Making History on the Panama Canal

Published: March 4, 2015


Animation of the water saving basins ©Tractebel Engineering


As the Panama Canal celebrates 100 years, the Autoridad del Canal de Panamà (ACP) expansion project is entering its final construction phases. From providing the original design concept, to ongoing technical assistance, Tractebel Engineering has long been helping ACP ensure one of the world’s greatest engineering realisations lives on.


With + 14,000 ships transiting every year, the Panama Canal’s importance to trade and the world economy is enormous. Even so, the original locks from 1914 aren’t large enough to accommodate modern Post-Panamax vessels (forcing a costly detour via Cape Horn).  This prompted ACP’s Panama Canal expansion project – calling for a ground-breaking but “proven” design. Read more


With the project consortium Consorcio Post Panamax (CPP) expansion design agreed, a further contract – covering critical design analysis and on-going technical assistance – proved essential to getting the project underway. Read more


As expected on a project of this scale, the Panama Canal expansion involves many engineering players associated with the contractor, subcontractor or ACP.  Nevertheless, confident of its expertise and project knowledge, ACP has frequently requested technical assistance from CPP… Read more



José De Regge (left) and Marc Sas (IMDC) recently visiting the construction site ©Tractebel Engineering

Taking over the Panama Canal from the USA in 1999; faced with increasing traffic, worn infrastructure and the Post-Panamax issue, ACP’s vision in 2001 was the design and construction of 2 new lock systems close to the existing locks on the Pacific and Atlantic sides of the Canal – to allow Post-Panamax transit, effectively doubling the tonnage capacity of the existing Canal.

From the start ACP had very clear idea of the specific criteria the “Third set of Locks” design should meet: while innovative, it should be based on proven technologies. It had to be capacity driven; assuring reliability, low maintenance and efficient, safe operation. It had to use fresh water sparingly and last, but not least, limit salt-water contamination of the interior lakes.

In 2002, awarded the contract for the conceptual design of the lock expansion on the Pacific side (up against the US Army Corps of Engineers working on the Atlantic side), Tractebel Engineering created a dedicated project consortium Consorcio Post Panamax (CPP) bringing together its ports & waterways, marine, Hydropower (dam and underground civil works) experts, as well as GDF SUEZ hydraulics company Compagnie Nationale du Rhône (CNR).

With all parties bringing special expertise to the project, CPP came up with the, now well-known, winning design of the new 3 step lock system with rolling gates and adjacent water saving basins – a design that ACP liked so much it decided to apply it to both the Pacific and Atlantic lock sites.


  • A new 6.1 km access channel connecting the Pacific lock and the deepened Culebra Cut (bypassing the Miraflores locks, Miraflores lake and Pedro Miguel locks), as well as 3.2km new channel between the Atlantic  and the new Gatun lock with some widening and deepening of existing navigation channels in Gatun Lake.
  • The 2 new sets of 3 step locks – with each chamber measuring 427 m long, 55 m wide and 18.3 m deep to accommodate Post-Panamax vessels.
  • Gigantic rolling steel truss double gates with recessed heads able to double as maintenance dry docks.
  • Recessed side culverts (Main and Secondary) for filling and emptying the lock chambers.
  • 3 water saving basins alongside the new locks that will reuse 60% of water each time chamber water levels are raised or lowered (by gravity – so saving the need to power pumps). The combined system will save a total 87% in water consumption; it will also greatly reduce lock-to-lake saltwater contamination.
  • Tug boats will be used to assist vessels into, within and out of the new locks, as opposed to the locomotive-based technology of the original design and currently operating on Panama’s older locks.

  • Positioning of the first rolling gates in lockhead 2 Atlantic locks (Dec. 2014) ©ACP Positioning of the first rolling gates in lockhead 2 Atlantic locks (Dec. 2014) ©ACP
  • Positioning of the first rolling gates in lockhead 2 Atlantic locks (Dec. 2014) ©ACP Positioning of the first rolling gates in lockhead 2 Atlantic locks (Dec. 2014) ©ACP
  • Positioning of the first rolling gates in lockhead 2 Atlantic locks (Dec. 2014) ©ACP Positioning of the first rolling gates in lockhead 2 Atlantic locks (Dec. 2014) ©ACP




By 2005 ACP had the design concept it wanted but, faced with an inflexible tight deadline of an upcoming national referendum on the project, needed to be able to present the facts as accurately as possible. Design analysis and results were needed fast. Dividing the tasks between the consortium members CPP was put to its second test.

