The journey of a 17th-century shipwreck continues as a unique knitted dress

In 2019, a rare discovery was made during the renovation of a hotel in Oulu: remains of a 17th-century cargo ship were uncovered beneath a parking lot. The vessel was named the Hahtiperä wreck after Oulu’s first harbour.

After years of conservation work, some leftover pieces of wood remained and were at risk of ending up in the trash.

‘The wreck had only partially survived, and not everything could be preserved, even though every piece was documented. It felt unfortunate, and I began wondering whether the wood fragments could still be of use somehow,’ says maritime archaeologist Minna Koivikko from the Finnish Heritage Agency.

Colour straight from the wreck

Susanna Ahola, coordinator at Aalto University’s Bioinnovation Center, heard about surplus wood and got a group of Aalto’s researchers excited about it.

Inge Schlapp-Hackl, a researcher at Aalto, along with her colleagues supervised by Professor Michael Hummel, converted over 300-year-old wood from Oulu into textile fiber.

First, the outer, impurity-containing layer was removed to expose the wood’s core, which was then shredded and processed into dissolving pulp. The pulp was subsequently transformed into fiber through the environmentally friendly Ioncell® process, which was developed at Aalto University in partnership with Helsinki University. Ioncell fibres have a silky feel and are stronger than cotton. In addition to new and reclaimed wood, the Ioncell® method can utilize recycled materials like paper, cardboard, textile waste, and straw for fiber production.

Leppisaari knitted the dresses on a Shima Seiki knitting machine as seamless, single three-dimensional pieces. This means no material is wasted at all.

‘I was nervous about how the yarn would behave in an industrial machine. It turned out to be surprisingly strong, and I’m very pleased with the final result,’ Leppisaari says.

Making invisible heritage visible

Aalto University was given free rein by the Finnish Heritage Agency to transform the material. The only wish was that the final result would honour the unique discovery and continue its story.

‘Underwater cultural heritage is often invisible, but the shipwreck dress brings it into people’s everyday environments. It’s almost like a spokesperson for history — with a modern twist,’ says Koivikko.

Material design expert Pirjo Kääriäinen and her colleagues at Aalto University have spent more than 15 years researching the use of different biomasses as raw materials for textile fibres.

‘We want to reduce the use of virgin raw materials and the waste of natural resources. A shipwreck is, of course, an exceptional case, but it is also a story that makes people pause and appreciate materials in a new way. If something this beautiful can be made from centuries-old wood, why do we keep throwing away materials that could still be circulated and reused?’

The project lasted nearly two years and involved dozens of experts in chemistry, forest products, textiles, and design.

‘Collaboration is one of Aalto’s strengths. I think it’s wonderful to work in a community that combines technical expertise with the enthusiasm to pursue ideas that might initially sound a little crazy,’ Kääriäinen says.

The Tomorrow’s Wardrobe exhibition opens at the Oulu Art Museum 22 May. The exhibition will close in stages: the upper floor on 27 September and the lower floor 11 October. Read more on the Oulu Art Museum website.

The Designs for a Cooler Planet exhibition opens at Aalto University 1 Septemeber. Read more on the Aalto University website.

Minna Koivikko
Maritime archaeologist, Finnish Heritage Agency.
minna.koivikko@museovirasto.fi