Question: When was the the ship launched ,that along with the Tripitz and the Lützow was a target for  Operation Source ?

Context articles: SS Washingtonian (1913)
KIS Yangmu
HMS Discovery (1789)
USS Zeilin (APA-3)
Operation Source
SMS Lützow
German battleship Scharnhorst
USS Proton (AG-147)
SS Kronprinzessin Cecilie (1905)
USS Harris (APA-2)

SS "Washingtonian" was a cargo ship launched in 1913 by the Maryland Steel Company of Sparrows Point, Maryland, near Baltimore, as one of eight sister ships for the American-Hawaiian Steamship Company.
 At the time of her launch, she was the largest cargo ship under American registry.
 During the United States occupation of Veracruz in April 1914, "Washingtonian" was chartered by the United States Department of the Navy for service as a non-commissioned refrigerated supply ship for the U.S. fleet stationed off the Mexican coast.
KIS "Yangmu" (양무호,揚武號) was the first battleship of the Korean Empire Armed Forces.
 This ship was built by Sir Raylton Dixon & Co and named "SS Pallas".
 This ship launched on 1881 and used in Clark George Ltd, Sunderland.
 In 1893, this ship sold to the Japan's Mitsui Corporation, and Named "Kachidate Maru".
 Next 1903, Japan's It was purchased by the empire from Mitsui Corporation with 1,100,000 Korean Won, or 550,000 Japanese Yen.
 This was about 30% of the total military budget of the Korean Empire.
 The battleship, however, was not as efficient as it looked because it was previously used as a cargo ship by the British since its construction in 1881.
 For the reasons above, another battleship was ordered to be constructed for a more efficient battleship- the  .
HMS "Discovery" was a Royal Navy ship launched in 1789 and best known as the lead ship in George Vancouver's exploration of the west coast of North America in his famous 1791-1795 expedition.
 She was converted to a bomb vessel in 1798 and participated in the Battle of Copenhagen.
 Thereafter she served as a hospital ship and later as a convict ship until 1831.
 She was broken up in 1834.
USS "Zeilin" (APA-3) was an Emergency Fleet Corporation Design 1029 ship launched for the United States Shipping Board (USSB) on 19 March 1921 by Newport News Shipbuilding and Drydock Company in Newport News, Virginia as Silver State.
 After operation by commercial lines for the USSB, during which the ship was renamed President Jackson, the ship was purchased and operated commercially until laid up in the late 1930s.
Operation Source was a series of attacks to neutralise the heavy German warships – "Tirpitz", "Scharnhorst" and "Lützow" – based in northern Norway, using X-class midget submarines.
SMS "Lützow" was the second "Derfflinger"-class battlecruiser built by the German "Kaiserliche Marine" (English: Imperial Navy ) before World War I.
 Ordered as a replacement for the old protected cruiser "Kaiserin Augusta" , "Lützow" was launched on 29 November 1913, but not completed until 1916.
 "Lützow" was a sister ship to "Derfflinger" from which she differed slightly in that she was armed with an additional pair of 15 cm (5.9 inch) secondary guns and had an additional watertight compartment in her hull.
 She was named in honor of the Prussian general Ludwig Adolf Wilhelm von Lützow who fought in the Napoleonic Wars.
Scharnhorst was a German capital ship, alternatively described as a battleship and battlecruiser, of Nazi Germany's "Kriegsmarine".
 She was the lead ship of her class, which included one other ship, "Gneisenau" .
 The ship was built at the "Kriegsmarinewerft" dockyard in Wilhelmshaven; she was laid down on 15 June 1935 and launched a year and four months later on 3 October 1936.
 Completed in January 1939, the ship was armed with a main battery of nine 28 cm (11 in) C/34 guns in three triple turrets.
 Plans to replace these weapons with six 38 cm (15 in) SK C/34 guns in twin turrets were never carried out.
USS "Proton" (AG-147/AKS-28) -- also known as USS "LST-1078" – was an "LST-542"-class tank landing ship launched by the U.S. Navy during the final months of World War II.
 "Proton" served as a troop ship, a cargo ship and as an electronic parts supply ship for the U.S. Pacific Fleet and was decommissioned following the Korean War.
Kronprinzessin Cecilie was a Hamburg-America Line passenger ship launched on 14 October 1905 by Krupp Aktiengesellschaft Germaniawerft at Kiel, Germany.
 The ship was placed on the South American service and soon to be overshadowed by the Norddeutscher Lloyd four stack liner "Kronprinzessin Cecilie" launched on 1 December 1906 that, at  GRT , was over twice the  GRT tonnage of the Hamburg-America Line ship.
USS "Harris" (APA-2) was an Emergency Fleet Corporation Design 1029 ship launched for the United States Shipping Board (USSB) on 19 March 1921 by Bethlehem Shipbuilding Corporation, at Sparrows Point, Maryland as Pine Tree State.
 After operation by commercial lines for the USSB, during which the ship was renamed President Grant and operated commercially until laid up in the late 1930s.