The Working Waterfront

Casco Bay Lines board votes on new diesel/electric Peaks boat


Tom Walsh
Posted 2020-06-24
Last Modified 2020-10-04

It’s bit more complicated than putting pontoons on a Prius, but hybrid diesel/electric ferries are on the horizon for both the Maine State Ferry Service and the Casco Bay Island Transit Authority, which operates Casco Bay Lines.

The board of directors of the Casco Bay Island Transit District voted June 25 to proceed with the design and construction of a new boat to be equipped with a 900 kWh diesel/electric propulsion system instead of a conventional diesel system.

Both ferry systems are evaluating how to best replace their aging fleets of passenger and vehicle ferries, and considering the benefits of hybrid vessels, which are engineered to lower operating costs and reduce environmental impact.

The Maine Department of Transportation’s ferry service connects the mainland with six island communities: Frenchboro, Islesboro, Matinicus, North Haven, Swan’s Island, and Vinalhaven. The service operates seven vessels, including two ferries built in 1959 and 1960. The service hasn’t launched a new vessel since 2012.

Maine State Ferry Service Manager Mark Higgins said that as the ferry fleet ages, overall reliability diminishes and maintenance and operating costs skyrocket.

“As we pursue our new-build program, Maine State Ferry Service wants to be a leader in carbon emissions reduction through use of new technology,” he said.

“We’ve been working with other (ferry) systems and with naval engineers and naval architects on the best strategy for powering these vessels. Hopefully, the next bids we put out, maybe as soon as this fall, will include specifications for a diesel-electric hybrid system with an onboard stored power (battery) system.”

The goal, Higgins said, is to eventually have a fleet of all-electric ferries.

“A propulsion system with two on-board generators will see fuel consumption go from 150,000 gallons a year to 112,000 gallons,” Higgins said

Bill Pulver, the service’s chief operating officer, told the Ferry Service Advisory Board in March the service “is taking a serious look at more climate-friendly and cost-effective propulsion systems, which are being phased into service throughout the world.”

Pulver noted that European countries “are way ahead of the U.S. and North America when it comes to the use of hybrid/electric powered ferries, with interest and implementation in the U.S. and Canada growing.”

Among the ferry systems DOT is assessing are transit, river crossings, and sight-seeing tours in Alabama, Texas, San Francisco, Washington state, and British Columbia.

“There are different types and configurations of these propulsion systems,” Pulver said, including diesel-electric, hybrid diesel-electric, fully electric, and others. “When these terms are used interchangeably, it causes confusion,” he noted.

“We’ve also learned that every ferry route is different when it comes to the potential and options for hybrid/electric propulsion,” Pulver said, “given the length of routes, the types of seas, the size and power requirements of the vessel, the daily schedule, and land-based power capacity and infrastructure at the dock. We’ve learned, too, that shore-based charging infrastructure upgrades and peak power costs can be costly and challenging.”

Pulver said the ongoing construction of a new replacement ferry for the Vinalhaven-Rockland route is on hold as the ferry service evaluates whether hybrid diesel-electric systems are technically and financially feasible. The $9.5 million vessel has been under construction for two years by Washburn and Doughty in East Boothbay.

The ferry service is now weighing costs and benefits of available propulsion options beyond two emission-reducing diesel engines originally engineered for the Captain Richard Spear, which will replace the Captain Charles Philbrook, which has run the Vinalhaven route for 30 years.

The new 160-foot vessel is designed to accommodate 23 vehicles and 250 passengers, up from the Philbrook’s 17 vehicles and 221 passengers. The Captain Richard Spear was originally expected to be completed in April, but delivery is now expected this fall.

As more ferries are commissioned and delivered, the Captain Richard Spear will likely be reassigned to the Swan’s Island and Frenchboro service that connects those island destinations with Bass Harbor, Higgins said. As new ferries are phased into use, the vessels they replace may eventually be sold. “There is always a secondary market,” he said.


In Portland, the board of directors of the Casco Bay Island Transit District and its Casco Bay Lines ferry system approved on June 25 the design of a new 599-passenger, 15-vehicle vessel it will add to its aging fleet of five ferries.

Launched over 150 years ago with coal-fired wooden ships that delivered tourists to island communities throughout Casco Bay, the Portland-based ferry system now handles one million passengers, 35,000 vehicles, and 500,000 pieces of freight each year, as well as U.S. mail deliveries. The destinations it serves from a dock on Portland’s Commercial Street waterfront include four islands—Peaks, Little Diamond, Great Diamond, and Cliff, all of which are within Portland’s city limits—as well as the independent towns of Long Island and Chebeague Island.

As proposed, the $11.2 million project—$1.2 million for design and an estimated $10 million for construction—would be equipped with a 900 kWh diesel/electric propulsion system instead of a conventional diesel system. The system’s newest vessel was built in 2013, and the oldest in 1985.

The hybrid propulsion system is projected to eliminate 800 metric tons of CO2 emissions annually, and eliminate exhaust fumes and excessive engine noise.

“We consider the useful life of our ferries to be 30 years, after which everything involved gets more expensive,” said Hank Berg, the Casco Bay ferry system’s general manager. “In terms of the alternative propulsion systems, we’ve received many positive comments from within the communities that rely on our ferry system.”

The Federal Transit Authority has committed $9.5 million to the project. Maine DOT has allocated $750,000, and the city of Portland will add another $59,000.

Another curious source of funding is expected to come from Maine’s share of the $21 million settlement of federal lawsuits against Volkswagen, the court-ordered penalty for intentionally tampering with emission control devices in some of its cars. Those funds are being allocated among all 50 states, Puerto Rico, Washington D.C. and Native American tribes, depending on VW sales of cars with faulty emissions software.