London Naval Treaty

Last updated

London Naval Treaty
International Treaty for the Limitation and Reduction of Naval Armament
London Naval Conference 1930.jpg
Members of the United States delegation en route to the conference, January 1930
Type Arms control
Context World War I
Signed22 April 1930 (1930-04-22)
Location London
Effective27 October 1930 (1930-10-27)
Expiration31 December 1936 (1936-12-31) (Except for Part IV)
Depositary League of Nations
Language English

The London Naval Treaty, officially the Treaty for the Limitation and Reduction of Naval Armament, was an agreement between the United Kingdom, Japan, France, Italy, and the United States that was signed on 22 April 1930. Seeking to address issues not covered in the 1922 Washington Naval Treaty, which had created tonnage limits for each nation's surface warships, the new agreement regulated submarine warfare, further controlled cruisers and destroyers, and limited naval shipbuilding.


Ratifications were exchanged in London on 27 October 1930, and the treaty went into effect on the same day, but it was largely ineffective. [1]

The treaty was registered in League of Nations Treaty Series on 6 February 1931. [2]


Menu and List of Official Toasts at formal dinner which opened the London Naval Conference of 1930 Londonnavalconference2.jpg
Menu and List of Official Toasts at formal dinner which opened the London Naval Conference of 1930

The signing of the treaty remains inextricably intertwined with the ongoing negotiations, which began before the official start of the London Naval Conference of 1930, evolved throughout the progress of the official conference schedule, and continued for years afterward.

During the first four decades of the 20th century, Prince Tokugawa Iesato led a political movement in Japan that promoted democracy and international goodwill with the United States, Europe, and the rest of Asia. During the 1921-1922 Washington Naval Conference, Tokugawa headed the Japanese delegation that ratified that treaty. The December 23, 1929 photograph to the right presents the Japanese, who again participated in the renewal of the 1922 Washington Naval Treaty. [3] [4]


The treaty was seen as an extension of the conditions agreed in the Washington Naval Treaty, an effort to prevent a naval arms race after World War I.

The conference was a revival of the efforts that had gone into the 1927 Geneva Naval Conference at which the various negotiators had been unable to reach agreement because of bad feelings between the British and the American governments. The problem may have initially arisen from discussions held between US President President Herbert Hoover and UK Prime Minister Ramsay MacDonald at Rapidan Camp in 1929, but a range of factors affected tensions, which were exacerbated by the other nations at the conference. [5]

Under the treaty, the standard displacement of submarines was restricted to 2,000 tons, with each major power being allowed to keep three submarines of up to 2,800 tons except that France was allowed to keep one. The submarine gun caliber was also restricted for the first time to 6.1 in (155 mm) with one exception, an already-constructed French submarine being allowed to retain 8 in (203 mm) guns. That put an end to the 'big-gun' submarine concept pioneered by the British M class and the French Surcouf.

The treaty also established a distinction between cruisers armed with guns up to 6.1 in (155 mm) ("light cruisers" in unofficial parlance) from those with guns up to 8 in (203 mm) ("heavy cruisers"). The number of heavy cruisers was limited: Britain was permitted 15 with a total tonnage of 147,000, the Americans 18 totalling 180,000, and the Japanese 12 totalling 108,000 tons. For light cruisers, no numbers were specified but tonnage limits were 143,500 tons for the Americans, 192,200 tons for the British, and 100,450 tons for the Japanese. [6]

Destroyer tonnage was also limited, with destroyers being defined as ships of less than 1,850 tons and guns up to 5.1 in (130 mm). The Americans and the British were permitted up to 150,000 tons and Japan 105,500 tons.

Article 22 relating to submarine warfare declared international law applied to them as to surface vessels. Also, merchant vessels that demonstrated "persistent refusal to stop" or "active resistance" could be sunk without the ship's crew and passengers being first delivered to a "place of safety." [7]

Article 8 outlined smaller surface combatants. Ships between 600 and 2,000 tons, with guns not exceeding 6 in (152 mm) with a maximum of four gun mounts above 3 in (76 mm) without torpedo armament and up to 20 kn (37 km/h), were exempt from tonnage limitations. The maximum specifications were designed around the Bougainville-class avisos, which entering[ clarification needed ] French service.

