Pumps in dewatering

The Panama canal

Without a doubt, the expansion of the Panama Canal can be considered as one of the most economically important engineering projects works of the last decade. The design and execution of this challenging project tested the capacity of a select group of engineering companies, as well as high-tech construction teams, who had to withstand the extreme tropical climate, day and night, uninterrupted for four years.

It was back in 2011 when Ferrer was awarded the contract to act as a subcontractor to the main construction consortium FCC – ICA – MECO. From that moment the Spanish dewatering company was responsible for the control of underwater and surface water of the Pacific Access Channel 4 sector. For his part, the president of the group recalled:

“Once the first emotions of signing the contract had subsided, our technical team had to get to work to select the best human team and technology resources to meet this challenge”

Based on Ferrer’s extensive experience in the field of dewatering and following an exhaustive evaluation of the available supply options, the Dutch pump manufacturer BBA Pumps was chosen to help meet this challenge. Their superior product capabilities were deemed particularly necessary for the surface water management of the Lake Miraflores water bypass, as well as rainwater management. The Pacific coast of Panama typically gets about 3000 mm per square meter of rain a year.

The decision to select BBA Pumps was approved following a visit to its factory. The manufacturing processes and reliability of the products greatly impressed. Energy efficiency, automatic level control, the ease of implementation of telemetry systems, as well as the design of its super silent canopies (certified to run in ambient temperatures of over 50 degrees Celsius) were all features which convinced Ferrer that he choose the right supplier for this dewatering project.

Twenty-five pumps

To meet the theoretical values calculated for surface water pumping from Lake Miraflores and precipitation runoff we purchased twenty-five BA150E D285 pumpsets. That number of pumps with a total flow up to 3500 l/s was derived from the need to distribute the pumps out into a number of geographical positions. And on the other hand to optimize the safety factor of each station.

Due to the unique operating requirements the pumping equipment was subjected to extreme working conditions. At times the equipment had to operate beyond its stated design capacities. However, despite the challenging demands, the 6-inch dewatering pumps continued to work satisfactorily.

When the construction of the Pacific Access Channel phase 4 project was completed successfully, the final phase started of which the filling of the new channel. The new canal was gravity filled using with water from Gatun Lake, until its equilibrium level was reached.

The construction consortium further appointed Ferrer with the responsibility for the “overfilling” of the channel up to its nominal level. Therefor we relied again on the BA150E D285 pumps to fill the channel in a sequential and controlled manner, until the level was reached.

The outstanding mechanical reliability of the pumping systems for the use of dewatering and bypass work, together with other positive experiences in using the gear, greatly strengthened relations between BBA Pumps and Ferrer. 

Tunnel dewatering

A number of BBA Pumps units and kilometers of pipes were used for a tunnel dewatering project in Central America. Based on this positive experience Ferrer did not hesitate to deploy the equipment for dewatering of the Changuinola Hydroelectric Tunnel. A project in the province of Boca de Toro where a power plant, with a capacity of more than 223 MW, generates energy via two turbines at the dam.

This dewatering project was necessary in order to provide suitable conditions for making the repair works to the tunnel. In this case, the challenge was to achieve a pumping capacity of 400 l/s with a height differential of 180 meters, and a distance of 1000 meters. This would be in successive re-pumping stations, with two independent lifting pipelines, with intermediate tanks of transfer.

Our engineers designed a model that should allow this flow to be raised inside the tunnel. Given the activity of heavy vehicles operating in the tunnel it was vital that the equipment should take up the minimum amount of space. In addition, there was a need for mobility and the ability to change position, both for the pumping equipment and the pipes, so the pumping equipment had to be able to work with HDPE pipes and quick couplings.

“The ability to easily repair and maintain the BBA Pumps equipment out in the field, reinforced the decision to select BA150E D285 and BA180E D315 type of pumps for this project”, stated Alejandro Ferrer during one of his technical inspection visits. 

Dewatering in Southern Morocco

Another international pumping project was the construction of World’s largest sea water desalination and irrigation plant in Agadir. The new plant is offering drinking water for the people of Ctouka Ait Baha region and also irrigate 15.000 hectares of land.

For this project we selected five BA180E D315 pumping units for dewatering work resulting from the construction of the seawater intake receiving station. The water received in the reservoir came from twenty-five deep pumping wells located on the periphery of the pumping site, each being equipped with a 30 hp submersible pump. Its objective was to deliver the temporary lowering of the water table during the construction.

The design had to allow 1000 l/s to be raised to a height of 30 meters and at a distance of 2000 meters, until it was gradually discharged into the sea in a controlled manner.

The perfect alignment of smart design with reliable resources, complimented with respect and care for the environment is a winning concept which is undoubtedly present in the DNA of both the BBA Pumps and Ferrer firms.