Qualla: Willem I Lock

Willem I Lock: Introduction

Sat, 16 May 2026 00:00:00 GMT

Photo credit Gouwenaar, CC0. In late April 1857 the brand-new Dutch steam frigate HNLMS Wassenaar arrived at the IJ-side of Willem I Lock, on the north bank opposite what is now Amsterdam Centraal Station. The lock had been open for thirty-three years. The Wassenaar would not fit. To get her through, the engineers closed the Buiksloot Flood Gate further up the canal, opened the lock to the IJ, and let salt water flood into the polders until the Noordhollandsch Kanaal sat level with the harbor. On 2 May the frigate was hauled through. A day later, the Wassenaar reached the identical lock at Purmerend - same dimensions, same builder - and passed it without difficulty. Why one worked and the other didn't became a debate that helped trigger the construction of the entire North Sea Canal.

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Image: Gouwenaar | CC0

Willem I Lock: The King's Canal

Sat, 16 May 2026 00:00:00 GMT

Photo credit Arch, Public domain. Willem I Lock sits at the headland called Volewijck, a stub of land that pokes south into the IJ. In 1818 the new Kingdom of the Netherlands needed a way to get ocean ships to Amsterdam without the awful navigation of the Zuiderzee, and King William I commissioned Inspector Gener...

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Image: Arch | Public domain

Willem I Lock: Big Lock, Small Lock, Three Sets of Gates

Sat, 16 May 2026 00:00:00 GMT

Photo credit Menno Huizinga, Public domain. Willem I was not one lock but two, side by side. The large chamber - originally 72.34 meters long, 15.70 meters wide, and 6.83 meters deep below the Amsterdam Ordnance Datum - handled the ocean-going ships. The small one, 25 meters long and 5.65 meters wide, served the canal barg...

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Image: Menno Huizinga | Public domain

Willem I Lock: The Wassenaar's Problem

Sat, 16 May 2026 00:00:00 GMT

Photo credit AWossink, CC BY-SA 4.0. The puzzle of the Wassenaar's 1857 passage was that two identical locks behaved differently. At Willem I, the water level dropped as the ship descended toward the IJ, and the frigate's bow and stern - lifting and falling against the gate-tops as the water moved - struck the upper...

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Image: AWossink | CC BY-SA 4.0

Willem I Lock: Shipworm and Brick

Sat, 16 May 2026 00:00:00 GMT

Photo credit Unknown author, CC BY-SA 4.0. On 16 December 1864, one day after Willem III Lock opened next door, Willem I Lock was decommissioned and cut off by a dam so it could finally be repaired. The reason for the damage turned out to be entirely biological: the wooden floor of the lock had been chewed apart by shipwo...

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Image: Unknown author | CC BY-SA 4.0

Willem I Lock: Still Working

Sat, 16 May 2026 00:00:00 GMT

Photo credit Alf van Beem, Public domain. Willem III Lock is now closed off and silent. The Noordhollandsch Kanaal has lost most of its commercial traffic to the bigger North Sea Canal that runs west from Amsterdam to IJmuiden. But Willem I Lock still operates. The large chamber handles commercial and recreational vessel...

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Image: Alf van Beem | Public domain