Ehrenskjold class Destroyer (1926)

Svenska Marinen Two destroyers: Ehrensköld, Nordenskjöld 1927-63.

Today we start a new cycle of Swedish Destroyers from the interwar to the end of WW2. By building its own designs and bringing many classes, the Swedish Navy copied no one and none copied them. They completed enough destroyers to fulfill a variety of roles aside their cruisers and coastal battleships, which saw quite a long service in the cold war as well. The first in this lineage since WWI was the Ehrensköld class, first “modern” destroyer, introducing new features like their 12 cm guns and new 53 cm torpedo tubes. A prudent start with only two vessels launched in 1926 and remaining in service until 1963, Ehrensköld being used as target ship until scrapped in 1974.

Development

Starting Point: Legacy Destroyers in 1920

Wrangel class destroyers (launched 1917)

It’s not like Sweden started spawning destroyers out of nowhere. In 1920, the Sedish navy could count on the three Mode class (1902), Sigurd class (1908) Hugin class (1910) and the two Wrangel class (1917), all in the 450-490 tonnes range. They would serve themselves until the 1940-50s. One key caracteristic was the durability of these ships, in design but also careful maintenance to be kept in service for at least 40 years, whereas the norm in UK for example was 30 years and in the US, 20 years. This was not true only for destroyers. 1900s coastal battleships soldiered on until the early cold war as well.

The previous Wrangel class were a pair of 5-funneled “classic” destroyers with a forecastle, but only armed, like the precedessors, with single 75 mm (3 inches) Bofors guns and a combo of twin and single 457 mm (18 inches) torpedo tubes. By 1918 standards when they entered service, they were completely off the mark compared to the latest British designs like the 1,200 tonnes V-W armed with 12 cm guns and 53 cm torpedoes, or even late German designs, as well as post-Novik (1911) designs in Russia. The Swedish Navy staff was acutely aware they would not be able to cut it against enemy destroyers in any engagement. This never happened as Sweden maintained its neutrality, partly also thanks to a generous fleet of torpedo-boats, interwoven with a network of coastal battleships and naval fortifications, that appeared deterrent enough along with other factors.

Genesis of Modern Destroyers

In 1920, the Swedish Naval Staff started working on the preliminary study for a modern destroyer design, notably to replace these pre-WWI designs.
They established soon the most desirable qualities, an armament as standard comprising now 12 cm guns and 53 cm torpedoes like their contemporaries, coupled with a top speed of 36 knots, to contrast with the 34 knots of the Wrangel class. This of course meant a much larger hull, and the obligation to keep a reasonable draft to operate in fjords and shallow waters around islands, a vital part of the Swedish coastal defensive network.

The result was the Ehrensköld class, named after Nils Ehrenskiöld (1674-1728), an admiral that fought in the “great northern war” against Russia. It was agreed to order two ships and “test the waters” of this new design before more of the same type in the future. In the interwar, that incremental approach was continued by the Klas Horn (1931) and the confident Göteborg class (1935-40) and Visby (1942). The 1945 öland class, with infusion of Italian designs in between (Romulus and Psilander classes).

But the Ehrensköld-class destroyer did not landed out of nowhere, they were part of a new naval program that planned for six modern destroyers for 1931. Instead of starting completely from scratch, the admiralty requested the Riskdag provisions for an international tender open to many yards, including to the US.

In 1922 the Admiralty studied and retained a tender from a US shipyard part of the Ford Company network that produced Clemson class destroyers, based on 1,100 tons. However they had 10 cm guns. The Swedish Navy wanted instead 12 cm guns and the purchase never took place but the design went a long way, and in 1924, the Riksdag granted funds for the construction of two new destroyers.

The first two were thus ordered, once their design was approved the same year in 1924, at Kockums, Malmö for the first and Götaverken, Gothenburg for her sister ship, named after Admiral Otto Henrik Nordenskjöld. The design choices that were made we all quite interesting and cemented these ships as truly original design, in contrast to many peer navies that went to close copies of the British V-W classes like the Spaniards and others.

These Swedish designs presented notably the immediate singularity of a flush-deck hull, in opposition to the global trend of forecastle cut designs. Their bridge was quite peculiar too, and armament was a bit inferior to the standard of the time, with three main guns instead of four, none in superfiring positions. In any cases, the design was cemented as standard until 1942.

