Submarine evolution: a comprehensive look at general characteristics, service history, and the fleet of AA-1 Class Ships

While they had operational difficulties while serving in the latter phases of World War I, the AA-1 class submarines played a crucial role in influencing naval developments. Once renamed T class, they had an impact on the popular V-boats.

Three experimental submarines, known as the AA-1 class, were built between 1916 and 1919 and were put into service by the US Navy in the closing phases of World War I. Their development was primarily focused on building a fleet submarine with fast speed, which is representative of the Navy’s continuous efforts to improve its maritime capabilities. Though the design had high expectations, there were significant issues that prevented any of the class of submarines from entering active duty.

The AA-1 class, unfortunately, did not achieve the desired results, exposing several flaws in both its functionality and design. However, for naval engineers and designers, this failure was a useful teaching moment. The subsequent development of a more successful submarine class, the V-boats, was greatly influenced by the lessons learned from the AA-1 class project.

The AA-1 class submarines were eventually renamed as the T class in a calculated move that represented a change in nomenclature while keeping the knowledge gained during their testing phase. Although the AA-1 class did not directly contribute to ongoing naval operations, its legacy persisted in the form of advances that were eventually integrated into later submarine designs, thus influencing the advancement of naval technology.

General Characteristics:

When underwater, the AA-1-class submarine had a displacement of 1,482 long tonnes (1,506 t) compared to 1,107 long tonnes (1,125 t) when it surfaced. The submarine’s overall length was 268 feet 9 inches (81.92 metres), and its beam and draft were 22 feet 10 inches (6.96 metres) and 14 feet 2 inches (4.32 metres), respectively. It was propelled by four NELSECO diesel engines, each of which produced 1000 horsepower (746 kW), and two Electro Dynamic electric motors, each of which produced 675 horsepower (503 kW). It also included two 60-cell Exide batteries, one NELSECO auxiliary diesel generator, and two shafts for propulsion.

Performance-wise, the AA-1-class submarine could reach a surface speed of 20 knots (23 mph; 37 km/h) and a submerged speed of 10.5 knots (19.4 km/h; 12.1 mph). At 14 knots (26 km/h; 16 mph) while surfaced, its range reached 3,000 nautical miles (5,600 km), and at 5 knots (9.3 km/h; 5.8 mph) when submerged, it reached 100 nautical miles (190 km). 38 crew members could be accommodated in the submarine, which had a test depth of 150 feet (46 metres).

The AA-1-class submarine’s armament configurations differed depending on the version. The submarine was originally designed with eight 18-inch (450 mm) torpedo tubes. These were located in four trainable pairs under the deck, fore and aft of the conning tower, and four internal tubes in the bow. The submarine was given the designation AA-1. This arrangement had two retractable deck guns of 3-inch (76 mm)/23 calibre and could accommodate up to 16 torpedoes. Later variants had four bow internal torpedo tubes and a fixed deck cannon of 4-inch (102 mm)/50 calibre ahead. The AA-1-class submarine offered an all-around adaptable platform that could be used for both surface and underwater missions.

Service History:

Originally stationed in Hampton Roads, Virginia, the AA-1-class submarines served as part of Submarine Division 15 in the Atlantic Fleet, mostly being used for manoeuvres and training. The class’s lead submarine, Schley, was renamed AA-1 on August 23, 1917, before its launch, as the original designation was required for the destroyer Schley. This change was made to avoid naming disputes within the Navy.

The three submarines underwent a major reclassification on July 17, 1920, when they were renamed as Fleet Submarines instead of their former classification. They were given the revised hull numbers SF-1, SF-2, and SF-3 as a result. On September 22, 1920, their names were also changed from the AA series to T-1, T-2, and T-3. The changing duties and responsibilities of these submarines throughout the naval force were reflected in their categorization.

All three of the submarines had been decommissioned by 1923 and were stored in Philadelphia, Pennsylvania. However, the T-3 was decommissioned a few years later, between 1925 and 1927, with the express intention of using it as a test bed for German-built diesel engines. T-3, which was outfitted with 2,350 horsepower MAN engines, was tested and experimented with before being put back into storage in Philadelphia.

The three AA-1-class submarines were officially struck from the Naval Vessel Register on September 19, 1930, marking the end of their service lifetime. They were sold for scrap a short time later, on November 20, 1930. The early 20th century’s dynamic naval technology and strategic considerations are reflected in the limited but significant operational history of these submarines.


Designed for the US Navy, Fore River Shipbuilding in Quincy, Massachusetts built the AA-1-class submarines, which include USS Schley (AA-1, T-1), USS AA-2 (T-2), and USS AA-3 (T-3). After being set down on June 21, 1916, and launched on July 25, 1918, USS Schley—also known as Submarine No. 52, SS-52, and SF-1—was put into service on January 30, 1920. Before being decommissioned on December 5, 1922, the USS Schley was used for training and trials. On November 20, 1930, it was sold for scrap.

USS AA-2 (T-2), also known as Submarine No. 60, SS-60, and SF-2, was the next in class. It was laid down on May 31, 1917, launched on September 6, 1919, and put into service on January 7, 1922. After a limited period of duty, USS AA-2 was decommissioned on July 16, 1923, with her operational priority being training duties. It was eventually sold for scrap on November 20, 1930.

The last ship built was USS AA-3 (T-3), also known as Submarine No. 61, SS-61, and SF-3. It was launched on May 24, 1919, after its keel was laid down on May 21, 1917. It was put into service on December 7, 1920, and was used for engine trials and training until July 14, 1927, when it was decommissioned. USS AA-3 met a similar end to those of its brethren, being scrapped on November 20, 1930. Throughout their active lives, these submarines were essential to the advancement of submarine technology because of their responsibilities in trials, training, and engine testing.