From surface to submerged: navigating the general characteristics, service history and boats of the US K-class Submarines

From 1914 until 1923, the US Navy’s K-class submarines—which were created by Electric Boat—saw significant action in World War I. The London Naval Treaty forced the K-class’s decommissioning in 1923, although it was still armed and had strong diesel-electric propulsion and a good range.

Eight submarines from the United States Navy’s K-class class were involved in several naval actions during the turbulent years of World War I, from 1914 to 1923. Electric Boat designed this prestigious fleet, which was built under subcontract agreements by several shipyards. While K-3, K-7, and K-8 were built at Union Iron Works in San Francisco, K-1, K-2, K-5, and K-6 were made at Fore River Shipyard in Quincy, Massachusetts. The Moran Company in Seattle, Washington, also constructed K-4.

As a result of conforming to the limitations specified in the London Naval Treaty, the K-class submarines were scheduled to be decommissioned in 1923, despite their valuable service. The submarines had to be retired as a result of this international accord requiring naval disarmament steps. The last K-class fleet to serve in the US Navy was scrapped in 1931, which was the fleet’s ultimate demise.

General Characteristics:

At 392 long tonnes (398 t) when surfaced and 521 long tonnes (529 t) while submerged, the US K-class submarine was a powerful undersea machine. The submarine had a length of 153 feet and 7 inches (46.81 metres) with a beam and draft of 16 feet and 8 inches (5.08 metres) and 13 feet and 1 inch (3.99 metres), respectively. It was a streamlined design.

K-class submarines were propelled by a powerful combination of diesel and electric motors. Their surface-dwelling NELSECO diesel engines produced 950 horsepower (710 kW), while their submerged Electro Dynamic electric motors produced 680 horsepower (510 kW). The submarine was able to reach a top speed of 26 km/h (16 mph) and a bottom speed of 19.4 km/h (12.1 mph) at 10.5 knots because of this powerful power plant.

The K-class submarine had an amazing range: when surfaced, it could go 4,500 nautical miles (8,300 km) at 10 knots (19 km/h; 12 mph) and 120 nautical miles (220 km) at 5 knots (9.3 km/h; 5.8 mph) when submerged. The submarine’s capabilities were demonstrated at a test depth of 200 feet (61 metres), demonstrating its adaptability to a variety of underwater environments.

A crew of twenty-eight officers and men were needed to man the K-class submarine and operate its armament. Four 18-inch (450 mm) torpedo tubes at the bow of the submarine were its weapons, and they could fire an impressive eight torpedoes. During its time, the United States K-class submarine was an effective weapon in naval operations due to its potent combination of weapons, range, and power.


The K-1, K-2, K-5, and K-6 American K-class submarines began service on the East Coast and were later forward deployed to the Azores in World War I. In this role, they served as convoy escorts, demonstrating their efficiency and flexibility in difficult circumstances. 

Importantly, their experience had a significant impact on how future submarines were designed and modified, especially in improving surface operations during high seas.

The early deployments of the remaining four K-class submarines were concurrently stationed on the West Coast. They were moved to Key West, Florida, at the beginning of 1918, where they received training and took part in patrols for coastal protection. This transfer demonstrated the K-class submarines’ adaptability as they went from serving on the West Coast to assisting with East Coast security operations in the latter phases of World War I.

All eight of the K-class submarines were permanently based on the East Coast for the duration of their operational careers after World War I. This choice may have been influenced by the understanding acquired throughout the conflict as well as the East Coast’s strategic significance for both naval operations and national security. 

Boats in class:

The first four submarines, which were initially assigned the names USS Haddock, USS Cachalot, USS Orca, and USS Walrus, were renamed K-1 through K-4 on November 17, 1911, as part of a force-wide redesignation. Keel was laid down on February 20, 1912, USS K-1 (SS-32), originally USS Haddock, was launched on September 3, 1913, and put into service on March 17, 1914. The submarine served its purpose and was finally demolished in 1931. It was decommissioned on March 7, 1923.

The USS K-2 (SS-33), formerly known as USS Cachalot, was launched on 4 October 1913, had its keel laid down on 20 February 1912, and was commissioned on 31 January 1914. It was demolished in 1931 after being decommissioned on March 9, 1923.

Launched on March 14, 1914, USS K-3 (SS-34), formerly known as USS Orca, was sent into service on October 30, 1914, after construction began on January 15, 1912. It finally saw scrapping in 1931 after being decommissioned on February 20, 1923, following years of service.

Before being put into service on October 24, 1914, USS K-4 (SS-35), originally known as USS Walrus, was built starting on January 27, 1912, and launched on March 19, 1914. It met its end when it was scrapped in 1931 after being decommissioned on May 10, 1923.

The life cycle of the following submarines, USS K-5 (SS-36), USS K-6 (SS-37), USS K-7 (SS-38), and USS K-8 (SS-39), between 1912 and 1931, was likewise identical in terms of construction, launch, commissioning, decommissioning, and final scrapping.