Out on the open see in a folding rubber kayak

Messe Düsseldorf is holding “boot”, the biggest yachting and water sports trade fair in the world, this year between 21. and 29. January 2012. 1,600 exhibitors from 60 countries are showcasing everything that water sports enthusiasts are keen to see, from A for air mattresses to B for boat equipment and C for charter trips. The organisers of “boot” have again come up with plenty of different ways to make visitors’ stay on the exhibition site as interesting and varied as possible – including opportunities to try out diving (in a huge water tank) or skimboarding as well as to consult a frontloop trainer. The exhibitors of exclusive yachts also anticipate large crowds, even though most visitors with normal incomes will only be able to dream about owning one due to their incredibly high prices. Anyone can become the captain of a boat of his own nowadays, however – for comparatively little money! This is mainly thanks to the innovator Alfred Heurich (1883 – 1967) and the tailor Johann Klepper (1868 – 1949), who was more skilled than anyone else at folding rubber.

Who hasn’t ever dreamed of standing on the wooden boards of a boat at the coast with his eyes closed and a sea breeze blowing and of having all the time in the world to go on an expedition across the vast expanses of the ocean – without knowing where he would end up and when he would return? People have always had an emotional attraction to the sea. It worries us when dark clouds start to form in the distance and the horizon disappears in a blur of water. When the air is crystal clear, the water is calm and the sky is cloudless, on the other hand, we have an insatiable longing for faraway places. While it is not unusual for love affairs to start on the beach watching the sunset reflected in surface of the water ... Whatever reason people have for going to, into, onto or under the sea – what they all have in common in some way or other is a passion for water. What exactly drove Alfred Heurich, who was born in Merz, Lorraine, in 1883? The records show that he was interested in kayaks – fast, manoeuvrable boats in which Eskimos have always gone hunting.

What Heurich did not like about the Eskimos’ original kayaks was their cumbersome design: the basic structure was made of wood and bone, over which the Inuit – as the Eskimos are also known – stretched animal skins. Heurich, who wanted a more easily handled kind of boat, used his imagination to design a kayak that met his requirements precisely: it could be folded up in a matter of minutes and could be transported from A to B by hand or train without any great effort or cost. When the destination was reached, all that was needed was a little skill and a few operations to put a boat with enough space for two people into the water that was suitable for the high seas, as history shows.

The creative innovator and his “Luftikus”

It was on 30. May 1905, a beautiful spring day, much too warm for the time of year. In Central Europe, the thermometer had topped the 25°C mark considerably and the only place where there was even a slight chance of rain was near the coast. The troops of the Ottoman Empire were battling hard with those of the Kingdom of Montenegro and Albert Einstein was looking forward to the publication of his special relativity theory in Switzerland. In the spa of Bad Tölz, the architecture student Alfred Heurich went to the River Isar for the maiden voyage of what he called his “Luftikus”.

In German, the word “Luftikus” makes one think more of an inflated car tyre than of a boat, particularly since it wasn’t even recognisable as such to start with. Then, however, Heurich took a large piece of waterproof sailcloth from his rucksack and pulled a number of bamboo rods out of a narrow container that was a man’s height. The architecture student made a skeletal framework out of the rods and stretched the sailcloth over them.

Heurich had finished everything that needed to be done within a good quarter of an hour. With some trepidation, he went down to the water and pushed the four-and-a-half-metre-long, folding boat that resembled an Eskimo kayak off the shore, getting into the open hull of the boat at the same time. And it floated rather than sinking. Delighted about this tremendous initial success, Heurich set off for Munich on the river, reaching the city 50 kilometres away after paddling for five hours. He described his memories of this trip as follows later on: “The trip on the Isar – where the water was high – was a very risky undertaking. I was in serious danger three times, but got out of the situations each time by keeping cool and making quick and determined decisions”.

Before his death, Alfred Heurich is said to have travelled more than 100,000 kilometres in folding kayaks that he himself had built. Was he aware of the importance of his invention at the time when he went on the maiden voyage of the “Luftikus”? He did at any rate fail to link his name inextricably with the concept of the folding kayak and did not participate to anything like an appropriate extent in the success that folding kayaks enjoyed in the subsequent years and decades. The man that became famous instead was the tailor and sports goods retailer Johann Klepper, who acquired the licence to produce a second-generation folding kayak called the “Delphin” in series from Heurich in 1907. The company that goes back to Klepper – Klepper Faltbootwerft AG – is now one of the world’s leading manufacturers.

