The high-tech shipbuilding methods that helped Vikings dominate the seas
- Written by The Conversation
Images of the sleek keels, elegant planks, and dragon-headed prows of Viking longships have been reproduced countless times on postcards, book covers, souvenirs and in television shows and movies.
These vessels are, quite literally, the poster-ships for the Viking Age, which was between around 750 and 1100 CE.
So what made these ships so special? And why were these advanced shipbuilding techniques so crucial to the Vikings’ success?
What drove this shipbuilding boom?
In Old Norse, there are two words for Viking: víkingr refers to a person, while víking is an activity. Neither word is inherently negative nor associated with violence.
A víkingr is someone (who may or may not identify as a pirate) who undertakes víking expeditions (sometimes to pillage, sometimes not), and whose life and livelihood have strong connections to the sea.
By the mid-eighth century, these people were keen to expand their horizons and branch out from local economies.
This coincided with a number of large and lucrative mercantile towns springing up around north-west Europe in this period.
Among other factors, Vikings travelled further westward and eastward as part of an ongoing and complex power grab for portable wealth, territory, and control of trade routes.
From the 750s on, the Vikings’ advanced shipbuilding technology helped give them the edge.
Gamechanging technology
The unique design of Viking ships and their trademark square sails were absolute gamechangers in this period.
There are many different types of Viking ship, but the most relevant here are the langskip (longship) and knörr (cargo ship).
Like all Viking vessels, these are clinker built. That means the hull’s long, curved sides are assembled out of slightly overlapping planks, and are held together by iron nails (the “clinkers”).
Along with their strong but slender keels and stems, this innovative construction made for incredibly flexible, light, and sinuous vehicles that could be powered by oars or by sail and withstand wild ocean swells.
With their narrow silhouettes and their ability to gently twist and yield to the waves, it’s no wonder longships were called snekkja (serpents), dreki (dragons) and skeið (sliders).
Another small but significant improvement that made longer-distance travel possible was the oar-hole.
Until the early Viking Age, pegs called tholepins stuck up from the gunwales (upper rim of the boat) to hold oars in place and act as fulcrums for rowing. This meant ships’ sides could never be very high above the water. (Imagine trying to row with your oar at head height.)
But by cutting holes through the side planks, which could be plugged when the oars were shipped and the sail raised, it became possible to build taller, more seaworthy ships.
The boats had shallow drafts (meaning not much of it was under the waterline). This enabled these “sea-snakes” to slither further inland than ever before, since they could tackle riverways other boats simply couldn’t navigate. They could also be dragged across land.
Longships also had symmetrical prows (meaning the “back” of the boat was just as high as the “front”).
This design allowed Viking raiders to pull right up on the riverbank, then “hit and run” – without all the slow awkwardness of reversing and turning the whole boat around for the getaway.
Square sails also increased both the distance and speed of Viking travel. Norse explorers like Eirik rauða (“the Red”) and his son Leif (who went to North America nearly 500 years before Columbus) wouldn’t have taken a warship to Iceland or Greenland.
Instead, they probably kitted out a knörr, a heavy-bellied merchant ship much like the one described in an ancient Icelandic text called Egil’s saga
richly painted above the plumbline and fitted with a black-and-red sail […] loaded with stockfish, hides and ermine, and a great quantity of squirrel skins and other furs […] a very valuable cargo.
When powered by four oars, a modern reconstruction of just such a knörr reached a speed of 1.5 knots. With the sail raised it sped along at 13 knots (around 24 km an hour).
A much larger longship with 60 oars could row at 4.5 knots and reach a maximum sailing speed of 17 knots (31.5 km an hour)!
Crafted by hand
The most impressive stats about Viking ships aren’t about how fast or far they went, but rather how much time, effort, and natural resources went into building them. The sheer industry of it all is astonishing.
Every piece was crafted by hand. Axes shaped the floor timbers, planking, masts and beams.
Dozens of oak trees (8-10 metres long and at least a metre across) went into the hull. Dozens more pine trees were burnt to make tar for sealing the wood (600 litres for a 60-oar longship, which took more than 2,000 hours to produce).
More pine and alderwood went into the oars and mast.
Then there’s all the iron: 450kg of it to make the 8,000 nails needed for this same longship.
An average knörr’s sail was 90m² (smaller than the longship’s) and used the wool of 200 sheep, all of which had to be spun into thread and woven into continuous lengths of fabric, each 65cm wide.
This spinning and weaving work took experimental historians 7,850 hours to recreate (around 4.5 years for one person).
Another month was needed to sew the sail panels together, cut it to shape and reinforce its edges. Then there’s the ship’s cordage: so much horsehair, hemp and linden bast (a plant fibre) for 3,000 metres of rope.
This constant and large-scale manufacturing paints an evocative picture of the Vikings’ everyday, shipbuilding life.
It was all hands on deck, so to speak.
