Hello- I found the following report regarding coaling of the U.S.S. Hartford in Series I, Volume 18, page 476 of the ORN. Some of the questions you posed might be answered by Ward's book on steam engineering, pubished 1860. I'm waiting on it.

A site that has answered almost all questions regarding sailing:

http://southseas.nla.gov.au/refs/falc/search.html

I searched for the definition of a "sponson" on this site. No go. That is a relatively recent term.

U.S. Flagship Hartford
At anchor off Baton Rouge, May 10, 1862

Sir: I find upon examination a quantity of coal at the foundry recently employed by the Confederate Government, casting shot, etc. This coal I shall require for the use of my vessels, and shall therefore take it, but as a general thing I desire to trade with the people and pay for whatever I require.

I am, very respectfully, your obedient servant,
D.G. Farragut
Flag-Officer Western Gulf Blockading Squadron
His honor the Mayor, Baton Rouge.