The details always make the difference

By the way: folding kayaks are not a modern invention. The Armenians are said to have transported goods to Babylon in collapsible boats made from wood, bone and animal skins as long ago as 500 BC. The Unangans, the indigenous inhabitants of the Aleutian Islands – a group of islands that are now part of Alaska – used kayaks known as baidarkas. Although they were not collapsible like the folding boats used by the Armenians, they did consist of a comparable framework made from drift wood and bones with animal skins stretched over it. The Unangans went hunting for sea lions in the Bering Sea in their baidarkas, which are said to resemble modern folding kayaks most closely in their size and shape.

The way the folding kayak works that Alfred Heurich designed on the basis of the Eskimo kayak and the Armenian baikarka and that Johann Klepper was later successful in selling all over the world has hardly changed at all to this day. In simplified form, the description is as follows: as soon as the paddler has sat down in the folding kayak after it has been put into the water, the lateral pressure exerted by the water is transferred from the sailcloth cover to the stem – the upward extension of the keel – as a result of the counterpressure exerted by the thin longitudinal slats and the transverse ribbing. The tension created as a result, which is comparable to the architectural principle of the Gothic ogive, gives the boat its resistance.

Heurich was particularly keen not only on a stable design for the framework of the boat but also on flexible sides for the boat, which were not supposed to consist of animal skins any longer. The new material needed to repel water reasonably well or – ideally – be waterproof, while it was at the same time required to be flexible enough so that it could, on the one hand, be pulled over the frame of the boat and so that it was, on the other hand, stable enough not to tear or be damaged in other ways even in contact with solid ground underneath it. It was also supposed to be of a size and weight that enabled it to be carried and manoeuvred easily.

Heurich opted for sailcloth, a fabric tightly and firmly woven from a strong yarn that repels water to a reasonable extent. The sailcloth was rubberised to make it waterproof. This is done by applying an elastic layer of rubber to the substrate material and vulcanising it by adding sulphur. The process starts by applying the bonding agent to the clean surface of the sailcloth. After the rubber layer has dried, it is vulcanised in hot air or with saturated steam at about 130°C. Depending on the compound and the thickness of the layer, the vulcanisation operation can take between 30 minutes and 24 hours. Rubberisation is still carried out today wherever equipment, containers and pipes need to be protected against corrosion, oils, fats, waxes, acids and lyes or surfaces are expected to demonstrate elastic recovery, abrasion resistance and stretchability properties.

Across the ocean in a folding kayak

Although their name alone suggests that they are not particularly stable and really able to cope with all weather conditions, folding kayaks have been used to complete a number of spectacular voyages – not just on inland waterways but also and above all on the high seas. In his book entitled “Voyage from fjord to fjord in a folding kayak”, for example, Erich Wustmann describes the journey he took from Schleswig-Holstein through the North Sea and up the West Coast of Norway that lasted into the winter of 1926. In 1928, Captain Franz Romer, who was born in Konstanz, was the first person to cross the Atlantic in a Klepper folding kayak; for this project, he used a boat that included a sail, starting in Lisbon and stopping in such places as Puerto Rico before disappearing on his way to New York – since then Romer has been registered as missing. Oskar Speck even chose a trip that was much longer. In 1932, the German left Ulm alone in a folding kayak and paddled to Cyprus to work there. However, he then paddled on through the Suez Canal to Australia, where he arrived in 1939 after about seven years and was interned as a German prisoner of war until 1945; the boat in which Speck made his voyage is on show at the National Maritime Museum in Sydney. Talking of museums: the Aerius II Klepper folding kayak (5.20 metres long) used by the German doctor Dr Hannes Lindemann to cross the Atlantic unharmed in 72 days in 1956 is on show at the Deutsches Museum in Munich. Lindemann regularly attracted publicity for years thanks to his Atlantic crossings in smaller and smaller boats.

It is certainly the case that the folding kayaks used in the early days differ significantly in looks and technology from those in which British soldiers landed on the Falkland Islands in 1982 undetected by the Argentinian radar systems and established the first beachhead for the subsequent invasion. Not to mention the folding kayaks that are now being exhibited at “boot” in 2012. High-tech materials are used for the boat structure and surface in particular: the internal framework consists of wood, carbon fibre or aluminium, while the waterproof skin is made from Hypalon (chlorosulfanated polyethylene, CSM), a high-quality, extremely UV-resistant, temperature-resistant, non-ageing and tear-resistant elastomer, and/or polyurethane (PU), a plastic that can be used for many different purposes and that we will be reporting about here at a later date.

PS: If this article has whet your appetite for taking to the water: everything you need to know about the biggest yachting and water sports trade fair in the world can be found at The Klepper company is one of the exhibitors there too, incidentally (Hall 13, Stand D 90), or can be found in the Internet at

Copyright: Guido Deußing