Largely due to his pleas for better medical care for the men of the Navy, Congress passed a bill authorizing the construction of hospitals at several naval stations, but the first official U.S.
[1] The class were initially armed with five 5-inch (127 mm)/38 caliber guns in Mk30 dual-purpose turrets for anti-aircraft and surface warfare, aligned along the centreline.
[2] After shakedown training out of San Diego, California, Heermann joined the 5th Fleet on 21 October 1943 for Operation Galvanic, the assault on the Gilbert Islands.
Her guns sank a small enemy craft inside the lagoon and the next two days assisted troops ashore with close-in fire support.
With the island secured, she returned to Pearl Harbor for repairs and training which ended on 23 January when she sailed in the screen of an attack transport reserve force.
[2] Heermann was then assigned to the Third Fleet and Task Force 39 on 18 March 1944 after stopping at Majuro Lagoon and then Port Purvis on Florida Island, in the Solomons.
For the next month the destroyer escorted convoys which were occupying Emirau Island and seeking out enemy supply barges along the coast of New Hanover.
Destroyers Hoel and Johnston joined her in screening Rear Admiral Clifton Sprague's unit, "Taffy 3" which also included his flagship Fanshaw Bay and five other escort carriers.
In an effort to withdraw away to the south from Kurita's force, the escorts began to make smoke screens to mask the movement of the larger ships.
[2] Heermann laid another smoke screen along the starboard quarter of the carrier formation and then returned to engage the Japanese force of four heavy cruisers.
A series of 8-inch (203 mm) hits stuck the forward section of the destroyer, flooding it and pulling the bow down so far that the anchors were dragging in the water.
One of the 5-inch guns was put out of action but in conjunction with strikes from the carrier aircraft forced Chikuma to withdraw, and the Japanese cruiser sank during her retreat.
On 1 July she helped to screen the fast carrier force that devoted the ensuing five weeks to almost continuous air strikes and bombardment.
In the following weeks Heermann operated in the screen of the fast carrier task force providing air cover and air-sea rescue service.
The destroyer entered Tokyo Bay on 16 September 1945 and remained in the area to support the occupation forces until 7 October when she sailed for the United States.
She spent 1952 training along the eastern coast from New England to the Virginia Capes, followed by ASW and fleet problems during winter months in the Caribbean.
After a two-day replenishment in Yokosuka, she set course for Okinawa where she acted as part of the escort for 3d Marine Division amphibious warfare landings and conducted barrier patrol in support of the exercise.
After more maneuvers took her to Korea, Iwo Jima, and the South Coast of Japan, she returned to Yokosuka which she cleared 22 May 1954 to resume her world cruise, calling at Hong Kong and Singapore on her way to the Suez Canal.
Heermann operated out of Newport until 6 November, when she sailed for the Mediterranean where she proved to be a first-rate antisubmarine ship in joint exercises with the Italian Navy.
She served as gunnery school-ship out of Newport until 30 June when she joined Charles J. Badger in the screen of antisubmarine warfare carrier Leyte for two weeks of air operations for the training of Naval Academy midshipmen.
[4] On 14 August 1961 Heermann was formally transferred on a loan basis to the government of Argentina under terms of the Military Assistance Program.