After years of wrangling, work to expand the Panama Canal is finally scheduled to begin this year. Cliff Schexnayder reports from central America.
Shortly before 5pm on 15 August 1914, the steamship SS Ancon passed through the Miraores Locks near Panama City and became the first vessel to complete an ocean-to-ocean passage through the Panama Canal.
Writing for the Bulletin of the Pan-American Union, correspondent John Barrett described the ship’s 10-hour trip as almost mundane.
‘So quietly did she pursue her way that - a strange observer coming suddenly upon the scene would have thought that the canal had always been in operation, and that the Ancon was only doing what thousands of other vessels must have done before her.’ His words seem almost prophetic to anyone watching the massive vessels wind their way through the 80km waterway today. Since the Ancon’s historic voyage, more than 900,000 vessels have passed through the canal - in excess of 14,000 last year alone.
Today, the canal operates at about 90% of its operational capacity and demand is growing. Ships can wait for days at peak times and for weeks during maintenance periods.
Even worse is the shipping industry’s move to the use of post-Panamax ships that are too large to fit through the canal’s locks. There are around 3,000 ships, about 92% of the world’s fleet, that cannot pass through the current canal, ’ says director of maritime operations for the Panama Canal Authority Jorge Quijano. ‘Obviously these (cargo) ships are not the only vessels to use the canal but the bulk of the income from the canal comes from this business segment.’ As a result, canal authority ACP - the quasi-governmental organization that oversees the waterway’s administration - has undertaken an ambitious seven-year, $5.25bn (2.6bn) expansion effort.
The project will include the construction of two new massive sets of locks, the excavation of nearly 8km of channel and the dredging of several million cubic meters of material. The canal will continue to operate as normal throughout the project.
ACP offcials say the expansion is self-financing, paid for out of the tolls brought in by the canal. As part of that strategy, the authority plans to increase tolls by 3.5% annually over a 20-year period, starting in May next year. The increased capacity allied with the toll increase is expected to bolster the canal’s annual revenue from 500M to 3bn.
Yet ACP will be seeking approximately 1.2bn in loans or bonds to defray costs over the life of the expansion project.
ACP estimates that at the peak of the expansion project, between 2009 and 2011 when the lock construction begins in earnest, the canal will require as much as 250M per year in additional funding.
To further safeguard the investment, ACP made a decision to subdivide the work into three components, locks, dredging and dry excavation, in order to minimize the risk involved.
‘Because we don’t put everything on the shoulder of a single contractor or a single group we are minimizing the risk, ’ says Agustin Arias, who led negotiations as director of engineering and projects until he stepped down last month. ‘And we have significant competition that will reduce the possibility of problems occurring.’
Given the sheer scale of the expansion, Parsons Brinkerhoff (PB) was brought on board in 2002 in a 14.5M contract as programme management advisor. The PB team has acted as the chief consultant on a broad spectrum of issues relating to expansion other than the engineering itself.
‘They (ACP) knew they wanted to expand the locks and how big they wanted the canal to be but from that point to awarding the contract there are a million different decisions that have to be made, ’ explains principal consultant for PB Laurie Mahon. ‘Basically we brought our contacts book to the job.
We gave them access to our experts from all over the world.’ The canal was made possible by the damming of the Chagres River in 1908 and the creation of the 43,000ha Gatun Lake.
Today the reservoir is a critical component of the canal but it also provides 95% of the country’s drinking water. Every day, more than 200Ml of fresh water is lost from the lake due to canal transits.
In the 1990s ACP began looking at how to protect that water source and decided to expand. The sheer size of the locks required to accommodate post-Panamax vessels made it impossible to use systems that demand the quantities of water the current system uses.
‘The challenge for creating the plan for the new locks was finding a design that would maximize throughput but minimize water usage, ’ explains Canal Capacity Division structural engineer Cheryl George.
There were eight lock proposals for the Atlantic side and 16 proposals for the Pacific side. The proposals even included the construction of a synchro-lift. They finally selected a design primarily because of its proven efficiency with water conservation.
That is achieved by building a series of water-saving basins approximately 70m wide by 5.5m deep for each individual lock, allowing the water to be re-used rather than flushed out to sea. Although the sheer size of the new lock chambers will require 65% more water than the existing locks, they will use 7% less water per opening.
The planned locks and watersaving basins are the most expensive component of the expansion by a wide margin.
Their combined price tag of 1.7bn is almost 60% of the entire project cost. The sheer size of the locks also makes them the most daunting aspect of the project.
The new lock chambers will be 427m long by 55m wide and 18.3m deep, more than sufficient for the 366m long post-Panamax ships. Instead of ‘mitre’ gates used by the existing locks, the new locks will use rolling gates similar to those used on the Berendredt canal in Anbres, Belgium. Similar but smaller water-saving basins are featured on the Hohenwarthe Locks on the Elbe River in Germany.
‘In terms of the locks, what we are recommending is proven technology that is in use elsewhere, ’ Arias explains. ‘But no-one has ever built locks of the size we are proposing.’ The dry excavation for the new locks will be facilitated by work done by the US Army in 1939 to add an additional lane, an effort that was interrupted by World War II and never resumed.
‘The locks will be built in the footprint left behind from the excavation in the 1930s, ’ Quijano says. ‘The Atlantic channel will follow the former excavation almost exactly.’ The contractors undertaking the lock and water basin construction will be responsible for the excavations for those portions of the expansion but the ACP plans to contract out the dry excavation work on the access channels to them.
Both sets of lock contracts will be bid together in one design & build contract.
While the locks are the key to the expansion, a substantial upgrading of the canal’s navigational channels will need to be performed as well.
That means the authority will undertake a new massive dredging programme to widen and deepen the existing navigation channels within the waterway itself.
The expansion project will increase the width of the cut and navigational channels to 280m in straight sections and 366m where it bends.
And to permit cross navigation in the Gatun Lake, the lake level will be raised by half a metre to 27.1m, gaining additional draft as well as increasing Gatun Lake’s water reserve capacity by a daily average of 625Ml.
Each sea entrance navigation channel will be expanded to 225m wide and deepened to 15.5m deep below the level of the lowest tides. Currently, some sections of these approach channels are only 192m wide.
‘Although the canal authority is already the largest dredging company in central America, we don’t have the resources to provide all the dredging that the expansion will require, ’ says Yolanda Chin of ACP’s engineering and projects department.
As a result, ACP will contract out the dredging of around 9Mm 3 of material for the Pacic entrance and offer another contract to remove 14Mm 3 from the Atlantic approach.
The Pacific job is expected to go out to bid early next year and the Atlantic work will follow in 2009, Chin says.
A substantial amount of dry excavation will be required as well. On the Atlantic side that will include the excavation of a 3.2km long access channel to connect the new locks with the existing sea entrance of the canal. On the Pacific side things are a bit more complicated.
A 1.8km channel must be dug to connect the new locks to the Pacic entrance but, in addition, a 6.2km channel 218m wide will have to be excavated to circumvent Miraores Lake and reach the entrance to the Gaillard Cut.
The latter is expected to require the excavation of more than 47Mm 3 of dry material and the dredging of almost 4Mm 3 more. ACP will split this particular section into ve separate contracts to put out to bid, the rst going out this month.
If all goes as planned the upgraded canal will be ready for use in 2014, just in time for the 100th anniversary of the SS Ancon’s journey accross the Isthmus.