USS Monitor: The Not-So-Super Weapon at Drewry’s Bluff

The revolutionary ironclad USS Monitor became an icon of American ingenuity, industrial strength, and naval prowess following her famous clash with the Rebel ironclad Virginia/Merrimack on March 9, 1862. As with all emergent technologies, however, she had her problems.

On the following May 15, 161 years ago today, Monitor joined the ironclad frigate USS Galena and a few wooden gunboats in her only other major engagement, the unsuccessful attack on Fort Darling atop Drewry’s Bluff blocking the James River approach to Richmond. The Galena, unlike Monitor, was a traditional sea-going hull design with iron cladding that would prove to be inadequate. Monitor’s commanding officer, Lieutenant William Jeffers, reported his experiences.

“At half past seven [a.m.] I discovered an extensive fortification on an elevation of about two hundred feet, with several smaller batteries, all apparently mounting guns of the heaviest calibre ; at the foot of the bluff in the river an obstruction, formed of sunken steamers and vessels, secured with chains, and the shallow water piled across the river.”

Galena anchored about one thousand yards from the fort and became warmly engaged while the wooden gunboats hung back out of range. Jeffers: “I endeavored to pass ahead of [Galena] to take off some of the fire, but found that my guns could not be elevated sufficiently to point at the fort. I then took position on the line with the Galena, and maintained a deliberate fire until the close of the action.” Three plus hours later, Galena was forced to withdraw with heavy damage and many casualties; Monitor and the gunboats followed.

“The fire of the enemy was remarkably well directed,” continued Jeffers, “but vainly, towards this vessel. She was struck three times—one solid 8-inch shot square on the turret, two solid shot on the side armor forward of the pilot-house. Neither caused any damage beyond bending the plates. I am happy to report no casualties.”

“The action was most gallantly fought against great odds but with the usual effect against earthworks. So long as our vessels kept up a rapid fire they rarely fired in return, but the moment our fire slackened they remanned their guns. It was impossible to reduce such works, except with the aid of a land force.”

This lesson would be reinforced against well-constructed and heavily armed forts at New Orleans, Port Hudson, Vicksburg, Mobile, and Fort Fisher. The navy learned to bypass but could not—without the army—conquer them.

Jeffers followed his initial report with a detailed analysis of Monitor’s performance. “The opportune arrival of this vessel at Hampton Roads, and her success in staying the career of the Merrimack . . . caused an exaggerated confidence to be entertained by the public in the powers of the Monitor, which it was not good policy to check. I, however, feel that I owe it to you, sir, as the commander of the fleet, and to the department, to put on record my deliberate opinion of her powers.”

The captain’s first concern was directing the two mammoth 11-inch Dahlgren smoothbores, what we would now term “fire control.” In battle, the captain normally stood on a platform in the bow with his head and shoulders in the little iron-box pilothouse, shoulder to shoulder with the pilot and helmsman steering the vessel.

The pilothouse protruded a few feet above the main deck, which was itself just a few feet over the water. From that low vantage point, Jeffers viewed the enemy through narrow slits in the iron. In the revolving turret, the officer in charge of the guns could see his targets only through the narrow space between the big gun barrel and the top of the gunport directly in line of fire.

“The commander could have very little control of his guns if in the pilot-house,” Jeffers noted while “the process of turning the turret successively backward and forward, searching for the object through the small aperture of the ports, was so slow, that an active enemy with a large number of guns must inevitably fire into the ports during the operation. . . . The firing at Sewall’s Point, on the 9th instant, clearly demonstrated this fact.”

So, at Drewry’s Bluff, Jeffers climbed atop the turret, from where he could spot the shot. Sighting along parallel seams of the iron plating as reference lines, he was able to increase the rapidity and accuracy of fire. The captain was, however, fully exposed to enemy shell, as was also the open hatch to the turret interior at his feet, even with a barricade of hammocks around the turret edge.

In addition, the river was lined with riflemen on both banks. “I had no means of replying with musketry, nor could I elevate my guns to their position on a high bank, so that every time I stuck my head up to observe the fire, they had a deliberate fire at me.”

“As against a fort,” reported Jeffers, enemy guns in fixed embrasures had advantages: They could be loaded with impunity while the turret guns were turned away for loading and, with a wide field of view, they could be carefully aimed at Monitor’s open gun ports when the turret rotated to fire. Meanwhile, turret gunners had to aim through the narrow port by stopping the turret in line of fire—a slow and cumbersome process—or continue around and fire on the fly as the target swept by the muzzles.