Design of the class

The elephant in the room was the major influence for this new class, the US design that was reviewed. The closest in general approach to various design solutions was the late WWI mass-produced Wickes and Clemson class indeed. The latter called for a flush deck hull for the advantages it broughts in terms of construction simplicity, ruggedness, whereas preserving seawothiness, and with the tradeoff of somewhat unusual internal arrangement, with sloped decks all the way, even so this slop was very gradual and moderate.
< The gun arrangement on three mounts, one on deck forward, one aft, and one on a bandstand amidship also was very similar to the US designs, however the approach for torpedo tubes was more conventional and European, with two triple banks in the centerline, instead of the US choice of four pairs on the broadside. These destroyers were also designed as “minelayers by default”, as mine warfare in the Baltic sea had been a reccuring theme that impressed all actors present in the first world war.

Hull and general design

Kokcums Coll. original 1926 plan. src

Overall, the Ehrensköld class was rather on the “light side”, smaller than the Clemsons at 974 tons standard and above 1,000 tons fully loaded, in any cases much larger than previous Swedish classes. The hulls were built of riveted, nitrated steel, with a sloping bow or “precipitating stem” and “cruising stern”, rounded. The angle of the stem was a bit more pronounced that the Clemson’s as well. These hulls however later proved to provide poor stability and they rolled heavily, triggering a serie of modifications in the next classes.

Just ahead of midship was the other recoignizable Swedish bridge, three-story heigh with a streamlined face unlike the US wedge-like bridge. To adress stability issues from the start, superstructures were kept minimal, with a quarterdeck house aft procufing a main entrance to the aft compartments below. As usual in these designs, the whole amidship space was blind (no portholes) as it housed on two stages the massive machinery.

The hull was divided into three decks forward, two aft. The bridge had three level, on top was the open bridge with navigation equipment, torpedo sight and rangefinder. Below was the enclosed bridge with with the steering wheel and engine telegraph, and aft was the radio cabin and artillery control center. The lower bridge at deck level had the medical department and crew’s galley. The crew was housed mostly in the forward section of the hull, with ratings sleeping either on bunks and hammocks, and NCOs in cabins. Top officers were housed in single and double cabins in the aft section as it was still traditional in most navies, an inheritance from the sailing navy.

Powerplant

By setting the bar at 35 knots, power requirements were drastic and the machinery took a susbstantial space. To go between the fore and aft interior, any one had to climb up and cross that amidship section by foot until the other side of the main deck. Strong bulkheads indeed separated the machinery space from the bow and stern sections, with only access by the top deck hatches. This applied to all Swedish destroyers until Halland class, inspired by the Gearing class, another US influence for late WW2 designs.

If the general design had a strong US influence, the machinery came from the world’s best at the time. The machinery consisted of three Thornycroft steam boilers, oil-fired (another novelty) and requiring less space as well as generous oil tanks, they were thus taking a much larger space than on traditional coal-fired designs that needed space for the stokers and coal. These three double-ended 3-drum boilers worked at high pressure (300 psi (2.0 MPa)/600 °F (316 °C). Her sister however tried French Penhöet boilers instead.

In turn, they fed two Swedish turbines de Laval (patented by Gustaf de Laval), as a development of the Wrangel-class own turbines. These generated 24,000 horsepower, driving each a 3-bladed constant pitch bronze propeller. The normal top speed was 35 knots as contracted for the Navy, but as often trials speeds were greater. Nordenskjöld achieved 36.9 knots on trial for example. The semi-experimental British boilers, also fitted on the contemporary British A-class destroyers soon proved to be not completely problem-free and the superheaters were removed after a few years.

Armament

The main artillery consisted of three 12 cm m/24 guns placed one on the quarterdeck, aft deck, and amidships between the funnels. They were 46 caibers ling and could elevate at 45 degrees for limited anti-aircraft use. The anti-aircraft artillery comprised two Vickers 40 mm m/22 autocannons that placed on a superstructure at the stern. The two triple torpedo tube non-reloadable for 53.3 cm torpedoes were fore and aft of the AA guns. On the aft deck were installed two m/24 depth charge racks and two m/24 depth charge throwers. 20 mines were optional, with rails mounted aft as well.

Main: 3x M24 12cm/46 Bofors

These were common to both Swedish and NL destroyer. They were called the 12 cm/50 (4.7″) Models 1924, 1924B and 1924C. The Bofors M1924 and 1924B were slightly different, but the Model 1924C introduced a loose barrel construction. The Dutch called them the Mark 4 guns and they were licenced to Hollandsche Industrie-en Handelsmaatschappij (HIH) later as Mark 5 guns, but still interchangeable with the Mark 4. Munitions were produced by Bofors and Artillerie-Inrichtingen. True bore size was 4.724 inches. After scrapping all interwar Swedish DDs, their guns ended in thirteen fortifications in northern Sweden, with new ammunition for ground use until they were gradually demilitarized after the end of the cold war.

