Researcher recreates ancient boat model using modern technology
REPORT | A håp is a Sámi boat model dating from the 9th century. When Per Lindström Lussi constructs a modern håp he does this using modern engineering methods. One of the objectives of his research is to create more environmentally friendly patrol boats made of fossil-free steel. Or why not rotor blades for wind turbines?
In June 1732, Carl Linnaeus sits in a boat northwest of Umeå, travelling in Lappmarken. At Tuggenforsen, it is not possible to continue rowing. He has to disembark and carry his luggage, while the forest Sámi farmer transporting him lifts the boat over his shoulders and “runs with it over mountain and across valley”.
The boat is a so-called håp, a model that has been used very skillfully by the forest Sámi to transport themselves on the rushing watercourses in northern Sweden. Weighing around 25–40 kilos, these boats were quite easy to row and to carry. This is the type of boat that Per Lindström Lussi, senior lecturer in marine technology at Linnaeus University, has recreated, 60 years after the last håp was built.
“The word håp comes from the Finnish happio, which means aspen. Written sources show that that the word was used as early as in the 16th century, but it is probably even older than this. In Sámi language it has come to signify a small gig of this particular type”, Lindström Lussi explains.
Photo: Gustaf Axel Hallström, National Museums of World Culture, BY-NC-ND
“Building marine structures is my job, I’ve been trained as a ship builder. And this is what I conduct research on. Therefore, when SSAB and Sandvik, which have developed a type of high-strength steel, asked me what we could construct using this steel, I knew straight away what I wanted to. When people ask me these things my answer always tends to be something involving boats or marine cranes. Unless it’s relating to boilers or nuclear plants”, Lindström Lussi adds laughing.
From patrol boat to håp
Thus, Lindström Lussi proposes that they build a patrol boat. A high-speed boat that is used, for instance, as rescue boat or police boat. They start designing a patrol boat with the name Snöfrid, but soon realise that the new steel is very challenging to work with and that they must start by making a smaller boat.
“I have a great interest in paddling, so perhaps a kayak? However, while this process was going on there was a Sámi Parliament election and I came into contact with the member Ronny Svartå who said “what do you think about this boat?”
Despite the fact that Lindström Lussi is a forest Sámi he had never heard about the håp, a type of boat that is at least 1,200 years old, probably even older. Around year 890 it is mentioned in England, as King Alfred the Great interviews the Viking Ottar from Hålogaland. Ottar informs the king that his neighbours, the Sámi from Cap of the North, use this type of boats to travel upstream and downstream rushing rivers. The håp is a clinker boat, with overlapping hull planks, a construction technique that has recently been included on UNESCO’s World Heritage List.
A 40 kg portable boat
First, an operational wood model is constructed, a mockup Lindström Lussi explains, as this is much cheaper. “If we can’t do that, how would we be able to build one in steel?”, Lindström Lussi asks. However, to begin with, a paper model in scale 1:10 is built, in true engineering spirit.
The newly-constructed håp is 4.3 metres long and 1.3 metres wide. We do not know exactly how heavy, or rather how light, a traditional håp was as no one has described this in writing, but we know that the Sámi could easily carry the håp on their shoulders.
“The one we have now constructed weighs 40 kilos. It has an expected lifespan of 40 years, without maintenance. It can be kept outdoors in ice-free water year round”, Lindström Lussi continues.
It is extensive work just to write down the specifications, Lindström Lussi explains. How long, how wide, the draught, the shape… Once this is done, Lindström Lussi instructs kayak designer Johan Wirsén on Öland and his son Josef to design the lines and the hull. The lines are important as they affect how the hull behaves in water, but also the appearance – it is important both to Lindström Lussi and Wirsén that the boat looks good.
Object for researchers and students
The finished boat now serves as a reference object that one can continue working with. The blueprints are available and we know how to do everything. This means that researchers, teachers and students can carry out different engineering exercises.
“The håp is constructed in five-layer birch plywood, according to what is called Nordic boat standard. The garboard, the planks nearest to the keel at the bottom, are 6 mm thick and the upper planks are 4 mm thick. For the next boat we are planning to use 4 mm for the lower planks and 3 mm for the rest. What is more, we will not paint the boat with epoxy plastic, which will save us about six kilos. By removing everything that is there for the looks but is not necessary we expect to bring the weight down to 25 kilos.
