It’s a hot summer day in the city and we are dreaming of the cool waters of Ontario’s lakes. Fair weather boaters might take it for granted that boat design is simple – keeping the boat afloat is the main goal, right? But a closer look at the designed object with an eye to problem context suggests that design isn’t always so simple. For instance: What uses are imagined for the water craft? What are the technical limitations of the available materials? What are the characteristics of the environment of use? What are the needs, wants, expectations and capabilities of the user? Design history teaches us that the framing of the design problem influences the design solution.
Shipbuilding is an interesting topic in design history, and I particularly like the Viking longship. During the so-called Viking Age (800AD – 1050AD), Scandinavian (Norse) Vikings explored Europe by its oceans and rivers for trade and conquest. Experts at sea travel, the Vikings also reached the Faroe Islands, Iceland, Greenland, Anatolia, and Newfoundland (Canada). The Vikings who invaded Western and Eastern Europe were chiefly pagans from Denmark, Norway and Sweden. The sea was the easiest way of communication and transportation between isolated Viking settlements.
Today our knowledge of the Vikings’ ship-building techniques comes from excavations of burial mounds that included the remains of large, intact ships, such as the Oseberg Longship. The longship was class of sea vessels made and used by the Vikings for trade, commerce, exploration and warfare. These graceful, long, narrow, light, wooden boats had shallow-draft hulls designed for speed. The shallow drafts allowed navigation in waters only one metre deep and permitted beach landings, while their light weight enabled it to be carried over portages. One vessel served many needs.
Built built in western Norway around the year 820, the Oseberg Ship is double-ended, with symmetrical bow and stern. This trait allowed the ship to reverse direction quickly without having to turn around, a particularly useful feature in northern latitudes where icebergs and sea ice posed hazards to navigation. It had oars almost the length of the boat itself and a single mast with rectangular sail. It was constructed of old-growth oak and iron rivets.
During the Viking Age, ships were usually built using the ‘clinker’ technique – also known as the ‘lapstroke’ method – in which the lower edge of each hull plank overlaps the upper edge of the one below. Planks (strakes) were riveted together using valuable iron rivets. According to a popular Viking skills website, during the Viking era the spacing of the iron rivets on longships was wider than modern safety conventions would allow:
“Historical ships spaced the rivets as much as 60cm or more (24 inches) apart along the strakes, so the ship would be flexible in rough seas, bending and riding over the waves, rather than trying to resist them and taking the full impact of each swell. Thus thin-hulled Viking ships could survive the rough seas of the North Atlantic.” (Hurstwic, “Viking Ships”)
The flexibility that was gained with wide rivet-spacing in the clinker construction, however, also meant more movement resulting in gaps between the planks. Even though cracks were sealed with moss or animal hair coated with tar, Hurstwic points out that “the elasticity of the ships made them prone to leaks, especially in rough seas.” It was likely that one crew member had the constant job of removing water from the boat by scooping it out using a container. This action is called ‘bailing’. While few boaters today would tolerate a boating experience that required near constant bailing, the Vikings evidently did.
Viking longships were designed to serve a variety of conditions of use. Their light, flexible, ultimately porous construction technique was a design solution that ensured the vessel’s passage across shallow water, over portages and through rough seas. But this solution depended on a related condition of use that was acceptable at a time when human comfort was not considered.
In the contemporary era of leisure boating, we enjoy a wide variety of watercraft depending on the desired use. We depend on advanced technical capability of materials and construction techniques. We have legislation governing design, manufacturing and operation to ensure safety. And the high value that we place on lifestyle and experience puts human comfort at the foreground of design decisions. Even so, as you glide across the still waters of your chosen body of water this weekend, don’t forget to bring the bailing bucket. And enjoy the water like a Viking!
NOTE: When the travelling exhibition “Vikings” came to the Royal Ontario Museum in Winter 2018, Torontonians got a chance to see authentic iron rivets from a Viking longship, installed in a ghost-like formation to recall the absent oak strakes and clinker technique. (photo: whitestudiolo, February 2018)