in the early 20th century new works were made in order to further improve the installations, which led to the creation of the 'base naval almirante castro e silva', or 'naval base admiral castro e silva' in english.

the submarines of the brazilian navy are stationed here.

the northern sector, the old smaller mocangué, belonged to a civilian shipbuilder, the brazilian lloyd. during the 1970s these installations would be slowly transferred to the navy, and in 1986 the naval base rio de janeiro was officially commissioned.