A hidden gun on a Q-ship in World War I.
The Q-ship or Q-boat was a weapon used against German U-boats during World War I primarily by Britain and during World War II primarily by the United States.
World War I
In the First Battle of the Atlantic, by 1915, Britain was in desperate need for a countermeasure against the U-boats that were strangling her sea-lanes. Convoys, which had proven effective in earlier times (and would again prove effective during World War II), were rejected by the resource-strapped Admiralty and the independent captains. Depth charges were very primitive, and the only method of sinking a submarine was by gunfire or by ramming. The problem was to lure the U-boat to the surface.
The solution to this problem was the creation of the Q-ship, one of the most closely-guarded secrets of the war. Known to the Germans as a U-Boot-Falle ("U-boat trap"), it was an old-looking tramp steamer loaded with wooden caskets, wood, or cork, and armed with hidden guns and torpedoes. Its buoyant cargo made it almost unsinkable, so after firing a few torpedoes, a U-boat would surface to use its deck gun at close range. The Q-ship would then hoist the White Ensign and overwhelm the U-boat with its heavy guns.
The first victory of a Q-ship occurred on July 24, 1915, when U-36 was sunk by HMS Prince Charles, commanded by Lieutenant Mark Wardlaw RN. In August of that year, an even smaller converted fishing trawler named His Majesty's Armed Smack Inverlyon successfully destroyed UB-4 near Great Yarmouth. The Inverlyon was an unpowered sailing craft fitted with a 47mm cannon.
On August 19, 1915, Lieutenant Godfrey Herbert RN of the HMS Baralong sank UB-27 and killed all of the German survivors in the infamous "Baralong Incident".
Despite some spectacular actions and a great deal of romanticization, Q-ships were not particularly successful (see HMS Dunraven). In the course of 150 engagements they were only able to kill 14 U-boats and damage another 60, at a cost of 27 Q-ships lost out of 200. Q-ships were responsible for about 10% of all U-boats sunk, ranking them far below naval mines in overall effectiveness.
World War II
By January 12, 1942, the British Admiralty's intelligence community had noted a "heavy concentration" of U-boats off the "North American seaboard from New York to Cape Race" and passed along this fact to the United States Navy. That day, U-113 under Kapitänleutnant Reinhard Hardegen, torpedoed and sank the British steamship Cyclops, inaugurating Paukenschlag (literally, "a roll on the kettledrum"), known to the Allies as Operation Drumbeat. U-boat commanders found peacetime conditions prevailing along the coast: towns and cities were not blacked-out and navigational buoys remained lighted; shipping followed normal routines and "carried the normal lights." Paukenschlag had caught the United States unawares.
Losses mounted rapidly. On January 20, 1942, Commander-in-Chief, United States Fleet (Cominch), sent a coded dispatch to Commander, Eastern Sea Frontier (CESF), requesting immediate consideration of the manning and fitting-out of "Queen" ships to be operated as an antisubmarine measure. The result was "Project LQ."
Five vessels were acquired and converted:
The careers of all five ships were almost entirely unsuccessful and very short; all Q-ships patrols ended in 1943.
Other usages of the name
The term (or "Q-car") has subsequently been used to describe cars that have much higher than average performance (often through extensive modification) but look like conventional, uninteresting family transport. As well as the ships, this term may also be reinforced from the United Kingdom's system of registration plate numbering - the first symbol on a British plate is a letter code for the year of manufacture, but for vehicles of uncertain or mixed age, a plate beginning with "Q" is used.
- Für Kaiser und Reich (http://uboat.net/history/wwi/part3.htm), His Imperial Majesty's U-Boats in WWI