Something is not quite right. A meadow on the shore of the Steinhuder Meer is a hive of activity. A brand-new, four-and-a-half metre-long skiff is standing between boxes full of tools and ropes, and two men are rigging it. The futuristic sailing machine, with outriggers and double trapeze, flared mainsail and extendable gennaker pole, is not the only fun machine of its kind here, and yet it is strikingly different from the others.
Instead of a sailing sign, the letters "TH OWL" are emblazoned on the hull. What they mean is written on the hull: Technische Hochschule Ostwestfalen-Lippe. The boat's name is also there. The abbreviation "Owl" is the English word for "owl" and the symbol of science. Obviously a university project. Not a secret. And yet, as I said, something is wrong.
75 per cent of the skiff is made from renewable raw materials
As is so often the case, the obvious is not immediately obvious. But as you approach the virgin vessel, gleaming in the sun, you suddenly realise its uniqueness: the delicate skiff is made entirely of wood. From the hull and appendages to the rigging and fittings, the eye catches sight of naturally varnished wooden surfaces. The boat sinks ten centimetres deeper into the water than comparable planing dinghies made of high-tech materials. But then the men lift it up and demonstrate, to the amazement of the bystanders, that the "Owl" is just as light as its counterparts made of GRP or carbon fibre laminate.
The men are Steffen Wenk and his professor Dr Adrian Riegel, wood technicians at the Lemgo-based TH OWL. Together with numerous students, they have developed the boat to take part in the 1001 Vela Cup. This is a regatta in which university teams compete with their boats, which are built according to strict regulations and have one thing in common: no less than 75 per cent renewable raw materials were used in their construction.
Ultimately, an article in YACHT gave me the idea to take part in the competition," says Riegel. "There was an interview on the last page that began with the question: 'What do cashews have to do with boat building?" A PhD student from Chalmers University of Technology in Gothenburg, Sweden, had his say. Under his guidance, students built a skiff from a balsa wood and linen fabric sandwich. The composite was made with epoxy resin, which is obtained from the chemically processed oil of cashew nut shells."
The goal: With the "Owl" to the 1001 Vela Cup
The 1001 Vela Cup design competition, Riegel learns on the Internet, has existed since 2005 and is judged on the one hand on the technical aspect, i.e. the engineering performance and how strictly the building regulations have been adhered to. And then, of course, the sailing skills. The teams have to compete against each other in nine heats on classic up-and-down courses.
The professor of wood technology is enthusiastic and doesn't think twice about it. He has already realised other projects with his department, built large canoes or even entire kitchen units from the natural material and presented them at trade fairs. As a passionate sailor of an RS 800, the idea of the Vela Cup challenges him both professionally and athletically. Riegel points to his boat, which also stands on the lakeshore and served as a model for his "Formula Sailing" team. Its dimensions fit exactly into the regulations. "We call it reverse engineering," says Riegel and laughs.
The fact that the "Owl" is to take to the water for the first time today makes the gradually arriving team and the university lecturer noticeably happy. The atmosphere is relaxed. However, there is still one crucial shortcoming to overcome: Very few of the students involved in the project can sail.
The helmsman is missing
How they will be able to compete directly against the other teams in the Vela Cup on the water is still a mystery. In particular, they lack a helmsman who can bring the skiff to the finish line without capsizing, reports Riegel. Although a special training week was organised last year, further practice sessions on the water unfortunately had to be cancelled this summer due to the nationwide coronavirus restrictions.
The fact that the regatta, which should have taken place on Lake Garda a long time ago, also had to be postponed gives us some hope. This has given the team time to gain sailing experience after all.
The professor takes the problem in his stride: "According to the regulations, we would have had to sew the profile sails ourselves. He holds two identical mainsails made of thin Dacron in his hand, which he inserts into two adjacent mast grooves. A wooden device directs various stretchers from the neck and horn of the sail through the boom to the swivelling mast. It is designed to adjust the various angles of the components so that the cloths form a profile under wind pressure.
Sustainability and technology first and foremost
The idea is typical of the Lemgo team's project. Numerous detailed solutions set the skiff apart from the classic model. "At the beginning, I simply wrote down everything that could be done," says Riegel almost apologetically. The list was actually only intended to illustrate the possible technical challenges. The team then took on all of them.
The list was long. In addition to the "swivelling profiled wooden mast with double sail and automatic downhaul adjustment", the list includes a "centreboard with laminar profile" and a "rudder with humpback whale tubercle". It also features a "swivelling gennaker bowsprit", a "110 percent overlapping self-tacking jib", "sandwich strip planks made of balsa, khaya and okumé" and "wrapped ash veneer tubes for boom and racks" - to name just a few of the gimmicks.
As there was a foreseeable lack of sailing experience compared to the competition, it was clear from the start that they wanted to score points at the 1001 Vela Cup, especially in the technical classification. "We tried to make as much as possible out of wood, because we are wood technicians. We didn't take a boatbuilding approach," says Riegel. "We try to solve things differently."
"The dinghy was created in the lab instead of on the drawing board"
Several of the tasks on Riegel's list were assigned as projects at the university. "For example, the double sail," explains the professor. "I have a colleague who offers a master's course in simulation technology, so we assigned the topic to her." The rotating centreboard box was also created as part of a project, as were the deck layout and fittings, as well as the development of the hollow spars made from veneer wood and the planking.
It consists of four to six millimetre thick plywood in the freeboard and strip planks made of balsa sandwich underwater, which were specially developed in a master's thesis. Their core consists of an inner layer of two 0.5 millimetre thick khaya veneers glued crosswise and a middle layer of balsa veneer. The outer layers, in turn, are made of 0.6 millimetre thick veneer from Gabon. The planks are rebated and interlock.
The frame was made from six-millimetre plywood panels. These were first primed with epoxy and then cut on a water jet cutting machine at 3000 bar pressure with abrasive. The individual parts were then inserted into each other and stiffened with stringers made from pinewood strips.
"Many details are based on the students' research work"
The students developed the plywood for the outer skin above water specifically for the respective hull areas. An okumé core was used in the centre of the boat with a total thickness of around six millimetres, while all layers of the four-millimetre panels in the bow area are made of sapele. According to Professor Riegel, this results in the best possible compromise between lightness and rigidity.
The goal was one hundred kilograms, and the finished hull was not to weigh more than that. The Lemgo team made it. And tackled all the other tasks with similar vigour. For example, the mast made of Oregon pine flanks with Okumé plywood stays in the form of a double T-beam. The wood technicians clad the leading edge with oak veneer on GRP. At twelve kilograms, the weight is right on the limit of what was planned. "It can't be much more than that," says Riegel, otherwise the boat would be too tippy.
The maiden voyage as the first step towards the 1001 Vela Cup
How tippy it really is, how it sails, whether it will hold - all these crucial questions remain unanswered as the crew ceremoniously pushes their "Owl" towards the lakeshore. It is a special moment, says Steffen Wenk, who has been involved in the project from day one. What existed in abstract form for months in the form of figures and drawings on the screen and in tables and was then put together from individual parts by the various project groups - today it stands before them as a whole and is supposed to work. In practice. On the water.
Professor Adrian Riegel doesn't miss out and grabs the tiller himself for this first test. Equipped with an orange-coloured solid waistcoat and crash helmet, he stands next to the skiff in the water as it slips off the slipway and floats up. Together with foreskipper Sebastian Plate, he climbs aboard the wooden high-tech skiff, and in a light breeze they are soon speeding across the Steinhuder Meer.
And somehow it's true after all.
