Amsterdam’s Difficult Route to Sea

Until in 1876 the North Sea Canal provided a short direct route to the North Sea, Amsterdam’s ships faced a long and dangerous trajectory across the former inland Zuiderzee (Southern Sea) with its many sandbanks, before they could even start on their real journey. Even more remarkable that the city in the 17th century became a maritime presence to be reckoned with, despite its quite convoluted access to the sea. When in 1585 the competing harbor of Antwerp — then under Spanish rule — was closed off by Dutch ships, Amsterdam became a major hub for overseas trade.

Flagship the Gouden Leeuw on the IJ in 1686, painting by Willem van de Velde the Younger (Amsterdam Museum).

Zuiderzee

A series of floods in the early Middle Ages had transformed an existing lake into a shallow inland sea, by separating West-Frisia and Friesland. Several towns gained access to the North Sea, Amsterdam among them. The Zuiderzee was a very busy inland sea for centuries. The ships of the Dutch East and West India Companies (VOC and WIC) passed through here, as well as the national transport of persons and goods.

Map from 1658 of the Republic of the Seven United Netherlands by Johannes Janssonius, showing the many sandbanks in the former Zuiderzee, especially near the Wadden Islands in the north (Hoogheemraadschap van Rijnland).

Between 1550 and 1700 there were least 1.2 million peat ships which provided the growing Dutch towns with fuel (wood was getting scarce). The once rich fishing grounds for herring, anchovies, shrimp and eel disappeared after the sea was closed in 1932 and the water went from salt to fresh. Large portions of land were reclaimed from the former Zuiderzee between 1936 and 1968.

Regular barge service between Amsterdam and Lemmer across the Zuiderzee (Fries Scheepvaartmuseum).

Navigating the Zuiderzee

Because of the shifting shallows, tidal currents and water depths depending on wind direction, navigating the Zuiderzee was a dangerous undertaking. Initially boats stayed close to the coast to navigate by towers and landmarks. Even from before the 14th century the main tidal gullies were marked with poles and casks, later with lit buoys. Casking rights (and the associated passing fees) were first given to Kampen, in 1527 to Amsterdam and in 1573 to Enkhuizen. Lighthouses and beacons were constructed at strategic points from the 17th century on. The VOC used very strict sailing routes and maps.

Part of a map of the Zuiderzee from 1725-1750 by Reinier and Josua Ottens, with sailing route (Zuiderzeemuseum Enkhuizen).

From the IJ, after the shallows of Pampus, there was a broad channel towards the island of Urk. The former island of Schokland (now poldered in) was an important refuge, providing needed shelter during storms. From there on there were two trajectories towards the North Sea. The eastern route was between Vlieland and Terschelling, the western route was between Den Helder and Texel. It could take days for the ships to reach open North Sea water — the channels were hard to navigate during unfavorable winds.

Parting trading ships were assisted by Amsterdam pilots, incoming trading ships by pilots from the islands in the north. At the IJ at the former Haringspakkerstoren (current Prins Hendrikkade near Singel) was the office of the Amsterdam pilots. Once at Urk, they would get half their fee, the rest once the ship was past the northern islands.

The pilot office at the foot of the Haringpakkerstoren in 1770, drawing by Jan de Beijer (Stads­archief Amsterdam).

Amsterdam’s IJ

The IJ was originally an inlet of the Zuiderzee, wider after various storm surges which gnawed away at the surrounding farmlands. With northwestern storms the water of the North Sea would be forced into the shallow Zuiderzee and the even shallower IJ, resulting in quickly rising water levels (up to 3.25 m or 10 ft above normal level) and dike breaches. During storms the water of the IJ would be extremely turbulent and choppy. While a threat because of frequent flooding, the IJ was also Amsterdam’s economic lifeline.

The location of the deeper tide channels gradually moved towards the north side of the IJ. Around 1750 strong southwestern winds could even cause the IJ and the Pampus exit to go dry completely, blocking even smaller boats. Even at normal water levels it often took hundreds of workers to pull large war ships through the mud into the eastern harbor — where once large ships still moored in 1672 there was now only about 1.5 m (5 ft) depth. Only constant costly dredging secured a somewhat useable depth of the Amsterdam harbors.

Map of Amstelland and the surroundings of Amsterdam from 1749 by Covens & Mortier, showing the still wide IJ and the shallow muddy exit towards the Zuiderzee via the Pampus strait (KOG, Stadsarchief Amsterdam).

The name IJ is said to originate from old West-Frisian Ie, meaning water, later written as Y. On old maps it was sometimes marked as Tye Oort, meaning “Place of Tides”. After the IJ was closed off from the inland sea — by the construction of the Oranjesluizen in 1872 — there were no more tides and large parts of the original IJ were poldered in on both shores.

