America had not yet entered World War I when President Woodrow Wilson called upon Congress to pass an emergency bill to fund the rapid expansion of what he called “incomparably, the greatest navy in the world.” The rise of Germany’s unrestricted submarine warfare and concern for the safety of Allied military and merchant ships in the Atlantic shipping lanes led to the August 1916 passing of the “Big Navy Act.” Earlier that June, the success of a massive German U-boat campaign attack on the British Royal Navy fleet at the Battle of Jutland drove this legislation calling for the construction of 10 battleships, six “battle cruisers,” and 10 scout cruisers.1

Assistant Navy Secretary Franklin D. Roosevelt believed it was time for the United States to support Allied forces in combatting insidious submarine warfare. Newport News Shipbuilding and Dry Dock Company was awarded a contract to build four capital ships; and the yard promptly began construction. Two classes of ships were viewed as critical to successful anti-submarine warfare: destroyers and subchasers.

Destroyers, already in production by 1917, were well suited for anti-submarine warfare because of their size and durability. On “Liberty Launching Day,” July 4, 1918, three Newport News-built destroyers – Haraden, Abbott, and Thomas – slid into the James River with much fanfare. However, due to construction delays, destroyers simply could not be built fast enough to meet wartime demand. (The shipyard did launch 25 destroyers during the war, but many that were laid down during the war were not commissioned until after the armistice.)

Edward O. Smith photograph of
Wartime demand for more ships is clear in this Edward O. Smith photograph of “Liberty Launching Day” at Newport News Shipbuilding and Dry Dock Company, July 4, 1918. (P0001.019/-#PS456)

Subchasers could be built quickly, requiring fewer, readily available materials. The typical subchaser was a 110-foot wooden vessel, armed with limited weapons. As they were wooden-hulled, subchasers freed up steel for the fabrication of larger vessels. Undeniably, subchasers performed a vital role in deterring U-boats, but it is unlikely they destroyed any without the assistance of larger ships and vessels. Subchasers were supposed to locate and destroy submarines, but they mainly served as patrol vessels along the Atlantic and European coasts, as well as convoy escorts overseas.2

Construction of subchasers in 1917
Construction of subchasers in 1917. Burnell-Poole, now National Archives photograph 165WGZ-L-4; taken prior to January 1, 1923. (

As chasing submarines was an entirely new concept for the US Navy, the tactics for conducting this sort of warfare were developed and fine-tuned on the fly, giving the men “a certain independence in the execution of the tasks assigned,” allowing them “initiative in meeting the different situations as they arise.”3

The Navy ordered subchasers be divided into Hunting Units which consisted of three chasers each, and that the units remain the same throughout the course of the war to create unity. There were three stages of action for submarine chasers: hunt (or search), chase, and attack. The hunt consisted of locating submarines in the area through radio, aircraft, and patrolling reports. In the chase, the units worked together to follow and surround the submarine. The attack differed for submerged submarines and those on the surface. If the submarine was submerged, the unit waited for the commander’s orders, but if it was visible, the unit was to attack immediately. In the event a sub was sunk, the Hunting Unit was tasked with taking precise location readings and recovering any evidence of the sinking. The best evidence? “A few survivors.”4

Historians continue to debate whether or not subchasers successfully sank any German submarines during the war. Yet, it is generally acknowledged that subchasers effectively performed escorting and mine-clearing duties, as well as combatted U-boats. Following the war, many subchasers were sold by the US Navy. During World War II, a great number were sent to the British in exchange for bases overseas. The role of subchasers continued with new, updated vessels being built for wartime use.

Picture postcard of subchasers at the Navy Yard in Portsmouth, Va.
Picture postcard of subchasers at the Navy Yard in Portsmouth, Va. (MS0647.01.07.01)
WWI Subchaser Stats5
Construction statistics
# ordered448
# completed441
# used as US Navy vessels in wartime303
# assigned to overseas service133
Beam14′, 8 ¾”
Frame/FloorWhite Oak
PlankingYellow Pine
Deck plankingOregon Pine
Propulsion System
Three main engines6-cylinder, 220 hp
One auxiliary engine2-cylinder
FuelGasoline — 2,400-gallon tank
Top speed14 to 16 knots
Cruising speed12 knots
ArmamentOne 3″ deck gun forward, one Y-gun amidships, depth charge racks on stern, machine guns on bridge wings
Submarine detectionSC-type C-Tube hydrophone, K-Tube hydrophone, trailing wire. Later, MB-Tube hydrophone was used.
Communication systemsRadio telephone and radio telegraph, shape signals, bearing indicator
The Subchasers Doctrine
– A Mnemonic
(Memory Device)6

Seek the sub always.
Utilize all information.
Be ready for every contingency.

Chase by 60 degree method.
Hunt according to visibility.
Attack en masse.
Secure some evidence.
Exercise patience.
Report all useful information.

Develop initiative.
Organize for every contingency.
Cooperate in all things.
Think alike and signal little.
Remember your guns.
Identify suspicious sounds.
Never assume the defensive.
Excell {sic} in subchaser spirit.

