Herrmann of Innovative Composite Solutions (ICS, a joint venture company set up to market the developed products), who is also a qualified composite boatbuilder and technical project manager on the AZ Project. “The foam is much lighter and can be engineered to reinforce parts of the hull where traditional filler is susceptible to cracking. It also provides better insulation, which means the steel or aluminium doesn’t heat up so much, so there is less expansion. That’s a good thing especially on dark-painted hulls because expansion creates stress between the metal hull and the filler, which is liable to break off.”<img src="https://photo-assets.superyachttimes.com/photo/320903/image/large-5452aa98024a9135d6058270d2928122.jpg" data-gid="gid://syiq/Photo/320903">Whereas filler serves only an aesthetic purpose, composite fairing also has a practical function. Different grades of foam can also be used for different parts of the hulls according to the pressure loads. The stiff skins provide high bending stiffness, while the foam core supports the shear and compressive stresses and stabilises the skins, preventing global and local instabilities. The weight reduction results in fuel-savings, lower inertia, as well as increased stability and buoyancy.Other probable advantages include reduced risk of galvanic corrosion since the hull is covered by closed-cell foam; and no condensation as the insulating effect of the foam on the outside means the inside shell temperature remains above the dew point. In addition, damaged panels can be easily replicated from the 3D files and replaced (in fact, nowadays structural and/or filler problems are usually repaired using the sandwich system).<img src="https://photo-assets.superyachttimes.com/photo/320897/image/large-fdf69e2a0c644eca4071951d594722d7.jpg" data-gid="gid://syiq/Photo/320897">However, the research program does not stop there. In order to compare performance with conventional fillers over time, the portside of the hull has been covered with the composite fairing solution while the starboard side has been treated in the traditional manner using different types of filler in collaboration with <a data-gid="gid://syiq/Company/340" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Pinmar (Company)">Pinmar</a> and <a data-gid="gid://syiq/Company/7254" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="AkzoNobel (Company)">AkzoNobel</a>. Standard 830 two-ingredient epoxy filler has been used in the bow area and Awlfair SF hot spray filler system elsewhere on the hull. Sensors imbedded in the coating materials will measure relative temperature, expansion rates and wave pressure loads. &nbsp;<img src="https://photo-assets.superyachttimes.com/photo/320898/image/large-5fd779c9965a36fcc3460828207ebf6a.jpg" data-gid="gid://syiq/Photo/320898">Composite claddingThe second phase of the AZ Project is to research a method of gluing laminated foam panels to existing metal structures to create perfectly shaped superstructures. Welding superstructures out of steel or aluminium is challenging when it comes to creating complex shapes and the end result still has to be fully faired. Further, care has to be taken with aluminium superstructures that twist and flex in a seaway, which again can lead to unsightly cracks in the filler. &nbsp;&nbsp;“Like the composite fairing system, the basic idea behind the composite cladding for the deckhouse is to make the the yachts lighter and the whole build process faster and more efficient,” says Wrede. “So we’ve developed three prototype sandwich panels that can be glued directly onto the steel framework of the superstructure to replace the metal plating.”<img src="https://photo-assets.superyachttimes.com/photo/320900/image/large-8157600d6cd53786735cfcb8df026d99.jpg" data-gid="gid://syiq/Photo/320900">Again, composite superstructures on superyachts are not new. <a data-gid="gid://syiq/Company/23" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Lürssen Yachts (Company)">Lurssen</a>, <a data-gid="gid://syiq/Company/5" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Nobiskrug (Company)">Nobiskrug</a> and <a data-gid="gid://syiq/Company/44" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Abeking & Rasmussen (Company)">Abeking &amp; Rasmussen</a> have built yachts with at least partial composite superstructures. &nbsp;Notably, when Paris-based <a data-gid="gid://syiq/Company/999" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Pierrejean Design Studio (Company)">Pierrejean Design Studio</a> the sleek, modern design for the Swift 141, the former Dutch frigate that became 141-metre Yas, the company’s engineers determined that the steel superstructure should be replaced with a composite construction throughout. Even the helicopter landing pad is made of sandwiched panels of Divinycell foam and eight plies of carbon fabric. These were all hugely expensive one-off projects, however. <a data-gid="gid://syiq/Company/2988" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Wrede Consulting GmbH (Company)">Wrede</a>’s composite system, on the other hand, is conceived with pre-fabrication and ease of assembly in mind.