Page 26: of Marine News Magazine (July 2026)

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Tech Feature

Marine Electrical Systems

Organized Lightning: © Amarylle/AdobeStock

Understanding the Evolution of Marine Electrical Systems

By Will Ayers, PE | Chief Electrical Engineer, Elliott Bay Design Group ow well do we really understand the electrical sys- Atlantic Marine Shipyard, now BAE Jacksonville.

tems powering today’s vessels? Many of us realize Like offshore oil and gas, autonomous landing barges how important electricity is to our modern world usually depend on dynamic positioning (DP) to maintain

H but may be a bit shaky on the speci? cs. The Welsh precise coordinates. And, like offshore, this leads to a clear comedian Tommy Cooper once joked, “Electricity is a advantage for diesel-electric propulsion. Another area that wonderful thing. Do you realize that if we didn’t have elec- we’ve been working on involving DP and diesel-electric tricity, we’d be watching television by candlelight?” propulsion is that of research vessels. For all of these diesel-

For those who have worked on vessels for many years, electric vessel types, it can become a complicated analysis the increasing complexity may be a sore point, especially to decide between the increasingly popular DC grid pro- for those who have been hands-on in their careers and been pulsion system vs the conventional constant-speed variety. zapped a few times. George Carlin once joked, “Electricity is really just organized lightning.” DC Grid Systems: A Shift in Propulsion Architecture

The Growing Complexity of Marine Electrical Systems A DC grid retains the use of standard AC generators

All kidding aside, the growing complexity of marine and AC motors. However, it replaces both the AC pro- electrical engineering is becoming a de? ning factor in pulsion switchboards and propulsion Variable Frequency modern vessel design and operation. At EBDG, we have Drives (VFDs) with a single DC grid “switchboard”. With been fortunate to develop signi? cant experience in hybrid the main propulsion bus now DC, generators connect technologies over the last decade. However, if that imme- through recti? ers located in the DC grid line-up which diately elicits thoughts of a Prius or Tesla, there is much also includes inverters feeding AC propulsion motors and more happening electrically onboard today’s vessels and an AC ship service switchboard.

understanding these systems is becoming increasingly im- There are several advantages. The DC grid is composed portant as vessel designs continue to evolve. of the same recti? ers and inverters that are the front and back halves of the VFDs in a standard diesel-electric. Yet,

From Space to Sea: Expanding Electrical Capabilities large AC propulsion switchboards and their circuit break-

One exciting area that the US leads the world in is the ers are no longer needed. The large phase-shifting trans- marinization of space technology. Such examples include formers from older systems can also be eliminated with the

Rocket Lab’s autonomous station-keeping barge Return potential for considerable volume and weight savings. The

On Investment being converted at Bollinger Shipyards in generators can operate at variable speed improving fuel ef-

Amelia, La. Blue Origin used the advanced barge Jacklyn ? ciency and can also come online faster. There is no fre- last year to successfully land a rocket. SpaceX led the way quency to synchronize; the recti? ed generator voltage just having landed its ? rst rocket on an autonomous drone needs to match the DC bus voltage. barge with Of Course I Still Love You dating back to 2016.

And, not surprisingly, NASA has a long experience in this Challenges and Considerations area. For instance, they operated two specially-designed The primary disadvantage with this new approach is the ships for space shuttle booster recovery built in 1980 at the DC short circuit current. While DC grids can achieve sig- 26 | MN July 2026