Rovings August/September Issue 144

from Professional BoatBuilder magazine No. 144
Compiled by Dan Spurr


Flandre electric ferry launchJean-Yves Poirier

Flandre , a 50′ (15.2m) electric ferry launched by Alt.En in May, summarizes  the French company’s experience with zero-emission craft.

Zero-Emission Mission

The inspiration for the French company Alternatives Energies (Alt.En) dates to 1996 in La Rochelle during the European solar boat challenge. The event highlighted the potential to run a vessel for an extended period on solar energy alone.

The prototype vessel, called CREA2000, was designed and built by CRAIN (Centre de Recherche pour l’Architecture et l’Industrie Nautique/Research Center for Naval Architecture and Nautical Industry) as a volunteer student project, and it won all its races by a large margin. CRAIN was founded in 1988 by Philippe Pallu de la Barrière, a mathematics teacher at the Collège de France; for the solar boat project, CRAIN was joined by Christian Bouly, a professor of mechanical engineering at the University of La Rochelle who helped develop the propulsion system, and by manager Alain Bernicard.

Tilt-up pod driveJean-Yves Poirier

Tilt-up pod drives are efficiently maintained and easily serviced from on board the boat or from a tender.

Alt.en shuttleJean-Yves Poirier

Beginning in 2009, Alt.En’s two electro-solar shuttles operate daily in La Rochelle, between the city’s old harbor and Les Minimes marina

Solar powered CREA2000Alt.En

The solar-powered CREA2000 won the European solar boat challenge in 1996; she was the beginning of her inventors’ work in electric propulsion, which in 1997 became Alternatives Energies.

First electric outboardA. Tissandier

In 1881, Gustave Trouvé invented the first electric outboard, and it was able to run his skiff a full day on the Seine River.

Bolstered by winning, the team decided to develop a solar-driven version of a ferry the city intended to run between the two sides of the main entrance channel to the old harbor. The mayor, Michel Crépeau, had already developed a popular public service network of rental electric cars and bicycles. He was so enthusiastic that he arranged financing for the ferry project. Building the 30-passenger ferry required a new independent technical and commercial organization, and in 1997 it took the name Alternatives Energies. Due to the uncertainty of zero-emission markets, it had to share offices and calculation services with CRAIN.

As annual traffic grew close to 350,000 passengers, a new boat was ordered. The catamaran platform was selected as the best combination of cargo capacity and easy maneuvering. Retractable pod drives allow easy maintenance of the boat in the water, and the low-drag hulls are the most efficient for the limits of electric propulsion. Everything had to be kept lightweight. Hulls are conventionally built in a female mold to keep finishing costs as low as possible, while allowing extensive use of sandwich structure (polyester resin and PVC foam core). Superstructures are composite or aluminum, the latter not requiring large investments in tooling.

Another Alt.En trademark is its finishing standards, which are as close as possible to those for yachts—the main industry in the La Rochelle area. All work is subcontracted to various businesses that are close together and work in an informal but effective network.

In 2007, the French real estate investment company Icade invited Alt.En to bid on two floating 75-passenger shuttles, to link its business and tourist complex (called Parc du Millénaire) to the metro station of Aubervilliers through the Canal Saint-Denis, in the northern suburb of Paris. Winning the contract, Alt.En developed a 50′ (15.2m) catamaran, its biggest project to date. A requirement was four hours of autonomous operation at 4 knots. The best solution at that time was a bank of nickel-cadmium (NiCad) batteries, weighing more than 5,500 lbs (2,492 kg), and an electronic control system for reliability.

Since then, Alt.En has created a real-time monitoring system that records data (such as power fluctuations, battery temperature, engine power, etc.) every minute and sends them to the Alt.En office through a mobile phone network. Engineers can keep track of the 11-ferry fleet and its other electric vessels and have a 24/7 log on hand. They can anticipate problems and advise pilots by phone on how to make the best use of their energy resource. Alt.En offers operators a full-time assistance service, which is vital for creating wider acceptance of zero-emission technology.

Batteries are charged every night from a 380VAC dockside plug. The main challenge was to have the ship operational 100% of the time scheduled. At 98%, the goal seems to have been reached. Six years later, with annual traffic of more than 1.2 million passengers, and proof that low energy cost per passenger of 22 Wh per kilometer could be profitable, Icade ordered another shuttle.

