[1] A rail spur, sided off the Old Colony Greenbush Line, was built to facilitate the transfer of ammunition, stored in cement bunkers at the Annex, to the Depot at the Hingham Shipyard.
The Commonwealth of Massachusetts took possession of the Annex, in 1966, and later turned the 3,500 acres (14 km2) into the present day Wompatuck State Park.
This task was completed in the Spring of 2015, with the former building sites having been razed and covered with earth and new hiking and biking trails established, roadways refinished as walking and biking trails and access improved via the former rail bed, connecting to Route 3A in Cohasset near the Greenbush rail line.
Bunkers here, as well as those in the remains of the original Hingham Naval Ammunition Depot in what is now Bare Cove Park, had been used as shelter by homeless persons.
[2] However, local Boy Scouts have worked to preserve some of these bunkers, including N9, as a memorial to the military and civilian personnel who served at the Depot.