Because the monitors used in the attack had to be towed to Fort Fisher, the navy would leave with a twelve-hour head start over the transports. The warships would refuel at Beaufort, then meet the transports at Fort Fisher, when the Louisiana would be detonated and the troops landed under the fire of the warships. Fort Fisher, on Confederate Point, nicknamed the "Gibraltar of the Confederacy", was a formidable target commanding the Cape Fear River. It encompassed 14,500 ft.² and was surrounded by a 10-foot parapet and a network of bombproofs, most of which were 30 feet high. Many obstructions were laid around it, including land mines (called torpedoes in this era), abatis, and deep ditches. There were more than 50 heavy cannon, including 15 Columbiads and a 150-pounder Armstrong gun, behind a 60-foot mound of earth near the sea, named the Mound Battery. The fort's garrison of 1,400 men was commanded by Colonel William Lamb. Additional reinforcements were available from General Braxton Bragg at Sugar Loaf, 4 miles away. This force consisted of Major General Robert F. Hoke's division from the Army of Northern Virginia, which arrived on December 23. Opposing forces Union Army Expeditionary Corps (Army of the James) – MG. Benjamin F. Butler, MG Godfrey Weitzel (second-in-command) 2nd Division (XXIV Corps) – BG. Adelbert Ames 1st Brigade - Brevet BG. Newton M. Curtis 3rd New York – Cpt. George W. Warren 112th New York – Ltc. John W. Smith 117th New York – Col. Rufus Daggett 142nd New York - Ltc. Albert M. Barney 2nd Brigade - Col. Galusha Pennypacker 47th New York – Cpt. Joseph P. McDonald 48th New York – Ltc. William B. Coan 76th Pennsylvania – Col. John S. Littell 97th Pennsylvania – Lt. John Wainwright 203rd Pennsylvania - Col. John W. Moore 3rd Brigade - Col. Louis Bell 13th Indiana – Cpt. Samuel M. Zent 4th New Hampshire – Cpt. John H. Roberts 115th New York – Maj Ezra L. Walrath 169th New York – Col. Alonzo Alden Artillery 16th Independent Battery New York Light Artillery - Cpt. Richard H. Lee Naval Brigade - BG Charles K. Graham 3rd Division (XXV Corps) – BG. Charles J. Paine 2nd Brigade - Col. John W. Ames 4th USCT – Ltc. George Rogers 6th USCT – Ltc. Clark Royce 30th USCT – Ltc. Hiram A. Oakman 39th USCT – Col. Ozora P. Stearns 3rd Brigade -