Eckoldt returned to Germany in late 1940 for a refit and was transferred to Norway in June 1941 as part of the preparations for Operation Barbarossa, the German invasion of the Soviet Union.
The Wagner geared steam turbines were designed to produce 70,000 metric horsepower (51,000 kW; 69,000 shp) which would propel the ship at 36 knots (67 km/h; 41 mph).
On 23–24 March 1939, Z16 Friedrich Eckoldt was one of the destroyers escorting Adolf Hitler aboard the heavy cruiser Deutschland to occupy Memel.
[8] She participated in the Spring fleet exercise in the western Mediterranean and made several visits to Spanish and Moroccan ports in April and May.
[9] When World War II began, Z16 Friedrich Eckoldt was initially deployed in the Baltic to operate against the Polish Navy and to enforce a blockade of Poland,[8] but she was soon transferred to the German Bight where she joined her sisters in laying defensive minefields.
[8] On the night of 17/18 October, Rear Admiral (Konteradmiral) Günther Lütjens, aboard his flagship Z21 Wilhelm Heidkamp, led Eckoldt, Z19 Hermann Künne, Z17 Diether von Roeder, Z18 Hans Lüdemann, and Z20 Karl Galster as they laid a minefield off the mouth of the River Humber.
[13] Commodore Friedrich Bonte led a minelaying sortie to the Newcastle area with Heidkamp, Eckoldt, Anton Schmitt, Richard Beitzen, Galster, and Ihn.
The latter ship suffered tube failures in her boilers that reduced her maximum speed to 27 knots (50 km/h; 31 mph) and she had to be escorted back to Germany by Beitzen.
Eckoldt, Beitzen and Max Schultz laid 110 magnetic mines in the Shipwash area, off Harwich, on 9/10 February that sank six ships of 28,496 GRT and damaged another.
Eckoldt was training in the Baltic until she escorted the battleship Bismarck and the heavy cruiser Prinz Eugen from Cape Arkona to Trondheim on 19–22 May as they sortied into the North Atlantic.
[8] The following month, she escorted the pocket battleship Lützow from Kiel to Norway as the latter ship attempted to break through the British blockade.
Several Bristol Beaufort aircraft spotted Lützow and her escorts and one managed to surprise the ships and torpedo the pocket battleship early on the morning of 13 June.
[22] On 20 June, Eckoldt sailed for Bergen, Norway, with Galster and Schonemann where they waited until 4 July for the latter's main feed pump to be repaired and for Beitzen and Lody to arrive.
[8] During Operation Wunderland in August, Eckoldt, Beitzen and Steinbrinck escorted the pocket battleship Admiral Scheer at the beginning and end of its mission to attack Soviet shipping in the Kara Sea.
[24] On 13–15 October, Eckoldt, Beitzen, and the destroyers Z27 and Z30 laid a minefield off the Kanin Peninsula at the mouth of the White Sea that sank the Soviet icebreaker Mikoyan.
Three weeks later, the same four destroyers escorted Admiral Hipper as she attempted to intercept Allied merchant ships proceeding independently to Soviet ports in early November.
The destroyer HMS Obdurate spotted them in turn and closed to investigate when the German ships opened fire at a range of 8,000 meters (8,700 yd).
This took some time in the poor visibility and Hipper was surprised in the meantime by the British covering force of the light cruisers Sheffield and Jamaica.
After sinking Bramble, the German destroyers Beitzen and Eckoldt attempted to rejoin Hipper, unaware that British cruisers were in the area.