The Muddy Pampus

Pampus (an old word meaning thick mush) was the name given to a soft mud treshold east of Amsterdam and north of Muiden, where the IJ exited into the Zuiderzee. This tidal channel continually silted up with meters deep soft sludge, hindering ships to and from Amsterdam’s harbor. Even at high tide it barely had a depth of 3 m (10 ft). In the 17th century there were no efficient dredging tools available to remedy that situation. Pampus is now the name of an artificial island north of Muiden with a fort on it, constructed between 1887 and 1895 to protect the Pampus channel, part of a defense line called Stelling van Amsterdam.

Replica of the VOC ship Amsterdam, which was lost on its first voyage in 1749 in a storm near Hastings, England (April 2022).

During the colonial world trade large ships were often unable to pass — due to low tide or unfavorable winds — and needed to wait in queue for weeks and even months. This gave rise to the Dutch expression “voor Pampus liggen” (lie in front of Pampus), meaning to be unable to move, to be knocked out cold. More and more the really big ships were loaded and unloaded at Texel, their wares, guns and crews transported with smaller vessels. This came at a high cost in time, tools, manpower and money. The lighter ships could then — just — pass Pampus at high tide for maintenance at Amsterdam’s wharfs.

Ship Camels & Sailing Tugboats

Larger ships could pass the shallows near Pampus with the help of ship camels, wooden caissons made to fit the hull of a ship, created by city carpenter Meeuwis Meindertsz Bakker in 1688. They were partially sunk by filling them with water, fitted to the ship and then the water was manually pumped out again, thus raising the ship by 1.5 m (5 ft). Sturdy sailing Zuiderzee waterships were used as tugboats to get the ship with camels across the Pampus mud into the harbor. But even with the camels these big ships could only just pass. The Amsterdam Admiralty rented out their camels, mostly to the VOC.

Model from 1742 of a Dutch East India vessel with ship camels (Rijks­museum).

Preparing ships to cross the Pampus with camels was a very labor intensive and costly operation and there was only a limited number of ship camels available. A tugboat company with 15 heavy sailing ships (used for dragnet fishing) was located in Marken since the 16th century. They exclusively towed war ships and VOC ships with camels to and from the Amsterdam harbor, contracted by the Admiralty. But that only worked at high tide and with strong winds. They were in use until the North-Holland Canal opened in 1824.

A ship in camels towed across the shallows near Pampus by sailing tugboats, engraving by P. Blauw (Stads­archief Amsterdam).

Noord-Hollandsch Kanaal (North Holland Canal)

The Dutch economy was in a slump after the French period (1795-1813). Spurred on by King Willem I a canal was created between 1819 and 1824, from Amsterdam-Noord to Den Helder (via Purmerend and Alkmaar), to improve Amsterdam’s seaport access and avoid the difficulties of navigating the Zuiderzee. Although it was long and curvy, at least Amsterdam could now access the North Sea in 2-3 days, while the route across the Zuiderzee could take up to 2 weeks with unfavorable weather conditions. The distance was shortened from 150 km (93 mi) to 80 km (50 mi). But increasing ship sizes and traffic meant that the channel did not live up to the initial high expectations.

In blue the Noord-Hollandsch Kanaal, from Amsterdam-Noord via Purmerend and Alkmaar to Den Helder (OpenStreetMap).

North Sea Channel

Growing ship sizes and steam engines led to the construction of the Noordzeekanaal, which opened in 1876. Locks at IJmuiden and Schellingwoude (Oranjesluizen) closed off the IJ and made it into one large dock. The distance from Amsterdam to the North Sea was thus shortened quite a bit over time: through the Zuiderzee 150 km (81 nmi), through the Noord-Hollandsch Kanaal 80 km (43 nmi), through the Noord­zee­kanaal 30 km (16 nmi).

Drawing from 1862 showing the North Sea Canal and the projected land reclamation (KOG, Stadsarchief Amsterdam).

Land reclamation at the borders of the IJ (IJpolders) finished in 1872. During the construction of the Noordzeekanaal three islands in the IJ were created, using the sand dug out from the dunes near IJmuiden when the sea locks were created there. These islands were to hold Amsterdam’s Central Station, which opened in 1889. The Amsterdam harbor was moved from the east side of town to the west.

Satellite photo of the Noorzeekanaal (North Sea Canal) in 2020 (Copernicus Sentinel, European Space Agency).

Oranjesluizen near Schellingwoude

The locks of the Oranjesluizen (1870-1872) ended Amsterdam’s open connection to the Zuiderzee, closing off the IJ. These locks were started at the same time as the North Sea Canal. Amsterdam, fearing for its harbor activity, had at first protested vehemently against this plan and the creation of polders on both sides of the Inner-IJ. The initial steampowered pumping station was replaced in 1975 by an electric one. A separate lock, the Prins Willem Alexandersluis, was created for inland shipping in 1995.

Oranjesluizen in 2009, looking north. Zeeburger­eiland still empty (Dorian Kransburg, Stads­archief Amsterdam).

View of the IJ on a stormy day, painting from 1660 by Jacob van Ruisdael (Worcester Art Museum, Massachusetts, USA).