Willemsoord Dry Dock I is a historic dry dock in Willemsoord, Den Helder, Netherlands. It was constructed from 1813 till 1822, under the direction of Jan Blanken, and was part of the former Rijkswerf Willemsoord.
Context
Nieuwediep
In 1781-1785 the harbor of Nieuwediep was created just east of Den Helder. It was meant for heavy warships, which had trouble reaching their home towns on the Zuiderzee. These home towns (like Amsterdam) vehemently opposed the construction of a competing harbor, and wanted Nieuwediep's function to remain strictly limited to harboring heavy warships. Nevertheless, from 1792 onward, some field fortifications were made to protect the harbor. A careening facility called or was also created. Here ships could enter at high tide, be put on their side at low tide and careen while a lock door prevented the flood from returning. The 1799 the Anglo-Russian invasion of Holland led to the capture of the base at Nieuwediep and the surrender of the cornered Dutch fleet in the Vlieter incident.
Naval base Willemsoord
In 1811 Napoleon visited Nieuwediep and ordered the construction of a large well-fortified navy base. The fortifications would center on Den Helder, giving rise to the town of that name. The new navy base would be east of Den Helder, on the west side of the Nieuwediep, north of the Nieuwe Werk. The new navy base would later become known as Willemsoord, or Rijkswerf Willemsoord. Napoleon gave the order to design the new base to Jan Blanken. He was an engineer who had proved very effective in improving the navy base at Hellevoetsluis, and in designing the Hellevoetsluis Dry Dock.
Jan Blanken's design included a sea lock, a wet dock and a dry dock. The sea lock closed the wet dock from the tides. The wet dock provided safe anchorage, but its prime benefit was that ships stayed at the same height to the quays. They could also be brought in closer. It all led to easier handling and storage of ships. A dry dock was a facility that had recently become a necessity for any serious naval base. Heavy warships had become longer, and therefore more susceptible to damage from careening. Meanwhile, the problematic supply of good Scandinavian oak, and the practice of copper sheathing ships, had increased the demand for frequent below water maintenance.
Construction History
Foundations for the pumphouse
In 1813 construction of the pump building started with digging a pit for its foundation. Soon, quicksand and water seemed to have joined forces to prevent construction. However, perseverance prevailed and digging reached the required depth. Thirty piles were then driven into the ground, and work for that year was finished.
After the liberation, work on the pumphouse foundation was picked up again in 1816. The pit was pumped dry, and dug out again. However, the piles were nowhere to be found. They could neither be dug up, nor could they be found by exploring with iron sounding devices called s. The pit was kept dry by using three chain pumps, working round the clock. Suddenly, a well of 1 m diameter burst open. It filled the pit so quickly that the drivers of the horses that drove the chain mills had to cut the horses loose in order to save them. Jan Blanken was then Inspector-General of Rijkswaterstaat. He was assisted by the engineers Glimmerveen, Van Asperen and Wellenberg, and the later chief-engineer A. Greve, as well as the contractors Den Stok and Verschuur. They decided to continue construction at the same location, instead of changing the plans. After a lot of pumping, the well became visible. It continued to expel shells and water, and when a 36 feet pile was driven into it, it was launched like an arrow.
The well was stopped by layers of horse manure, rubble and other objects. Of course this was a stop gap measure, but at least the pit could be kept dry. The idea of pile driving was abandoned. Heavy fir beams were now laid down about 80 cm apart. The openings were closed by brickwork. Across this layer, a new layer of heavy fir beams was laid down, and closed by bricks. Any resulting depressions were again levelled by brickwork, and so a level foundation for the pumphouse was created.