AVP-10 Barnegat

The Barnegat (AVP-10) class small seaplane tenders also served in the Coast Guard as the Casco class [WHEC-370] cutters. These were actually quite interesting little ships, but they get overlooked. The first and only class of purpose-built small seaplane tenders in the US Navy, they were designed to operate out of small harbors and atolls and had a shallow draft. The fact that the class was very seaworthy, had good habitability, and long range made them well suited to ocean-station duty. Fast, heavily armed and exceptionally versatile, they served in a wide variety of roles during and after WWII.

An assessment made by the Coast Guard on the suitability of these vessels for Coast Guard service noted the workmanship on the vessel is generally quite superior to that observed on other vessels constructed during the war. The vessel has ample space for stores, living accommodations, ships, offices and recreational facilities. The main engine system is excellent. The performance of the vessel in moderate to heavy seas is definitely superior to that of any other cutter. This vessel can be operated at higher speed without storm damage than other Coast Guard vessels.

Once they were accepted into Coast Guard service, a number of changes were made in these ships to prepare them for ocean-station duty. A balloon shelter was added aft; there were spaces devoted to oceanographic equipment and a hydrographic winch as well as an oceanographic winch were added.

When fully loaded the vessels were down by the stern about two and a half feet. Under this condition of loading it is necessary to drive the ship into the sea at sufficient speed to cause heavy pounding in order to hold her head up, about eight knots being required for steerage way. As the tanks were emptied it was found that with the head down about six inches to one foot her head could be held up into the sea with about three knots speed. At this speed only occasional pounding was experienced. Under both conditions of trim the vessel had to be operated at two thirds speed down wind in order to maintain adequate steerage way.

In very heavy seas, however, being flat bottomed, the vessel pounds very heavily. She has an expansion joint which permits all the working to be absorbed by the hull. On heavy pounds observers counted as many as forty distinct vibrations. Constant check has been kept to observe and tearing away of hull plating from frames. The excessive amount of hull vibration also probably had an adverse effect on the piping, although the primary difficulty is due to electrolytic action.

Another cause of difficulty is that all the salt water piping is of heterogeneous material and fittings, being cast steel in some sections, copper in others and copper nickel in others. After only a few years of operation the saltwater piping through out the ships was in such deplorable condition that a gang of men were kept busy repairing sections of the salt water piping.

The primary internal difficulty was electrical. The two hundred KW generators theoretically furnish ample power for operation, but nearly all meters through out the ship are squirrel cage induction motors which put a tremendous load on the line when they are started.

USS Barnegat, the first ship in a large class of 1,766-ton small seaplane tenders, was built at the Puget Sound Navy Yard, Bremerton, Washington, and was commissioned in July 1941. The original seaplane-handling facilities included a large crane aft and a clear fantail. The original configuration had two 5"/38 guns forward and a large seaplane-handling crane aft. By 1944 the original large aircraft crane had been replaced with a smaller model and a third 5"/38 mount has been added on the fantail.

USS Barnegat spent her first ten months conducting trials of the new AVP design, first in the Puget Sound area and after November 1941 near Boston, Massachusetts. In May 1942 the tender deployed to Iceland where she tended a seaplane squadron and performed a variety of other support services, and in November she and her aircraft participated in the invasion of North Africa. Between June 1943 and May 1944 Barnegat operated in Brazil, where her seaplanes sank two U-boats. In February 1945 she arrived in Panama, where she tended seaplanes and conducted a wide range of other support activities until returning to the U.S. in November.

USS Biscayne, the second ship of the Barnegat class of 1,766-ton small seaplane tenders, was built at the Puget Sound Navy Yard, Bremerton, Washington, and was commissioned in July 1941 in a joint ceremony with Barnegat (AVP-10). She initially conducted trials of the new AVP design, first in the Puget Sound area and after December 1941 near Boston, Massachusetts. Between May and September 1942 she served as communications ship in Greenland supporting the buildup of U.S. air power in England. In November she supported the movement of a seaplane squadron from Guantanamo Bay, Cuba, to Freetown, Sierra Leone, then moved north with her squadron to particpate in the North African operations. In April 1943 Biscayne was converted to a communications vessel at Oran and became an amphibious force flagship.