The ships of the
Evertsen class were heavy frigates with auxiliary power. The prime objective of the designers of screw ships with auxiliary power was to create a steam ship with a full broadside. This led to screw frigates that were basically slightly longer versions of their sail only counterparts, the extra length being used for machinery and coal storage. Even so, the equivalent broadside was difficult to achieve. Weight had to be saved on engines and coal storage, and so these ships were intended to use their engines only in fights and emergencies, and to sail the rest of the time.
Design The
Evertsen class were the first frigates of the Dutch navy which were
designed to have (auxiliary) steam power. At the time that the lead ship
Evertsen was laid down the Dutch did not yet have a sailing frigate in commission, and therefore lacked any proof that either the previous lengthened sail frigate
Wassenaar or the
Evertsen would be successful. The
Evertsen was only 1.14 meters longer than the previous
Wassenaar, i.e. 1.8%. The beam of the
Evertsen was 1.4 meters wider, amounting to an almost 10% increase in beam. This sudden increase in width of the Dutch heavy frigates from 14.30 m to 15.70 m seems a strange development. Lieutenant H. Huijgens was a teacher in steam engineering at the Naval Institute in
Medemblik. In 1847 he published an introduction to naval steam engineering (Dutch: Handleiding tot de kennis van het Scheeps-Stoomwerktuig). In 1852 he published: De Schroef (the Screw), a work about screw propulsion. In 1853 he published: De schroef-machine (the screw-machine). In the introduction to the screw-machine Huygens clearly states that before ordering the construction of screw-machines for the new warships with auxiliary power, the secretary for the navy ordered him to investigate the subject in England. The investigation was to concern which kind of machines and screws the English thought most effective, and what kind of improvements had been made to steam machines in recent times. The findings would give directions for equipping the ships with machines and screws, and aid in an attempt to make ships that were equal to foreign ships in every aspect. Later Huygens would repeat the investigation in company of the chief-engineer Tromp. Tromp was responsible for ship construction, Huygens for machinery. In the final sentence of the introduction Huygens stated that it would describe the machinery for the
Medusa,
Amelia and
Wassenaar. Machines that were already under construction. Huygens would end the report of his first visit to England with the sentence:
We cannot rival the English in number of ships, but we should at least try to rival them in the capacities (hoedanigheid) of our ships. In his work The Screw Huygens stated: ''We believe that the best course is to follow other, bigger countries without experimenting to see what's good, but to use their experiments, and so to keep up with these other countries as much as possible.
On his second trip to England Huygens visited the frigate with auxiliary power Imperieuse
, the steam corvette Highflyer
of 250 hp, the screw ship of the line Duke of Wellington
, the Conflict
of 8 guns and 400 hp, the transport Vulcan
, the Tribune
of 32 guns and 300 hp, the Plumper
etc. etc. He mentioned all these in his book, but he only described the Highflyer
250 hp and the Imperieuse
of 360 hp. The Euryalus
, a sister ship of the Imperieuse
had 400 hp. Therefore there can be little doubt that these two ships: the frigate Euryalus
of 400 hp and the steam corvette Highflyer
, can be considered to be the types of the 1855 program, at least with respect to machinery. In 1855 Huygens published: Schroef-stoomschepen as a 4th appendix to Handleiding tot de kennis van het Scheeps-Stoomwerktuig. In Schroefstoomschepen, published in the same year as the Plan 1855, Huygens compared the frigates of the 1855 program to the Imperieuse
and Euryalus
. His conclusion was that the Dutch frigates had the same power to displacement ratio, i.e. 1 : 8. (400 hp to 3,200 t displacement), that the English ships had done well in service and had sometimes achieved 9–10 knots. He compared the 250 hp corvettes of the plan 1855 with the light frigate Tribune'' of 300 hp. Huygens then declared that from a steam-mechanical point of view the ships of the plan were completely in line with contemporary technical standards. The resemblance of the
Evertsen to the British
Imperieuse class, e.g.
Euryalus, is striking at first sight.
Evertsen length 63.5, beam 15.70, depth 6.80, displacement 3,300t, 400 nominal hp, 1000 ihp.
Euryalus length 65, beam 15.29, depth 5.11, displacement 3,125t, 400 nominal hp 1159 ihp. However equal these ships were in outward appearances, their capabilities differed significantly. Under steam the
Imperieuse class attained almost 10 knots. The
Evertsen ran closer to 8 knots. Considering the difference between the United Kingdom and the Netherlands in naval budget, engineering- and design capabilities this is no surprise.
Armament The armament of the
Evertsen consisted of 51 guns.
Propulsion The
Evertsen class had machines of 400 nominal
horsepower.
Names The
Evertsen was officially called
Evertsen, but sometimes she was also referred to as
Admiraal Evertsen. ==Ships in the class==