Tanjung Priok Dock of 8,000 tons was a floating dry dock built for Droogdok-Maatschappij Tandjong Priok (dry dock company Tanjung Priok) in the 1920s.
Context
Tanjung Priok, the harbor of Batavia/Jakarta
The Indonesian capital Jakarta is on the shore of the Java Sea. For most of its history the 'harbor of Jakarta' was a place at sea where ships anchored, so they could load and unload via smaller ships. This changed when the newly constructed Port of Tanjung Priok (Dutch: Tandjong Priok) was opened 1881–1883. At Tanjung Priok ships could attach to a quay. The idea was that when the expensive transloading was no longer needed, the competitive position of Batavia would be strengthened.
Droogdok Maatschappij Tandjong Priok
Tanjung Priok at first lacked a good repair facility, especially a dry dock. The repair shipyard of the Nederlandsch Indische Droogdok Maatschappij (NIDM) at nearby Amsterdam Island had Volharding Dock, but this was too small for most modern ships. The combination of a small dock and little traffic made that NIDM went into liquidation in 1884. The Maatschappij tot Exploitatie van Droogdokken en Scheepstimmerwerven in Nederlands-Indië then continued the business at Amsterdam Island into 1891. Just like her predecessor it failed to get the concession for exploiting drydocks in Tanjung Priok, and left Amsterdam Island in 1893.
What the Dutch government wanted, was to have a modern dry dock at Tanjung Priok. This required new capital that the public would not invest in the existing companies. In June 1890 it then made a deal that led to the establishment of the Droogdok Maatschappij Tandjong Priok (Tanjung Priok dry dock company). Part of the deal was that this company would lease Onrust Dock of 3,000 tons. It would also lease the cylinder dock free of charge. A new dry dock of 4,000 tons, i.e. Tanjung Priok Dock of 4,000 tons would be built in the Netherlands, and then be leased by the company instead of the 3,000 tons dock.
The Tanjung Priok dry dock company was an almost immediate success. In the company's first few years Onrust Dock of 3,000 tons was rather busy. After it started to use Tanjung Priok Dock of 4,000 tons in 1896, there were many years that this dock had more than 365 docking days a year. In 1904 the company got a patent slip of 2,000 tons. When the agreements with the government had to be renegotiated in 1915, government support ended, and the 4,000 tons dock was bought by the company for 350,000 guilders.
Ordering and construction
Ordering
World War I was a happy period for Tanjung Priok dry dock company. In 1914 profit was 124,622 guilders, in 1915: 384,950, in 1916 185,402, in 1917 487,500, and in 1918 an astonishing 867.370 guilders. This trend continued in 1919 with a profit of 902,687, and over 1920 716,536 guilders These profits resulted in very high dividends for the shareholders. Nevertheless, by 1921 the company had a huge amount of cash available to invest.
On 3 December 1921 the order for Tanjung Priok Dock of 8,000 tons was placed at Burgerhout shipyard in Rotterdam. In relation to this order Droogdok Maatschappij Tandjong Priok emitted a loan of 1,000,000 guilders in bonds at 7%. The new dry dock would be 156 m long and would be able to lift 8,000 ton. It was claimed that it could also lift big ships like the Coen and Patria. It was to be ready in March 1923. The price was about 2,500,000 guilders, because it was on the balance sheet of 1923 for 2,509,526 guilders.
Construction
For construction of the drydock Burgerhout shipyard cooperated with Hamburger Dockbaubüro of Paul Matthiessen and Max Müller, who also designed the dock. On 17 October 1922 the first part of the drydock, consisting of four pontoons, was launched. On 10 February 1923 the second part of the dry dock was launched. The shipyard did not make the planned end date in March 1923, because the plans were later changed to include a power station.
Characteristics
Tanjung Priok Dock of 8,000 tons was 156.40 m long overall. The pontoon deck was 146.40 m long. The beam was 29 m and the internal width on the pontoon deck was 21.4 m. The pontoons had a hold of 3.2 m. The sides were 10 m high. The 8,000 tons regarded the displacement of the ships which the dock could lift. The weight of the dock itself would be 4,000 ton. The maximum displacement would be 12,500 ton with a freeboard on the pontoon deck of 30 cm, which is what will happen if one puts a ship of 8,000t displacement on top of one of 4,000t: the combination will displace 12,000t.