The fourth ferry, called Flandre, was launched in 2012. Battery technology, developed by SAFT (Bagnolet, France), is based on lithium ferrophosphate (LFP) chemistry, which has a much better energy density than previous generations of NiCad cells. Two LFP banks of 85 kW (assisted by 3.5-kW solar panels) helped save 2,204 lbs (998 kg), resulting in a displacement of 12.7 long tons empty (and 18.7 tons full). This helped improve carrying capacity by 10 passengers to 85, and get a full workday from the two 400VDC/20-kW pods (made by Fischer Panda, Paderborn, Germany). Additional weight savings was achieved from Alucore ultralight aluminum sheet panels, stiffened with an aluminum honeycomb core.

Julian Helene, an Alt.En engineer, says that battery technology is the key to zero-emission solutions, and it has issues. The first is price: at around $780 to $1,300 per kW, it is quite high compared to conventional lead-acid batteries. In terms of weight, it is not much more attractive, because 1 ton of LFP batteries cannot store more energy than the equivalent of 5 gallons (19 l) of diesel fuel. In the real world, that means a 100-nm day, cruising nonstop at an average of 6 knots (or only 50 nm at 7.5 knots). Depending on the quantity of energy delivered over time, lithium batteries have at least five years’ life expectancy before replacement, meaning that amortization costs have to be carefully watched. For that reason, some lithium battery manufacturers are considering renting their products rather than selling them. Lithium batteries require precise charging and internal temperature control. Above 104°F (40°C), lithium cells begin to lose capacity and stability, so that a zero-emission craft, which requires balancing a lot of technical and financial data, is not a universal solution.

To break those barriers, Alt.En is studying two types of hybrid systems. One, called “range extender,” is based on the same “100% electric” equipment but with a diesel generator that charges batteries for exceptional conditions (heavy wind, strong current, long trip, etc.). The other solution is based on a diesel-electric system, the diesel generator feeding propulsion pods with high-voltage AC current when maximum power is needed or simply charging batteries when low speed is required in harbors or other protected waters. Alt.En hopes to launch its first hybrid system soon in a marine shuttle to service the Mediterranean coast, in Toulon. With its industrial partners, Michelin Recherche & Technique (Fribourg, Switzerland) and EVE System (Taluyers, France), Alt.En is also studying a hydrogen fuel cell system, with its own hydrolizer producing gas during overnight stops.

Alt.En, 52 Rue Sénac de Meilhan, 17000 La Rochelle, France, tel. +33 (0)5 46 50 29 87, fax +33 0(5) 46 44 65 36, website

—Jean-Yves Poirier

Zurn and New England Boatworks

Day cruiser
Zurn 50

Top and above—Recently launched at New England Boatworks (Portsmouth, Rhode Island) is designer Doug Zurn’s latest gentleman’s day cruiser, or commuter, the Zurn 50 (15.24m). The long, lean, and elegant yacht is evidence yet again of Zurn’s unerring eye for the perfect line.

Zurn 50 accommodationsDoug Zurn Yacht Design (ALL)

While the large cockpit and semi-open helm/entertainment area suggest enjoyable day cruises, overnight accommodations for a couple are generous with a centerline double berth, a galley, a head, and a separate shower.

When Bob Johnstone considered who he wanted to design his line of MJM sport cruisers, he said he chose Doug Zurn because he flat-out drew the handsomest boats. Nothing Zurn has done since suggests Johnstone wasn’t flat-out right. Witness the Zurn 50 (15.24m), launched in April at New England Boatworks, in Portsmouth, Rhode Island.

Unlike Zurn’s IS48 (14.6m) motoryacht (Professional BoatBuilder No. 134, page 8), which packs in far more accommodations in essentially the same-length hull, this one has a lean, low profile. Let’s call it a gentleman’s day cruiser or high-speed commuter, though of course it has accommodations for coastal cruising. The large cockpit is perfect for harbor cruises and entertaining.

Twin 1,550-hp (1,163-kW) MAN diesels coupled with Rolls-Royce Kamewa jet drives deliver a top speed near 60 knots.

Of her design, Zurn writes, “She is long and narrow with 15° [deadrise] at the transom transitioning to 17° and up, forward of amidships. Forward sections are bell shaped. Her entry is fine versus blunt. She is the second hull pulled from tooling built in the late ’90s. The first boat was Longevity, which provided her owner with 10 years of service, from Long Island Sound to Palm Beach, the Bahamas, and Caribbean working as a tender to a larger mother ship.”