Warships under 600 tons were also completely exempt. That led to creative attempts to use the unlimited nature of the exemption with the Italian Spica-class torpedo boats, Japanese Chidori-class torpedo boats, French La Melpomène-class torpedo boats and British Kingfisher-class sloops. [8]


The next phase of attempted naval arms control was the Second Geneva Naval Conference in 1932. That year, Italy "retired" two battleships, twelve cruisers, 25 destroyers and 12 submarines; in all, 130,000 tons of naval vessels were scrapped or put into reserve. [9] Active negotiations among the other treaty signatories continued during the following years. [10]

That was followed by the Second London Naval Treaty of 1936.

See also


  1. John Maurer, and Christopher Bell, eds. At the crossroads between peace and war: the London Naval Conference in 1930 (Naval Institute Press, 2014).
  2. League of Nations Treaty Series, vol. 112, pp. 66–96.
  3. "Introduction to The Art of Peace: the illustrated biography of Prince Iyesato Tokugawa". 13 April 2020.
  4. Katz, Stan S. (2019). The Art of Peace. Horizon Productions.
  5. Steiner, Zara S. (2005). The Lights that Failed: European International History 1919–1933, pp. 587-591.
  6. U.S. Department of State. "The London Naval Conference, 1930" . Retrieved 20 March 2014.
  7. Treaty for the Limitation and Reduction of Naval Armaments, (Part IV, Art. 22, relating to submarine warfare). London, 22 April 1930
  8. John, Jordan (13 September 2016). Warship 2016. Conway. pp. 8–10. ISBN   9781844863266.
  9. "Italy Will Retire 130,000 tons of Navy; Two Battleships, All That She Owns, Are Included in the Sweeping Economy Move. Four New Cruisers to go [plus] Eight Old Ones, 25 Destroyers and 12 Submarines Also to Be Taken Out of Service". New York Times. 18 August 1932.
  10. "Naval Men See Hull on the London Talks; Admiral Leigh and Commander Wilkinson Will Sail Today to Act as Advisers". New York Times. 9 June 1934.

Further reading

Related Research Articles

Cruiser Type of large warships

A cruiser is a type of warship. Modern cruisers are generally the largest ships in a fleet after aircraft carriers and amphibious assault ships, and can usually perform several roles.

Destroyer Type of warship

In naval terminology, a destroyer is a fast, maneuverable, long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in 1885 by Fernando Villaamil for the Spanish Navy as a defense against torpedo boats, and by the time of the Russo-Japanese War in 1904, these "torpedo boat destroyers" (TBDs) were "large, swift, and powerfully armed torpedo boats designed to destroy other torpedo boats". Although the term "destroyer" had been used interchangeably with "TBD" and "torpedo boat destroyer" by navies since 1892, the term "torpedo boat destroyer" had been generally shortened to simply "destroyer" by nearly all navies by the First World War.

Washington Naval Treaty 1922 pact by the Allies of WWI to limit naval construction, preventing an arms race

The Washington Naval Treaty, also known as the Five-Power Treaty, was a treaty signed during 1922 among the major Allies of World War I, which agreed to prevent an arms race by limiting naval construction. It was negotiated at the Washington Naval Conference, held in Washington, D.C., from November 1921 to February 1922, and it was signed by the governments of Great Britain, the United States, France, Italy, and Japan. It limited the construction of battleships, battlecruisers and aircraft carriers by the signatories. The numbers of other categories of warships, including cruisers, destroyers, and submarines, were not limited by the treaty, but those ships were limited to 10,000 tons displacement each.

