The Other Fort Knox Is Imposing
Guarding Maine’s Penobscot River


By Sherry Ballou Hanson

Roger Bennatti is a veritable font of facts about Civil War era Fort Knox that overlooks Bucksport on the Penobscot River in Prospect, Maine. Serving as both a Maine Department of Conservation–Bureau of Parks volunteer and as a seasonal interpretive tour guide, he has the facts down cold.

Occasionally a clueless tourist mistakes this place for Fort Knox, Ky., site of the U.S. Bullion Depository where gold is stored. Maybe “fools gold.” The bedrock of the area, Penobscot Formation, which was used as a foundation along the river side of Fort Knox, is a sulfide-rich schist. One of the sulfides is iron sulfide, known as iron pyrite, or fool’s gold.

Bennatti is a member of the Friends of Fort Knox, the group that beautifully maintains the site. Fort Knox is an imposing structure, especially from the sea. About 160,000 yards of rock and soil were removed to build the fort. It is part of the Third System forts built between 1816 and the Civil War and designed by engineers with the Department of War.

There were eventually 42 of these new coastal forts in the national system. Construction of Fort Knox began in July 1844 under the supervision of Lt. Isaac Stevens, who started with earthen batteries nearest the river so that cannon could be emplaced.

It wasn’t until 1851 that barges brought in granite from Mount Waldo, five miles upriver in Frankfort, to build the main fort building itself. It measures 252 by 146 feet and contains mounts for 64 cannon.

Fort Knox was the first of the granite forts built in Maine and is the only Maine fort with any guns still in place. The stone forts were a clear advance over wooden blockhouses given their large granite encasement to protect cannon.
Four Rodman guns still grace Fort Knox today. Three were original to the fort — two 15-inch cannon outside, one on a carriage, and a 10-inch inside on a carriage.
According to the National Registry of Known Surviving Civil War Cannon the M1861 15-inch Rodmans were cast by Cyrus Alger and Company in 1865. Fort Pitt Foundry made the M1861 10-inch gun in 1865.

The Big Guns: Civil War Siege, Seacoast, and Naval Cannon says the guns produced by Capt. Thomas J. Rodman’s water-cooled core barrel method allowed production of gigantic smoothbore guns, “the largest cast-iron ordnance then known in the world.”

Fort Knox also displays a 10-inch Rodman that was sleeved to an 8-inch rifle in 1879 at South Boston Foundry (Alger). It sits in the parking lot. Bennatti said the fort also has four flank howitzers in storage awaiting carriages.

Fort Knox was named after Maj. Gen. Henry Knox, America’s first Secretary of War and Commander of Artillery during the Revolutionary War. The grounds originally included officers’ and men’s quarters, blacksmith and carpenter shops, a large barn, implement houses and an unfinished kitchen building.

Congressional funding was typically sporadic and construction was on and off for 25 years. When it ended in 1869 nearly $1 million had been spent on the still-unfinished Fort Knox. The fort was to protect ship building and lumber interests, especially along the stretch of the Penobscot River lying between Castine and Bangor, Maine’s wealthy and unprotected lumber capital.

This 32-mile section of the river had seen many fierce conflicts during the American Revolution and the War of 1812 while under British control. Bangor still made an irresistible target and Fort Knox was built to prevent the British Navy from once more sailing up to Bangor and taking over.

Its impressive demi and full bastions of flank howitzers could fire canister into approaching enemy all along the waterfront.  The 1887 and 1897 inventories indicate that at one time the fort’s weaponry included 39 10-inch Rodmans at the coastal batteries (A and B), with another 15 in the casemates within the fort.

Additional ordnance included three 15-inch Rodmans, five 42-pdr. rifled cannon and 12 24-pdr. flank howitzers.

One good outcome with construction projects that stretch over many years is that innovations are sometimes easier to accommodate. Originally, A and B Batteries both had a hot shot furnace to heat cannonballs so hot that when they hit a wooden ship they set fires. These furnaces were designed for 42-pdr. cannon that were never placed; instead the Rodmans were installed when ironclads replaced wooden vessels.

The introduction of the new Rodman guns in 1865 required some modifications to A and B Batteries.

For one thing, seven men were needed to load and fire the 15-inch cannon in A Battery. The shell alone weighed 330 pounds, with a 17-pound bursting charge. “Powder used ranged from a low of 50 to a high of 125-130 pounds in the 15-inch gun,” according to Bennatti.

