Wisconsin's Great Lakes Shipwrecks - Explore Shipwrecks - Pretoria


	beam
	The width of a ship at its widest point.


	gross tonnage
	The overall volume of a ship's hull, including crew cabins, storerooms and machinery spaces. A ton equals 100 cubic feet. The calculation of tonnage is complex, and a major revision in tonnage calculation laws occurred in 1864. The term "old measurement" reflects measurements before this change. See also net tonnage.


	net tonnage
	The volume of cargo a ship could carry, equal to gross tonnage minus the crew cabins, storerooms and machinery spaces. One ton equals 100 cubic feet.


	bushel
	A unit of volume (dry measure) used in the United States, equal to 32 quarts or approximately 35.2 liters.


	keelson
	A structure of timbers or steel beams that are bolted to the top of a keel to increase its strength. Also spelled kelson.


	chord
	The principal horizontal member in a rigid framework. In Great Lakes shipbuilding, a heavy horizontal metal strap fastened around a hull at the level of the upper deck , supporting a framework of arches and cross bracing.


	arch
	A curved architectural structure used to support suspended weight. In Great Lakes wooden shipbuilding, a wide iron- or steel-fastened strap down each side of a ship, usually fastened low in the bow and stern and rising to the level of the upper deck amidships; provides longitudinal support to the hull.


	mast
	A long wooden or metal pole or spar, usually vertical, on the deck or keel of a ship, that supports spars and sails. On a sailing ship, supported on the keelson.


	topmast
	An upper, secondary mast on a sailing vessel, supported by a heavier, lower mast.


	pony boiler
	Variation of donkey boiler.


	stockless anchor
	An anchor that is not secured to the rail at the bow of a ship, as stock anchors are, but is pulled up into the hawsepipes until the flukes meet the hull.


	main deck
	The principal deck of a ship. In ships with multiple decks, the deck beneath the spar deck.


	steamer
	(A steamship.) A ship propelled by a steam engine.


	pilothouse
	A compartment on or near the bridge of a ship that contains the steering wheel and other controls, compass, charts, navigating equipment and means of communicating with the engine room and other parts of the ship. Also known as wheelhouse.


	aft
	(Or after.) Near, toward or at the stern of a ship.


	hoist
	A power unit for lifting, usually designed to lift from a position directly above the load.


	combination pump
	A dual-purpose steam engine that conducted multiple tasks such as pumping water and hoisting.


	amidships
	In or toward the part of a ship midway between bow and stern.


	syphon
	Variation of siphon. A tube, pipe or hose through which a liquid can be moved from a higher to a lower level by atmospheric pressure forcing it up the shorter leg while the weight of the liquid in the longer leg causes continuous downward flow.

Wisconsin's Great Lakes Shipwrecks - Explore Shipwrecks - Pretoria

PRETORIA

Service History



The schooner-barge Pretoria was one of the most colossal wooden vessels to sail the Great Lakes. It was 338 feet long - longer than a football field. It had a 44-foot beam and a depth of 23 feet. It reportedly had 11 hatches in its deck for loading cargo into the hold - each hatch was 7 feet by 26 feet. With a gross tonnage of 2,791 tons and a net tonnage of 2,715 tons, it could carry as much freight as 50 railroad cars. The Pretoria was built at the turn of the century in West Bay City, Michigan, by James Davidson, a ship-building marvel in his day. Davidson was well-known for building high-quality wooden vessels that could carry heavy cargoes. He also was regarded as one of the final holdouts in the wooden shipbuilding industry. The Saginaw (Michigan) Courier-Herald described the Pretoria's July 26, 1900, launching: The schooner Pretoria, the largest wooden boat ever built, was launched at Davidson's shipyard this afternoon, in the presence of a vast multitude. The Pretoria will carry 5,000 tons of iron ore, 175,000 bushels of wheat, or 300,000 bushels of oats. ... [S]he is very strong and substantially constructed in every way, has steel keelson plates, steel chords , steel arches , and is also diagonally strapped with steel. The vessel is supplied with three masts , each having a topmast , and these are all equipped with sails. The Pretoria when launched was ready for sea, and even her sails were bent and running gear all rove off when she went into the water. A large pony boiler is supplied, which is situated stockless anchors . The is built on the main deck , the same as a steamer , and this is entirely in hardwood, cabinet finish. The pilothouse is located aft , and the vessel is steered by the latest improved hydraulic steerer. A large deck hoist and combination pump is situated amidships for use of moving at the dock or hoisting sails or cargo, as well as for pumping the ship. Another large steam pump and steam syphons are situated forward. The Pretoria has a rating of A1 star in the Inland Lloyds Insurance Register, and also has the highest class in all the insurance registers of New York City and London. The Pretoria was enrolled at Port Huron, Michigan, on July 27, 1900, and served the Davidson Steamship Company without incident for five years. Read the tale of the Pretoria's final voyage



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