刚刚得到消息，今天（11月27日）又考了flip&hinge ship, 和古代纸币发展，外加一篇日本数学发展。
The Oceanographer's Dream Ship
摘自《真经》
It is every oceanographer's dream start to the day. Get out of bed, slip on a pair of jeans and a T-shirt, then take a lift to the bottom of the sea. No wetsuits, no submersibles, no decompression tanks, just a permanent trapdoor to the ocean floor.
Nobody's throwing away their wetsuit just yet, but a non-profit group of maritime engineers called the Ocean Technology Foundation reckon they can make the dream come true within ten years. They're planning to build a vessel that will take scientists, divers, tourists or anyone else who'll pay, to the bottom of the sea with the minimum of fuss.
One plan is for a vessel called the Deep Water Flip Ship. On paper at least, this is a huge, tubular boat that measures 330 metres from bow to stern --- longer than the Eiffel Tower is tall. To get access to the seabed, the ship first sails to wherever it's needed and then performs an astounding manoeuvre. Three huge ballast tanks on the stern flood with water and the rear part of the ship plunges beneath the waves, pulling the vessel through a 90° flip. Once vertical, more than three-quarters of the ship is submerged while the front end, with its cabins, control rooms and helicopter landing pad, sits up above the water. Most of the equipment on board is designed to rotate so it stays the right way up throughout the flip.
The idea may sound preposterous, but a smaller craft that performs similar maritime gymnastics has been around for nearly 30 years. Dubbed FLIP, or Floating Instrument Platform, it's operated by the Scripps Institution of Oceanography in San Diego, California. FLIP looks like a regular ship with the stern chopped off and a 100-metre pipe welded in its place. The pipe is basically one big ballast tank that floods to make the ship tip over. Once submerged, the tank provides stability so that scientists can park the craft and get on with their experiments.
Besides being able to perform the same manoeuvre, the ship designed by the Ocean Technology Foundation would bear little resemblance to FLIP. For one thing, it's more than three times as long. What's more, its rear portion isn't just a ballast tank but is designed to deposit the researchers as close to the seabed as possible while keeping them at atmospheric pressure. To do this, the hull is a sealed tube which, once flipped, turns into a lift shaft. Along the length of the shaft are laboratories linked to the surface by the lift and stairs.
The flipped ship could stay in one place for weeks or months at a stretch, stabilised by the submerged stern and the ship's propellers. And by varying the amount of water in its ballast tanks, the crew could control how much of the ship is submerged. The basic design has a depth range of 225 to 275 metres --- enough to visit the deepest parts of the continental shelf. A wider range would be made possible by removing or adding segments to the hull, because this plan calls for the segments to be bolted together rather than welded. This would also mean specialised labs could be slotted in if need be. At first this would have to be done in dock, but it is hoped that it would eventually be possible at sea.
Pumping the water back out of the ballast tanks would right the craft. The experts estimate the manoeuvre would take around 12 hours, as would flipping from horizontal, but in an emergency the tanks could be blasted out with compressed air and the ship flipped in about a minute.
The flip ship, however, has its drawbacks. While cheaper than the previous type, it would still cost an estimated $200 million. And its depth range is limited. With these problems in mind, Clifford Ness, a retired Electric Boat submarine designer and a member of the Ocean Technology Foundation, came up with an alternative plan. Why not build a massive hinged arm with labs at the end that could be lowered like a penknife blade from the bottom of a ship?
Ness has been working on a plan to attach a 200-metre arm to a disused oil tanker. The appendage would be bolted to one end of the ship and housed in a hollowed-out compartment on the bottom. As with the flip design, the labs at the end of the arm would be designed to rotate, meaning they could be used at any angle. That would give the hinge ship more versatility than the flipper: the arm could be lowered to any depth down to 200 metres.
Economically, the arm also has the edge. While the flip ship would have to be built from scratch, the arm could be added to a converted oil tanker. Thanks to new regulations requiring the phasing out of single-hulled tankers in favour of stronger double-hulled ships, second-hand tankers are two a penny. Ness thinks one could be purchased and converted for around $60 million.
Details remain sketchy, but Ness envisages a lift running up and down the arm to ferry people and equipment to the labs. Extending the arm would take several hours, but the design allows for a 10-minute emergency retraction. The arm would also act as a massive keel, giving the ship tremendous stability. This, of course, would put enormous strain on the hinge. Ness says he's solved the problem but his tricks are under wraps until he can file a patent.
The Ocean Technology Foundation still has some way to go before it has enough money to build a ship. It's prepared to rope in anyone with an interest in the deep sea, from the oil and gas industry to the Navy. But the overall aim is to open up a new era of ocean exploration. Bizarre they may be, but ships that flip or have giant hinged arms might just be the breakthrough oceanography has been waiting for.
[此贴子已经被作者于2004-11-27 20:54:02编辑过]