Wooden Subchaser Model, Charles J. Parker Jr. modelmaker
Wooden Subchaser Model, Charles J. Parker Jr. modelmaker. Model courtesy of Watermen’s Museum.

Ensign George Kennedy Briggs

The Mariners’ Museum archives contain two letters written by a sailor aboard Subchaser 180 to his mother. George Kennedy Briggs (1897-1980), grew up in Brookline, Massachusetts, and graduated from the University of Michigan. World War I interrupted his education when he was drafted into the Navy. Briggs served as ensign and later executive officer aboard SC-180. His correspondence discusses life aboard the subchaser, and he describes a submarine battle which took place off of Gibraltar. Briggs claims his subchaser played a vital role assisting in the sinking of a submarine stating, “That is the nearest that we came to real action although we shine in the reflected light of the whole operations, being flagship.”7

In his letter dated November 22, 1918, Briggs gives a detailed account of SC-180 tracking German submarines. He describes his travels onboard to Bermuda, the Azores, Gibraltar, and Leixoes, Portugal. While in Leixoes, the ship received orders for a “special mission,” sending them to Gibraltar. Briggs notes: “When Austria quit there were a large number of German Submarines operating in the Mediterranean. With Austria out, they had no port short of Kiel. The secret service reported that German Subs had sailed from the Adriatic for Kiel. All we had to do was beat them to the Straits.”8 Once they reached Gibraltar, the subchaser immediately went out for patrol to prepare for the arrival of the Germans. He writes, “We had a regular Navy LT. Commander aboard… In other words the 180 was flagship for the entire American operations.”9 The following morning, after receiving a message confirming a submarine sighting, SC-180 found the battleship Britannia had been torpedoed. After the unnamed German submarine sank Britannia, it attacked USS Parker, but the Parker successfully sank the submarine. Briggs sums things up, writing, “That is about all there is to tell of our action in the Great War.”10 While at sea, Briggs was notified of the end of the war when his ship was busy, “fishing for something to blow up.” Briggs describes how the crew celebrated the “news of the end of hostilities,” and tells his mother that “the British know how to celebrate.”11

Ensign Walter G. “Red” Thomson

Ensign Walter G. “Red” Thomson served aboard SC-126 which was stationed at the Norfolk Navy Yard (NNSY) between November 1917 and January 1918. Thomson’s correspondence presents another side of life aboard subchasers. His vessel did not actively travel or participate in any battles or chases as George Kennedy Briggs’s ship did. Instead, Thomson’s ship SC-126, was stationed in Norfolk for the majority of the war. The Mariners’ Museum archives contain the Arthur K. Thomson and Walter G. Thomson Collection. Walter Thomson’s correspondence reflects the duties he performed as ensign while at NNSY. In a letter dated January 13, 1918, Thomson states, “…we have been trying to get in commission for the last week but have been having trouble with getting a crew.”12 He continues to write about how the crew is unprepared and there are no supplies aboard the vessel, therefore he is constantly ordering items for the ship. In a letter dated January 30, 1918, Thomson writes his family about the possibility his subchaser would be sent overseas: “Where we go has been changed by rumor so often that we may be anywhere. One thing is consistent and that is that this boat goes across.”13 Subchaser 126 eventually left Norfolk in March 1918, headed for Bermuda. Unfortunately, the ship sank off of Bermuda and was not repaired until October. It arrived in Gibraltar just as the war ended, on the most notable date of November 11, 1918.

Photograph is believed to be of Ensign Walter G. Thomson who served on Subchaser 126.
This photograph is believed to be of Ensign Walter G. Thomson who served on Subchaser 126. (MS0133.

  1. Mark St. John Erickson, “Newport News shipyard’s WWI destroyer boom driven by U-boat fears,” Daily Press, July 3, 2018,
  2. James Mitchell Varnum, “World War I Splinter Fleet: The Sub Chasers that Challenged the U-Boat Menace,” Varnum Continentals (blog), February 4, 2018,; Paul E. Pedisich, “A Case for Submarine Chasers,” Naval History Blog (blog), U.S. Naval Institute, November 7, 2016,
  3. L.A. Cotten, Captain, U.S.N., Commanding. Instructions and Doctrine for Sub Chaser Detachment One, The Subchaser Archives,
  4. “Submarine Hunting by Submarine Chasers,” The Subchaser Archives (website), Todd A. Woofenden, ed., accessed July 24, 2018.
  5. The Subchaser Archives,
  6. Cotten, page 9,
  7. George Kennedy Briggs to Edith Briggs, November 22, 1918, MS03441, box 01, folder 01, item 02, page 2, George Kennedy Briggs Letters, The Mariners’ Museum.
  8. Ibid., page 3.
  9. Ibid., page 2.
  10. Ibid., November 12, 1918, page 3.
  11. Ibid.
  12. Walter G. Thomson to his family, January 13, 1918, MS0133, series 02, box 01, folder, 03, item 16, page 1, Arthur K. Thomson and Walter G. Thomson Collection, The Mariners’ Museum.
  13. Ibid., January 30, 1918.