If you like reading about military history, you will like this story. Some of the most unique uses of the 13” Mortar during the Civil War are discussed in these two and a half pages.
One of the most interesting, if not the most massive, uses of the Seacoast and Naval 13” Mortar, Model 1861 can be found in the pages of the excellent book,
Blue and Gray at Sea, Naval Memoirs of the Civil War edited by Brian M. Thomsen and published by Tom Doherty Associates, New York, New York. It comes from the Incidents and Anecdotes of the Civil War by Admiral David Dixon Porter and features the details of horse-marine adventure, the Steele Bayou Expedition.
After the unsuccessful Yazoo Pass Expedition in which some Federal, Western River Ironclads attempted to get behind Vicksburg, called the ‘Gibralter of the Confederacy’ on the Mississippi River to investigate whether or not troopships could be delivered over flooded plains and bayous in the rear of Vicksburg’s 40,000 man Confederate rear guard, Porter decided to try a different route with his ironclad flotilla, following a trace taken by he and General Grant on an earlier scouting mission.
The following text, in the words of Admiral Porter, explains some details of this expedition. “I determined to go myself, and, to make it a success, I omitted nothing that might possibly be wanted on such an expedition. I selected the ironclads Louiseville, Lieutenant-Commanding Owen; Cincinnati, Lieutenant-Commanding Bache; Carondelet, Lieutenant-Commanding Murphy; Mound City, Lieutenant-Commanding Wilson; Pittsburg, Lieutenant-Commanding Hoel and four tugs and two light mortar boats built for the occasion, to carry each a thirteen-inch mortar and shells enough to bombard a city.
I really do believe I thought I was sure of getting in the rear of Vicksburg, and could send some shells into the hills that would keep them fastened down to eternity.
General Grant was so much interested in this work that he went up to the end of the woods on one of the transports to see Sherman start on his march alongside of the gunboats.
It was intended from the first that we should travel along together for mutual support. We to transport him across rivers and marshes, he to keep off sharpshooters, whom we could not reach with our guns on account of the high banks.”
Although this was supposed to be a secret expedition, Confederate scouts had the ironclads and steamers well located on their maps and infantrymen were closing in on Porter’s gunboats as they passed through the immense flooded area of Cypress Bayou in search of the Sunflower River some 75 miles distant. Nature gave them the most trouble, with thick forests to be hacked through and large trees to be pulled down to clear a channel and most difficult were the extremely narrow canals which had to be followed to keep water under the keel. Miles and mile of high banks made their large broadside guns useless, leaving the flotilla with 4 or 5 12 pounders and two 13” mortars and about two hundred troops onboard.
In Porters words this is how Confederates brought the fight to this secret expedition; “I heard the faint reports of two guns, and directly after the shrill shriek of rifle-shot, which came from directions at right angles from each other.the shells burst over the Indian Mound where Lieutenant Murphy was studying the strategy of war. They were Whitworth shells. I knew the sound too well to be mistakenThere were two six-gun batteries with a cross-fire on us.The two field batteries were keeping up a rapid fire, and fifteen shells a minute wee coming from the enemies spitfires and bursting in all directions, throwing the pieces of iron and the bullets of the shrapnel down on the decks of the ironclads, where they rattled like hail.
The fire from the enemy’s Whitworths was incessant, and everyone was running to cover.
The shells from the enemy came so rapidly that it became annoying, so I ordered the mortars manned, measured the distance by the sound—2,800 yards on one range, and 2,600 on the other—and opened fire. The shells seemed to be well timed; they fell in the midst of their artillerists, and the two batteries ceased by mutual consent.”
The Confederates landed two thousand men from transports near one of the Whitworth batteries. With Porter’s flagship stuck fast in a mass of small submarine willows within the narrow canal with high banks, he was starting to realize his position was less than ideal. He knew that Sherman’s army was close, but not where it was. He ordered his infantry troops to debark the steamers and man the canal banks. The incessant Whitworth rifle fire started up once more. 20 shells a minute. Porter thought they would be carried by boarding before Sherman would arrive.
Once again in Porters words: “Only the enemy didn’t know what a fix we were in. They didn’t know how it was that we could fire those 13” shells, that would burst at the root of a great tree and would throw it in the air. They didn’t know that we had only four smooth-bore howitzers free to work, that our heavy guns were useless, below the bank.
Sharpshooters made their appearance in the morning. About sixty of them surrounded us. At first it was like an occasional drop of rain. Then it was pat, pat against the iron hull all the time. The smokestacks seemed to be favorite marks to aim at. They, no doubt took it for the captain, or the main motive power which kept us a-going.
The sharpshooters were not, as a rule, the brightest I have seem, but they had bomb-shell falling among them, and now and then a tree, behind which they were, would suddenly be lifted out of the ground or canted sideways. The bomb-shell were demoralizing.
I adopted a new plan. I turned all the guns into mortars by firing them at the greatest elevation (to clear the banks). And with very low charges. With short time fuzes and a range of about six hundred yards this had a good effect, and the sharpshooter kept a long way off.”
Finally, with numerous log obstructions cleared, the enemy sharpshooters closed in again to keep the flotilla’s attention. And from another direction came real trouble.
In Porter’s words, “We had no sooner got rid of the obstructions than we saw a large column of gray-uniformed soldiers swooping down on us from the woods.
We opened mortar fire on them. They didn’t mind it. On they came. They were no doubt determined to overwhelm us by numbers, and close us in. Their sharpshooters had taken up positions behind trees about one hundred yards from us and our men were firing rapidly at them as they opened on us.
