Watertown Arsenal, Building No. 311, Arsenal Street, Watertown, Middlesex County, MA

Significance: Building No. 311 is essential to understanding Watertown Arsenal activities from World War I to the present day. Reputed to be one of the largest structures in the world in 1917, it was designed to accommodate erection of carriages for 16-in. seacoast guns, and disappearing, railway, and barbette carriages during World War I. Doubled in size in 1942 and equipped with large X-ray facilities in 1942 and 1956, Building No. 311 was vital to the industrial manufacturing and materials research achievements of Watertown Arsenal.
Survey number: HAER MA-20-E
Building/structure dates: 1956 Subsequent Work
Building/structure dates: 1964 Subsequent Work
Building/structure dates: 1968 Subsequent Work