Evertsen-class coastal defence ship

The Evertsen class or Kortenaer class was a class of coastal defense ships^[a] of the Royal Netherlands Navy.^[1] The class comprised Evertsen, Piet Hein and Kortenaer.^[3]

HNLMS Evertsen at sea.
Class overview
Name	Evertsen class
Builders	Rijkswerf, Amsterdam Koninklijke Maatschappij De Schelde, Flushing Nederlandsche Stoomboot Maatschappij, Rotterdam
Operators	Royal Netherlands Navy
Succeeded by	Koningin Regentes class
Built	1893-1896[1]
In service	1895-1920
Completed	3
Retired	3
General characteristics [2]
Type	Coastal defense ship
Displacement	3,464 tons
Length	86.2 m (282 ft 10 in)
Beam	14.33 m (47 ft 0 in)
Draught	5.23 m (17 ft 2 in)
Propulsion	4,700 hp (3,500 kW), two shafts
Speed	16 knots (30 km/h)
Capacity	289 tons of coal storage
Complement	263
Armament	2 × 8.2 in (21 cm) (1 × 2) 1 × 8.2 in (21 cm) (1 × 1) 2 × 15 cm (5.9 in) (2 × 1) 6 × 7.5 cm (3.0 in) (6 × 1) 8 × 1-pounder (8 × 1) 3 × 45 cm (18 in) torpedo tubes
Armour	6 in (15 cm) belt 9.5 in (24 cm) barbette 9.5 in (24 cm) turret 2.25 in (5.7 cm) deck

History

The protection of the Dutch East Indies came into the spotlight at the end of the nineteenth century. Many countries began expanding their battle fleets. In 1887, two medium-sized Chinese battleships became operational and were considered superior to the Dutch defence. This led to a reassessment of the defence of the Dutch East Indies. In April 1892, the foundations for modernisation were formulated by a committee consisting of three officers J.H. Kromhout, F.J. Haver Droeze and G. Kruys.^[4]

Naval expert, rear admiral and Chief of the Naval Staff Gerhardus Kruys advocated for a squadron of artillery ships. The recommendations were adopted by the government, which led to the construction of HNLMS Evertsen, HNLMS Kortenaer, and HNLMS Piet Hein. Ultimately, only the Piet Hein was sent to the Indies from 1899 to 1901, because the financing of the ships was dependant on their suitability for coastal defence of the Netherlands and the Dutch Caribbean.

Design

The ships of the class were 86.2 metres (282 ft 10 in) long, had a beam of 14.33 metres (47 ft 0 in), a draught of 5.23 metres (17 ft 2 in), and had a displacement of 3,464 ton.^[2] The ships were equipped with 2 shaft reciprocating engines, which were rated at 4,700 ihp (3,500 kW) and produced a top speed of 16 knots (30 km/h).^[2] In addition, the machinery had two sets of triple expansions.^[5]

When it came to naval armour all three ships were equipped with Harvey armour.^[2] The ships had belt armour of 6 in (15 cm), 9.5 in (24 cm) barbette armour and 9.5 in (24 cm) turret armour.^[5] Deck armour of the Evertsen class was 2.25 in (5.7 cm).^[5]

Armament

The main armament of the ships consisted of three 21 cm A No. 1 guns. Two of these were placed in a Barbette on the bow.^[3] The third was behind a shield on the stern.^[6] These were second hand guns re-used to economize, while the newer 21 cm A No. 2 gun used on HNLMS Koningin Wilhelmina der Nederlanden was already available. This led to sharp criticism.^[7] The 21 cm A No. 1 gun was a 21 cm L/35 Krupp gun first built in 1882. The 9 guns required were taken from 9 gunboats instead of buying 9 new 21 cm A No. 2 guns. The 21 cm A No. 2 was a newer model of the Krupp gun, had the same length (L/35) and was only 700 kg heavier, but had about 10% more penetrative power at 2,000 m.^[8]

Secondary armament included two single 15 cm (5.9 in) guns and six single 7.5 cm (3.0 in) guns.^[3] Furthermore, it had three 45 cm (18 in) torpedo tubes.^[5]

Ships

Construction data

Name	Laid down	Launched	Commissioned	Decommissioned	Shipyard
Kortenaer	1893	27 October 1894	17 December 1895	1920	Rijkswerf, Amsterdam
Evertsen	1893	29 September 1894	1 February 1896	1913	Koninklijke Maatschappij De Schelde, Flushing
Piet Hein	1893	16 August 1894	3 January 1896	1914	Nederlandsche Stoomboot Maatschappij, Rotterdam