An intriguing experiment is under way to investigate how Russians in the 19th century (and probably earlier) took steps to expand logboats while the tree was still growing. The project involves Jaan Keerdo, who wrote a Masters thesis on Estonian logboat building, Aivar Kriiska, Professor of Archaeology at the University of Tartu (Estonia), Irina Khrustaleva, a Research Fellow in Archaeology at Tartu, and Aivar Ruukel, a nature guide (https://soomaa.com/), logboat expert, and PhD student at Estonian University of Life Sciences, who showed me the project recently in a state forest near Soomaa National Park in Estonia.
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| An osinovka, a Russian expanded-extended logboat. (Bogoslavsky.P.A 1859, plate 5) https://drive.google.com/file/d/1NWKIEjyq4PLduhANkFzK1JMVuGDDg_vy/view |
In an article whose title translates as "On merchant shipbuilding in Russia, river and coastal" (1859), P.A. Bogoslavsky describes the construction of an expanded and extended logboat used for fishing by Pomor people around the Mezen River on the White Sea in Russia. The double-ended boat, called an osinovka, was up to about 5 meters long, 1 meter wide, and 1/2 meter in depth, and had capacity of 320 kg. The boat was propelled by two to four pairs of oars or a spritsail, and steering was done with an oar. An osinovka cost up to 10 rubles and gave 10-15 years of service.
Built of aspen, construction of the osinovka began while the tree was still growing. Wooden wedges were driven into the trunk of the living tree and pounded a bit deeper every three days. When the opening became too large to be held open by wedges alone, braces were inserted into the split. After five years of "living expansion," the tree was felled, then additional hollowing was performed with axes or carefully tended fire. The carved trunk was filled with water and allowed to soak for a week, then it was emptied, and a low fire was built within the hollow. After the wood had softened from the combined effects of water and heat, the hull was expanded and braced with wooden stretchers.
Bogaslavsky's text says that "several" pine planks, 60-90cm wide and 2.5cm thick, were added as washstrakes, but his illustration shows only two planks, apparently much narrower than described. These were stitched to the logboat base and to up to four spruce frames which were fastened into the hull. The planks were laid flush and caulked with moss. The hull was tarred inside and out, and runners were added to the bottom.
There is no formal term in the boatbuilding lexicon for the expansion method Bogoslavky described, but Aivar Ruukel calls it wedge-cracking or live-tree expansion. Using Bogoslavsky's description as a starting point, Ruukel and his associates began their experiment in May, working with four large aspen trees all within a few dozen meters of each other. The experiment's objectives are to learn more about the technique, and to discover what (if any) benefits it confers to the boat or the boatbuilder. The team is in contact with Mikhail Stolyarov, a Russian boat builder who has firsthand memories of the wedge-cracking method from his childhood in the 1960s. (Stolyarov runs a private boat museum in Vologda Oblast, Russia. See https://bit.ly/belozersk.)
Aivar Ruukel, on the ladder with a mallet, explaining the experiment.
When I visited the site in August, the cracks were already wide enough so that some of the first set of wedges were being driven flush with the outer surface of the tree, and in some places a second wedge was placed beside the first to continue the expansion. The splits were between 2 and 3 meters long, and a ladder was used to reach them and to drive the wedges with large mallets.
One of the four aspen trees with wedges inserted to open up the living trunk.
Many questions have already arisen. Will the cracks promote rot or disease in the trunk? How will live expansion affect the strength of the boat? Will it achieve a wider beam in the finished boat than is possible by conventional expansion methods? Will it reduce the amount of labor required for hollowing? How will this expand our knowledge of vernacular boatbuillding in Russia and elsewhere? We look forward to more questions, and hopefully answers, as the experiment continues.
Sources
Most information for this post was provided by Aivar Ruukel, including a translation of Bogaslavsky's article:
Богославский, П. А. О купеческом судостроении
в России, речном и прибрежном / Павел Алексеевич Богославский. –
Санкт-Петербург : [Изд. Морской Ученый Комитет], 1859. – 10, IV, 188 с..
Available in the original Russian at: https://webirbis.aonb.ru/irbisdoc/kr/2015/06kp083/68/ See pages 50-51.
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