Heavy cruiser Type of cruiser warship

The heavy cruiser was a type of cruiser, a naval warship designed for long range and high speed, armed generally with naval guns of roughly 203 mm (8 inches) in caliber, whose design parameters were dictated by the Washington Naval Treaty of 1922 and the London Naval Treaty of 1930. The heavy cruiser is part of a lineage of ship design from 1915 through the early 1950s, although the term "heavy cruiser" only came into formal use in 1930. The heavy cruiser's immediate precursors were the light cruiser designs of the 1900s and 1910s, rather than the armored cruisers of the years before 1905. When the armored cruiser was supplanted by the battlecruiser, an intermediate ship type between this and the light cruiser was found to be needed—one larger and more powerful than the light cruisers of a potential enemy but not as large and expensive as the battlecruiser so as to be built in sufficient numbers to protect merchant ships and serve in a number of combat theaters.

Second London Naval Treaty International naval treaty in Interwar era

The Second London Naval Treaty was an international treaty signed as a result of the Second London Naval Disarmament Conference held in London, the United Kingdom. The conference started on 9 December 1935 and treaty was signed by the participating nations on 25 March 1936.

Imperial Japanese Navy Naval branch of the Empire of Japan

The Imperial Japanese Navy was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender in World War II. The Japan Maritime Self-Defense Force (JMSDF) was formed between 1952–1954 after the dissolution of the IJN.

Washington Naval Conference 1921–22 disarmament conference in Washington D.C., US

The Washington Naval Conference was a disarmament conference called by the United States and held in Washington, DC from November 12, 1921 to February 6, 1922. It was conducted outside the auspices of the League of Nations. It was attended by nine nations regarding interests in the Pacific Ocean and East Asia. Germany was not invited to the conference, as it had already been disarmed under the terms of the Versailles Treaty. Soviet Russia was also not invited to the conference. It was the first arms control conference in history, and is still studied by political scientists as a model for a successful disarmament movement.

<i>Trento</i>-class cruiser Heavy cruiser class of the Italian Royal Navy

The Trento class was a group of two heavy cruisers built for the Italian Regia Marina in the late 1920s, the first such vessels built for the Italian fleet. The two ships in the class—Trento and Trieste, were named after the redeemed cities of Trento and Trieste annexed from the Austro-Hungarian empire after the victory in World War I. The ships were very lightly armored, with only a 70 mm (2.8 in) thick armored belt, though they possessed a high speed and heavy armament of eight 203 mm (8.0 in) guns. Nominally built under the restrictions of the Washington Naval Treaty, the two cruisers nevertheless exceeded the displacement limits imposed by the treaty.

Japanese cruiser <i>Myōkō</i> Myōkō class heavy cruiser

Myōkō (妙高) was the lead ship of the four-member Myōkō class of heavy cruisers of the Imperial Japanese Navy (IJN), which were active in World War II. She was named after Mount Myōkō in Niigata Prefecture. The other ships of the class were Nachi, Ashigara, and Haguro.

<i>Mogami</i>-class cruiser Class of Japanese heavy cruisers

The Mogami class (最上型) was a ship class of four cruisers built for the Imperial Japanese Navy (IJN) during the 1930s. They were initially classified as light cruisers under the weight and armament restrictions of the London Naval Treaty. After Japan abrogated that agreement, all four ships were rearmed with larger guns and reclassified as heavy cruisers. All participated in World War II and were sunk.

<i>Fubuki</i>-class destroyer Class of destroyers of the Imperial Japanese Navy

The Fubuki-class destroyers were a class of twenty-four destroyers of the Imperial Japanese Navy. The Fubuki class has been described as the world's first modern destroyer. The Fubuki class set a new standard not only for Japanese vessels, but for destroyers around the world. They remained formidable opponents to the end of World War II, despite being much older than many of their adversaries.

<i>Porter</i>-class destroyer Destroyer class of the US Navy

The Porter-class destroyers were a class of eight 1,850-ton large destroyers in the United States Navy. Like the preceding Farragut-class, their construction was authorized by Congress on 26 April 1916, but funding was delayed considerably. They were designed based on a 1,850-ton standard displacement limit imposed by the London Naval Treaty; the treaty's tonnage limit allowed 13 ships of this size, and the similar Somers class was built later to meet the limit. The first four Porters were laid down in 1933 by New York Shipbuilding in Camden, New Jersey, and the next four in 1934 at Bethlehem Steel Corporation in Quincy, Massachusetts. All were commissioned in 1936 except Winslow, which was commissioned in 1937. They were built in response to the large Fubuki-class destroyers that the Imperial Japanese Navy was building at the time and were initially designated as flotilla leaders. They served extensively in World War II, in the Pacific War, the Atlantic, and in the Americas. Porter was the class' only loss, in the Battle of the Santa Cruz Islands on 26 October 1942.