The Rodman guns originally placed outside the fort overlooking the river were two 15-inch guns in Battery A and one in Battery B, and 31 10-inchers in Battery A and eight in Battery B.
“Rodman’s 15-inch gun, with its abnormally low bore, length-diameter ratio, fired its 330-pound shell at a muzzle velocity of 1,735 feet per second, much faster than the velocity achieved with any other gun,” making this an excellent weapon for the fort’s riverfront location, Bennatti said. From 1,000 yards their round-ball projectile could penetrate 10 inches into an iron hull. No warship of the time could afford a close encounter with a Rodman.

According to the National Park Service at Fort Washington Park (Maryland), when the 15-inch Rodman was finally tested at Sandy Hook, N.J., in 1883, it was found that 130 pounds of black powder created 25,000 pounds of pressure in the chamber. At 20 degrees elevation it could send a 440-pound shell over 3-1/2 miles.      

The Rodman in Battery A could fire a 350-pound shell or a 450-pound shot. The solid shot was used against structures or ships because of its capacity to inflict heavy damage on impact. A friction-fit shell with a timed fuse, known as the “seacoast fuse,” was ideal as an anti-personnel weapon. It had a lead covering to protect the fuse from water, important for a seacoast location.

Sometimes the shell, with a fuse of appropriate length, was aimed to ricochet over the water before hitting its target.

Today one of the 15-inch Rodmans lacks a carriage because, like many gun carriages, it was melted down for scrap in the build-up to World War II.
The 10-inch Rodman inside the fort sits on its original carriage.

The embrasures that these cannon were fired through were reduced to one-fifth of the original size, further protecting the soldiers firing the guns. Fort Pitt also had ingenious shutters. This entire casemate of embrasures and shutters was developed by Brig. Gen. Joseph Totten of the Army Corps of Engineers.

The cannon pivoted about the narrowest part of the embrasure, allowing for the smaller embrasure and wider field of fire. The shutters opened and closed automatically for the firing of the cannon.

The soldiers at Fort Knox became proficient in operating the Rodman guns and could sponge, clean, load, aim and fire in just over a minute. They would have been a devastating threat if the fort ever saw action.

Fort Knox experienced two periods of military activity, from 1863-1866, when it was garrisoned by some 117 Maine volunteers, and in 1898 when about 500 Connecticut troops were stationed there during the Spanish-American War.

This granite fort was Maine’s first, and was the model for Fort Popham at Popham Beach (see sidebar), Fort Gorges on Hog Island off Portland and Fort Preble on Spring Point in Portland.

Fort Knox and other Maine state facilities usually open May 1.  Groups may schedule tours through October with The Friends of Fort Knox, P.O. Box 456, Bucksport, ME 04416, (207) 469-6553,

To reach Fort Knox, travel north on U.S. Route 1 to Prospect and turn left at the Fort Knox sign, just before the bridge. You’ll be looking down on Bucksport.



Fort Popham’s Guns Long Gone

Its guns are long gone, scattered before they could even be placed. Fort Popham at Popham Beach, now a state historic site, was built in 1861 near the 1607 site of the original Popham Colony, the first English attempt to colonize New England.

The fort sits literally on the river and visitors can climb the one accessible spiral granite staircase and look out on the currents of a swift-moving and sometimes treacherous portion of the Kennebec River. 
Original fortifications on this site were garrisoned during the Revolution and the War of 1812, and this granite structure itself was constructed during the Civil War. It was briefly manned again in 1898 and for World War I. Like so many of the grand old forts, Fort Popham became obsolete with changes in weaponry and ships.

Seals feed here daily, riding the tide, and gulls and cormorants swoop for the fish. This fort is in bad need of repair, but its location at the end of a point of land and overlooking this section of the Kennebec makes it a great visit.

Take Route 209 south from U.S. Route 1 in Bath. Follow 209 to its end 15 miles down and you’ll come to the fort.

What happened to its guns? One is practically next door, between Spinney’s Restaurant and Percy’s Market and is accessible from a path on the beach. It is a West Point Foundry 6.4-inch Army Parrott rifle cast in 1865.
Another, an 8-inch Rodman manufactured at Seyfert, McManus and Company in Reading, Pa., found its way to the Knights of Pythias in Bowdoinham, Maine.

The cannon was bought from Fort Popham and placed on its base on May 1, 1905, and its memorial tablet was dedicated in August 1908.

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