HMNZS Leander

Page 2 – Leander-class light cruisers

Cruisers were New Zealand’s biggest warships. In 1920 the New Zealand Division of the Royal Navy began its post-First World War life with the eight-year-old coal-burner HMS Chatham. Six years later HMS Diomede joined HMS Dunedin (which had replaced Chatham in 1924), making New Zealand a two-cruiser station, a strength it would maintain until the early 1960s. Both D-class cruisers were late First World War designs, modern oil-burners.

Borrowing British cruisers benefited both countries. New Zealand avoided shipbuilding costs and Britain was spared the cost of operating them (while still able to call on them in emergencies).

In the mid-1930s the governments agreed to another upgrade. In 1936 and 1937 respectively, the modern Leander-class cruisers Achilles and Leander joined the New Zealand station.

Treaty limits

Although Britain completed several light cruisers in the 1920s, these were First World War designs. The Washington Naval Treaty of 1922 had set tonnage and gun calibre limits for cruisers. The big ones, heavy cruisers, were restricted to 10,000 tons standard displacement and to guns no bigger than eight inches (203 mm). The smaller light cruisers carried guns of 6.1 inches (155 mm) or less.

What’s in a name?

The Royal Navy has had several Leander classes, the most recent being frigates, four of which – Waikato, Canterbury, Southland and Wellington – served in the Royal New Zealand Navy between 1966 and 2003.

In British service, the classes took their names from mythological figures. In Greek mythology young Leander fell in love with the priestess Hero and every night swam across the Hellespont to be with her. Achilles was a Greek hero of the Trojan War.

A further cap was applied in 1930 by the London Naval Treaty. This set overall cruiser tonnage levels for the major navies: for heavy cruisers it was Britain 147,000, the United States 180,000 and Japan 108,000 tons; for light cruisers the respective limits were 192,200, 143,500 and 100,450 tons.

The Leander class

Britain needed 70 cruisers for its battle fleet and to protect far-flung trade routes, so it had to juggle the mix of large and small cruisers. At 7000 tons, the five Leanders were designed to do both roles, as economically as possible.

In a fleet of two-and three-funnel cruisers, the Leanders stood out. Their main innovation was their gun battery, with all main guns being mounted in twin armoured turrets instead of the single shields seen on Dunedin and Diomede. Turrets protected gunners from shell splinters and from the weather, and brought Britain’s light cruisers up to the same standard as its heavy cruisers.

The Leander class was innovative in another way. Britain’s need to stay within its tonnage allocations led the ships to being the first cruisers in the world to make more than token use of welding. The shipyards learned as they worked. Leander, the first, was the heaviest at 7178 tons standard displacement; the Orion, the last, was just 6837 tons.

The D-class and Leanders compared




Std displacement

4650 tons

7178 tons


29 knots

32.5 knots

Main armament

6 x 152-mm

8 x 152-mm

Secondary guns

3 x 102-mm

4 x 102-mm

Torpedo tubes

12 x 533-mm

8 x 533-mm







The Royal Navy considered the Leander class a success. Three Amphion-class ‘Improved Leanders’ were built and transferred to the Royal Australian Navy.

How to cite this page

'Leander-class light cruisers', URL:, (Ministry for Culture and Heritage), updated 10-Jan-2022