Last time around the HornJul 26, 2007
Sailors on yachts and passing ships won't believe their eyes. They'll check it again with binoculars and then rush to call up fellow crewmembers so they can see it as well. That ship on the horizon way down here near the tip of South American is an aircraft carrier, and it's being towed by that tugboat. It's sure to be the most memorable voyage sight of those who see it at any particular time this summer.
They are the ex-U.S.S. Oriskany, CVA- 34, and the 150-foot tugboat, Sea Victory. The 46,000-ton carrier is on her way to a scrapyard in Texas expected to arrive sometime in August. The 7,000-hp tugboat is among the largest or the 90 or so owned by Crowley Marine Services of Seattle.
Under command of ex-U.S. Navy captain Kaare Ogaard, Sea Victory was, as of early June, not even halfway through the 15,000-mile voyage that is unrolling at a traditional speed for such undertakings: six to seven knots. Too wide to fit through the Panama Canal, the carrier was due to be towed through the Straits of Magellan in June or July and arrive in the Gulf of Mexico in late August.
Now, imagine yourself in the shoes of Capt. Ogaard. Despite the presence of all modern forms of navigation devices in Sea Victory's wheelhouse, there is also a sextant, nautical almanac, and appropriate books and tools needed to put them to work. In late May, the tug and tow extending almost half a mile in total length on the open sea were making their way south at an average rate of 150 miles per day, consuming about 7,500 gallons of diesel fuel every day (Sea Victory carries 200,000 gallons of fuel in her tanks). In the early morning hours of May 25, we assumed that the tug was a few hundred miles off the coast of Columbia at a latitude of about 5 degrees North. She was fresh from a refueling stop at Balboa, starting out again with full tanks, heading directly south.
A. When would we expect her to arrive at the 42nd parallel of southerly latitude?
B. Once at that latitude, how many more days could she proceed before running out of fuel, assuming benign weather and uneventful towing conditions?
To keep driving ahead despite the incredible weight of an aircraft carrier astern (still with two of her four propellers dragging through the water) Sea Victory draws upon the power of a pair of 20-cylinder diesel engines produced by the Electromotive Division of General Motors. Each 3,600-hp engine turns a shaft leading to a 12-foot diameter, four-bladed propeller that rotates within a steel nozzle designed to enhance water-flow through the propeller and increase thrust. At full power, the tug can exert a towing force on the Oriskany of 120 tons.
Unfortunately for the skipper and his six crewmembers, they are heading south towards the region of Cape Horn at the beginning of Austral winter. June 21st, which heralds the start of summer for most Americans, marks the start of the opposite season for citizens of Chile.
C. What is the length of day sunrise to sunset when the tug reaches that 42nd parallel of latitude (the southern one)?
D. What would be the brightest object in the evening sky?
Known as the O'Mighty O, Oriskany was commissioned in 1950 as the last of the famed Essex class of carriers. When on duty she carried a crew of 3,500 sailors and aviators and 80 to 100 aircraft. Her career, unfortunately, was marred by a shipboard fire off the coast of Vietnam in 1966 that resulted in the deaths of 44 crewmembers with hundreds more injured.
Decommissioned in 1996, Oriskany will be broken up; those who see her will be looking at her final voyage.