HSwMS Folke

HSwMS Folke was the last of the seven Hildur-class monitors built for the Swedish Navy in the mid-1870s. Unlike her sisters, her gun turret was fixed to the rear. The ship was placed in reserve in 1919 and ultimately sold in 1942.

Design and description
The Hildur-class monitors were designed by Lieutenant John Christian d'Ailly, from a proposal by John Ericsson, for the defense of Lake Mälaren and the Stockholm archipelago. They had fixed turrets mounting 240 mm guns and someone on the defense staff realized that they could be destroyed while retreating because none of the ships could fire to their rear. Folke was designed to protect her sisters in that situation as her turret was fixed to the rear.

Folke was 39.78 m long overall and had a beam of 8.72 m. She had a draft of 2.7 m and displaced 460 t. Her crew numbered 48 officers and men. The ship had a rudder at bow and stern.

The Hildur-class ships had two horizontal twin-cylinder steam engines, each driving a single propeller. Their engines were powered by two cylindrical boilers. The engines produced a total of 155 ihp which gave the monitors a maximum speed of 8 kn. The ships carried 23 - 25 t of coal.

Armament
Folke was equipped with one 240 mm M/69 rifled breech loader, mounted in a long, fixed, oval-shaped turret that faced to the rear. The gun weighed 14670 kg and fired projectiles at a muzzle velocity of 397 m/s. At its maximum elevation of 7.5° it had a range of 3500 m. The ship also mounted two 75 mm guns.

Folke was rearmed with a 120 mm quick-firing gun as well as three 57 mm quick-firing guns sometime in the 1890s or the early 1900s.

Armor
Folke had a complete waterline armor belt of wrought iron that ranged 38 to 76 mm thick from front to rear. The deck was 19 mm thick. The face of the gun turret was protected by 418 mm of armor, while its sides were 356 mm thick. The conning tower protruded from the top of the turret and was protected by 254 mm of armor.

Construction and service
Folke was launched in 1875 by Motala Verkstad at Norrköping. She was decommissioned in 1919 and was eventually converted into a heating plant for mothballed submarines. The ship was sold in 1942 for conversion to a barge.