Figure 1. David Rababy is head of sales, E-Mobility North America for Stäubli. Source: Stäubli, courtesy of the Port of Long BeachFigure 1. David Rababy is head of sales, E-Mobility North America for Stäubli. Source: Stäubli, courtesy of the Port of Long Beach

Trade ties between Asia and North America are bookended by two powerhouse ports: Singapore and Long Beach, California. Both are in the process of electrifying their operations to get off fossil fuels. Other ports seeking a U.S. Environmental Protection Agency (EPA) grant to do likewise can learn from their experience.

Singapore ranks as one of the world's busiest ports in terms of total shipping tonnage. One fifth of the world's shipping containers pass through here. On the American side of the Pacific, the Port of Long Beach in Southern California handles nine million 20-ft container units every year, accounting for another fifth of all containers moving through U.S. ports.

Both ports share a goal to electrify port-side vehicles as part of aggressive goals to cut the air pollution that results from the near round-the-clock operation of container handling equipment such as yard tractors, rubber-tire gantry cranes (RTGs) and autonomous guided vehicles (AGVs) that shuttle containers around the port. They typically run on diesel fuel, emitting both air pollution and greenhouse gases.

Electric versions are available, and in April 2023, the Port of Long Beach applauded a “welcome and needed” first-of-its-kind rule by the California Air Resources Board requiring a transition toward such zero-emission medium- and heavy-duty vehicles at the state’s ports, as well as on its highways. The rule noted that while trucks represent only 6% of vehicles in California, they account for more than 35% of the state’s transportation-generated nitrogen oxide emissions, and a quarter of on-road greenhouse gas emissions.

Successfully electrifying the trucks used in ports requires attention to at least three key components:

First, and always, is safety. Electric vehicle (EV) chargers used in port operations can deliver anywhere from 75 kW to 250 kW of power to recharge the batteries, which may increase in the future. To keep charging safe, Stäubli Electrical Connectors offered these early adopter ports its Quick Charging Connector (QCC) system as part of a “hands-free” charging strategy to support their electrification.

As a yard tractor, AGV or RTG driver pulls into a parking space, the QCC system guides a pin from the charger into a funnel connected to an enclosed socket on the vehicle. It automatically completes the connection hands-free, and charging begins without having to involve the user in the charging process. In-between, it is fully enclosed and touch-protected.

Second, mission-critical port operations cannot allow for failures. Port real estate is some of the most valuable in the world, and some of the most important real estate within the port is where the ships are unloaded, moved and queued for distribution. This is also where yard tractors, AGVs and RTGs operate.

Even a single electric charger going out of service can disrupt port operations, with a high economic cost.

Third, charging must be rapid to get these special-purpose vehicles back into revenue-producing operation as quickly as possible. The QCC plugs in in less than 10 seconds as soon as the vehicle is in position, without the operator being forced to get out or plug in the vehicle. Other robotic connections range from 30 seconds to a few minutes. If a driver needs to get out of the vehicle to plug in, it can similarly take minutes until high-power DC current is flowing into the battery.

A few extra minutes of charge time each time goes a long way toward optimizing the operation. With those goals in mind, both the Port of Singapore and Port of Long Beach operator SSA Terminals selected the QCC system.

Singapore plans for the future

Such automated systems take center stage in an entirely new port that PSA Singapore is building. The goal is nothing short of revolutionizing the future of shipping.

Plans call for totally automating terminal operations and related infrastructure to strengthen Singapore’s ability to deliver to some 600 ports worldwide. As envisioned, a fleet of fully battery-powered yard tractors will each carry 65 tons of cargo at a cruising speed of 15.5 mph (25 km/h). These self-driving platforms will be charged automatically in about 20 minutes; that amount of charge will provide up to five hours of continuous use.

Cleaner air for Long Beach

Figure 2. The innovative system is designed to align with international standards, for interoperability between charging infrastructure and electrified trucks. Source: Port of Long BeachFigure 2. The innovative system is designed to align with international standards, for interoperability between charging infrastructure and electrified trucks. Source: Port of Long Beach

At Long Beach, 33 tractors designed to transport shipping containers around the terminal were delivered with an EV powertrain. SSA Terminals chose high-power 175 kW DC chargers to power the tractors, and Stäubli to install its QCC equipment for automated, rapid charging. The system entered service in November 2023.

The project with SSA Terminals was part of a $50 million grant to the Port of Long Beach obtained from the California Air Resources Board’s Zero and Near Zero Emission Freight Facility program to cut air pollution as well as greenhouse gas emissions.

More grant money from EPA’s Clean Ports program

The push to electrify the rest of America’s ports got a boost in late February when the EPA announced the launch of a $3 billion Clean Ports Program to fund zero-emission equipment, infrastructure and climate planning.

Most of the money – nearly $2.28 billion – funds a Zero-Emission Technology Deployment Competition for port equipment and infrastructure that reduces mobile source emissions. Eligible projects may include human-operated and maintained zero-emission cargo handling equipment, electric charging infrastructure and other technology investments.

How hands-free charging works

Stäubli’s QCC system uses an enclosed pin-and-socket design that is self-cleaning and touch-protected on both sides of the connector.

At the Port of Long Beach, the 33 QCC systems automatically connect the chargers to an electric receptacle on each terminal tractor. All 33 of the tractors can be charged simultaneously with no manual intervention. Operators pull into a charging station and the QCC deploys to plug in the tractors. Recharging can be done during work breaks or shift changes, maximizing charging uptime and labor productivity.

Each QCC features UL-rated components that withstand contaminants that can foul port equipment including salt air, high humidity and airborne rust and rubber. The scalable QCC system, which is based on the open international standard SAE J3105/3, helps future-proof port operations for when transport vehicles might have higher power needs. Stäubli is always working on breaking the boundaries of charging power, with a 7.5 MW liquid cooled QCC system on the horizon and the megawatt capable Megawatt Charging System (MCS) for commercial vehicles already on the market.

The Long Beach project is helping the Port of Long Beach and the Port of Los Angeles fulfill their joint Clean Air Action Plan to achieve 100% zero-emission terminal operations by 2030.

Stäubli also is actively involved in a number of standards-writing efforts, including IEC 61851-23-1 for EV conductive charging systems and SAE J3105-3 for medium and heavy-duty vehicle conductive charging.

The Stäubli system is designed to align with these international standards for interoperability between charging infrastructure and electrified trucks. That means EV manufacturers and service equipment providers will face few, if any, obstacles to adopting the hands-free connection equipment.

The recent deployments in Singapore and Long Beach offer positive proof that zero-emission electric yard tractors can operate economically and reliably in a challenging salt-water environment while meeting stringent air quality goals.

Qualifying for the EPA grant program will improve the economics for any U.S. port embarking on electrification.


David Rababy is Head of Sales, E-Mobility North America for Stäubli.