Northern Seafaring Fellowship | Vodlozero National Park | Sewn boats at Foteviken |
same in Russian | Main page | Internet Links | Contact us |
Third season, shnjaka launched and tested (July-October 2003)
full scale picture(47Kb) Before launching, the shnjaka had to be caulked with moss and coated with tar, which could not be done properly without turning her upside-down. Lines of the subwater part are clearly visible. August 2003. |
full scale picture(76Kb) First fitting of the mast and sail on dry land. Later on, the rigging and tackle required numerous "field changes". August 2003. The sail was hand sewn of machine-made tarpaulin, with modern polyamide cables for tackle, so this is not an exact historical replica. Only the hull was built in complete accordance with old techniques. Just the same, the rigging and tackle are made as close to old drawing as possible, and with due regard for all preserved indications on shnjaka in Oslo. The boat has one mast with square sail ~27 m2, the mast is "collapsible", it can be easily taken down and hoisted up, otherwise it would make a considerable hindrance when fishing and rowing up wind. It is stepped a little to the bow from the middle. If the boat is supposed to beat against wind, it is essential to trim it so that her aerodynamic force application centre would be positioned a little to the aft from the hydrodynamic pressure centre, the resulting torque bringing her slightly into the wind. This torque can be equilibrated by turn of her rudder, then the rudder itself would work against sideways drift. Trimming is achieved through leaning her mast to the aft, by hauling the shrouds and slackening the stay, or through shifting her hydrodynamic pressure centre forward, by moving ballast and cargo there, and thus tilting her to the bow. On a larger ship these ways are not plausible, and the only natural solution then is to step second small mast at the stern, carrying a simple spritsail, not unlike on vodlozerka boat. This additional area would cause aerodynamic pressure centre to move after. This was indeed the rigging system on bigger shnjakas of 19th century (Bogoslavsky), and I thought about it, too, when I discovered that the replica's aerodynamic centre lies too far to her bow. Although, this defect was cured by just leaning mast and trimming tackle, while second mast in a smaller shnjaka would be an inconvenient cramming. Another essential thing is tack (otherwise, bow-line), the gear that holds weather clew forward, when beating up against wind. Without a tack, at a slightest wind change or helmsman's mistake, the sail would spill air, bulge backwards, the vessel would be immediately brought into the wind and come to a stop, ceasing to obey her rudder. It would be a gruesome job to put her back on the right track every time. Shnjaka can go close-hauled, in good sailing weather the sharpest achievable angle between wind direction and true course (with regard to sideways drift) is 60o-70o. Square sail is very awkward to tack with, in comparison to fore-and-afters. When alone on board, I was forced to cast anchor every time I changed tacks, -- the job took so much time. |
full scale picture(34Kb) When launched, the replica surpassed my expectations a little, (though, in autumn 2003 the shnjaka was not tested in a storm, so I cannot judge reliably about her seaworthiness). But the hull does not leak (almost; some 20 liters per 24 hours), it is light on oars, even one man can pull her against temperate breeze, a crew of four can row 5-6 km/h. It seems that shnjaka can make about 10-15 km/h under sail, without dangerous overburdening with sail area in too fresh weather. When her sail was properly trimmed, she was found able to tack and gain against wind. September 2003. |
full scale picture(73Kb) Shnjaka is ready for sailing tests. See also "sailing performance" . September 2003. |
Northern Seafaring Fellowship | Vodlozero National Park | Sewn boats at Foteviken |
same in Russian | Main page | Internet Links | Contact us |
last update: December 2006 report problems with this page to