<i>Somers</i>-class destroyer Destroyer class of the US Navy

The Somers-class destroyer was a class of five 1850-ton United States Navy destroyers based on the Porter class. They were answers to the large destroyers that the Japanese navy was building at the time, and were initially intended to be flotilla leaders. They were laid down from 1935–1936 and commissioned from 1937–1939. They were built to round-out the thirteen destroyers of 1,850 tons standard displacement allowed by the tonnage limits of the London Naval Treaty, and were originally intended to be repeat Porters. However, new high-pressure, high-temperature boilers became available, allowing the use of a single stack. This combined with weight savings allowed an increase from two quadruple center-line torpedo tube mounts to three. However, the Somers class were still over-weight and top-heavy. This was the first US destroyer class to use 600 psi (4,100 kPa) steam superheated to 850 °F (454 °C), which became standard for US warships built in the late 1930s and World War II.

Geneva Naval Conference

The Geneva Naval Conference was a conference held to discuss naval arms limitation, held in Geneva, Switzerland, in 1927. The aim of the conference was to extend the existing limits on naval construction which had been agreed in the Washington Naval Treaty. The Washington Treaty had limited the construction of battleships and aircraft carriers, but had not limited the construction of cruisers, destroyers or submarines.

<i>La Galissonnière</i>-class cruiser

The La Galissonnière-class cruisers were commissioned by the French Navy in the 1930s. They were the last French cruisers completed after 1935, until the completion of De Grasse in 1956. They are considered fast, reliable and successful light cruisers. Two cruisers of this class, Georges Leygues and Montcalm took part in the defence of Dakar in late September 1940 during World War II. With the cruiser Gloire, they joined the Allied forces after the successful Allied landings in North Africa in November 1942. The three other cruisers of the La Galissonière class, held under Vichy control at Toulon, were scuttled on 27 November 1942.

<i>Shimushu</i>-class escort ship Japanese ship class

The Shimushu-class escort ships were a class of kaibōkan built for the Imperial Japanese Navy just prior to World War II. Four ships out of an initially planned 16 vessels were completed. The class was also referred to by internal Japanese documents as the "A-class" coastal defense vessel.

Treaty battleship Battleship built in the 1920s or 1930s under the terms of one of a number of international treaties governing warship construction

A treaty battleship was a battleship built in the 1920s or 1930s under the terms of one of a number of international treaties governing warship construction. Many of these ships played an active role in the Second World War, but few survived long after it.

Japanese destroyers of World War II included some of the most formidable destroyers of their day. This came as a surprise to the Allies, who had generally underestimated Japanese technical capabilities. The Japanese had reassessed their naval needs in the mid-1920s and, placing an emphasis on ship and weapons technology and night-fighting expertise, developed a completely new destroyer design. Subsequent development from one destroyer class to the next was not, however, a smooth progression. Aside from the usual changes arising from experience, serious design faults also came to light and naval treaties imposed restrictions. As a result, the early "Special Type" destroyers required significant changes and the specifications of subsequent classes was reduced in one way or another. Naval treaties were later abrogated in 1937 and so destroyer development continued without regard to limits.

<i>Lexington</i>-class battlecruiser US class of battlecruiser

The Lexington-class battlecruisers were officially the only class of battlecruiser to ever be ordered by the United States Navy. While these six vessels were requested in 1911 as a reaction to the building by Japan of the Kongō class, the potential use for them in the U.S. Navy came from a series of studies by the Naval War College which stretched over several years and predated the existence of the first battlecruiser, HMS Invincible. The fact they were not approved by Congress at the time of their initial request was due to political, not military considerations.