Monitor’s armor could endure severe bombardment, he continued. She should concentrate fire to dismount enemy guns one by one, or for a masonry-casemated work, “quarry a hole into the face of the wall until it tumbled down by the superincumbent weight.” This outcome, however, required “the concurrence of many favorable contingencies.”

The ironclad must be able to approach within a couple of hundred yards. “Otherwise, the fire is not sufficient in either accuracy or rapidity.” And the fort must be “on nearly the same level,” which Fort Darling was not. If Monitor approached close enough to be truly effective, she could not elevate the guns to the bluffs. At longer range, they could hit the target, but much less accurately. “After we deliver our fire, if we do not dismount the gun, they reload without risk for another trial.”

During the engagement with Virginia, this maneuver also opened Monitor’s side to ramming, which almost happened. The impact was minimized only by the Union ironclad’s superior maneuverability as she turned aside just in time to receive a glancing blow. “This would have been the difficulty had a second encounter taken place with [Virginia].” And, the Rebel ironclad mounted an unobstructed forward-facing gun. “For these reasons, it is essential that [Monitor’s] lookout and steering apparatus shall be placed on top of the turret.” The change was made on subsequent monitor-class ironclads.

Finally, reported Jeffers, “a new and most important defect” emerged belowdecks in the hot summer weather. “It is essential that some other mode of ventilation shall be provided.” With the ship’s hull buttoned up underway or in battle, two ventilation blowers behind the engines sucked fresh air through gratings in the main deck, the only source supplying the boilers and the entire interior.

It was quite warm below during cold weather but “no inconvenience was felt.” Recently, however, the temperature inside the turret climbed to 140° in action, which, added to gasses, smoke, and heat of the gunpowder, boilers, and lamps, along with “emanations from the large number of persons stationed below,” produced “a most fetid atmosphere, causing an alarming degree of exhaustion and prostration of the crew.” At Drewry’s Bluff, he had to discontinue the action for a quarter of an hour while the men below moved to the forward part of the ship for purer air.

Captain Jeffers concluded his report: “Notwithstanding the recent battle in Hampton Roads, and the exploits of the plated gunboats in the western rivers, I am of the opinion that protecting the guns and gunners does not, except in special cases, compensate for the greatly diminished quantity of artillery, slow speed, and inferior accuracy of fire, and that, for general purposes, wooden ships, shell guns, and forts, whether for offence or defense, have not yet been superseded.”

The Union built over fifty monitors in a bewildering array of one, two, and three-turret classes. Incremental improvements were made to the design, but despite high-level command and public enthusiasm, i.e., “Monitor fever,” fundamental limitations remained.

The abortive attack by a squadron of monitors on forts ringing Charleston Harbor in April 1863 illustrated another. This time, the problem was not elevation—the forts were near water level—but fire volume. Hundreds of guns in multiple forts and batteries, backed up by fields of torpedoes, beat back with severe damage seven monitors and sank one experimental ironclad, all of which mounted only two guns each.

In the battle of Mobile Bay, August 5, 1864, the USS Tecumseh was leading a column of three other monitors when she hit a torpedo and immediately sank. Admiral David Farragut’s traditional warship squadron successfully bypassed Fort Morgan without much help from the ironclads. Once again, they were not effective against forts.

As a warship type, monitors were of limited utility. With a low profile, they were not seagoing vessels and therefore not useful against standard enemy warships or on the blockade. They were, however, almost indestructible floating batteries mounting the heaviest naval artillery, valuable for coastal and harbor defense and shore bombardment. Monitors also successfully countered several Rebel ironclads like Virginia. And they vividly captured the public imagination then and since.

For much more on the USS Monitor and the Battle of Hampton Roads, see our newest publication for the Tenth Anniversary Series: The Civil War on the Water: Favorite Stories and Fresh Perspectives from the Historians at Emerging Civil War and the Emerging Civil War Series volume Unlike Anything That Ever Floated: The Monitor and Virginia and the Battle Hampton Roads, March 8-9, 1862.

Source: Report of the Secretary of the Navy in Relation to Armored Vessels (Washington, DC: Government Printing Office, 1864), 26-29.