U. S. A. H. Sevier; Snag Boat No. 4

These double-hulled craft incorporated and iron-sheathed
snag beam at the bow joining the two hulls.  During operations
 the boat was run full speed at the projecting snag,
forcing it up  and out of the water.  The snag was then hauled
 onto the boat deck and cut into pieces.  Snag boats
were capable of removing snags weighing up to seventy-five tons.

The A. H. Sevier, Snag Boat No. 4 worked
under the direction of the Superintendent of Western River
 Improvements, within the War Department.  Built during the 1840's
 each hull of the Sevier was about one hundred and fifty
 feet long, twenty-two feet wide, with twelve feet between the hulls.
 -- 19th Century"xxxxxx, St. Louis, 1858" sketch book.