HMS Ruler

HMS Ruler was the name ship of the Ruler class of escort carriers, built in the United States as the Prince William class and based on a standard merchant ship hull. The Ruler served as a replenishment carrier with the British Pacific Fleet from the spring of 1945 until the end of the war. She was launched on 21 August 1943 as USS St. Joseph (CVE-50).


She was completed only four months later, on 22 December 1943, but didn't enter service for another year. No.885 Squadron and its Grumman Hellcats embarked on her on 16 December 1944, and remained onboard for the rest of the war.


In January 1945 a detachment from No.716 Squadron, the School of Safety Equipment briefly served on the Ruler. No.1772 Squadron's Fireflies embarked on 21 January 1945, and the Ruler departed for the Far East. She reached the Far East in March, when No.1772 Squadron disembarked, just leaving No.885. 

After arriving in the Far East the Ruler became part of the fleet train for the British Pacific Fleet. Her role was to provide fighter cover over the fleet replenishment area. During the invasion of Okinawa this was known as 'Area Cootie', and the Ruler provided cover while the main fleet took on supplies on 6-7 May, 10-11 May and 18-19 May. The pattern was broken on 20 May when the destroyer HMS Quilliam was badly damaged in a collision with the Indomitable. The Ruler was summoned to provide air cover for the damaged destroyer while the cruiser Black Prince towed her to 'Area Cootie'.

Another break came in June, when the British Pacific Fleet carried out a raid on the Japanese base on Truk. The main strike force was provided by the newly arrived Implacable, but the Ruler was included in the new Task Force 111/2 to provide an emergency flight deck. On 14 June, the first day of the attack, six Seafires landed on the Ruler having lost sight of the Implacable. The Ruler continued to serve as a replenishment carrier until VJ Day. Shewas returned to the US Navy on 29 January 1946, and was scrapped later that year.


No.716 NAS

A detachment from No.716 Squadron (School of Safety Equipment) served on the Ruler for a short period in January 1945.

No.885 NAS

No.885 Squadron embarked on the Ruler on 16 December 1944, equipped with the Grumman Hellcat. While in the Far East the squadron gained a number of Corsairs and Avengers. The squadron provided fighter cover for the fleet replenishment area but was also used during the British attack on Truk in June 1945.

No.1772 NAS

No.1772 Squadron's Fireflies joined the Ruler in home waters on 21 January 1945 and disembarked at Schofields on 18 March 1945.

Displacement (loaded)

11,400t standard
15,390t deep load

Top Speed



495ft 3in-496ft 8in oa


18-24 aircraft
Two 5in/38 US Mk 12 in two single mountings
Sixteen 40mm Bofors guns in eight double mountings
Twenty seven to thirty five 20mm cannon

Crew complement



21 August 1943


22 December 1943



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How to cite this article: Rickard, J (22 July 2010), HMS Ruler ,

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