Construction is E-glass and epoxy resin infused over a foam core.

Zurn Yacht Design, 89 Front St., Marblehead, MA 01945 USA, tel. 781–639–0678, website

New England Boatworks, 1 Lagoon Rd., Portsmouth, RI 02871 USA, tel. 401–683–6110, website


Infused With Enthusiasm

Learning about composites
Resin transfered to buckets
Resins flowKen Olson (ALL)

Top to bottom—In Murdo Cameron’s shop, in Hayden, Idaho, volunteers interested in learning about composites—and building and racing vintage outboard replicas for fun—position reinforcements in a 10′ (3m) C-class shovel­nose hydroplane mold. Resin is transferred to the buckets from which the feed lines draw. Cameron, a self-proclaimed “composites nut,” holds a feed line as resin begins to flow.

As I wrote on page 14 in PBB No. 128, Murdo Cameron of Coeur d’Alene, Idaho, is a composites nut. A former airline pilot and flight instructor, he got interested in advanced composites by splashing a flight simulator in 1980—seems the materials and processes of that project were more captivating than teaching aviation. Anyway, the subject of that write-up was his building a replica of Miss Spokane, a 31′ (9.4m) Unlimited-class hydroplane from the 1960s. He and his cadre of friends and volunteers hoped to have her participate in some of the various nautical events staged on Lake Coeur d’Alene.

Last spring he began another build, this time a 10′ x 5′ (3m x 1.5m) C-class shovelnose hydroplane that he and the same cadre hope will inspire the construction of others for some freshwater group therapy.

Cameron works out of his hangar at the airport in Hayden, Idaho. For the infusion of the hydroplane hull, he invited interested people to come observe the process. Among the attendees was well-known aerospace engineer Burt Rutan.

Here’s Cameron’s materials list:

  • Fiberglass C-stock hydroplane mold
  • Premade fish scales
  • 7781 fiberglass
  • 7-ply IM7 graphite stiffeners
  • 3-ply Saertex (90/–45/+45) fiberglass
  • Rohacell 57g foam
  • 0/90 unidirectional fiberglass

One of Cameron’s volunteers, Ken Olson, provided the following description of the day’s events:

“We set this up almost like a cooking show on TV. We had the top deck mold ready to lay all the material down layer by layer to show everyone how the layers went together. It was exactly the same as the bottom of the hull except that we didn’t use foam to reinforce the top deck like we did for the bottom. Once that was all down, we moved over to the bottom mold, which already had the vacuum bag on and pump running. All we needed to do was pour the mixed resin into the bucket and unclamp the lines.

“The infusion process took approximately 25–27 minutes and used 6–7 gallons of Reichhold 33375 vinylester resin. Once the resin reached all the places we needed, we clamped off the feed lines to stop the flow and kept the part under pressure for another 6–8 hours until the resin was cured. Murdo pulled the part out on Monday and said it looked pretty good.”

When asked the purpose of the project, Olson wrote, “We are hoping to get a few people interested in making a few more and run them as vintage outboard replicas at the smaller hydroplane races. No trophies, just go out and have fun and buzz around. This hull is an older style and would probably never keep up with the more modern hulls out there anyway. We need to find a motor and running gear and should get it on the water this summer.”

Cameron says the molds for the shovelnose hydroplane were given to him by a local fiberglass shop, and that when finished, he’ll donate them to the North Idaho College composites program.

Cameron Aircraft, Coeur d’Alene, ID 83835 USA, tel. 208–765–9295, fax 208–765–9415, website www.cameron

Arthur DeFever: 1918–2013

Longtime naval architect Arthur DeFever, often credited with helping develop and popularize the modern trawler yacht, died last April 10 at his home in San Diego, California. He was 95.

After earning degrees in engineering from the University of Southern California and in naval architecture from the University of California, Berkeley, he apprenticed for naval architects Carl Shield and Ted Geary. During World War II he designed boats for the military at the Hodgson-Greene-Haldeman yard in San Diego. Afterward he specialized in tuna clippers from 90′ to 125′ (27m to 38m), which soon featured several of his signature elements, the Portuguese bridge and large raised pilothouse that he continued to incorporate in many of his larger recreational designs, such as the Alaskan 46 (14m), built by American Marine (Hong Kong and Singapore) in the 1970s. Boats to his design were built in yards around the world, including Japan, Taiwan, China, Mexico, the U.S., and Europe. In fact, a DeFever brand was created, with yachts built by the Pacific Ocean Countries Trading Association. In addition to trawler yachts and commercial fishing boats, he designed sportfishermen and ferries, and megayachts built by the Perini Navi and Feadship De Vries shipyards.