⚙ Bofors M24C Specs

2.95 tons barrel alone, lenght 251.6 in (6.39 m), bore 236.2 in (6 m).
Shell: HE L/4,2 94.1 lbs. (42.67 kg) or Starshell L/4,2: 74.0 lbs. (33.57 kg).
Muzzle Velocity HE L/4,2: 2,952 fps (900 mps), Starshell L/4,2: 1,640 fps (500 mps)
Rate Of Fire: 10 rounds per minute
Range: +30°: 21,300 yards (19,500 m), on the Bofors 8.56 tons mount (with shield).
Recoil 22.8 in (58 cm). Traverse 120° either side.

40mm/22 Vickers Pompom AA

Initially two 40 mm luftvärnautomatkanoner m/22, a local name for the Vickers 2-pdr AA gun of WWI, the first “pompom”, installed on a platform in between the torpedo tube banks aft amidship. They were replaced by 40mm/56 K/60 M32 AA guns in the 1930s, albeit most sources points out they were replaced in turn in 1939 by two twin 25 mm lvakan M/32 light AA guns and two 8 mm lvksp M/14-29 AA machine guns.

Torpedo Tubes

It seems Sweden built its own torpedoes, probably licenced from British Whitehead designs. These were 53.3 cm torpedo tubes m/30. More info in research.

Depth Charges

These were m/24 depth charge racks (seemingly 8 charge per rack, 16 m/24 total) and two m/24 depth charge throwers. The m/24 were replaced by m/33 throwers on the next classes. The topic of Swedish depth charges is also in research.

Mines

Likely the Kontaktmina m24 and later m31. No info yet, topic in research.

⚙ specifications
Displacement	947 long tons (962 t) standard
Dimensions	91.4 x 8.88 x 3.8m (300 x 29 ft 2 in x 12 ft 6 in)
Propulsion	2 shaft de Laval geared steam turbines, 3 Thornycroft/Penhoët boilers 34,000 shp (25,000 kW)
Speed	36 kn (41 mph; 67 km/h)
Range	1,600 nmi (1,800 mi; 3,000 km) at 16 kn (18 mph; 30 km/h)
Armament	3× Bofors M24 120 mm, 2× Vickers 40 mm pompom, 2×3 53 cm (21 in) TTs
Sensors	Modernized: Sonar, see notes
Crew	120

Modernizations

In the mid-1930s, their Vickers 40mm/39 pompom were replaced by Bofors 40mm/56 K/60 M32. In 1939, both had new boilers installed and their 40mm replaced by two twin 25mm/55 K/58 M32. In 1950-1951 they were rebuilt as frigates with a single remaining forward 120mm/45 M24C two twin Bofor s Swedish pattern 40mm/60 M36, one 20mm/66 M40, eight DCT, radars and sonar. The torpedoes were removed. The 40 mm m/36 anti-aircraft were radar-assisted autocannons with prox. fuses, and the m/48 anti-aircraft autocannon was also radar-assisted. In addition to their eight depth charge throwers and racks, 250 depth charges were in store.

Career of the Ehrenskold

Ehrensköld (11)

Ehrensköld laid down at Kockums in Malmö in late 1924 and launched on 25 September 1926, named after Admiral Nils Ehrenschiöld, initially carrying the full name, but dropped to the simpler form like her sister after christening. By the summer of 1929 with her sister Nordenskjöld, she escorted the coastal “pansarskip” HMS Sverige on an state trip to Estonia and Latvia. On board was King Gustaf V, and the voyage went to Tallinn and then Riga, with the King landinfg each time to meet the head of states here, until returning to Sweden.

The following year, they took part in another overseas trip this time escorting HMS Gustaf V and HMS Drottning Victoria to Swinemünde in Weimar-headed Germany. This was another official trip, to retrieve the remains of Queen Victoria, wh recently died in Rome. In 1934, Ehrensköld ran aground while underway from Karlskrona to Stockholm. A large gash in her hull, torn open on her bottom aft saw severe flooding, until the stern was completely underwater, albeit thanks to a strong reverse maneuver she managed to be lifted off the ground and able to reach the Stockholm shipyard under her own power, followed by long repairs.

Ehrensköld during World War II, camouflaged, with white neutrality bands and new pennant, 1.