CNR took on the first hydraulic studies: numerically modelling the velocities of water flow vs lock wall strength etc. and physically building a 1:30 scale replica of the locks to test the systems.
Tractebel Engineering managed the civil engineering aspects: the lock walls, heads, gates etc. and oversaw the building of a 2nd scale replica by Flanders Hydraulics Research Centre to analyse the currents and hawser forces on the vessels, as well as the lock chamber filling/emptying system and its impact on the number of vessels the system can process. Tractebel Engineering also worked on all aspects relating to the electro-mechanical equipment, and contributed its vast knowledge in dam and underground works to analysing the geotechnical and seismic data in relation to future structural engineering.
IMDC – Tractebel Engineering’s affiliated marine and dredging expert company carried out the initial studies and modelling of the density currents impacting the vessels entering the locks from the Pacific entrance.

Achieving its goal, ACP was able to finalise the project (based on CPP’s analysis and optimised design) and move forward into contractor tendering and the early construction phase in 2007.

  • Panama locks-site works ©Tractebel Engineering Panama locks-site works ©Tractebel Engineering
  • Panama locks-site works (Dec 2014) ©Tractebel Engineering Panama locks-site works (Dec 2014) ©Tractebel Engineering




Based on proven expertise and early development studies, CPP is well positioned to assist ACP as needed in cases requiring specific intervention. In Panama the most important issues have been: concrete production, basalt aggregate production, concrete quality, dam stability (earthquake design), and dam impermeability drawing extensively on the hydropower expertise of Tractebel Engineering (France).

More recent interventions have involved the numerical analysis of currents at the lock entrances by IMDC and the physical modelling of ships entering/exiting the locks subcontracted to Flanders Hydraulics measuring the hawser forces and predicting vessel behaviours.

These latest studies relate to the future operation of the locks – notably the impact of density currents and their possible mitigation. The studies, focussed on the Pacific locks where high tidal ranges and seawater salinity exaggerate the density current effect, extend from those originally done during design analysis – but are now being modelled on the contractor’s “as-built” plans to ensure the outcomes correspond to the end reality. This is particularly important to training tug boat operators and pilots in preparation for the official opening of the locks in 2016.


Both modelling methods are complimentary to getting the physics right. But our numerical modelling is also used directly as input in the simulation tools used to train the pilots to respond to the phenomenon commonly created by density currents. In effect, due to the difference in salinity of the sea and lake water, when the lock gates open and the two bodies of water exchange, visible on the surface will be a huge body of (fresh) water pushing towards the vessel, while the vessel will actually be pulled forward towards the lock by the denser saline undercurrent. What you see is not what you get and the operators must be prepared for this.
Marc Sas – Manager Coast & Marine Division – IMDC

Although both sets of new Panama locks have the same design, the reality/intensity/forces created by currents will be different on the Atlantic side due to the different tidal and water conditions and, ideally, measurement and modelling of the Atlantic locks will be the next CPP challenge.

CPP Consortium

▪ Tractebel Engineering SSI ▪ Tractebel Engineering (France) ▪ Compagnie Nationale du Rhône (CNR)

Direct Value

“ACP has always trusted CPP as consultants as we bring a lot of experience in large lock construction (Antwerp, Zeebruges….). Plus, in the Tractebel Engineering group there is always strong, not always common, expertise on hand. It sees us continuing to work in direct contact with ACP which is where we can offer the highest added value to this extraordinary project”
José De Regge , Project Director CPP & Product Director Ports & Waterways, Tractebel Engineering SSI

Proven Concepts

The rolling gate designs to be used in the new Panama locks are used effectively in the world’s biggest lock500m long x 68 m wide Berendrecht sea-lock in Antwerp – designed by CPP partner FITA. Berendrecht has also benefited from IMDC density current studies (although the focus was sedimentation control).

More information

José De ReggeProject Director CPP & Product Director Ports & Waterways, Tractebel Engineering (SSI)

Marc SasManager Coast & Marine Division – IMDC

Philippe CazalisProjects Director, Senior Hydropower expert, Tractebel Engineering (France)

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