OAKLAND (KPIX 5) — At the Port of Oakland, officials are trying to save money by switching some of the cargo cranes to operate on a mix of electrical and diesel power.

The workhorse cranes at the Port are not be the large white ones visible from the freeway. Rather, the five-story gantry cranes are doing a bulk of the heavy lifting.

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The cranes are called RTG’s, which stands for rubber-tired gantry cranes. The machines move containers onto waiting trucks that line up at the port.

SSA Marine Crane Manager Ken Larson says the cranes are having their 1000 horse-power turbo diesel engines replaced.

“Basically, what these are is a battery pack and a small generator to recharge it,” explained Larson.

SSA Marine says the fuel savings from the new engines is enormous. The old engines used to burn through 12 gallons an hour. The new diesel-battery hybrid power pack burns only a half a gallon of diesel per hour.

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Port of Oakland spokesperson Marilyn Sandifur says the improvement is a game changer from an environmental standpoint.

“It’s going to cut diesel emissions by 95 percent from each one of these [cranes],” said Sandifur.

There are 13 RTG’s at the Port of Oakland. So far, four have been converted, with the rest set to be completed by the summer of 2020.

SSA Marine client relations manager Susan Ransom says if all continues to go well, they plan to convert many more cranes to hybrids.

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“Oakland is the focus, as well as Long Beach. And we hope to just keep going,” said Ransom.