Monday answer.
Inauguration Day! There were numerous names for flat bottomed river boats in the late 1700�s--flat boat, barge, broadhorn (if it used steering poles on either side along with the rear sweep), Kentucky Boat (if going only as far as Kentucky), New Orleans Boat (if making to complete journey to there). The big boat, the name I was asking, was called an Ark. They appeared as if a flood lifted a house off of its foundation and floated it off. These not only were 3/4 story house boats, but floating forts, built as no keel flat boats with only a slightly pitched gable roof, which served as a platform for stored feed and hay, a wagon with wheels removed, maybe a plow, possibly a small cannon, and often laundry on a line. TOn an Ark the walls of the "house" were flush with the sides of the boat and there was no deck not enclosed (except the roof). Animals lived inside with the people-which could total over fifty. People on long duration trips separated themselves by canvas partitions. The house had origins to the habitable riverboats of Europe, but was much heavier because it used four inch thick planks and was trenailed. An Ark had a draft of roughly three feet and if it was to travel from Pittsburgh to New Orleans the width was limited to 15 ft because the 26 foot drop at �Falls of the Ohio� around modern day Louisville, KY, has a channel through the rapids that wide. Windows were firing slits to repel boarders (Indians and river pirates). It apparently did well in a fight because it attempted to stay in the river center, but could be trapped by an awkward current. Often other boats would tag along and in emergencies the Ark would serve by as a shelter for others in more exposed craft. It had a top hatch accessed by a ladder inside. There was also a wide, thick, and heavy livestock door on the side, it could be removed to the inside or hinged on the bottom that made a sort of gangplank. The ark had no prow and the steering oar or sweep was as long as the boat and steered from the roof. Arks had a minimum male crew of three. They often towed a small skiff or a larger bateau, for channel to shore stops. These were credited as the early start of the Pittsburgh river barge business.
The terms I asked about were wood dangers to navigation on the river. �Planters� were trees anchored on the bottom with the trunk angled upward. �Sleepers� were more dangerous entirely submerged trees and branches, and �sawyers� were slow floaters that rose and fell in a river rhythm that could allow one boat to pass, but stove in another twenty minutes later. Few people know that the rivers at Pittsburgh and much of the Ohio until fairly recently were only 2 to 3 feet deep much of the year. Travelers had to wait until the ice broke and the spring runoff increased depth. A bridge wasn�t needed to cross the river near Pittsburgh until the Corps of Engineers built the lock and dam system that deepened the river pool. Dredging did the rest. The average depth of the Ohio River from Pittsburgh, PA, to Cairo, IL, is now about 24 feet. The Ohio has been dredged since the civil war, but only to a depth of first 6, then 9 feet until the 1940�s when the coal and coke barges were needed for the mills during WWII.
Sources:New Nation. Anita Vickers, Popular Culture of a New Nation, p228; Dixie Frontier, Everett Dick, A Nation on the March, p 19;
Frontier Living, Edwin Tunis p62; Keelboats and Flatboats, Dallas Bogan, internet, no page. The only drawing I could find was in the Tunis book
