Posts tagged Two Oceans
The Panama Canal Expansion Project
Nov 12th
The idea of taking advantage of the narrow isthmus in Panama to connect the Atlantic and Pacific Oceans was first mentioned in the 1500′s. A railway was built in 1855 where the canal is situated today. This railway was a great influence on trade and really got people thinking about the advantages of an all-water passage between the two oceans. After many years of jockeying for control of the canal and battling malaria and yellow fever, the canal was finally finished in 1914.
The Panama Canal has always had to adjust to meet the demands of international ocean shipping. Not only has the size and shape of ocean shipping vessels changed, but the amount of traffic that the canal would see was grossly underestimated. It was originally estimated that the canal could support a maximum of 80 million tons per year. However, the reported traffic in the past few years has hit over 300 million tons per year. It has become apparent that it is time for some major changes in the canal system.
The demand on the canal has been steadily rising. Ships are getting too large to use the Panama Canal. Over half of the ships that use the canal now barely fit. Over 30% of cargo ships are already too big to use the canal. As ocean freight and cargo ships get larger, the canal will begin to lose its importance in the world trade market. This is why it has become so important that the canal, once again, adjusts to meet the demands of the market.
The Panama government has approved the project and construction began in 2007. It is expected to be complete and in full operation by 2015. The new expansion consists of six new locks, all operating parallel to the old Panama Canal. The new passage will allow cargo ships up to 1,200 feet long and 160 feet wide to pass. It is expected that the new expanded portion will make repairs and upkeep of the older part of the canal much easier.
The current Panama Canal has two lanes that operate independently of each other, allow ships to pass in two directions at once. The new, third lane, will allow larger ships to pass one direction at a time. Two new access channels will be built to route the expanded lanes to the locks. The locks will help to transport ocean shipping vessels up to the level of the Gatun Lake and then back down to sea level again. The new locks will be emptied and filled by gravity, the same as the old locks. However, the gates have a different construction and will be rolling gates instead of miter gates, which will be safer in the larger locks.
Miter gates are essentially doors that swing open to allow water to flow through. Roller gates are constructed of round steel drums, they are much stronger and can cover a much wider passage way. Because the pressure of the water creates the seal at the bottom and sides of the roller gate, it is considered to be much safer and is much less likely to leak. Roller gates can be raised above or below the water (depending on the type) and allow for clear passage without obstruction.
The growth and use of the Panama Canal has increased so much over the past few years that its profitability is feared to become stagnant. The expansion project is expected to help the Panama Canal handle new business and boost its viability in the ocean shipping market. With larger ocean freight vessels being supported and efficiency being increased, the Panama Canal project is expected to save it from becoming obsolete in the future.
Panama Canal – Challenge of Connecting Two Oceans of Different Levels
Nov 5th
Many would be surprised to know that the Panama Canal runs north to south to link the Atlantic and Pacific Oceans, not east to west.
By shortening the route and reducing the cost of transportation between the two oceans, the Panama Canal allows for lower-cost imported goods and commodities in many part of the world. (It saves almost 8,000 miles on a trip from New York to San Francisco.) By eliminating for the majority of shipping the treacherous route around the tip of Argentina, it has no doubt saved countless lives and millions of dollars in lost vessels. However, it is estimated to have cost some 30,000 lives in the two attempts – French and American – to build it between 1880 and 1914.
Reducing the distance between the two oceans provides Panama with a major share of its gross domestic product. Some 13,500 ships transit the canal each year, almost 40 a day.
Not commonly known is the fact that the two oceans have different sea levels, and different levels of high tide. At the entrance to the Panama Canal, the Pacific Ocean can rise as much as 20 feet, but 45 miles away, the difference between high tide and low in the Atlantic is just three feet.
The longest part of the canal, sandwiched between gigantic sets of locks at either end, is manmade Gatun Lake and the Gaillard Cut. Gaillard Cut actually rips through a low point in the mountain chain that runs all the way from Alaska to the tip of Argentina.
The Panama Canal has six locks, three near either end. From the Pacific Ocean, near Panama City, the Miraflores Locks’ two chambers each raise vessels 27 feet. A short distance away, the Pedro Miguel Lock lifts shipping a further 31 feet. Most of the passage through the canal is at 85 feet above sea level.
The Gaillard Cut is followed by the town of Gamboa, where the Chagres River enters the canal. Without the Chagres and the immense amount of water that flows from it, there could be no Panama Canal.
The three steps of the Gatun Locks each lower ships about 28 feet, to the level of the Atlantic Ocean.
The locks are gravity fed from the Chagres and Gatun Lake. No pumps are needed. Water pours through a huge culvert in the center wall of each lock, a culvert so massive that a locomotive could pass through it. Other large culverts pass through the side walls. Water fills or empties through vents along the bottom of the locks, 26 million gallons in just eight minutes.
Each lock chamber is 110 feet wide and 1,000 feet long, and each gate weighs 700 tons. When the Panama Canal was completed in 1914, the locks were large enough for the largest vessel in the world to pass through. And since then, most marine architects have been careful to design hulls with the canal’s measurements in mind. That changed in 1934 when the Queen Mary was launched. She was 118.5 feet wide, but it didn’t matter: she was built for transatlantic service, like the Queen Elizabeth, launched a little later.
But shipping economics call for ever larger loads. There has been talk for a number of years about widening the canal, one possibility being the construction of wider parallel locks beside the existing ones. One limiting factor could be the availability of water in greater volume. Other options that have been discussed, including building a canal at sea level that would need no locks. One problem with this is the current that would be created because the oceans are at different levels.
Another option that Panamanians don’t even want to think about is the original idea: to build a canal through Nicaragua.
All naval vessels except aircraft carriers can squeeze through the Panama Canal, and do so without damage, though the occasional battleship loses some paint. The flight deck on aircraft carriers is angled to give greater runway length, and they cannot clear the canal. The world’s largest oil tankers cannot make it, either, and have to offload their cargoes to smaller vessels at terminals on either end.
Apart from being the crossroads of the world’s shipping, the Panama Canal is a great attraction for tourists. There are daily cruises that ply either the whole length or part of it. It’s an excellent way to view part of Panama’s history, past and present.
