The technological leap between the two vessels—partially bridged by the steel supply and fuel ships Charlestown built in the World War I period—was considerable. Except for its coal-fired auxiliary steam propulsion, the 216-foot _Vandalia_ did not differ significantly from the old _Constitution_. _MacDonough_ was a modern destroyer—the sloop-of-war’s 20th-century counterpart—incorporating the advances of the past 60 years. It was powered by geared turbines driven by steam generated in oil-burning boilers, and relied on sophisticated electrical, hydraulic, and communications systems. At 341 feet, its steel hull took up most of Dry Dock 1. As soon as _MacDonough_ was moved out of the dock, the destroyer _Monaghan_, just floated from Dry Dock 2, was moved into #1 for completion and outfitting. Two more keels were immediately laid in #2. It is noteworthy that neither dry dock was being used to repair ships. In fact, the whole yard’s traditional role as repair facility had given way in the past year to a new one as shipbuilder, a status it maintained through World War II. Charlestown built 12 destroyers in the 1930s and 24 more by the end of the war. Of course the yard built and serviced other types of vessels—especially destroyer escorts and LSTs (Landing Ship Tank)—but Charlestown acquired a reputation as a “destroyer yard” and thereafter specialized in this workhorse of the Navy. [Illustration: Navy Yard Complex During World War II _This map of Boston Harbor in 1942 shows the five units of Charlestown Navy Yard during World War II. By war’s end the South Boston Annex was the largest, with dry docks big enough to repair battleships and heavy cruisers. The Chelsea and East Boston Annexes repaired small vessels, and the Fuel Depot Annex served the great number of naval vessels entering the harbor during the war._] CHELSEA Chelsea Naval Hospital Chelsea Naval Annex Fuel Depot Annex CHARLESTOWN Navy Yard EAST BOSTON East Boston Annex Pipeline DOWNTOWN BOSTON _BOSTON HARBOR_ Deep Water Pier SOUTH BOSTON South Boston Annex Ironically, the change had been brought about by the same economic crisis that almost put an end to the yard. After considering closing all yards but Norfolk and Philadelphia to save money, the Hoover administration in 1931 proposed closing only the Charlestown yard. Reaction was swift: committees were formed in Boston; petitions protesting the closing were signed. But it was probably the fact that _MacDonough_ had been ordered a month earlier that tilted the scales in the yard’s favor. The keel was not laid for two years, however, and 1932 was the yard’s bleakest year since before the Spanish-American War, with only 1,500 people employed.