great question, Jack. An associated one would be where the coal was bunkered. From the reported layout of the vessel's smokestack,the question is whether the longitudinal axis of the boilers were fore or aft of the stack. You start thinking about weight distribution along her hull. Since she had a relatively deep hull form and was probably heavily constructed, she probably was not as subject to hogging and sagging as the shallow draft gunboats. I've never heard, for instance, that she had or required "hogging chains". This was not the case for the shallower draft Missouri. In regard to bunkring, you want the coal readily available to the "black gang". In later vessels, coal bunkers were distributed to port and starboard with chutes that fed coal into an area in front of the boilers and in shovel range for the coal heavers. Kind of similar in concept to the dirty clothes chutes in multi-story houses that dropped to a utility room in the basement. Bunkers of this type had a vertical chute from the upper deck using gravity as the feed system. Another issue was her bunker capacity. She didn't survive long enough to give some idea about her operational endurance. In a pinch, she could have substituted wood from the riverboat woodlots along the river. It is also interesting to question just how available coal remained in Vicksburg? One reported reason that Montgomery stood and fought with the River Defense Fleet at Memphis was a lack of coal so that his vessels could make a run to Vicksburg.