September 19, 2017
George Berman
GBerman@ingeotec.net
How to Power a Navigation Lock with Electricity
Navigation locks facilitate navigation uphill by allowing boats to take vertical steps. Navigation locks date back to ancient Egypt, the first “modern” lock was part of China’s Grand Canal that dates back to 600 AD. Essentially a navigation lock is a chamber with gates at both ends where the water level can be adjusted. The measure in which the water level can be adjusted is the measure of the vertical step the navigation lock can lift the boat. The water level in the navigation lock is increased by adding more water.
During the eighteenth and nineteenth century, navigation locks revolutionized transportation in Europe and the United States. The advent of trains and automobiles reduced the importance of navigation locks in inland transportation, primarily because these transportation modes require less infrastructure than inland navigation, if inland navigation is possible at all. The construction of the Panama Canal extended the application of navigation locks to maritime shipping. The Panama Canal allows ocean shipping shorter and safer routes.
An innovation in lock design has been the addition of water savings basins to reduce overall water consumption. Multiple tier water saving basins can save up to 60% of the water required to operate the navigation lock without the water savings basin. The need for introducing water savings basins arises from the ever increasing scarcity of the water available to many navigation systems with locks.
On the Panama Canal, the number of transits has been stagnant since 1967 because of limited water. The ACP has successfully increased the Canal’s capacity by significantly increasing the size of the average ship. Presently, the growing population has placed additional demands on the available water, increasing the urgency to develop new water sources to sustain the current water supply to the Canal.
The purpose here is to modify navigation lock design such that the source of energy used to lift the boats in the navigation lock is electricity instead of the hydraulic energy obtained from adding more water to the navigation lock. The use of electricity taps an endless supply of energy allowing unrestricted use of the navigation lock. Hydraulic energy is the potential energy of the water. The benefit of this innovation is proportional to the scarcity of water where the navigation lock operates.
The nature of the proposed modification to navigation lock design is the inclusion of a device that will transform electrical energy to hydraulic energy. This device would be part of new lock design but it should also be possible to incorporate it as a“retrofit” to existing locks. The addition of such a device to the Panama Canal would allow the number of transits in the Canal to increase without compromising the Canal Authority’s role as custodian of Panama principal source of potable water.
According to the first law of Thermodynamics, described first by Rudolf Clausius and William Rankine in 1850, energy is transformed, not created or destroyed; we propose a device that transforms electrical energy to hydraulic energy for the purpose of operating a navigation lock.
The device proposed to transform electrical energy into hydraulic energy is named the AIR LOCK. The AIR LOCK for the Panama Canal is an accordion, 3.50 m. square, that extends 9.00 m. high. The accordion is made of steel and plastic, it is extended with a hydraulic cylinder positioned at the center. The AIR LOCK has the power to raise the water level in the lock chamber in 15 minutes.
How to raise the water level in the lock chamber without adding water? According to Archimides principle, 250 BC, introducing a solid at the bottom of the lock, will raise the water level in the lock as the solid displaces the water. Conversely, the water level is reduced when the solid is removed.
The AIR LOCK is an accordion like device on the bottom of the chamber floor, connected to the atmosphere, that fills with air at ambient pressure, as it is expanded by a central hydraulic piston to form the solid that displaces the water. The AIR LOCK, in a closed position, is flush with lock chamber floor, in an open position, the accordion is fully extended.
The hydraulic piston is the technology with sufficient power to expand the accordion of the AIR LOCK in a few minutes. According to Pascal’s law, 1648, the force applied by a hydraulic piston is directly proportional to the pressure of the fluid. The operating pressure of the fluid in hydraulic pistons can be 100 times greater than ambient pressure. The volume of the fluid used to exert force is reduced proportionally to the pressure difference, namely 100 times. Therefore the power requirement can be met with 100 times less fluid compared to pumping water at ambient pressure. Hydraulic power systems include power accumulators that further reduce the hydraulic pump’s power requirements.
The pumps of the hydraulic pistons of the AIR LOCK are powered by electricity. They develop the power to raise the water level in navigation locks, not with water but with hydraulic fluid at high pressure. The high pressure is distributed through the accordion to displace the water.
The Air Lock achieves its design goal, not a single large complex device but as multiple small devices that operate simultaneously to displace the water in the lock. View the AIR LOCK as tiles on the chamber floor of a navigation lock, the fraction of the floor that is covered corresponds fraction of water saved.
This paper presents the design of the installation of the AIR LOCK as a “retrofit” on the original Panama Canal locks to describe its features. In this design, the existing hydraulic system is not compromised. The initial investment for a fully operational pilot system only needs to address a one unit for each lock chamber. The use of a single unit will save 110.25 m3 or 29,120.