The new Drive-In L solution from Conductix-Wampfler is an innovative development specifically devised for the electrification of diesel RTG cranes.
For years, rubber tyred gantry cranes (RTGs) have driven up costs considerably for port operators with the diesel-driven cranes taking up half of the total fuel consumption at a port. To noticeably reduce fuel costs, more and more port operators are converting their cranes from diesel to electric. This environmentally-friendly approach has already saved several million Euros and tons of CO2 around the globe.
The new Drive-In L solution from Conductix-Wampfler already works without any pneumatic or hydraulic components.
Claus Burger, Director of the E-RTG business unit at Conductix-Wampfler explains the conversion of RTGs from diesel to electric saves up to 95 percent on diesel consumption. During normal operation, E-RTGs no longer require a diesel motor; this is only necessary when driving from one container corridor to the next or in the waiting area. According to Burger, it is paying off with operators achieving significant savings to the extent that the conversion costs, which is around EUR 150,000 per RTG are fully amortised in as early as two years. The conversion to electric operation foregoing the use of diesel minimises maintenance and operating costs by up to 70 percent in addition to achieving reductions in CO2 emissions and noise pollution around the port.
Four solutions for each individual range of use
Conductix-Wampfler offers port operators four different systems for the electrification of RTG cranes. The conversion can generally be implemented with motorised cable reels in addition to conductor rails in combination with ‘plug-in’ or ‘drive-in’ systems. In the case of the ‘Drive-In P’ (pantograph) system, the connection between the RTG and conductor rail has an automatic mechanism that makes the manual attachment/detachment required in the case of the ‘plug-in’ solution unnecessary. The brand-new ‘Drive-In L’ (linear) system is completely electrically driven and used without the need for any pneumatic or hydraulic components.
Electrification with motor-driven cable reels
A motorised cable reel is installed to provide an RTG with power. Since each RTG is a self-contained system, Conductix-Wampfler offers two basic options with both applications precisely adapted to the unique workflows at the port where they are being used.
On the one hand, Conductix-Wampfler offers modular motorised cable reels with a permanent magnetic coupling, which is a ‘plug-and-play’ system consisting of interchangeable electrical and mechanical components. On the other hand, the port operator can utilise a constantly controlled motorised cable reel system that is equipped with several control units – either in the form of hardware with pre-programmed operations or in the form of software that can be integrated into the existing PLC control systems. Here, built-in video cameras and optical sensors control the movements of the RTG.
Burger adds the range of systems offered by Conductix-Wampfler covers both low and high-voltage applications. A fibre optic core and transmitter can be integrated into the reel or into the cable. One or more container blocks in the same corridor can be supplied with power from the same motorised cable reel system.
Conductor rail systems with ‘plug-in’ collector trolley
The conductor rails are attached to a steel structure that stands atop a concrete foundation. Depending on the port operator, this can be anchored to the ground. The conductor rails can also be installed at various different heights for flexibility.
The electrical energy is sourced from the conductor rails through the movement of the collector trolley back and forth on the steel construction. A power cable and plug-type connector allow the collector trolley to be directly connected with the RTG. For safety, conductor contacts that also disconnect the power supply of the plug when the connection is not active are used. Two plugs are mounted on the RTG, one on each side to ensure the necessary flexibility for the RTG. Conductix-Wampfler installs limit switches on the collector trolley to prevent the crane from leaving the block during electrical operation.
The system upgrade: ‘Drive-In P’ port cranes
When using the ‘plug-in’ solution with the conductor rail, the RTG must be ‘unplugged’ and ‘plugged in’ again when switching between container corridors. The conversion to E-RTG with the ‘Drive-In’ system makes this manual step obsolete since the system upgrade from Conductix-Wampfler makes the manual ‘plugging in’ of the RTG crane into the pantograph carriages of the conductor rail system unnecessary. Instead, when moving in the RTG crane into the corridor, the pantograph carriage is automatically steered into the guide rails of the steel construction and the pantographs are securely guided into the conductor rails. This ‘drive-in’ solution saves time and energy, and improves the efficiency of a terminal while having an equal or lesser impact on the environment.
The ‘drive-in’ solution has been implemented at the Shekou Container Terminal in Shenzhen, China. According to David Wan, Deputy General Manager & COO at the Shekou Container Terminal, by electrifying the RTGs, they are not only protecting the environment, but also benefitting from a safety perspective. The location of the port exposes it to high winds and typhoons. Apart from a solution that saved on fuel and CO2 emissions, the terminal was also seeking to reduce the number of staff needed for dangerous jobs such as working on power-conducting cables. Additionally, the Drive-In system also offers impressively smooth operation and low noise emissions.
The new ‘Drive-In L’ solution: maximal flexibility
The new ‘Drive-In L’ system has an extremely compact design, works completely without pneumatic or hydraulic components and is currently the lightest on the market, making it possible for use with any type of RTG, including those with little space for additional components. First introduced in September at the TOC Middle East in Dubai, the ‘Drive-In L’ received great response from customers and is expected to set completely new standards in the market of RTG electrification.
Thanks to its compact design, the ‘Drive-In L’ – unlike a diesel motor or generator – can be installed on both sides of the RTG, which makes it extremely flexible. The drive-in or drive-out time of the RTG in the case of the ‘Drive-In L’ system is less than 20 seconds. A short drive-in zone also makes it possible to operate the RTG with power from the first row. In addition, this guarantees the compensation for tolerances resulting from moving the RTG into the container block or due to lifting and lowering. The procedure with ‘Drive-In L’ is fully automatic and controlled exclusively from the cabin of the RTG. No ground personnel are needed when switching blocks, which also improves work safety at the terminal.
The increasing demand for E-RTG technologies is accompanied by lower costs for port operators and a reduced impact on the environment. The use of E-RTG technologies has resulted in savings amounting to over EUR 71 million worldwide while preventing more than 51 million kg CO2 from entering the atmosphere.
Burger concludes that the current demand for E-RTG systems will continue to grow, with diesel-driven cranes in future to be used only where there is no power supply.