DRAUGHT AND CALCULATIONS OF THE LAKE PROPELLER "ORIENTAL."
The "Oriental" was built at Buffalo, in 1854, by Messrs. Bidwell and Banta, and is the largest screw vessel on the Lakes.
She is of 950 tons register, and carries 750 tons of freight.
The weight of engine, boiler, and 100 tons of coal, is equal to
208 tons. The loaded draught of water is 11 feet. Average
speed when loaded is equal to 9 miles per hour in good weather,
but she runs much faster and steers better when light.
The semi-circle described in the engraving of body-plan represents the periphery and position of the screw propeller as now
fitted. The first screw was made 22 feet in diameter, but was
impracticable for use -- the vessel refusing to steer. The present
screw was found best adapted for propulsory purposes, having
less diameter and pitch ; and no difficulty is now experienced in
working ship. It will be observed that the dip of screw-blades
is small (60 square feet immersed when loaded) in proportion to [p. 140]
the transverse area of midship section, (equal to 297 feet) and
the bulk of displacement. The engines are also light, weighing
less than 100 tons, working steam at a moderate pressure, and
consuming only three-fourths of a ton of coal per hour. The
weight of vessel and cargo, at 11 feet draught of water, may be
set down at 1,400 tons gross. Under such circumstances, an
extraordinary speed cannot be expected.
The stern is shaped and built like that of a yawl boat, in order
to permit the wheel to extend above the transom; the guards
being carried around the stern as usual.
We have not yet been placed in possession of the particulars
of her construction ; but in connection with the draught, and
the remarks concerning her engines, and also those of the propellers "Buffalo" and "International," to be found in the following article, page 141, we give the calculations of hull, as we
have worked them out from the draught.
|Length on load line for calculations,||217 |
|Height of same above base line, ||10 |
|Height of planksheer above base line, ||14.50 |
|Breadth moulded on load line at dead flat, ||33 |
|Breadth extreme, ||33.66 |
|Area of load water-line section in square feet, ||5629.28 |
|Exponent of the same, ||0,757 |
|Centre of gravity of same abaft mid-length, ||8.58 |
|Area of greatest transverse section (moulded,) sq. feet, ||296.77 |
|Exponent of the same (full) ||0.90 |
|Location abaft mid-length on load line, ||4.50 |
|Moulded displacement in cubic feet, ||45068.86 |
|" " in tons gross, ||1287.68 |
|Exponent of displacement, ||0.63 |
|Centre of gravity of same below load line, ||4 34 |
|Centre of gravity of same abaft mid-length,|| 5.77 |
|Moment of stability (s. 2-3 y3 dx) ||=3919,69 |
|Height of meta centre above buoyancy, ||8.69 |
The "Oriental" was built for freighting purposes only. Her
upper deck extends the entire length of vessel, as usual in
Lake propellers, upon which the cabins for the accommodation
of officers and crew, only, are constructed.