This thesis presents the results of a naval architecture analysis of the Civil War Ironclad CSS Virginia, built by the Confederate States Navy to break the Union Blockade of Hampton Roads, and which famously engaged the USS Monitor on the second day of the Battle of Hampton Roads, March 9th, 1862.
The purpose of the analysis was to examine the ship from a naval architectural standpoint pertaining to hydrostatics, stability, weight and center of gravity, sea keeping, and basic resistance/powering requirements. The overall objective was to see if the story of the CSS Virginia, destroyed on May 11th, 1862 by its own crew to keep it from falling into Union hands, could have ended differently with an attack on Washington, a northern city such as New York or Boston, or a run to a friendly Southern port such as Savannah or Charleston.
Paramarine software was used to build a geometry model based on lines included in a book by Sumner B. Besse for ship modelers. The geometry model provided the basic measures of displacement for the hull form at a draft of 21 ft forward and 22 ft aft which in turn allowed for a weight estimate to be undertaken. The goal of the weight estimate was to obtain, in particular, an estimate for the VCG of the vessel. It also allowed for gyradius calculations based on the resultant weight distribution to be calculated. Historical information coupled with the Paramarine geometry was used for the weight analysis.
Paramarine was used to obtain Random Amplitude Operators (RAOs) for a sea keeping analysis and long term effectiveness ratings considering MSI and Deck Wetness criteria were obtained based on statistical wave data from NOAA taken from stations in the Chesapeake Bay and in the Atlantic, 64 miles east of Virginia Beach.
A NAVCAD analysis was made for resistance requirements, though any resistance analysis of such an antiquated hull form that is also in its way unique has large uncertainties associated with it.
The results of the analysis shed some light on the CSS Virginia and its history.
The hydrostatic analysis leads one to speculate that draft reduction efforts made to allow the Virginia to escape Union capture by sailing up the James River were known to be hopeless, but undertaken anyway to save the honor of those involved and shift blame for the loss of the ship elsewhere.
The resistance and powering analysis suggests that an upper speed of 6 knots was probably not outside the CSS Virginia's capabilities. Speeds much higher seem unlikely. The only way to know more would be to get better estimates of power provided by the ship's steam engines and do a tow tank test of a ship model. Assuming a speed of 6 knots and based on a coal consumption rate, it was found that range of the CSS Virginia was at best around 614 nautical miles, giving it the distance to attack New York or sail to Charleston or Savannah.
However, the sea keeping analysis shows that the Virginia was very much at home on the relatively calm waters of the Chesapeake Bay, but would have run great risks in sailing on the open sea either to attack a Northern city or make a run to the South for safer waters to fight another day. The officers of the Virginia felt that the ship was likely to flounder; based on the deck wetness criteria chosen for the sea keeping analysis their professional judgment was correct.
Details of the weight analysis and a full set of RAOs are provided in the Appendices. / Master of Science / This thesis presents an analysis of the Civil War Ironclad <i>CSS Virginia</i>, built by the Confederate States Navy to break the Union Blockade of Hampton Roads in Southeastern Virginia, using modern engineering techniques. The <i>Virginia</i> famously engaged the Union Ironclad <i>USS Monitor</i> on the second day of the Battle of Hampton Roads, March 9th, 1862. The analysis gives critical insight into how they ship may have performed in different scenarios (i.e. on the relatively calm waters of the Chesapeake Bay or the more unpredictable seaways of the eastern Atlantic Ocean).
This thesis begins with a brief overview of the history behind the <i>CSS Virginia</i>, including the development of ironclad vessels up to 1862. Ironclad vessels featured wooden hulls that were covered in a layer of iron plating, held together by bolts. Ironclads were developed because the introduction of the exploding shell for naval use posed a significant threat to the wooden hulled warships that had been state of the art for centuries. The shells could penetrate the wooden hulls and explode inside the ship, causing tremendous damage. The iron plating which gave the ironclad its name deflected these exploding shells, allowing an ironclad to survive a naval engagement that a wooden ship of war could not. Ironclads were propelled by steam engines, which also representeded a recent technological development in maritime propulsion.
