Douro-class destroyer

The Douro-class of destroyer included five ships used by the Portuguese Navy (the Marinha Portuguesa) between 1933 and 1967.

Design and construction
In 1930, the Portuguese navy drew up a 10 year shipbuilding programme to replace its aging fleet, with planned purchases including two cruisers, twelve destroyers and a number of submarines and sloops. The competition for the design for destroyers was won by Yarrow Shipbuilders beating bids from Thornycroft and Italian shipyards. An order was placed for four ships on 12 June 1931, with two ships, Vouga and Lima to be built by Yarrows and the remaining ships, Tejo and Douro to be built at Lisbon with machinery to be supplied by Yarrow. A fifth ship, Dão, again to be built in Lisbon using Yarrow supplied machinery, was ordered on 18 January 1933.

Yarrow's design was based on HMS Ambuscade (D38), a prototype destroyer built for the Royal Navy in 1926. The ships were 323 ft long overall and 307 ft between perpendiculars, with a beam of 31 ft and a draught of 11 ft. The ship displaced 1219 LT standard and 1563 LT full load. Three Yarrow boilers fitted with air pre-heaters and superheaters supplied steam at 400 psi to geared steam turbines, driving two propeller shafts and generating 33000 shp, giving a speed of 36 kn. Sufficient fuel was carried to give a range of 5400 nmi at 15 kn.

Armament was similar to contemporary Royal Navy destroyers, with a gun armament of four 4.7 in (120 mm) Vickers-Armstrong Mk G guns, and three 40 mm (2-pounder) pom-pom anti-aircraft guns. Two quadruple banks of 21 inch (530 mm) torpedo tubes were carried, while two depth charge throwers and 12 depth charges constituted the ships' anti-submarine armament. Up to 20 mines could be carried. The ships complement was 147 officers and men.

The two Yarrow-built ships were laid down in October 1931, and commissioned in 1933, while the first two Lisbon-built ships, Tejo and Douro, laid down in 1932, were sold to the Colombian Navy before completion in response to the Leticia Incident between Columbia and Peru, and Peru's purchasing of two ex-Russian destroyers (Almirante Guise and Villar) from Estonia. Renamed the Antioquia and the Caldas, respectively, they served the Colombians as the. Two further ships were ordered by the Portuguese Navy to replace them.

Service
The five destroyers carried out patrols to defend Portugal's neutrality during the Second World War. Their anti-aircraft armament was revised during 1942–43, with the three pom-poms and one of the banks of torpedo tubes replaced by six 20 mm cannon. They were refitted by Yarrow from 1946–49, with the machinery refurbished, anti-aircraft armament again revised to three Bofors 40 mm gun in powered mounts and three 20 mm cannon, and sonar and radar (British Type 285 and Type 291) fitted. Douro reached a speed of 34.05 kn at 28085 shp during post-refit trials.

Four of the five destroyers were refitted and modernised again in 1957, (Douro was not refitted, and was disposed of in 1959 ) with two 4.7 in guns removed, allowing a Squid anti-submarine mortar to be fitted and the anti-aircraft armament to be increased to five 40 mm Bofors guns and three 20 mm cannon. The last of the class, Vouga, was discarded in 1967.