In September 1938, as Germany laid claim to Czechoslovakia, Ehrensköld and Klas Horn were prepared for a possible war, as the only fully equipped destroyers in the Swedish fleet. On April 1940, as Germany launched Operation Weserübung and invaded Denmark and Norway, it ws was however decided to disarm her in Karlskrona due to personnel shortage within the fleet. Only after many exercises she had a new crew capable of returning her into service on 2 September. She was assigned to the Karlskrona Squadron, part of the South Coast Naval District. In 1942, she was part of the Coastal Fleet, the largest and most effective unit of the Navy. She was then then transferred back to the Karlskrona Squadron in 1944.

Her final post-war years like her sister were questioned in 1946 as her tech was 1920s. It was decided to convert her on new plans, reclassified as a frigate in 1950, with the refit made in 1951-52, with the modifications seen above, including radar and sonar and reclassified as frigates, F71 in that case. She performed that way until decommissioned in 1963. In her precise case she was not not sold for BU outright but instead used from 1 April 1963 after beoing stricken as a target ship, until sold for BU this time in 1973 and scrapped in Ystad.

Nordenskjöld (12)

Nordenskjöld was laid down at Götaverken in Gothenburg, launched on 19 June 1926, named after Admiral Otto Henrik Nordenskiöld with her name simplified after christening, when commissioned. By the summer of 1929 like her sister Ehrensköld, she escorted HMS Sverige to Estonia and Latvia for a Royal visit at Tallinn, Riga, and back Sweden. In 1930 she took part on another state visit, escorting HMS Gustav V and HMS Drottning Victoria to Swinemünde to gather the remains of Queen Victoria who died in Rome.

At the outbreak of the war she had her Penhöet boilers examined and juged in such poor condition they needed to be replaced but this had to be postponed due to the lack of ships available to protect Swedish waters. This started at the Epiphany weekend of 1940 at Götaverken, until 18 April whe she was back into service with the Gothenburg Squadron.

Nordenskjöld during World War II with white neutrality bands and new pennant “2”.

At the end of April 1940, she was transferred at Kalvsund on high alert after repeated German and Soviet violations of Swedish waters. One night when Nordenskjöld was anchored in the Marstrandsfjorden, she was flew over agressively by German aircraft, opened fire with their automatic guns and managed to shoot down one of the could-be attackers. The incident led to a more prudent approach of the Luftwaffe in coming months.

In September, Nordenskjöld escorted the Swedish tanker M/T Sveadrott through the mine barrier running through the Skagerrak. The tanker was loaded with 13,700 tons of oil from the Gulf of Mexico, bound for Gothenburg. To be allowed to pass in waters controlled by the Kriegsmarine, the belligerents asked the tanker to be escorted through the Skagerrak by Swedish warships, acting as a guarantor of neutrality both towards the Kriegsmarine and Royal Navy. Nordenskjöld was also assisted by the auxiliary cruiser Waria.

25 mm lvakan M/32, installed in 1940.

By late August, white bands were painted over blue-and-yellow at the bow and stern and searchlights installed to illuminate her silhouette and avoid taking fire from any belligerents, preventing a misidentification. The crews were kept unaware of the missio though, until only told underway this was going to last ten days. On 1 September 1940 she left Gothenburg with the tanker Tvåan for Kristiansand, southern coast of Norway. In the waters off Strömstad, the commander told the crew: “A convoy is a piece of Sweden, relocated to the sea. It is inviolable and should any belligerent attempt to inspect it, it will be met with force.”

A depth charge is thrown in 1950.

In Kristiansand, the two warships refuelled and then departed for their meeting point while the Tvåan was left behind. On the evening of 5 September, they met Sveadrott in the North Sea, between Bergen and the Shetland for the journey home. A British reconnaissance plane and later German bombers were sighted dhadowing them underway, but no attacks follwoed, so by 8 September the convoy arrived in Gothenburg. From 1941 and until 1945, HMS Nordenskjöld was part of the Karlskrona Squadron, South Coast Military District. Her tasks of neutrality guard were completed by escort missions of various merchant ships along the Swedish coast.

In 1951 to 1952, Nordenskjöld was converted into a frigate. In addition to her new armament, new boilers, she had also a new sonar, and for the first time, a combat control center plus a radar. Still by 1960 standards her armment was antuiquated against Soviet submarines so it was decided to retire her. She was at last decommissioned on 1 April 1963, and like her sister used as a target ship but only for a year. In 1964, she was sold for BU and scrapped in Gothenburg.