The Panama Canal, the narrow but essential shipping lane that has connected the Atlantic and Pacific for over a century, is undergoing a $5.25 billion expansion effort.
The project will allow for ships of 2 1/2 times the size of current restrictions to pass through the canal, loosening a long-standing bottleneck on international commerce.
It is an immense effort by any scale, requiring 5 million cubic meters of high-strength concrete – enough to build a highway from New York to St. Louis – and some very impressive engineering.
Unlike the current system, the new locks – scheduled to be completed this weekend – alongside the current, century-old ones, are designed to recycle more than 60% of the water used via a series of basins built alongside the channel.
Mike Newbery, a Vice President at MWH, the water-engineering firm responsible for the new design, told Business Insider that the project was filled with some serious challenges.
“I don’t think I’ve ever come across a design specification where the concrete had to last for a hundred years,” Newbery said. “Maybe nuclear.”
These are the old locks. For a century, they have restricted ships to 106 feet of width. Larger ships coming from Asia are forced to either sail their cargo around South America or to the West Coast, where it would be transported by rail.
The class of ships that can fit through the current canal is referred to as “Panamax.” The width of “New Panamax” ships will now be expanded to 180 feet.
While not as visually exciting as the lock gates or water-saving system, finding the right concrete formula to withstand a century of seismic activity and corrosive salt water was a huge engineering hurdle, Newbery said.
Lengthy concrete-testing periods and setbacks caused years of construction delays. Last year, a crack in one of the new lock sills was found to be the result of insufficient reinforcement. It was an expensive mistake that required time-consuming repairs.
There are sixteen lock gates. They have three different designs, largely due to different seismic conditions on the Atlantic and Pacific sides of the canal.
Each lock has two gates at either side. That redundancy is part of the reason the designers can promise the required level of reliability of the system, a level that Newbery claimed is rarely surpassed in civil-engineering projects of almost any kind.
The gates, which weigh about 8 million pounds each, are also buoyant, meaning if they need replacement or heavy repairs they can be floated out of the channel while the other gate remains in service.
“We have to have a maintenance program for planned and unplanned outages that provides 99.6% availability. That translates into less than three hours a month [of downtime],” Newbery said.
Unlike the old ones, which have two, there is only one lane of new locks. That’s why the Canal Authority had to demand the system be operational virtually all of the time.
Newbery’s company is also responsible for delivering operations and maintenance manuals to the Canal Authority. It’s kind of like the owner’s handbook you’ve got in your car. But the ones for the canal are “enormous,” Newbery said.
Those pools beside the channel — there is a set of three next to each lock — are the water-saving basins. They allow water to be recycled for each act of moving a ship up or down. That’s a big deal, because currently low water levels in Lake Gatun already require draft restrictions on ships traversing the canal.
Like the original locks, the new ones use only gravity to move water around. The control system needed to operate the many, many valves is one of the most complex Newbery has ever seen.
As was the case when Theodore Roosevelt oversaw the American takeover of the construction of the original canal, the expansion project has stretched engineering possibility.
“I mean literally: The best experts in the world were all brought by either the Panama Canal Authority, ourselves, or our client,” Newbery said.
- Panama Canal