The Cape May-Lewes Ferry’s Cape Henlopen vessel is powered by engines so old that its maintenance team has to scrounge eBay, scrapyards and 100-year-old sawmills to find replacement parts when things go wrong. That’s according to Derek Robinson, port captain at the ferry and a Cape May County local who has worked on and around boats his entire life.
Soon to take Cape Henlopen’s place is a smaller, more aerodynamic ferry that supplements two 4,000-horsepower diesel engines with batteries and three smaller diesel engines that serve as generators for four electric motors. The end design makes for a more reliable, efficient and ultimately more adaptable ferry.
Why a new ferry?
Fixing the old engine, and the systems around it, has become time-intensive and expensive.
“The vessels themselves have been excellently maintained,” Robinson told the Herald at an interview in the ferry’s Cape May office. “But the steel is 50 years old. All the original equipment is obsolete. It is very hard to get parts for anything anymore. A lot of my and the chief engineer’s time is spent finding parts for these old vessels. I’ve gone to scrapyards, to a 100-year-old sawmill in the Carolinas to find a special transformer that would power the bow thruster that failed on the New Jersey.”
The Cape Henlopen’s engine was recently rebuilt to buy time until the new hybrid vessel’s arrival. “But there are not enough pieces in the world to rebuild those engines again,” Robinson said.
The new ferry is expected to cost $74 million, $20 million of which comes from a U.S. Department of Transportation grant that demands 70% of the components be made in America. It will transport 75 cars instead of Cape Henlopen’s 100. Robinson said the smaller capacity is a good middle ground for now because the extra capacity is unneeded most of the year.
Arriving at a final design has been a long journey. Plans for a hybrid vessel began in 2021 with a search for a naval architect to help design the ferry from scratch. The design, by Louisiana- and Washington-based Elliot Bay Design Group, is all new, but the idea of an electrically assisted ferry is decades old. Robinson told the Herald that hybrid and all-electric ferries are the norm in Scandinavia, from which some of the technology in the new ferry will be sourced.
Robinson stressed that the hybrid technology is tested; they aren’t working with untested concepts, motors or batteries. And besides, there’s a clock ticking on the ferry’s current three vessels, the Cape Henlopen, the New Jersey and the Delaware. The latter two received new engines in 2021 and 2015, respectively, which greatly expanded the vessels’ lifespans and fuel efficiency. There were early pitches to install hybrid systems into these old boats, but Robinson said that it would have cost five times as much.
“It’s always cheaper to build new,” he said.
The Cape Henlopen, although not the oldest of the three ferries, is the first slated for replacement. Robinson said it would have been prohibitively expensive to retrofit the old vessel with hybrid or electric tech.
“The legacy fleet is 50 years old,” he said. “We can stretch their life, but at some point they need to be replaced. This is the initial replacement vessel.”
How does it work?
Today, the Cape Henlopen is powered by a World War II-era Fairbanks Morse 38 8-1/8 diesel engine used in American submarines through the 1940s and ’50s. The two-stroke design is battle-tested. It sees occasional contemporary use as a generator in nuclear power plants and in other industrial settings. Eight of these engines provide backup power for the Limerick Generating Station, a massive nuclear power plant in Limerick Township, Pennsylvania. Many of these engines live on in museums as examples of still-working technology that helped carry the Allies to victory.
And the old engine is thirsty, gulping up 180 gallons of diesel per hour. The new system uses between 20 and 30 percent less fuel per hour between the new vessel’s three MTU 12v4000M engines, which serve as generators for onboard batteries. The engines are a product of MTU Friedrichshafen, a German engine manufacturing company designing engines for more than a century.
The ferry’s hybrid power generation system is similar in some ways to the two-motor system found in Honda’s new hybrid system implemented in cars like the CR-V, Civic and Accord. Those cars have a gasoline engine that generates electricity to power onboard batteries, which power an electric motor hooked up to its transmission system, which ultimately propels the car.
The new ferry operates similarly but with more built-in redundancy, which means less downtime when things go wrong. Three diesel engines work together on the ferry to charge the onboard Corvus Orca batteries, which feed the four electric motors attached to the ferry’s two shafts, which are attached to propellers that ultimately propel the vessel. The diesel engines can also power the electric motors directly. Michael Lynch, Port Engineer, said the engines kick in to provide the motor with additional power “when the ship propulsion requirements change rapidly.”
Like the Honda hybrids, the combustion engines on the ferry directly power the electric motor in high-stress situations.
Redundancy is the name of the game here: two motors per shaft instead of one, three smaller diesel engines instead of two. Without this built-in redundancy, Robinson warned, “you could potentially have the boat down for three to six months waiting for a replacement to come in if you had, for example, just one massive motor per shaft instead of two.”
And why three diesel MTU engines? Robinson explained that they do not all operate at once but instead take turns operating to give each a longer life. Each motor has an estimated 64,000-hour operating life.
“We alternate between using two this week, two next week,” he explained.
Even if all of the engines broke down at the same time, an extremely unlikely occurrence, the ferry can return to port on stored power alone, even from the middle of the ferry route. Without the generators, the ferry can operate for an hour at a speed of 12 knots.
A non-electrical design improvement on the yet-unnamed ferry is a bulbous bow that sits just under the water line at the front of the vessel. Director of Ferry Operations Heath Gehrke said that the bulbous tip changes the water flow around the hull, reducing drag to help the ship achieve 20 to 30 percent better fuel economy. Michael Lynch, Port Engineer, is optimistic that all of the new systems can work together to be as efficient “as 55 gallons per hour at the same speed of our current fleet.”
The Corvus Orca batteries in the new ferry will not be discarded when they arrive at the end of their 10-year life. “It’s not like a Duracel that ends up in a landfill,” Robinson said. “They have a long life cycle and are re-cycled to different uses.”
Batteries this large, he said, have different “tiers” of usage. A high-tier usage would be to power a major vessel like the new ferry. Once the battery’s capacity depletes past a certain threshold, it is demoted a tier and could be used as ferry power packs back at the port. When they are no longer fit for that use, they are demoted again and used for things like backup power at a hospital.
What is the timeline?
The new hybrid ferry is just phase one of what Robinson called a three-phase plan for an all-electric future at the Delaware River and Bay Authority. The new ship can accommodate an all-electric setup.
Phase two requires extensive infrastructure investments at both the Cape May and Lewes ferry terminals and would add more batteries aboard the ferry. Charging stations on each side of the Delaware Bay would allow for at-port charging, reducing the load of the onboard diesel engine generators.
Robinson explained that this second phase requires massive, permanently stationed batteries at each port that can “dump” power to the vessel’s onboard batteries when the ferry returns to dock.
“You need an abundance of electricity that charges permanently mounted shoreside batteries,” he said.
The final phase requires a fast-charging system on both sides of the bay. Phase three, Gehrke told the Herald, “can be accomplished with fast charging or some combination of charging from the grid and a shoreside battery energy storage system.”
Robinson said that, from his perspective, phase three could be achieved in 20 years.
“This isn’t a flash in the pan or a trend, this is where we are going,” he said.
The new ferry is extremely unlikely to be built in New Jersey or Pennsylvania. Robinson explained that the shipyards in both states typically work on larger-scale projects; they are unlikely to bid on a “smaller” project like the new hybrid ferry.
The new ferry is expected to go to bid in February. It takes two to three years from final bid to shipment.
Contact the reporter, Collin Hall, at chall@cmcherald.com or by phone at 609-886-8600, ext. 156.