The sharpshooters were beginning to be troublesome about this time, when suddenly I saw the advancing column begin to fall into confusion; then they jumped behind trees, or fell into groups, and kept up a rapid rate of musketry. It looked as if they were fighting among themselves. But no! they were retreating before some one. They had run afoul of Sherman’s army, which was already driving them back.
The enemy were surprised at encountering such a force. They never dreamed of meeting an army of five or six thousand men. I believe there were more.
“Old Tecumseh” came riding up about half an hour after the last mishaps, on an old horse he had captured.”
“Halloo, Porter,” said the general when he saw me, “what did you go get into such an ugly scrape for? So much for you Navy fellows getting out of your element; better send for the soldiers always. My boys will put you through.”
US Army Corps of Engineers New Orleans District
Cultural Rescores Series
Report Number: COELMN/PD-89/04
A Research Design for Cultural Resources Investigations in the Vicinity of Fort Jackson, Plaquemines Parish, Louisiana Coastal Environments Inc.
Baton, Rouge, LA., 70802
Final Report
April 1990
“By 16 April 1862, Farragut had towed all of his fleet across the bar at the mouth of the river and had moved upstream to a point just below the forts. The Federal Fleet contained 21 armed vessels (Table 2) in addition to an equal number of mortar schooners (Table 3), commanded by Captain David D. Porter. The guns in the Federal fleet greatly outnumbered those in the Confederate flotilla. Most of the northern ships mounted two heavy-rifled guns in addition to numerous broadside cannons of various sizes. Porter’s mortar schooners each carried one 13-in seacoast mortar, capable of delivering 200-pound projectile a distance of 4300 yards, as well as two 12-pounder howitzers. By 18 April, Farragut had positioned Porter’s mortar flotilla behind a line of woods some 3000 yards below Fort Jackson.”
Also, the investment of Confederate held, Fort Pulaski, near Savannah, Georgia by Quincy Gilmore in 1862, used a dozen 13” Seacoast Mortars, Model 1861. From the excellent site, http://ourgeorgiahistory.com/wars/Civil_War/ftpulaski.html we get the following, the chart of which has appeared in many different books, coming from Quincy Gillmore’s original battle report:
Battery Armament Yards to
Target
Totten 2 10-inch Siege Mortars 1,650
McClellan 2 84-pounder James (Rifled)
2 64-pounder James (Rifled) 1,650
Sigel 5 30-pounder Parrott
1 48-pounder James (Rifled) 1,670
Scott 3 10-inch Columbiads
1 8-inch Columbiad 1,740
Halleck 2 heavy 13-inch Mortar 2,400
Sherman 3 heavy 13-inch Mortar 2,650
Burnside 1 heavy 13-inch Mortar 2,750
Lincoln 3 heavy 8-inch Columbiads 3,045
Lyon 3 heavy 10-inch Columbiads 3,100
Grant 3 heavy 13-inch Mortars 3,200
Stanton 3 heavy 13-inch Mortars 3,400
The Battle:
“Batteries lined the northern end of Big Tybee island, the closest slightly more than 1600 yards from the nearest wall of Fort Pulaski, the furthest almost two miles away. The order to commence firing was given and at 8:10am a 13-inch mortar shell from Battery Halleck exploded harmlessly in the air beyond the fort. The second shell, a 13-inch mortar from Battery Stanton, fell in the south channel. At first, while ranging the artillery, the cannon fire was ineffective. Finally, the trajectory was set so that most shells landed in the fort or hit the walls. Hitting the same spot over and over took time and patience but the artillerymen slowly gained accuracy. By the end of the first day Fort Pulaski was in serious danger; the Confederates' ability to return fire had been negated and 2-4 feet of the southeast corner from the parapet to the base now lay in the rocks below. The artillery fire was taking its toll.
Inside the fort Colonel Olmstead held out little hope of help from Savannah. Both Fort Pulaski and his command were falling to recent technological advances in artillery. During the night Captain Gillmore kept up occasional fire, if only for the psychological value.
Cool morning air greeted the men on either side of the sound on the morning of April 11, 1862. The Norwich, a U.S. gunboat and artillery mounted on a barge in Tybee Creek joined the battle. By noon the walls of Fort Pulaski had been breached in two places and Union forces were preparing to launch an assault. Gillmore, breveted to a brigadier general, ordered the artillery fire to concentrate on the remaining parapets to reduce the Rebel's ability to withstand a direct assault. Now shells were passing through the breachand striking the north magazine where 40,000 pounds of powder were stored. Colonel Olmstead ordered the Confederate flag lowered at 2:30pm, then raised the white flag of surrender. Gillmore demanded an unconditional surrender. Olmstead had no other options.”
Information on the Battle for Island No. 10 can be found at the excellent web site: http://showme.net/~fkeller/quake/mapscivilwar.htm Studying these and other maps over the years, I found that the Federal Mortar boat bombardment on Island No. 10 at New Madrid on the Mississippi River occurred at the greatest range of any significant bombardment for which records exists, this range being between 3,800 and 4250 yards or 2.2 and 2.4 miles. The three week bombardment produced mixed results, but did not dislodge the tenacious Confederate artillerymen on Island No. 10.
A map featured on the Show Me website.
A small scale map from the Show Me website. It's easier to see where the mortar boats were. The Eads Ironclads are also named and positioned.
