How hard can it be to sail a Viking ship?

The Annual TS Regional Meeting in Roskilde, October 16th 2021

Yesterday, October 16th 21, around 40 wooden boat people, mainly from Sealand, met at 10 am outside Roskilde Viking Ship Museum, life-vest clad for action, ready to board three of the museum’s reconstructed Viking ships.

Romed, representing Hawila together with Ankie and Lars, wrote about the experience they had on this special day:

If you think that sailing Hawila with a random, inexperienced crew is challenging, try this with a Viking ship! Already rowing out of the harbour with 8 people, was a revelation: the roughly 40’ slender boat accelerated like a canoe, reaching a top speed of about 7 knots within 30 seconds, even with a poorly synchronising crew of mostly greybeards (greyer than myself) at the oars!

Hoisting the pretty huge square sail was easy with the wind aback. But the first attempt at a tack failed miserably. Second time we tried, the skipper wisely decided to convert the manoeuvrer into what the Danes call a “cow turn” – like in cow-ardly turning by falling off the wind, a jibe by capitulation, rather than choice.

Wind at that time blowing with > 10 m/s, we reefed the sail by two reefs after which we got lucky the third time. But if you would ask me how the sail was brought leewards, I’d have to pass.

A square sail doesn’t luff naturally, you have to move and hold the sail a-haul by hand, but somehow we did manage without casualties. Which makes a point for that Vikings definitely didn’t wear horned helms…

After 1½ hours running ahead of the wind, we rowed swiftly back into the harbour.


Next, was a tour through the museum, with the resident leading boatbuilder Søren Nielsen explaining technical details of the 5 recovered Skudelev boats that were recovered in the fjord of Roskilde. Lucky for us, the late Vikings had deliberately sunk these 5 ships to create a defensive barrier in the then narrow straights of the fjord.

All of these 5 boats have been reconstructed by the museum and we sailed 3 of these reconstructions today. The largest reconstruction is the famous Sea Stallion, a longship of 30 m, built in Dublin around 1040, close towards the end of the Viking era.

After a lunch break we got a tour through the boatbuilding workshops where even more Viking ships are being reconstructed: Fishing boats, cargo ships and longboats of various sizes.

This was followed up with a lecture by Vibeke Bischof, a well known Danish naval engineer and expert in experimental archaeology. Vibeke told us in meticulous details about the reconstruction of the Oseberg ship, one of the best preserved Viking ships, measuring almost 22m loa. The ship dates back to around AD 800 end ended its life as a burial monument near Toensberg, Norway. It had been excavated in 1905 and. In 1987 a full-scale replica, “Dronningen” (the queen) was built. However, this copy didn’t last very long, it capsized and ended as flotsam already on its first trial at a speed of 10 knots.

Vibeke was then on the team analysing the calamity. It was found that a few small errors in the dimensions of the reconstruction, a misunderstanding of how side-rudders work and misplaced ballast were responsible for the loss. In 2010 a new replica “Oseberg Saga” was made, correcting the errors of earlier attempts and this ship became a great success.

Learning so many of the Vikings’ technical boatbuilding details, it became clear that it had been totally underestimated how sophisticated and high-tech these early warships actually were. They were built for velocity, with a very tight risk-calculation of speed vs safety, leaving extremely small margins for errors, just like with modern ocean-going racing yachts. Longboats were constructed as lightly as possible, with thin, split and hewn planks and sleek frames. However, the clinked and riveted planks combined with sideways bracing floor pieces and frames gave them an incredible flexibility and these boats could run through heavy seas as fast as the wind would carry them. Looking at technical drawings from these ships, they seem to resemble more model plane construction than boatbuilding. The Vikings however, did all this without scientific calculations and computer-aided design software.

The day ended with us boarding the Sea Stallion, one of the world’s most ambitious experimental archaeology project. Built in Roskilde from 2000 – 2004 with replicated tools and rediscovered techniques, a crew of 50 sailed the ship to Dublin after years of testing and training.

A clearly emotional Carsten Hvid (ropemaker, sailor and former educator at Kystliv Center in Holbaek) told us his story as the skipper on this amazing trip. These 50 adventurers, our dear Lars Toft among them, sailed through 6 rainy and stormy weeks, in what basically is a giant canoe with a 120 sq m woollen square sail. The only difference between then and now being modern clothing and that they brought along safety and navigation equipment instead of war axes and swords.

Most challenging though, so Carsten said, was neither wind and weather, but the social dynamics and psychological challenges with 50 men and women being stuffed together, cooking, eating, sh…ing, sleeping and otherwise doing what adult humans do, in such a confined but also totally exposed space for 1½ months!

Carsten was sharing his opinion, that these human challenges might have been a lot easier in the old days. Keeping a tight ship, he contemplated, might have been a lot easier under a strict hierarchy, where disciplinary measures like keelhauling were equivalent to a raised index finger and decapitating corresponded to “did you get it now?”

The answer to this would probably require yet another project of experimental archaeology.