July 12, 1920 – Company organized at the quarters of, and replaced, Ladder Company 31 at 425 Faneuil Street , Brighton. The company was equipped with a 1919 American LaFrance Type 12 Triple-combination 750gpm pumper (Single-unit), Serial # 2655, Shop # 126 , ex-Engine 15.
This was the first Engine Company equipped with ladders, with one 25ft extension ladder and one 12ft roof ladder.
October 20, 1927 – Company changed from Single-unit operation to Double-unit operation. Company was assigned a 1920 American LaFrance, Type 40, Hose & Chemical Wagon, Serial # 2806, Shop # 328 , ex-Engine 8, and a 1921 American LaFrance, Type 75, 750gpm pumper, Serial # 3613, Shop # 145 , ex-Engine 52, replacing the the 1919 ALF pumper, Shop # 126 , which was reassigned to Engine 52.
September 21, 1928 – Company received a 1920 American LaFrance, Type 75, Hose & Chemical Wagon, Serial # 3151, Shop # 333 , ex-Engine 10.
November 3, 1931 – Company received a new 1931 American LaFrance, Type 212, Hose & Booster Wagon, Serial # 7379, Shop # 391.
August 9, 1939 – Company changed from Double-unit to Single-unit operation. The 1931 ALF Hose Wagon, Shop # 391 , was reassigned to Engine 29.
February, 1944 – Company received a new 1944 American LaFrance ‘600 Series’ 1000gpm pumper, Serial # 8194, Shop # 108.
August 16, 1948 – Company changed from Single-unit to Double-unit operation. Company was assigned a 1931 American LaFrance, Type 212, Hose & Booster Wagon, Serial # 7377, Shop # 390 , ex-Engine 37.
March 15, 1950 – Ladder Company 34 was organized at the quarters of Engine Company 51.
May 25, 1954 – Ladder Company 34 was deactivated.
July 27, 1954 – Company changed from Double-unit to Single-unit operation. The 1931 ALF Hose Wagon, Shop # 390 , was placed in reserve.
August 11, 1954 – Company received a 1948 Ward LaFrance, Model 85T, 750gpm pumper, Serial # 48-2324, Shop # 104 , ex-Engine 15, converted for Single-unit operation.
July, 1968 – Company received a 1948 Mack, Model 85, 750gpm pumper, Serial # 85LS-1256, Shop # 195 , ex-Engine 28.
September 16, 1970 – Company received a 1962 Ward LaFrance 1250gpm diesel pumper, Serial # 62-4785, Shop # 113 , ex-Engine 28.
November 13, 1972 – Ladder Company 22 was permanently relocated to the quarters of Engine Company 51. Ladder 22 had previously been quartered at 44 Monument Street, Charlestown.
July 30, 1976 – Company received a 1970 Hahn 1250gpm pumper, Serial # C12-31, Shop # 111 , ex-Engine 16.
April 10, 1981 – Ladder Company 22 at Engine 51’s quarters was deactivated.
January 20, 1983 – Company received a 1971 Hahn 1500gpm pumper, Serial # C15-18, Shop # 158 , ex-Engine 49.
January 29, 1985 – Company received a new 1985 Ford/Emergency One 1250gpm pumper, Serial # 3889, Shop # 106.
1998 – Fire Fighter Eugene B. Fortes, Engine Company 51, was awarded the Roll Of Merit. Citation
1999 – Company received a 1996 Emergency One ‘Cyclone II’ 1250gpm pumper, Serial # 16496, Shop # 143 , ex-Engine 41.
May 29, 2007 – Fire Fighter David A. Middleton, Engine Company 51, died in the Line-Of-Duty from injuries received at Box 5247.
2010 – Due to firehouse renovations, Engine 51 moved to the quarters of Engine 41/Ladder 14 at 460 Cambridge Street, Allston.
July 18, 2011 – Upon completion of renovations, Engine 51 moved back to 425 Faneuil Street.
2018 – Company received a 2008 Emergency One ‘Cyclone II’ 1250gpm pumper, Serial #134063, Shop # 171, ex-Engine 28.
2019 – Four members of Engine Company 51, Fire Lieutenant Mark E. Williams and Fire Fighters Colin J. Dockins, James A. Cooley and Allan P. Morse, were awarded the Commissioner’s Unit Citation for their actions at 20 Washington Street, Brighton, Box 531, on February 14, 2019. Citation
2021 – Fire Fighter Louis Palermo, Engine Company 51, was awarded the Roll of Merit for his actions at 32 Perthshire Road, Brighton, Box 5485, on September 6, 2021. Citation
2021 – Four members of Engine Company 51, Fire Lieutenant Steven Perry and Fire Fighters Louis Palermo, Sean Gillespie and Mohan Pilwah, were awarded the Commissioner’s Unit Citation for their actions at 32 Perthshire Road, Brighton, Box 5485, on September 6, 2021. Citation
October 28, 2022 – Company received a new 2022 Emergency One ‘Typhoon’ pumper, 1250gpm, 560g/30f tank, Serial # 145010, Shop # 135.