The AMC 30 is a new launch design that will be purpose built for the Appalachian Mountain Club to ferry members and guests to the Three Mile Island camp on Lake Winnepesaukee in New Hampshire. The finished launch, expected to enter service in the summer of 2023, will be christened Appy VI, and will offer several upgrades to her predecessor, Appy V, replacing gas power with electric propulsion in a slippery hull that offers a reduced wake. Drawn by the talented team at Zurn Yacht Design in Marblehead, Massachusetts, and built by Boston Boatworks in Charlestown, Massachusetts, the AMC 30 epitomizes the values shared by the late Mark Lindsay, founder of Boston Boatworks and the Appalachian Mountain Club, including efficiency, durability, respect for nature, reduced environmental impact, near-silent operation, and ease of repair.

“The Appalachian Mountain Club is a very environmentally conscious group and the island is totally self-sufficient, and it relies on a solar farm for electricity,” says Doug Zurn, founder of Zurn Yacht Design. “They’re really trying to be as close to a zero carbon footprint as possible. So going back and forth to the island with a 40-year-old deep-keeled wooden boat that put up a three-foot wave—it sort of rubbed Mark the wrong way and planted a seed in him.”

Efficient hull form

The AMC 30 is a modern take on a traditional launch, but one in keeping with a strict ferry schedule of four round trips to Three Mile Island Camps each day—efficiency is a requirement in keeping with the sensibilities of the membership and guests of the non-profit Appalachian Mountain Club.

“Mark was all about building slippery boats and this was no exception,” Zurn says. “It fulfills another aspect of Mark’s rich legacy to have this project come to fruition now.”

Zurn Yacht Design ultimately relied on the computational fluid dynamic services of BAR Technologies Ltd. of the UK, which offered data and suggestions that decreased drag resistance of the hull by 11 percent, while comparing wave-height effects of various hull forms.

“We achieved our target cruising speed of 8.6 knots with a full load of 22 passengers and gear,” Zurn says. “Her very fine entry at the bow transitions to a full-bodied hard-chine midsection that optimizes her stability, while aft sections provide lift while keeping the bow-up trim to a minimum.” 

A short keel provides lateral stability in a crosswind, and aids in turning in tight quarters while also offering protection to the running gear and rudder. The launch is expected to achieve a speed of 9.4 knots at half load.

Construction

One cannot talk about a project considered by Mark Lindsay and Boston Boatworks without addressing the construction requirements. Mark’s history of building high-tech, lightweight composite structures played a substantial role in the development of the various laminate schedules, and as always, emphasis is placed on using the right amount of materials where appropriate.

“Appy VI is a perfect application of our high-strength, lightweight construction skill set,” says Scott Smith, CEO and founder of Boston Boatworks. “This is just the kind of project we love, where environmental sensitivity is a top criteria for what ‘high performance’ means to the owner we’re building boats with. Appy VI was to be Mark’s first ‘retirement’ project, with his hands-on labor working side-by-side with phenomenal composite craftsman Bruce Dyson and Boston Boatworks’ team to create another work of art.”

Mark’s firsthand experience with how Appy V had been handled during his more than 30 years as a member of AMC gave him a unique perspective on where the high-impact areas might require extra reinforcement, and where lighter construction areas could be employed.

“Beyond the hull construction, Mark had a vision for a yacht that met all the requirements,” Zurn says. “He basically had the idea to build something that doesn’t require gasoline and a whole bunch of maintenance each year, because there’s wood to varnish and more.”

Electric Propulsion

The design brief called for electric propulsion to help further reduce carbon intensity, and several systems were reviewed. Because Boston Boatworks had an existing relationship with Torqeedo, and used their battery outboard systems to power yacht tenders, while Zurn Yacht Design had specified the systems in several designs.

“We looked at a couple of systems,” Zurn says. “Torqeedo has I think the cleanest solution as far as one-stop shopping with regards to controls and motors, and battery-charging systems.”

A 25kW water-cooled electric motor and 400Vdc water-coooled lithium battery, throttle controls, and a battery-monitoring system comprise the Torqeedo propulsion system. She will be kept inside at the Three Mile Island Dock House and plugged into a battery-charging system that will take a maximum of six hours to recharge the battery from full discharge.

Celebrating the Legacy

From the traditional lines, to the high-technology layup and advanced electric propulsion, the stakeholders believe Mark Lindsay would be proud of the role he played in the development of the AMC 30 Appy VI and how it solves the challenges of replacing Appy V.

"Reducing the use of fossil fuels in our facilities’ operations is foundational to achieving AMC's goal of net zero emissions no later than 2050," said Susan Arnold Interim CEO of the Appalachian Mountain Club. "We are honored to celebrate the legacy of Mark Lindsay through this project, which supports access to recreation opportunities on Three Mile Island and furthers our conservation goals.”