A wonderfully humorous story that I related in PBB No. 134 bears repeating. Ray Greene, the Ohio boatbuilder credited with building the first fiberglass-polyester boat (in 1941, in Toledo), recounts his friendship with DeFever when they worked together during World War II. “Art DeFever was my counterpart as a naval officer during the war,” Greene told me while I was researching my book Heart of Glass. “We were so interested in mixing things that we’d send his girl and my wife out to a show while we started mixing pots in the kitchen. After the stuff went off we couldn’t clean the bowls, so we buried them in the garden. For years after, my wife would ask what happened to those bowls, but I never did tell her.”

Old School, New Tricks

The ApprenticeshopJohn Snyder, courtesy The Apprenticeshop

The Apprenticeshop team leader and second-year apprentice Tim Jacobus, center, works to finish the replica of a 29′ (8.8m) New Bedford Whaleboat designed by Ebenezer Leonard from plans dated 1935. The boat will be installed aboard Mystic Seaport museum’s newly restored whaling ship Charles W. Morgan this summer.

The Apprenticeshop, a 40-year-old school for traditional boatbuilding in Rockland, Maine, has created a new training program intended to better meet the needs of the shop’s mix of vocational and avocational students. The school, which has turned out a steady stream of skilled boatbuilders since its founding in 1972, has always been structured around a two-year hands-on apprenticeship program focused on teaching plank-on-frame boatbuilding and traditional seamanship. But until now there has not been a well-defined curriculum that would allow students or prospective employers to know what a graduate is likely to be capable of.

oldschool2-400John Snyder, courtesy The Apprenticeshop

Starting in September 2013 the traditional boatbuilding skills taught at the 40-year-old school in Rockland, Maine, will be codified in a formal curriculum that breaks the education program into two distinct one-year segments. This new format defines for students, and their would-be employers, the skills they will have after graduation.

Executive director Margaret Macleod said the new well-defined program was developed partly in response to the Maine boatbuilding industry’s need for skilled workers as productivity of shops and yards gradually return to pre-recession levels. Apprenticeshop staff and directors sought input from a range of boatbuilders in the state as the curriculum took shape. They produced a practical program of study—CORE Concepts of Wooden Boatbuilding—that can be completed in a nine-month academic year with the opportunity to add a second year to finish a more advanced self-directed boatbuilding project, as has been the tradition at The Apprenticeshop. As an example of such a project, this summer’s graduates built a replica of a 29′ (8.8m) whaleboat, which will serve as part of the display on the newly restored whaling ship Charles W. Morgan at the Mystic Seaport museum, in Mystic, Connecticut.

The new program shows that the school will continue to focus on traditional wooden boat building and restoration projects in teaching a basic set of skills. Sound shop safety and tool use, lofting, design principles, wood joinery, planking, sparmaking, hardware fabrication, and basic rigging are relevant skills even for modern composite boatbuilders and service yard employees. In addition, the new curriculum specifies components to familiarize students with modern tools and practices such as composite boatbuilding materials and construction methods, and most importantly, assures students and their future employers that specific lessons and skills are being taught to every apprentice.

One message the school heard from numerous boatbuilders during conversations about curriculum redesign was that employers were looking as much for a good attitude as for abilities in prospective employees. With that in mind, Macleod said, the school is maintaining the shop’s commitment to building character and seamanship as well as the school’s tradition of experiential education, which encourages thought and action simultaneously. In short, apprentices are still expected to be self-motivated, independent thinkers, a model that has served the industry well. Past graduates of the shop have gone on to run numerous boatyards, build and rebuild remarkable boats, run composites supply and consulting firms, design software, teach sailing, and operate nonprofit organizations, to list just a few occupations.

The first cohort of CORE program students will start September 3, 2013, and graduate in May 2014.

