The two ships took part in an ambush on a convoy in the North Sea, where they sank two destroyers in a surprise attack, before hunting down and sinking nine merchantmen, after which they returned to port unscathed.

The Kaiserliche Marine considered sending the two ships to attack convoys in the Atlantic Ocean, but the difficulties associated with refueling at sea convinced the Germans to abandon the plan.

At the start of World War I in August 1914, the German firm AG Vulcan had a set of four steam turbines that had been ordered by the Imperial Russian Navy for the cruiser Svetlana.

Her propulsion system consisted of two sets of steam turbines powered by two coal-fired and four oil-fired Marine-type water-tube boilers, which were ducted into three funnels.

The failure of the operation (coupled with the action of 19 August 1916) convinced the German naval command to abandon its aggressive fleet strategy.

Admiral Reinhard Scheer, the commander of the High Seas Fleet, came aboard Bremse in early October for a voyage to Libau.

Their high speed and large radius of action, coupled with their resemblance to British light cruisers, made them suited to the task.

[12] Half an hour after dawn, Brummer and Bremse attacked a westbound convoy about 70 nautical miles (130 km; 81 mi) east of Lerwick.

The convoy consisted of twelve merchantmen and was escorted by the destroyers HMS Strongbow and Mary Rose and a pair of armed trawlers which had departed from Bergen.

Mistaking them for British cruisers Strongbow flashed recognition signals, but was suddenly fired upon at a range of 2,700 m (8,900 ft) by a barrage of 15 cm shells from Bremse.

[13] None of the ships were able to send a wireless report, and despite having a squadron of sixteen light cruisers at sea to the south of the convoy, the British did not learn of the attack until 16:00, when it was too late.

'[3] The success of the two cruisers promoted the British to escort future convoys with a detached squadron of battleships from the Grand Fleet.

Nevertheless, the preliminary planning carried out formed the basis for later work that resulted in the deployment of long-range surface raiders during World War II.

[7][14] In March 1918, Bremse and several other cruisers and torpedo boats carried out a raid into the Skagerrak and Kattegat between Denmark and Norway in an unsuccessful attempt to disrupt British merchant shipping in the area.

[15] The British reaction to the raid off Lerwick presented the Germans with opportunity for which they had been waiting the entire war: a portion of the numerically stronger Grand Fleet was separated and could be isolated and destroyed.

Hipper, aboard the battleship Baden, ordered wireless transmissions be kept to a minimum, to prevent radio intercepts by British intelligence.

[17][18] Along with the most modern units of the High Seas Fleet, Brummer and Bremse were included in the ships specified for internment at Scapa Flow by the victorious Allied powers.

Reuter believed that the British intended to seize the German ships on 21 June 1919, which was the deadline for Germany to have signed the peace treaty.

On the morning of 21 June, the British fleet left Scapa Flow to conduct training maneuvers, and at 11:20 Reuter transmitted the order to his ships.

[21] An armed British naval party had attempted to board Bremse and close her bottom valves, but found that they were already below the rising waterline.

The hull was patched up and an airlock fitted, but the team ran into difficulties with the large amount of oil which covered the wreck, more than had been found in any other of the ships salvaged previously.

Compressors were then used to pump air into the hull and bring her to the surface, while she was supported by 9-inch wires attached to two floating docks anchored on her port shoreward side.