Introduction
To cope with the global demand for the reduction of greenhouse-gas emissions, Mitsui Engineering & Shipbuilding Co. Ltd. (MES) provides the advanced solutions for environmentally friendly container terminal operation. According to the Tokyo metropolitan government, in the case of a model terminal (with a 680m quay and area of 275,000m2) 31.1 percent of carbon dioxide is emitted from RTGs; 37.0 percent from reefer containers, 13.5 percent from top lifter/ chassis and 8.8 percent from STS cranes [1].
MES is currently developing carbon reduction technologies for implementation in all these machines and eventually across the entire container terminal. This article introduces the MESecoTT Transtainer® crane, an environmentally friendly solution that contains engine variable speed control (EVSC), regenerated power storage (Hybrid model shown in Figure 1) and shore power electrification (eRTG) technologies.
Fuel-saving Transtainer
The MESHybrid Transtainer crane has been developed to reduce 50 percent of diesel fuel as well as toxic exhaust gas, including carbon dioxide. MES has delivered 17 of these cranes worldwide since 2007.
The technology consists of MES’s self-developed EVSC logic and energy storage system for regenerated power during lowering, as shown in Figure 2. The energy storage system boosts the performance of EVSC by using stored energy to assist power, which increases the diesel engine’s rate of acceleration. Although performance is dependent on handling productivity, fuel consumption data from actual operation achieves almost the designed level.
To reduce initial investment, the EVSC Transtainer is available without an energy storage system pre-installed. Especially, it shows a good return of investment (ROI) for retrofit, and two retrofitted cranes have been delivered in Japan so far. Four new EVSC Trainstainers have been delivered to date.
