Criterion A: Military
Criterion C: Architecture
Period of Significance: 1908-1950
Local Level of Significance
The Torpedo Storehouse on Great Diamond Island in Portland, Maine, and the associated Hoister House are locally significant in Maine under the National Register of Historic Places Criterion A, in the area of military history, for their associations with Fort McKinley and the United States government's efforts to defend Portland Harbor in the early twentieth century. The Storehouse and Hoister House were utilized during both World War I and World War II and were of major significance among the tactical buildings at Fort McKinley. The Torpedo Storehouse is also significant under National Register Criterion C, in the area of architecture, as a rare surviving example of an unusual building type and method of construction. The Torpedo Storehouse is the only surviving building of its type in Maine. It was one of two nearly identical torpedo storehouses erected in Maine in the early twentieth century; the other was located at Fort William in Cape Elizabeth but is no longer extant. Even in its deteriorated state, the property possesses integrity of location, design, setting, materials, workmanship, feeling and association. The period of significance extends from the 1908 construction date of the Torpedo Storehouse to 1950 when the U.S. Army harbor defense commands were disbanded.