At first Onrust Dock of 3,000 tons was simply known as: 'The iron dry dock', because there was only one such structure in the Dutch East Indies made of iron.
Before its construction, in the 1850s, there were only two floating dry docks in the Dutch East Indies, both made of wood.
The admiralty in the Dutch East Indies wanted to have a third bigger floating dock.
It foresaw that during the scheduled maintenance and repairs of the docks themselves, the remaining dock would not provide enough capacity to repair the screw powered ships, which also had a higher need for dry dock capacity.
Furthermore, the existing dry docks were not capable of receiving the biggest ships.
The Surabaya dock handled the Groningen-class corvettes of 1,780 tons with great difficulty.
The wooden dock at Onrust Island was longer, but still not long enough, and was not capable to receive loaded ships.

On 3 February 1863, there was a public tender for the iron dock in the East Indies.
It would be stationed at Onrust (island) near Batavia.
Of 17 contestants Van Vlissingen en Dudok van Heel was the cheapest at 366,685 guilders.
The floating dock was 90 m long, and up to 21 m wide on the inside.
It would be able to load a screw frigate of 3,000 tons.
On 9 June 1864 some members of the Royal Institute of Engineers visited the floating dock after attending their annual meeting.
Van Vlissingen en Dudok van Heel made pictures and sent them to the members of the institute.
The final cost of the floating dock would be 460,852 guilders, of those 41,018 were for transport.
After transport to Surabaya the floating dry dock was re-assembled in a basin at Surabaya from 3 April 1865.
In October 1869 it was finally towed to Onrust by the Amsterdam and Ardjoeno.
It would have a remarkable long life, serving up to 1933.
At first Onrust Dock of 3,000 tons was simply known as: 'The iron dry dock', because there was only one such structure in the Dutch East Indies made of iron. Before its construction, in the 1850s, there were only two floating dry docks in the Dutch East Indies, both made of wood. The admiralty in the Dutch East Indies wanted to have a third bigger floating dock. It foresaw that during the scheduled maintenance and repairs of the docks themselves, the remaining dock would not provide enough capacity to repair the screw powered ships, which also had a higher need for dry dock capacity. Furthermore, the existing dry docks were not capable of receiving the biggest ships. The Surabaya dock handled the Groningen-class corvettes of 1,780 tons with great difficulty. The wooden dock at Onrust Island was longer, but still not long enough, and was not capable to receive loaded ships. 
On 3 February 1863, there was a public tender for the iron dock in the East Indies. It would be stationed at Onrust (island) near Batavia. Of 17 contestants Van Vlissingen en Dudok van Heel was the cheapest at 366,685 guilders. The floating dock was 90 m long, and up to 21 m wide on the inside. It would be able to load a screw frigate of 3,000 tons. On 9 June 1864 some members of the Royal Institute of Engineers visited the floating dock after attending their annual meeting. Van Vlissingen en Dudok van Heel made pictures and sent them to the members of the institute. The final cost of the floating dock would be 460,852 guilders, of those 41,018 were for transport. After transport to Surabaya the floating dry dock was re-assembled in a basin at Surabaya from 3 April 1865. In October 1869 it was finally towed to Onrust by the Amsterdam and Ardjoeno. It would have a remarkable long life, serving up to 1933.
Van Vlissingen en Dudok van Heel