“We have students who want to do seaworthiness calculations. How durable is the boat, how seasick will you become in it? We can then do practical experiments to see how correct our calculations were. Thus, we have established a platform for research and development that can help us build a large number of these boats in different versions. If someone in Småland gets the idea to build a glass boat, well, then we can do it”, says Lindström Lussi.
Currently, one of Johan Wirséns kayaks in plywood and high-strength steel is being built at the laboratory in Växjö. Shortly, they will start building a new, more light-weight håp. The aim is to bring the weight down to 25 kilos and that it should have a 10-year lifespan. The downside is that it must be brought ashore, washed down and lubed up after it has been in the water. It must be stored in a damp, shaded, and cool place to prevent it from cracking, and indoors during winter. Once these boats are completed, a steel håp will be constructed.
Tips from the extended family
The håp was launched in mid-January. The plan was to exhibit it at Jokkmokk’s market in February, at the Swedish mountain and Sámi museum Áttje, but the market was cancelled due to the pandemic. Lindström Lussi, whose name Lussi coincidentally means pilot, guide or seafarer in Lule Sámi language – had been looking forward to meeting knowledgeable relatives and market visitors from Lappland.
“They could have told me what I’ve gotten wrong about the håp and what I’ve not thought of, because I’m certain that I’ve not gotten everything right. The forest Sámi have not built this type of portable boat in 60 years, as far as we know. If I have done the maths correctly, that would mean that the person who had it was my paternal grandfather’s third or fourth cousin”, Lindström Lussi informs.
The håp will now instead be exhibited at the fair Kalmar WaterExpo on 13–15 May. After that, Lindström Lussi, together with some others, plan to take the boat down Pärlälven, a free-flowing tributary to the Lule River. Pärlälven has both waterfalls and rapids, which means that they will get to try both rowing and carrying the håp in practice.
Systems engineering
So, in what ways have Lindström Lussi’s experience and research been useful in the construction of the håp?
“First of all, the engineering method systems engineering, which I almost always use. It’s a general, well-established, foolproof method for solving complex problems. It’s also the method I teach my students. In addition, we have also used advanced calculation methods like finite elements, fluid mechanics, and thermodynamics”.
Lindström Lussi categorises the håp as a stiffened shell construction. And, the larger the structure, the more profitable to use steel instead, he explains. If you can use high-strength steel to build a small håp, then you can use the same knowledge and technology to start constructing, for instance, rotor blades or wings.
“The wings of an airplane and the rotor blades on a wind turbine are shell constructions. The same goes for ships, rockets, trains – more or less all larger craft for which you wish to bring down the weight”, Lindström Lussi explains.
“We have now started looking into how we can build rotor blades for wind turbines using this high-strength steel. It is stronger and more durable. Today, these rotor blades are quite environmentally harmful, made from plastic and even tropical wood. Sweden has a large steel production and it is better and more environmentally friendly to use steel than to import plastic”.
Ship with steel sail
Another idea has presented itself in the maritime industry. Lindström Lussi and his colleagues are in contact with the shipping company Wisby tankers, a company that was started by four Linnaeus University alumni. It concerns the possibility to build steel sails for their ships. Such a sail would basically be an upright airplane wing, which could save 20–30 percent fuel.
Finally, the fact that the håp was built on Öland is no coincidence. Local businesses and industries are close to Lindström Lussi’s heart.
“Much of what I do in my research has links to local industries. I like when you get something spinning here in Småland and on Öland. For instance, there’s a kayak factory at Degerhamn, why would you not be able to produce rotor blades for wind turbines there as well? And leisure boats could be mounted anywhere between Växjö and Kalmar. One can really see that these communities have taken a battering when you travel through them”, Lindström Lussi concludes.
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The håp is part of the research on the project Demonstrator Environment for Smart and Innovative Automation in Manufacturing (Smart-IAT) and the research group Welding Mechanics Laboratory (WML), and Linnaeus Knowledge Environment: Advanced Materials.
