Repairs to YFD-21

Dad's repair ship, Vestal, was equipped to conduct a wide range of repairs to almost any vessel of the fleet. While stationed at Espiritu Santo in 1943, crews from Vestal worked for several weeks in June and July on an unusual vessel—unusual at least to a non-Navy and maritime person like me.

The Yard Floating Drydock, YFD-21, although considered a medium size dry dock, was still an enormous floating apparatus. (Apparently, during the war, auxiliary ships like these didn't warrant actual names. However, the YFD-21 came to be known by its unofficial name, USS Rebuilder.) Sixty-six YFDs were constructed for the war effort (although there are numerical designations through 82). Most of the YFDs were placed in service at commercial repair yards, but a few, like YFD-21, were utilized overseas by the Navy to supplement its auxiliary dry dock fleet.

YFD-21 / AFDM-5
Source: NavSource Online

Commissioned in 1943, the YFD-21 was designed with a huge center section that could be lowered to allow a ship to be floated in. When the drydock was raised, the ship then rested on a dry platform from which it could be serviced, especially the sections that ordinarily would be underwater. Floating dry docks, like the YFD-21, had a lifting capacity up to 20,000 tons. They supplemented land-based dry docks that were in short supply as the war progressed in the Pacific. These floating docks provided the flexibility and mobility needed as circumstances evolved during the war.

While not the most glamorous of Navy vessels, the ready availability of the mobile dry docks like YFD-21 at advance bases, and the dedicated service rendered by their own crews and those from repair ships like the Vestal, saved many ships and minimized the time they were out of action for repairs. As one writer noted, these grand floating dry docks may well have represented the margin between the success and failure for the Allies. They certainly should be named among the vessels that helped to win the war.

Former USS YFD-21 / AFDM-5 / Resourceful in Subic Bay, 2011
Source: NavSource Online

After her commissioning in 1943, YFD-21 served at the strategic naval base on Espiritu Santo Island. Next it was shifted to other islands in the New Hebrides, then to the Philippines. In 1945, the vessel was redesignated Auxiliary Floating Dock Medium (AFDM-5). It served in the Navy fleet until it was struck from the register in 1997. Today, it is one of the few surviving vessels from WWII, now in commercial service in Subic Bay, Philippines. In 1979, it was given an official name: Resourceful.

Sources: USS Vestal War Diary, June & July; Building the Navy's Bases in World War II: History of the Bureau of Yards and Docks and the Civil Engineer Corps 1940-1946, Department of the Navy