Boat sewing techniques overview

Boats being sewn in the inner Finnish area, from woodcut by Olaus Magnus (1539, 1555).

A Saami boatbuilder from the title page of Schefferus book Lapponia (1674)

People started to build wooden boats presumably in the stone age, long before they developed the technology of melting metals out of ore; and even when metals became known, the nails, rivets, or other metal fastenings remained quite an expensive luxury for a long time. So, along with big and rich ships with metal fastenings, such as Viking ships with their iron rivets, there existed a lot of small boats, belonging to poor fishermen and peasants, who could not afford iron. (Actually, in some rural areas of northern Russia nails were deficient even in 19th century). These boats had to be built in some other way, using either treenails or sewing techniques. The later way was the most common, since treenails can only hold when the planks are thick enough, which is not the case with small light boats. Apparently, sewing was used in most parts of the world -- in Northern Europe, in Indian Ocean area,the "Mahasagar boats" firm, in Mangalore, India, can custom-build a traditionàl stitched canoe. See also boatbuilding tradition in Goa, in ancient Rome (boats, sewn with hemp twines), in Polynesia, etc.

Sewing technique common in NW Russia and Baltic states

Sewing arrangement of the Hjortspring joints (Smolarek, 1963).

The simple 'lashed' sewing, Finnish nide ("Merkijärvi") type, Keuru No. 9 (after Korhonen, 1982a; redrawn from Hirsjärvi, 1937).

One of the youngest sewn boat finds in Europe was made in Hjortspring bog in Denmark, the boat was dated for 3rd century BC. The sewing material not preserved, but the the stitching technique could be judged of by well preserved imprints on the caulking stuff (resin, linseed oil, ox tallow).
See also reference in the paper.

Many finds are attributed to the Viking and Middle ages, when sewing techniques coexisted with metal nails and rivets; even in a same ship sometimes both ways were present, expensive iron was usually used in toughest and most critical places; a kind of similar technique, when bottom parts of ribs were lashed to the planking by means of spruce roots, was implemented in famous Gokstad and Oseberg ships.
Often sewing was used as a repair technique for cracks and clefts in dugout boats.

For the sewing material roots of coniferous trees (spruce or pine) were most commonly taken; they were the cheapest and most available stuff -- in a dark coniferous forest soil is so loose and grasless that one can easily pick the roots up (44Kb) with bare hands, using only a knife to cut them. Broad leaf tree roots (such as birch roots) were also taken sometimes, but they are probably harder to obtain, the soil in a birch forest usually has a firm layer or grassy turf. Other sewing materials known from archaeological finds are hemp and woolen twines, linden bast ropes, reindeer sinews and horsehair strands.

NW Russia and Eastern Baltic were one of the core areas, where the sewing traditions survived the longest, up until 1920's. Here boats were usually sewn with roots, twisted like withes to make them more flexible, ( rarely with hemp twines). Holes were drilled obliquely to the plank surface , to avoid unnecessary sharp bends, and were arranged in little zigzags to reduce the hazard of cracks spreading along the line of holes. Outer parts of the stitches were sunk into especial grooves, carved between holes. Stitches were fixed by means of treenails, hammered into the holes from both sides; these treenails at the same time served as plugs, making the seam watertight. Most common caulking material here was white moss. See:

• Reconstruction at Foteviken,
• Skeppargatan find; dated around 1700,
• (reference to the paper),
• Kola shnjaka, probably around 1905,
• (reference to the paper) and
• planks found in Carelia, from the same period.

In Finland there existed another type of sewing technique, christened "Merkijärvi" type, when a spruce root was just pulled several times through one pair of holes, but did not go to adjacent holes, making rather distant separate fastenings. See:
Merkijärvi replica project,
also reference to the paper.

Saami boatsewing tradition was particularly rich; The way of stitching was usually very much like russian, but other materials, such as reindeer sinews, were often used. Some sewn Saami boats were extraordinary thin and light, and could be carried over long distances between different waterways. See also:

• boats in Tromsø museum,
• reference 1 to the paper,
• reference 2 and
• reference 3 .

A comprehensive overview of sewn boat finds and traditions in Northern Europe one can get in Christer Westerdahl's paper.