Cold ironing 101
It sounds simple enough.
Pull ship up to dock.
Plug power cord into socket and—voilà—electricity to run everything from refrigeration to computers.
But the process of delivering high-voltage shore power to a large commercial vessel requires a careful minuet between the crew and longshoremen to ensure it is done safely.
American Shipper spoke with a top official at a container terminal at the Port of Long Beach to learn the basics of cold ironing.
Under California regulation, once a vessel comes alongside the pier it has three hours combined at arrival and departure during which it can operate on its own generator sets while preparations are made to transition to or from electric power.
Longshoremen first have to wait for U.S. Customs to board the vessel, verify the crew manifest and complete their rounds. That process usually takes about an hour.
Once the terminal is allowed to put its men onboard care must be taken to make sure the system is not live and can be safely touched. An individual on the ship communicates by radio with workers on the pier and there are strict safety regulations governing the type of clothing that can be worn and procedures for vessel electrification.
When the system is grounded dock workers start the process of putting the ship’s electric cables down in a vault located on the wharf and connecting them. There are sliding sleeves on the outside of the cable that are attached to chains to take the strain off the cable as the vessel moves due to tidal change or other factors.
A crew at the electric substation then begins to gradually start sending power to the ship. Powering up has to be done in stages to make sure equipment on both ends isn’t damaged. As the ship-board generators are automatically shut down the shoreside power starts to absorb the functions of the ship.
“It’s not like a light switch. It’s done in a very particular way so everything is protected,” the official, who only agreed to speak on background, explained.
Close communication with the onboard liaison and ship crew is critical, especially since crew changes are common and the person in charge on the vessel may not have a full understanding of the detailed procedures required.
The plug-in process takes about 45 minutes.
For the remainder of the stay the shore-side mechanics maintain radio communication with the ship in case there are any issues.
About an hour to 1.5 hours before the vessel heads back to sea, the terminal will start the disconnection process, releasing power back to the ship in a controlled manner. When the vessel is back on its own power, the plugs are disconnected from the vaults, the longshoremen ensure the cables are stored safely back on the ship and the vault is closed.
Some vessels are missing the three-hour CARB window because crews are still on a learning curve, Lee Kindberg, Maersk Line’s North American environmental director, said.
Ports still need to invest in shore power infrastructure, the terminal official said. More electric vaults on the wharf are needed because ship sizes have greatly increased since the infrastructure was planned in 2010. Carriers also have installed their equipment in different places and vaults aren’t always easily reached. Vessels, for example, can have equipment on the port side when a terminal has shore-power equipment on the starboard side of a pier, which then requires a ship to be turned.
The company will evaluate AMECS when the time comes, but adopting it would require a significant change in how the terminal does business.
“We’re not sure if we could use both the barge and cold ironing,” he said.
This article was published in the September 2014 issue of American Shipper.
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