By the 14th and 15th centuries, the Netherlands had experienced extensive deforestation due to rapid population growth, agricultural expansion, urban construction, and the demands of a burgeoning shipbuilding industry. The region, being densely populated and low-lying, had limited old-growth forests to begin with, and what remained couldn't supply the volume or size of timbers needed for large vessels like cogs, which required hundreds (sometimes thousands) of mature oak trees per ship.
Shipbuilding boomed under the influence of the Hanseatic League, a powerful trade confederation that included Dutch cities like Amsterdam and Rotterdam. This league's maritime activities amplified demand, making local wood insufficient. Early forest protection regulations in Western Europe further restricted domestic harvesting, pushing builders toward imports.
Poland (and the broader Baltic region, including Prussian territories under the Teutonic Order) had vast, untapped oak forests that produced timber in surplus. This wood was exported in massive quantities via rivers like the Vistula and through Baltic ports such as Danzig, facilitated by the Hanseatic trade routes.
Transportation was relatively efficient and cost-effective for the era: Timber was floated down rivers, loaded onto ships, and sailed to Dutch ports. Despite the distance (around 800–900 nautical miles from Danzig to Rotterdam), bulk shipping kept costs manageable compared to overland sourcing from elsewhere in Europe.
Not all oaks are equal for shipbuilding, and Polish oak from the Baltic stood out for its quality, which local Dutch wood often couldn't match consistently. Grown in a colder, continental climate, these trees developed slower, resulting in denser wood with tighter growth rings. This made it stronger, more durable, and better resistant to rot, warping, and marine borers—critical for hull planks, frames, and keels exposed to saltwater.
Baltic oaks were often taller and straighter, yielding longer, defect-free timbers ideal for specialized ship components like curved knees (for structural support) and straight planks. In contrast, Dutch oaks from warmer, wetter conditions grew faster but produced softer, less resilient wood prone to imperfections.
For the Svælget 2, the imported Polish timbers were used for primary structural elements, while some local wood handled secondary parts cut on-site, optimizing for both quality and logistics.
Importing Polish lumber was a practical necessity driven by scarcity and superior material properties, enabled by thriving medieval trade systems. This pattern continued into later centuries, helping the Dutch build one of Europe's most formidable fleets.
https://www.youtube.com/watch?v=o78bcxVXyVM&t=5s
Above is a 4 minute video of drummer Neil Peart talking about the making of his drum kit for their 40th anniversary tour. Made out of a 1500 year old oak log found buried in the Alt River of Romania (with photos of the log being taken out of the river). He loved the sound of the very dense wood.
I always find it interesting to think of the differences between then and now.
I have read that by Columbus’ time Europe was basically denuded of good oak trees for shipbuilding, and it had become a national security issue for many nations, like rare earth metals are today. So when the New World was discovered, the forests seemed to go on for infinity and shipbuilding for Spain and Portugal became a reality that would match the best of northern Europeans...............