April 10, 1946 – Company organized at Long Island, Boston Harbor. The company was assigned a 1923 American LaFrance, Type 14, city-service ladder truck, with 35gal. booster, Serial # 4366, Shop # 231. The ladder truck was delivered to the island via barge, as the only access to the island was by ferryboat.
July 23, 1951 – The Long Island Bridge, connecting Long Island to the mainland, was placed in service.
1956 – Company received a 1931 American LaFrance, Type 214, city-service ladder truck, with 100gal. booster, Serial # 7383, Shop # 262.
October 14, 1957 – Company re-designated LADDER COMPANY 31.