Placed out of commission 3 November, Barnstable was outfitted as an APA by Commercial Iron Works, Portland, Oregon, and recommissioned 22 May 1944.

Embarking troops and cargo she sailed to Guadalcanal for landing exercises 24 August-8 September, in preparation for the assault on the Palau Islands.

Returning to Manus, Admiralty Islands, Barnstable loaded troops and cargo and arrived in Leyte Gulf 20 October 1944.

Barnstable transported troops and cargo between New Caledonia and the Admiralty Islands and then returned to Leyte, where she landed reinforcements (19–29 November 1944).

In 1948 the Maritime Commission sold Barnstable to the Isthmian Steamship Company of New York, who renamed her Steel Fabricator.