At the outset of the American Civil War, the Confederate States Navy realized that the only way to break a Union Blockade (made up entirely of wooden vessels) was to construct an ironclad that could defeat the Union Fleet in Hampton Roads. An ironclad, armed with shell guns, would be a severe threat to the Union Fleet, as it could act with virtual impunity unless another ironclad vessel arrived to meet it. On March 8th, 1862, the <i>CSS Virginia</i> sailed into Hampton Roads and engaged the Union forces, sinking two ships while suffering very little damage. On March 9th the <i>USS Monitor</i>, which had fortuitously arrived on the evening of the 8th, fought the <i>CSS Virginia</i> to what most would consider a draw, with neither ship able to significantly damage the other. This engagement is significant in naval history, as it largely is viewed as the final death knell of the wooden hulled warship.
Historical information in the form of model plans and books was used to construct a 3D geometry model of the <i>CSS Virginia</i> in a naval architecture (ship design) software suite called Paramarine. The geometry model was used to determine various naval architectural characteristics of the <i>Virginia</i> which can be used in various analyses. In parallel, a weight estimate of the <i>CSS Virginia</i> was made to determine the overall weight and center of gravity (the location of the overall weight inside the ship). Microsoft Excel was used to estimate the weight, and a variety of sources and methodologies were used to estimate different aspects of the weight. These different aspects include but are not limited to:
• Ship’s structure (the hull, decks, iron armor, etc.)
• Armaments and ammunition
• Provisions
• Weight of personnel serving on board and their effects
• Propulsion machinery weights
The weight and center of gravity were input into the Paramarine computer program which, combined with the geometry model, could now analyze various aspects of the <i>Virginia</i>. Of particular interest was hydrostatics (i.e. how the ship sits in the water given its weight and center of gravity and how stable it is) and sea keeping characteristics (i.e. how the ship behaves in waves when moving at a certain speed: its seaworthiness). An analysis was also made concerning how much power from the steam engines would be necessary to propel the <i>Virginia</i> at different speeds. The <i>Virginia</i> was a slow vessel, only able to move between 4 – 6 knots (about 5 – 7 miles per hour). The range (how far the <i>Virginia</i> could travel) was also estimated.
The results from these disparate analyses were used to discuss the likelihood of the <i>Virginia’s</i> story having a different ending. After the battle of Hampton Roads, the <i>CSS Virginia</i> continued to play a cat and mouse game with the <i>USS Monitor</i> until May 11th, 1862, when Norfolk, VA (where the <i>Virginia</i> was based) was taken by Union soldiers as part of the 1862 Peninsula Campaign. The <i>Virginia’s</i> commander desired to sail up the James River towards Richmond, but the ship sat too deep in the water to get over a sandbar that lay at the entrance to the James. Efforts were made to lighten the ship but these proved futile, and it was decided that the only course of action was to evacuate and destroy the <i>Virginia</i>. One notable aspect of the hydrostatic results presented in this thesis is that they suggest that efforts to lighten the ship in a bid to escape James River were known to be hopeless, but were ordered anyway to shift the blame for the loss of the ship away from its commanding officer and onto the ship’s pilots.
But were there other options open? Could the <i>CSS Virginia</i> set sail for the friendly ports of Charleston or Savannah? Could it have made an attack on New York City or Washington DC? The results of the different naval architecture analyses were used to answer questions like these. It was found that the <i>CSS Virginia</i> was very much at home on the relatively calm waters of the Chesapeake Bay, but in all probability would have encountered seas too rough for it to successfully navigate a transit on the open ocean. In making a run to Savannah, Charleston, or New York, the <i>Virginia</i> in all likelihood would have sunk.
This thesis presents new insights into the <i>CSS Virginia</i> and its performance, and provides a useful springboard upon which future research might be conducted on this unique and historic vessel.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/74944 |
| Date | 06 February 2017 |
| Creators | Marickovich, Nicholas Edward |
| Contributors | Aerospace and Ocean Engineering, Brown, Alan J., Brizzolara, Stefano, Kery, Sean M. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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