Ragnar-class destroyer

The Ragnar-class destroyer was an improved version of the preceding Wale.^[1] The ships normally displaced 350 long tons (360 t) and 416 long tons (423 t) at full load. They measured 66.1 meters (216 ft 10 in) long overall with a beam of 6.3 meters (20 ft 8 in), and a draft of 1.8 meters (5 ft 11 in). The Ragnars were propelled by two 4-cylinder vertical triple-expansion steam enginess, each driving one three-bladed propeller using steam from four Yarrow boilers. The engines were designed to produce a total of 7,200 indicated horsepower (5,400 kW) for an intended maximum speed of 30 knots (56 km/h; 35 mph). On Vidar's sea trials, she reached 31.3 knots (58.0 km/h; 36.0 mph). The ships carried enough coal to give them a range of 1,400 nautical miles (2,600 km; 1,600 mi) at 12 knots (22 km/h; 14 mph). The ships' crew numbered 69.^[2][3]

The Ragnar's dispensed with Wale's 57-millimeter (2.2 in) M89/B guns in exchange for two additional 75-millimeter (3 in) M/05 guns. One gun each was located at the forecastle and stern; the other two guns were positioned on the main deck amidships, one gun on each broadside. The ships were equipped with two 457-millimeter (18 in) torpedo tubes in rotating mounts located between the rear funnel and the stern gun. Two 6.5-millimeter (0.26 in) M/10 machine guns were added to the ships in 1911–1912 and the single torpedo tubes were replaced by twin-tube mounts in 1916–1917.^[2]

• Borgenstam, Curt; Insulander, Per & Kaudern, Gösta (1989). Jagare: med Svenska flottans jagare under 80 år [Destroyers: Swedish Navy Destroyers under 80 Years] (in Swedish). Marinlitteratur. ISBN 91-970700-4-1. SELIBR 7792227.
• Harris, Daniel (2000). "Swedish Steam Torpedo Boats". In Preston, Antony (ed.). Warship 2000–2001. Conway Maritime Press. pp. 97–124. ISBN 0-85177-791-0.
• von Hofsten, Gustaf; Waernberg, Jan & Ohlsson, Curt S. (2003). Örlogsfartyg: svenska maskindrivna fartyg under tretungad flagg [Ships of War: Swedish Machine-powered Ships under the Triple-tailed Flag]. Forum navales skriftserie, 1650-1837 (in Swedish). Vol. 6. Svenskt militärhistoriskt bibl. i samarbete med Marinlitteratur. ISBN 91-974384-3-X. SELIBR 8873330.
• Westerlund, Karl-Erik (1985). "Sweden". In Gray, Randal (ed.). Conway's All the World's Fighting Ships 1906–1921. Conway Maritime Press. pp. 355–363. ISBN 978-0-85177-245-5.
• Whitley, M. J. (2000). Destroyers of World War Two: An International Encyclopedia. Cassell & Co. ISBN 1-85409-521-8.