[2][3][c] S49 was laid down at Schichau's Elbing (now Elbląg in Poland) as yard number 939,[5] was launched on 10 April 1915 and commissioned on 12 July 1915.

[2] Between 16 and 18 November 1915, S49, part of the 11th torpedo-boat half-flotilla, was one of 18 torpedo boats that carried out a sortie into the Skagerrak to intercept merchant shipping.

[7][9][10] On 25 March 1916, the British seaplane carrier Vindex, escorted by the Harwich force, launched an air attack against a Zeppelin base believed to be at Hoyer on the coast of Schleswig.

[11][12] On 24 April 1916, the German battlecruisers of I Scouting Group and the light cruisers of the II Scouting Group set out from Kiel on a mission to bombard the British East-coast towns of Yarmouth and Lowestoft, with the torpedo boats of the 6th and 9th Torpedo Boat Flotillas as escorts, and S49 as part of the 6th Flotilla.

[13] The battleships of the High Seas Fleet were deployed in support, with the hope of destroying isolated elements of the British Forces if they tried to intercept.

[16] In January 1917, the 6th Flotilla was transferred to Flanders to reinforce the German torpedo boat forces based in the Belgian ports.

[19][20][21][22] On the evening of 25 January, the 6th Torpedo boat Flotilla took part in a raid with the intent of attacking British patrols, but when none were encountered, shelled Southwold, damaging several buildings but causing no casualties.

[23] On the night of 25/26 February, the Flanders-based torpedo boats launched a three-pronged attack against Allied shipping in the English Channel and the Dover Barrage.

S49, commanded by Korvettenkapitän Werner Tillessen [de], led a force of six torpedo boats of the 6th Flotilla,[g] were to attack the Dover Barrage and bombard Dover, with five more torpedo boats to attack shipping on The Downs and three to operate off the River Maas against shipping running between the Netherlands and Britain.

Believing that British forces were closing in, Tillessen ordered the 6th Flotilla to turn back for Zeebrugge, with the drifters of the Dover Barrage unharmed.

[27][28][29] The force sent against The Downs briefly shelled the North Foreland and Margate before withdrawing, hitting a house and killing three civilians but doing little other damage, while the patrol off the Mass encountered no ships.