The Expansion of the Panama Canal
Posted on September 30, 2016
Built about a century ago, the Panama Canal was a feat of engineering and a revolution in shipping as it cut the navigation time around South America from 4 weeks to 10 hours, lifted ships by 26m (85ft) to be able to navigate Gatun Lake, an artificial body of water which was created by flooding a mountain range. From traffic of 1,000 ships a year, it now welcomes 14,000 of them a year, carrying 200 million tons of goods and accounting for 3% of worldwide shipping trade.
But it isn’t the only way the canal has seen an increase in volumes of goods passing through its locks. Container ships have been getting increasingly bigger, stretching its capacity to the full and causing congestion by the existing two lanes. They can handle ships up to 300m long and 32m wide – called Panamax by the Panama Canal Authority (PCA) – but so-called ‘superships’ can be three times as large and as long, meaning that they can’t use the canal.
Enlarging the current lanes to accommodate those giants would have been the simplest solution, but it would have entailed stopping traffic completely which wasn’t an option. Building a third set of lanes was investigated at various points over the last few decades but never carried out. However, the PCA had no doubt that failure to upgrade the canal would lead to business being diverted to the larger and wider Suez Canal and eventually to the decline of the South American canal.
The fate of this project was so crucial to the economy of the country that the decision to build it or not was the object of a referendum – which the population voted in favour of with 75%.
Plans were drawn to build a new canal parallel to the existing one. For a small country like Panama, it would be a massive undertaking: it would take 8 years, cost US $5 billion and use 5 million cubic meters of concrete and three times as much steel as the Eiffel Tower in Paris. Fifteen cubic meters of earth would have to be removed, the level of Gatun Lake would have to be raised by 45cm and they would need to install 16 gigantic lock gates 35m high and 10m long weighing 3,000 tonnes each.
But at the end of it, the canal would be able to accommodate ships of 14,000 TEUs – a TEU being a ‘Twenty-foot Equivalent Unit’, meaning ships that can carry 14,000 standard containers. Although some superships are as big as 19,000 TEUs nowadays, it would still be an improvement on its previous standards as ships bigger than 5,000 TEUs couldn’t fit.
One can only marvel at the technical ingenuity of the engineers who designed this new set of locks. One of the issues encountered in its construction was the gate doors. The new chambers were to be 427m (1,400ft) long, 55m (180ft) wide, and 18m (60ft) deep. That is a lot of water pressure on doors. It was necessary to find a material that could withstand the resulting pressure but wouldn’t be so heavy as to not be manoeuvrable.
The doors of the existing lock had been made of concrete, but they were much smaller. Using concrete for the new locks would make the gates so heavy that no mechanism would be able to move them, they would just crush it.
The solution was to make concrete gates that were hollow. It was discovered that they had the same strength as solid concrete gates, but they weighed far less. They could then be operated by sliding them over a set of wheels as the air in them would also give them some buoyancy.
Another challenge posed by the construction of the third lane was water supply. Each time a ship crosses the canal, 202,000 cubic meters of water are used, provided by Gatun Lake which was created when a dam was built for the canal. However, there are already issues with the supply of water towards the end of Summer, so it was clear that it wouldn’t be able to feed the new lane.
At the moment, the movement of water in the locks of the existing canal is produced simply by gravity and doesn’t use any pumps. Ships going towards the Atlantic Ocean need to be lowered while those going towards the Pacific Ocean need to be lifted so it all about emptying one full basin into the lower one next to it.
The solution to the supply issue for the new lane was building three water-saving basins.
Each lock is about 9m high and requires a minimum of 3.6m high of water. When the lock system starts operating, the first chamber is filled. To lower the ship, it is emptied, not into another lane but into three giant water containers. This water is then reused into the next two lock chambers as the ship’s journey progresses.
This means that water is needed only once, in the first chamber rather than all of them, and that the new canal only needs 60% of the water it would otherwise need without this water-saving system.
Although the new lane was supposed to be ready in 2013 or 2014, the construction suffered some delays and the new canal was finally open on June 26, 2016. TheCosco Shipping Panama, a Chinese container ship measuring 300m long, 48.25m in beam, and with a capacity of 9,472 TEUs, had the honour of having the canal to itself at an inaugural ceremony, marking the beginning of a new era, that of New Panamax ships.
Thanks to the visionary attitude of the PCA, the Panama Canal has been granted a second lease of life and will continue to see its traffic grow – it is predicted that the volume of goods passing through it will have doubled between 2005 and 2025.