The two ''Veinticinco de Mayo''-class

heavy cruiser 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 T ...

s served in the Argentine Navy through

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

. They were the only post-

Washington Naval Treaty 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 Nav ...

heavy cruisers built for a South American navy. Both ships of the class were built in Italy by the OTO company, and commissioned into the Argentine Navy in 1931.

Background

Prior to the First World War, Argentina engaged in a vastly expensive naval arms race with its neighbors and rivals Brazil and Chile. As all three countries were forced to acquire their warships from abroad, the war effectively halted the race. After the conflict's end, the Argentine Navy pushed their government to fund a new naval construction program and put their fleet on the same power level as Brazil's and Chile's. It took some time, but the Argentine Congress funded the modernization of the service's existing

dreadnought The dreadnought (alternatively spelled dreadnaught) was the predominant type of battleship in the early 20th century. The first of the kind, the Royal Navy's , had such an impact when launched in 1906 that similar battleships built after her ...

s and destroyers; they followed that three years later with 170 million Argentine pesos over ten years to expand the navy with new warships. Voting on the latter was quite contentious in the legislature's lower house, as it faced opposition from both opposition socialist politicians and a faction in the majority party that supported

Hipólito Yrigoyen Juan Hipólito del Sagrado Corazón de Jesús Yrigoyen (; 12 July 1852 – 3 July 1933) was an Argentine politician of the Radical Civic Union and two-time President of Argentina, who served his first term from 1916 to 1922 and his second ...

, the former president of Argentina. The bill passed only with Yrigoyen's explicit backing. After an

invitation to tender An invitation to tender (ITT, otherwise known as a call for bids or a request for tenders) is a formal, structured procedure for generating competing offers from different potential suppliers or contractors looking to obtain an award of business ...

, the two ''Veinticinco de Mayo''-class cruisers were ordered from Italy. In addition, the Argentine Navy contracted for five destroyers, three from the United Kingdom and two from Spain, and three submarines from Italy. Money remaining from the initial outlay was used to purchase seven additional destroyers in the mid-1930s, and additional monetary appropriations were used to purchase another cruiser ().Montenegro, "An Argentinian Naval Buildup," 121–3.

Design

The ''Veinticinco de Mayo'' design was derived from the Italian , identifiable by the closely paired main guns, similar to the last batches of the cruisers. The ships were smaller than the original, and carried significantly less armour. They had a clean and simple design, with a length-width ratio of almost 10:1. Three twin turrets were mounted with an elevation of 46 degrees for firing. They were not the first Argentinian cruiser class bought in Italy, as four armoured cruisers were brought into service 30 years before.

Armament

The main 190 mm (7.5 inch) guns were designed especially for this class for greater stability (the ''Trento'' class carried 203 mm (8 inch) guns). The guns had single mounts to simplify construction, and could fire a shell up to . Despite this reduction in size and weight, they were still too heavy, so the number of turrets were reduced from four to three. In most respects the resulting vessel was similar in profile to the British . The secondary armament was also a new design, similar to standard 100–102 mm guns of the time. It consisted of twelve 102 mm (4 inch)/45 DP guns, firing a shell, all in twin mounts. This was an unusual arrangement for Italian heavy cruisers, which generally carried sixteen of these weapons. However to counter the additional weight, gun shields were removed, which adversely affected their operability in bad weather conditions. Unusually, the torpedo tubes were in fixed mounts amidships firing abeam, which caused problems in aiming effectively. Light anti-aircraft artillery consisted of six Vickers-Terni 40/39 mm guns, all in single mounts, on the aft part of the superstructure. These guns were among the first automatic heavy weapons, firing 100-130

rounds per minute Round or rounds may refer to: Mathematics and science * The contour of a closed curve or surface with no sharp corners, such as an ellipse, circle, rounded rectangle, cant, or sphere * Rounding, the shortening of a number to reduce the numbe ...

, but were of poor reliability. Though single mounts were simpler and more reliable, they offered poorer fire concentration. The Royal Navy used similar weapons in quad or even octuple mounts. Finally, a catapult launcher for seaplanes was placed over the fore deck. Armour was within the standard for light rather than heavy cruisers. A

armoured belt Belt armor is a layer of heavy metal armor plated onto or within the outer hulls of warships, typically on battleships, battlecruisers and cruisers, and aircraft carriers. The belt armor is designed to prevent projectiles from penetrating t ...

was fitted from the first to the last main turret. was used for the command turret. was used for turrets and barbettes. Only was provided for the armoured deck and above aft machinery.

Post-war refit

After World War II the ships were modified to improve their stability by reducing weight. The powerful twin 102 mm gun batteries were replaced with six

Bofors 40 mm gun Bofors 40 mm gun is a name or designation given to two models of 40 mm calibre anti-aircraft guns designed and developed by the Swedish company Bofors: *Bofors 40 mm L/60 gun - developed in the 1930s, widely used in World War II and into the 1990s ...

s, one for each twin mount, drastically reducing the secondary armament. Another four Bofors replaced the six Vickers AA guns. US Mk.53 radar directors were also installed to improve the effectiveness of anti-aircraft fire. The gain in stability, with several tons removed for each 102 mm gun, was somewhat offset by the addition of radar installations to the superstructure and masts. The aircraft catapult launcher was moved from the fore deck to mid-ships.

Units

Although Argentina entered the Second World War with a declaration of war on the

Axis powers The Axis powers, ; it, Potenze dell'Asse ; ja, 枢軸国 ''Sūjikukoku'', group=nb originally called the Rome–Berlin Axis, was a military coalition that initiated World War II and fought against the Allies. Its principal members were ...

on 27 March 1945, the remaining Axis navies were such that neither ''Almirante Brown'' or ''Veinticinco de Mayo'' played a role in the conflict. The ships proved popular with the Argentine Navy, until they were superseded by two s acquired in 1951.

Planned units

Argentina originally planned to acquire three of the class, but were limited to having only two built. They would turn to the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

for their next cruiser, acquiring in 1938.

References

Bibliography

* Montenegro, Guillermo J. "An Argentinian Naval Buildup in the Disarmament Era: The Naval Procurement Act of 1926." In ''Warship 2002–2003'', edited by Antony Preston, 116–25. London: Conway Maritime Press, 2003. . OCLC . Also published by th
Universidad del Centro de Estudios Macroeconómicos de Argentina
* Whitley, M.J. ''Cruisers of World War II: An International Encyclopedia.'' Annapolis, Maryland: Naval Institute Press, 1995. . . * Article in "Storia Militare" magazine, October 2007.

External links

''(in spanish)'' {{Veinticinco de Mayo class cruisers Cruiser classes World War II cruisers of Argentina