&nbsp;A class actArguably the biggest single challenge for <a data-gid="gid://syiq/Company/2988" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Wrede Consulting GmbH (Company)">Wrede Consulting</a> and the <a data-gid="gid://syiq/Company/3838" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Maritime Technologies (Company)">Centre of Maritime Technologies</a>, a body that conducts its own technical research in strategic maritime areas, is gaining Class approval in a conservative industry where steel and aluminium are still the de facto building materials for ships and large yachts. In case of fire, they are required to prove that everything is equivalent to steel construction.“The issue with composite materials is that the resin used in the manufacture does not like heat, so part of our research was to come up with sufficient insulation to get Class approval for a system that we can always use for coating the steel superstructure frame,” says Wrede. “We were able to improve the fire rating with insulation on the inside and now have Class approval ‘in principle’ for the process.”<img src="https://photo-assets.superyachttimes.com/photo/320904/image/large-ef8fa714f90f9e212b5d31f801c2fa97.jpg" data-gid="gid://syiq/Photo/320904" style="box-sizing: inherit; border: 0px; font-family: &quot;Open Sans&quot;, sans-serif; position: relative; max-width: 100%; margin: 1rem 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-size: 13.6px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;">There are other drawbacks. Tooling design and development increases the lead times as well as cost, and cut-off wastage is also a factor. Reconfigurable tools or adaptive moulds to make the laminated thermoformed panels helps reduce the cost, delivery time and waste. Complex double curved shapes from 3D files can be shaped in minutes with a high surface quality and one mould can make many unique mould surfaces.Having invested around €2.5 million in the project to date, Wrede is looking to sell his floating laboratory and construction is paused while waiting for an owner to come forward. Her <a data-gid="gid://syiq/Company/1408" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Caterpillar Inc (Company)">Caterpillar</a> C18 main engines are already on site and the shafts and rudders have been ordered. There is also a complete interior design concept by <a data-gid="gid://syiq/Company/320" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="Schnaase Interior Design (Company)">Schnaase Interior Design</a>.&nbsp;“Ideally, we would like to see it used as a charter boat in different climates and conditions to have as much data feedback from the imbedded sensors as possible, “says Christopher Rothe, head of marketing at Wrede Consulting. ”Clearly it will take a client who buys into the research part of the project, but the advantage is that he or she could take delivery of a high-quality, Dutch-designed yacht in less than a year.”<img src="https://photo-assets.superyachttimes.com/photo/320901/image/large-cb8524209eff57274d655f759ad67614.jpg" data-gid="gid://syiq/Photo/320901">United SpiritIn the late 1980s, Swedish inventor Sven Jönsson decided to refit his all-aluminium motoryacht. The sleek, 100-foot vessel was launched as Edi in 1939 for the industrialist Torsten Kreuger, but her hull was a badly buckled and the deckhouse was in a very poor state of repair. Supported by the Royal Institute of Technology in Stockholm, Jönsson drew on his knowledge of teak-decking systems and adhesives to develep an elastic, waterproof glue to withstand the forces between a rigid closed-cell foam sheet and the twisting and flexing metal hull. A new superstructure was also created out of 3mm aluminium. Vacuum-glued sheets of closed-cell foam were added and the foam surface was then planed to shape, laminated and painted.&nbsp;In 2005, after 14 years of service in the Mediterranean and the North Sea, some areas were opened up to see how well the concept had worked in practice. In a bottom section below the engine room, a small area of foam had separated from the metal. The cause was a broken rivet that had allowed oily bilge water to penetrate the hull plating and dissolve the aluminium primer. All the other surfaces were like new.Fagerdala Marine Systems AB later became the owner of the prototype vessel M/Y <a data-gid="gid://syiq/Yacht/1439" href="#managed-by-system" rel="noopener noreferrer" target="_blank" title="United Spirit34.2m (112'2&quot;)Götaverken1938">United Spirit</a> and patented the Fagerdala Hull System (the patent has since expired). For reasons unknown, the thoroughly tested and proven coating technique never took off.&nbsp;

Filler and foam: In conversation with Wrede Consulting's Kay-Johannes Wrede

The AZ Project is aimed at researching new methodologies for fairing hulls and cladding superstructures.