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The hull was built using clinker (lapstrake) construction—overlapping planks secured to each other and to frames, creating shell-like structure that was simultaneously light and strong.
The Strakes:
Each plank—strake—ran full length of ship, carefully shaped to achieve proper curvature from bow to stern. The lowest strakes near keel were relatively straight, upper strakes increasingly curved as hull shape changed from keel to gunwale. Shaping these curves required skill—understanding how much material to remove, where to thin plank to encourage bending, how to avoid splitting or breaking during installation.
The planks overlapped—each strake’s lower edge covering previous strake’s upper edge. This overlap was secured with rivets—iron nails driven through both planks then clinched over small iron washers (roves) on the inside. The riveting created continuous connection between strakes, distributing loads, preventing separation while allowing slight movement between planks that gave hull its characteristic flexibility.
The Caulking:
The overlaps had to be waterproof—achieved through caulking with animal hair (typically cow or horse hair) mixed with tar. The caulking was pressed into groove between planks before riveting, compressed when rivets were tightened, creating seal that prevented water infiltration. The tar’s waterproofing combined with hair’s ability to compress and expand maintained seal despite wood’s movement as it swelled when wet and shrank when dry.
Maintaining caulking was ongoing necessity—checking regularly for leaks, re-caulking areas where seal had failed, ensuring hull remained watertight. Ships that weren’t properly maintained became waterlogged, sailed poorly, potentially sank.
The Flexibility:
The clinker construction created hull that could twist—bending with waves rather than rigidly resisting them. This flexibility was deliberate design feature, not deficiency. Rigid hull would experience higher stress loads as waves tried to bend it, potentially causing structural failure. Flexible hull distributed stresses, absorbed wave energy through motion, survived conditions that would break rigid vessel.
The flexibility required careful material selection and construction technique—planks had to be thin enough to flex but thick enough to maintain strength, rivets had to be tight enough to hold but not so tight they prevented necessary movement. The balance was subtle, achieved through experience and judgment.
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