The Commencement Bay class were built during World War II , and were an improvement over the earlier Sangamon class , which were converted from oil tankers. They were capable of carrying an air group of 33 planes and were armed with an anti-aircraft battery of 5 in mm , 40 mm 1. In , as United States participation in World War II became increasingly likely, the US Navy embarked on a construction program for escort carriers , which were converted from transport ships of various types. Many of the escort carrier types were converted from C3-type transports , but the Sangamon -class escort carriers were instead rebuilt oil tankers.
These proved to be very successful ships, and the Commencement Bay class , authorized for Fiscal Year , were an improved version of the Sangamon design.
The new ships were faster, had improved aviation facilities, and had better internal compartmentation. Vella Gulf was ft 1 in She displaced 21, long tons 21, t at full load , of which 12, long tons 13, t could be fuel oil though some of her storage tanks were converted to permanently store seawater for ballast , and at full load she had a draft of 27 ft 11 in 8.
The ship's superstructure consisted of a small island. She had a complement of 1, officers and enlisted men. The ship was powered by two Allis-Chalmers geared steam turbines , each driving one screw propeller , using steam provided by four Combustion Engineering -manufactured water-tube boilers.
Her defensive anti-aircraft armament consisted of two 5 in mm dual-purpose guns in single mounts, thirty-six 40 mm 2 in Bofors guns , and twenty 20 mm 1 in Oerlikon light AA cannons. The Bofors guns were placed in three quadruple and twelve twin mounts, while the Oerlikon guns were all mounted individually. She carried 33 planes, which could be launched from two aircraft catapults. Two elevators transferred aircraft from the hangar to the flight deck. The first fifteen ships of the Commencement Bay class were ordered on 23 January , allocated to Fiscal Year On 26 April, she was renamed Vella Gulf , after the Battle of Vella Gulf , which had been fought between American and Japanese destroyer flotillas during the Solomons campaign the previous year.
