More on the Possible Monitor Revelation
Jim Caiella
In his “A New Look for an Old Icon,” Francis DuCoin makes an interesting argument for a view of the ironclad USS Monitor that few have imagined. Although he sheds new light on two often ignored drawings and cites disparate references, his conclusion raises some questions from a physical point of view.
The turret shield, as represented by Peterkin’s drawing No. 182, would weigh approximately 5,250 pounds, based on Monitor inventor John Ericsson’s assumption of the 1-inch-thick side armor weighing 40 pounds per square foot. That cannot be the total weight, however, because the top view the author presents shows the flat shield attached to a glacis on either side, which in turn are attached to turret exterior plates. These would account for at least another 750 pounds (but most likely more) to bring the total to at least 6,000 pounds.
1. Where is there evidence of what must have been significant rivets and flanges to attach the three-ton shield to the turret and support it?
2. When stationary, this three-ton mass, positioned more than ten feet from the turret’s center, would put an added stress of more than 30 tons on the relatively thin spindle (and its bearings and lifting wedge) in one plane. Where is evidence of a counteracting 30-ton force?
3. To rotate the turret, that three-ton mass that far from the center of rotation requires significant additional force to start and stop. How was this accommodated?
4. The addition of the shield even a few inches in front of the turret would significantly narrow the already restricted view through the gunports. And could a gunner have stuck his head out of a gunport to view the action, as has been reported, through 8 inches of iron, several more inches of space within the shield, and then another 2 inches of iron?
Despite these criticisms, as President Abraham Lincoln is quoted as having said while holding a model of the innovative ship, “All I have to say is what the girl said when she stuck her foot into the stocking. ‘It strikes me there’s something in it.’”
The author responds:
I greatly appreciate Mr. Caiella’s kind remarks and his insightful questions. It is my pleasure to address these. The calculations I made for the weight of the shield are in close agreement with his. I believe three tons is an accurate estimation.
1. It is not known how the shield was attached to the turret. However, the turret itself was bolted together, so there are numerous bolt locations that could have held brackets to support the shield. Since it was removed shortly after the battle, while the Monitor was in Hampton Roads, the shield had to be attached to the turret by bolts, not rivets.
2. While I agree this additional mass, extending 12 inches in front of the turret, would cause imbalances in the turret system, one must remember that the entire turret, including the guns, weighed an estimated 163 tons, so the shield added only 2 percent to the total.
The torque caused by this mass lying outside of the turret was unbalanced so it would have caused stress, but apparently, countered by the total mass of the turret, not enough to have had a great effect. It also should be noted that the turret was not directly attached to the 9-inch supporting shaft, but was resting on only an 18 x 21–inch “clutch” that not only helped to distribute the load on the shaft, but also provided flexibility in the supporting system.
3. The donkey steam engines that turned the turret through a series of spur gears were quite powerful and could rotate the entire structure in 22.5 seconds, which is 3 feet per second, fast for such a massive structure. However, starting and stopping it was not quick and, I agree, the shield certainly did not improve this situation.
4. Ericsson, recognizing the limitations of aiming the guns through the gun ports, provided precision-aiming telescopes to correct this. However, these did not work well and were not used. There was about 8 inches of clearance in the gun port above the muzzle when run out, but the breech was 6 inches wider than the muzzle, thus reducing the view even more. If the gun was run in, the view would not have been affected greatly by the shield. When the gun was run out, the shield would not have had a great effect on an already very poor situation. The shield may have contributed to the poor firing by the Monitor as reported by those on board the Virginia. I believe if a gunner was crazy enough to look out of the gun port in the midst of the battle, the shield certainly would have been a hindrance, but unfortunately not a deterrent.
There are many unknowns with the proposition of the Monitor’s turret having a shield, but it really reduces to a logic problem. Gustavus Fox witnessed the battle in his official capacity as Assistant Secretary of the Navy, and he “Presented to the U.S. Naval Academy” the artifact that he states was part of the USS Monitor during her battle. The inscription is his, and the artifact was given while he was in office. It is self-evident that the artifact is genuine. In all of the drawings of the Monitor, this artifact matches only one—the one titled “Shield for Turret.” There is no other part of the ship that even vaguely resembles it.
Alban Stimers in his report to Ericsson on the day of the battle states he “does not think much of the shield,” and the Monitor’s log reports when the “shield of the turret” was removed from the ship. So, unless Fox allowed an inaccurate inscription, or someone can propose anything else on the ship this artifact resembles, or there is a different explanation for Stimers’ letter and the log entry, then the shield had to be on the turret on 9 March 1862. Hopefully, now new information that was not previously understood will come to light providing additional evidence for the shield’s existence.
—Francis DuCoin