## 2 Port Cranes Overview
### Evolution Timeline of Port Cranes
#### 2.2.6 Automation and Sustainability (1990s-2020s)  
* ASCs debut (1990s)--In the 1990s, fully automated rail-mounted ASCs were debuted in European terminals, such as Rotterdam's ECT Delta Terminal. These cranes eliminate the need for human operators for certain container-handling tasks, enhance safety, and significantly increase the throughput of large terminals. The use of sensors, computer-controlled systems, and automated guidance systems allows ASCs to move containers with high precision and speed [8].
* Electric/Hybrid RTGCs Developments (1997-2005)--In 1997, Kalmar introduced the next generation of AC electric-powered RTGCs along with its own PLC software, which provided in-house electrical engineering capabilities. This shift towards electric power has reduced emissions and noise pollution. In 2005, Kalmar launched the E-One RTGCs, the first fully electric RTGCs without hydraulics. These electric and hybrid RTGs not only improve environmental performance, but also offer better energy efficiency, with some models reducing energy consumption by 30-50% compared to diesel-powered RTGCs [11; 27].
* Energy-Saving RTGCs Retrofits (2007-2008)--In 2007, the Ministry of Transport issued Guidance on Energy Conservation and Emission Reduction in Ports. In response, the Water Transport Science Research Institute of the Ministry of Transport, Guangzhou Port Group Co., Ltd. (Guangzhou, China), and Shenzhen Jingsheng Textile Co., Ltd. (Shenzhen, China), initiated a project to retrofit RTGCs for energy efficiency. Through months of laboratory and field testing from 2007 to 2008, the retrofitted RTGCs achieved significant fuel savings of up to 40-65%. For instance, the Shanghai International Port Group retrofitted its RTGCs into hybrid diesel-battery RTGCs, reducing the fuel consumption by 65%. Additionally, in a Shanghai terminal, replacing diesel-powered RTGCs with electric RTGCs reduced the energy consumption by 54.9% and total energy costs by 29.7%. These results demonstrate the potential of retrofitted RTGCs to enhance the energy efficiency of existing port crane fleets [27]. Driven by green port initiatives, container terminal operators have replaced the environmentally and economically inefficient diesel-powered rubber-typed gantry cranes with new or retrofitted electric cranes. For example, 57 RTGCs in Tianjin Port were converted to electric RTGCs over two years, reducing the unit energy consumption of yard cranes by nearly 80% [28].
* Hydrogen Fuel Cell RTGCs Testing (2025)--In April 2025, DP World completed the initial testing of a hydrogen fuel cell RTGCs at the Port of Vancouver. This marks a significant milestone in decarbonizing port operations. RTGCs, traditionally powered by diesel, are crucial for cargo handling but are major contributors to greenhouse gas emissions. At the DP World's Vancouver terminal, 19 RTGCs account for 50% of diesel consumption and generate over 4200 tonnes of CO\({}_{2}\) annually. The adoption of hydrogen technology promises to drastically reduce or eliminate this environmental impact. The tested RTGCs are currently undergoing field trials, as the DP World evaluates the feasibility of electrifying its global fleet of 1500 RTGCs. If the trials are successful, the DP World may convert its 25 diesel-powered RTGCs to Vancouver and Prince Rupert to meet its zero-emission goals [29].  
Figure 2 depicts the evolutionary timeline of port cranes from ancient times to the present.