The Apprenticeshop, 643 Main St., Rockland, ME 04841 USA, tel. 207–594–1800, website

—Aaron S. Porter

Tools for Repairing Carbon

Dark Matter Composites

Dark Matter Composites’ step-sanding tool kit is said to be more accurate and efficient than conventional scarfing methods.

Dynabrade air router

A modified Dynabrade air router with dust extractor comes with four diamond planing heads.

Modified Dynabrade affexed to radius armDark Matter Composites (ALL)

The Dynabrade affixed to the end of the radius arm makes circular passes over the damaged area.

Dark Matter Composites, a United Kingdom–based company that provides high-level training in all types of composites, also sells a few types of equipment, such as portable and bench dust-extractors. Recently it began marketing a step-sanding tool kit for composites, including carbon, that it says is much more efficient than conventional scarfing methods.

The problem, DMC says, is that scarfed repair surfaces are not only time consuming, but quality depends on the skill of the technician. Step-sanded repair surfaces are better structurally, but also time consuming and difficult. DMC’s solution is a modified Dynabrade air router coupled with flexible jigs that allow sanding on parts even with internal or external double curvatures. The result: consistent step-sanded surfaces up to 48″ (122cm) in diameter, step increments as small as 1⁄6″ (1mm), and depth increments as small as 0.002″ (0.05mm).

The kit comes with a set of four diamond planing heads, from coarse to fine, for work on a variety of composite materials: gelcoat; conventional fiberglass fabrics such as chopped strand mat and woven rovings; and unidirectionals, stitched, and veiled products. In addition to the router and heads, the kit includes a circle jig assembly, radius arm assembly, a set of jig datum points and adhesive pads, a set of Allen wrenches, screwdriver, and wrenches for adjustments.

When asked if a planing head different from the one for conventional E-glass laminates is recommended for carbon, DMC’s Rodney Hansen replied: “Usually the grade of head is dependent on the production methods used and can be used on both carbon and glass. The reason for this is that different production methods will give different resin-to-fiber ratios and different resin hardness based on the cure temperature of the resin. For instance, where high-end racing yachts use prepreg materials, a fine head will cut both carbon and glass plies. Where wet-layup laminating is used, the composite material will have a lower fiber content, and a medium/general-purpose head is best suited and again will cut both carbon and glass.”

Carbon fiber dust can short out electrical and electronic devices, so dust extraction at the point of source is recommended; as noted, DMC sells those systems for about $2,800 (£1,850 excluding VAT). And if you need help, Dark Matter Composites, as one of its many advanced training courses, offers a two-day instruction on use of the kit and related repairs: 30% theory, 70% practical, for eight students maximum, $920 (£600 excluding VAT).

Dark Matter Composites, Unit 8 Redbourn Industrial Estate, Redbourn, Hertfordshire AL3 7LG, UK, tel. +44 (0) 1582 791001, fax +44 (0) 1582 791001, website

Svend Svendsen: 1932–2013

Sven Svendsen

California boatbuilder Svend Svendsen, a native of Denmark, died last May. His full-service yard, Svendsen’s Boat Works, in the San Francisco Bay Area, is well known for its quality work.

The well-known and—judging from the accolades flowing in—much-loved boatbuilder of Alameda, California, Svend Svendsen died on May 27. Born in Espergaerde, Denmark, he had as his first job delivery of fresh-baked bread on his bicycle. According to his obituary, during the Nazi occupation, beginning in 1940, he transported messages hidden in the bread loaves for the Danish underground resistance.

Following the war he attended a technical college for boatbuilding, and in 1956 emigrated to the U.S., where he found work at the Derecktor shipyard in Mamaroneck, New York. Soon after, he drove across country with several Danish friends in a car with no reverse gear, finding work in yards in Sausalito and Oakland, California. In 1963 he and his wife, Suzanne, formed their own company, Svendsen’s Boat Works, in Alameda. It’s a full-service yard, adept at wood and fiberglass repairs; mechanical, plumbing, elec­trical, and rigging systems; painting and finishing; and custom fabrications including hull extensions, metal­work, hardtops, and more. It is also a dealer for Laser Performance Sailboats, and a wholesale distributor of marine equipment, representing more than 300 product lines.

Active in the Folkboat fleet on San Francisco Bay, Svendsen was the first to build this legendary wood design in fiberglass. Indeed, a “sailing salute” was planned for June 2 in his remembrance, with the Folkboat fleet leading a procession of boats on the bay.

The end.