Djambi-class corvette Informations

The Djambi class was a class of steam corvettes of the Royal Netherlands Navy. The class comprised Djambi, Zoutman, Willem, Leeuwarden, Metalen Kruis and Curaçao. Later two ships of a slightly revised type were built, the Zilveren Kruis and Van Galen

In 1850 the French launched the screw battleship Napoleon, proving there was no future left for the sail-only warship. The screw was first introduced to the Dutch navy on some small vessels (sloops of war). In 1852 three real warships with auxiliary steam power were ordered: the frigate Wassenaar and the two corvettes of the Medusa class. In the late 1850s the Medusas were followed by the steam corvettes of the Groningen class. These were designated as Steamships second class and were primarily meant for the East Indies. The Djambis were meant to supplement the number of these Steamships second class.

Even before the first of the Djambis was launched, the whole class became technically obsolete when the French ironclad Gloire entered service in August 1860. The Djambis could not damage armored ships, and were slower than most of them. For service in the colonies however, many nations continued to use (and build) wooden corvettes.

When the first Djambis were ordered, they designated as screw steamships first class. When the Djambi was launched it was a screw steamships second class. Still later they were again designated as (Screw) Steamship first class. This had to do with the Dutch rating system. In 1858 the Dutch navy had: ships of the line in two classes; frigates in two classes; corvettes in two classes etc. They kind of doubled this system for steamships, having 3 frigates with auxiliary power (45-51), 2 corvettes with steampower (19), 3 screw steamships of the second class, 5 screw steamships of the 4th class. For Steam paddlers there were also 4 classes.

The change in designation of the Djambis had to do with this rating system. In the sailing age the Dutch had corvettes that had their guns below the upper deck (kuilkorvet), and corvettes that had their battery on the upper deck (gladdeks korvet). The classification of the Djambis (with their guns on the upper deck) as steam ships of the second class left room for a Steamship first class. Later on two wooden ships of the Anna Paulowna class would actually be laid down as Steamship first class.

Apart from the Dutch artificial classification in (screw)steamships of a certain class, the Dutch also spoke about ships in terms of actual type. This happened e.g. during the discussions about the 1862 naval budget. There were calls for a Kuilkorvet of 22 guns, 350hp and 250 men. At the same the Djambis were designated as corvettes, and in particular as Flush_deck corvettes. . While they were laid down in 1859-1860 the Leeuwarden and Curaçao were referred to as Steam Corvettes.

In all probability the design of the Djambis was based on the experience gained with the preceding corvette class that included the Groningen, VA Koopman and Citadel van Antwerpen. The Djambis were two meters longer, and about one meter wider.

At the time the Dutch built the Djambi England built the slightly larger Corvette HMS_Orpheus_(1860) of the Jason class.

All Djambis had machines of 250 nominal horsepower, which was the same as that of the preceding corvette class. When the Dutch shifted to using indicated horse power, the machines were measured at 700 indicated horse power. The difference is due to nominal horse power not taking steam pressure into account. Therefore indicated horse power is a better measure.

The machines for the Djambi were made by the NSBM in Rotterdam Feijenoord, and tried in April 1861. The machines for two other early ships of the class were made by Vlissingen en Dudok van Heel in Amsterdam.

In August 1862 the Zoutman made a trial course on the Nieuwediep that was deemed satisfactory. She attained a speed of 8-8.5 knots. In an 1875 overview all existing ships of the class were said to attain 8.5 knots maximum. The earlier English corvette Pearl of about equal size made 11.3 knots, but had 400 nominal and 1324 ihp, almost double the effective power.

The Djambis were initially each armed with 8 rifled muzzle loaders of 16cm and 8 long 30 pounders (smooth-bore ML). Both objects had a diameter of 16 cm. The former fired a cylindrical object. The latter fired a traditional circular bullet of 30 pounds. With the invention of the rifled gun nations switched from using bullet weight for classification of their guns, to using bullet diameter. The rifled gun was designated by its diameter, because it could fire an object of arbitrary weight. On the contrary the weight of the shot of the traditional smooth-bore gun could be derived directly from its bore. Later on, in the Memoriaal van de Marine (1880), the Leeuwarden and Curaçao had lost their old smooth-bore 30 pounders, and each had 16 rifled 16 cm guns. Probably from the by then retired Zoutman and Willem.

The rifled gun involved was the 16cm Rifled No.3, introduced in 1862. It was the first attempt to produce a large caliber rifled gun for the Dutch navy. The inspiration probably came from the massive amounts of old 30 pounder guns that the French navy converted. The Dutch navy had 38 old unfit bronze 60 pounder carronades lying around somewhere. In 1861 plans were made to fill these up, to rebore them to a smaller diameter of 16 cm (=30 pd), and to rifle them. Later on the army produced 12 more of these guns for the navy, bringing the total to 50.

These rifled 16 cm ML were soon known to be almost completely ineffective against armored ships. This was not such a problem for the Djambis because they were not meant to fight armored ships.

The classic smooth bore gun was the long 30 pounder No.4, at least thats what the Metalen Kruis had in 1880 The 30 pdr long No. 4 had been introduced in 1853 and had a barrel length of 3.19 meter. This was longer than the 30 pdr long No. 2 found in the previous corvettes, which was only 2.77 long.

There were rumors that with its beam of 12.25 meter the Djambi was too narrow to properly operate all the guns. The problem was probably caused by the smooth-bore guns. The Djambi was about 50 cm wider on each side than the previous class, and so the increased barrel length of (3.19-2.77) 42 cm should not have been a problem. However, that does not help if all kinds of obstacles are placed on the extra space.

Of the 6 ships 4 were built at the Rijkswerf in Amsterdam and 2 (Leeuwarden, Curaçao) at the Rijkswerf in Flushing.

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