Caterpillar Marine is introducing a new hybrid electric thruster system for ocean going ships. In the maritime world, cargo vessels have more than just one or two propellers to move them through the water. Many are equipped with digital placement (DP) systems that keep them located precisely in a certain spot in the ocean or in the same position relative to other ships.
DP systems use auxiliary thrusters for such low speed operations. The thrusters allow ships to shut down their main engines when not under weigh. That saves the owners money and reduces carbon emissions. Thrusters are also used in port to accurately position ships during docking and undocking maneuvers without assistance from traditional tug boats.
Until now, most of those thruster systems used diesel engines to turn their propellers. Caterpillar Marine says its new hybrid electric propulsion system outperforms diesel mechanical systems in all partial load conditions. For vessels that operate in standby or DP mode much of the time, the annual fuel savings can be as high as 35%.
“The efficiency gains are remarkable,” says Jonas Granath, manager of electrical design at the Caterpillar Marine Solution Center. “Of course, they differ from ship to ship depending on the ship service and [off shore vessels] come in a wide range of types and sizes. Typically, though, OSVs with DP capability spend a considerable amount of time in standby or in various levels of DP.
“With this new system, they will be able to use the diesel electric mode and run off the smaller gensets with the propellers operating economically at a very low rpm. It is in exactly these conditions where our new Marine Hybrid Thruster system offers the greatest benefits.”
The first of the new hybrid electric thruster systems is on its way to an undisclosed shipyard in Singapore. The company says the system is ideal for new vessels but can also be retrofitted to existing ships.
We here at Gas2 usually devote our attention the cars and trucks, but ocean going ships suck up a lot of diesel fuel. Typically, they operate on what is called “bunker oil,” the heaviest, thickest, dirtiest diesel there is.
The 15 largest ocean vessels produce as much carbon dioxide each year as all 760 million vehicles in the world, according to Gizmag. Anything that can be done to lower those emissions is a big step forward.
Source: Marine Log Photo credit: Caterpillar Marine