
From the control panel on the port side, Chris Maas demonstrates the hydraulic functions of the amphibious Fiat barge at his workshop.
A yacht designer and a boatbuilder walk into a bar. Says the yacht designer: “You might live on a beautiful island with a barn full of boats, but you can’t drive from your house to a grocery store.” Replies the boatbuilder: “Oh yeah? Hold my beer.” Granted, this exchange is a tad fictional, but it anticipated the design and construction of an amphibious barge with hydraulic wheels and electric propulsion. The original intent was to ferry a Fiat 500e compact electric car between Center Island and Lopez Island, Washington, to run errands. What makes this barge special is that it uses the vehicle’s front drive wheels for propulsion, hence the name “Fiat Barge.” Maas, readers might recall, also is the creator of Gizmo, the repurposed Hobie Cat 18 he turned into an electric foiler using mostly surplus and recycled parts and materials (see also “Frankenfoiler”, PBB 194).
A standard itinerary would look like this: Get into the Fiat that sits on the barge in the driveway. Start the car, put it in gear so it can drive the barge’s hydraulic wheels down a narrow, unpaved road to the launch ramp and into the water. Then switch the propulsion from the wheels, which fold up and out of the water, to an outdrive to push a couple of miles to the other launch ramp at the Hunter Bay County Dock on Lopez. Deploy the wheels, switch propulsion from the outdrive back to the wheels, crawl up the launch ramp, park the barge, lower the loading gate, and drive to the grocery store. For the trip home, simply reverse the process. Seeing this spectacle unfold time and again could have been a tourist attraction and a magnet for amphibious barge freaks; alas, it did not turn out that way, not quite at least. But it still is a tale worth sharing, especially because it recently took an interesting turn. But first things first.
The project’s protagonist is Chris Maas, known to readers of this publication as the master of recycling and repurposing, who converted an old Hobie 18 into a fully foiling electric commuter named Gizmo (see “Frankenfoiler,” PBB No. 194, page 30). Maas and his wife, Monique, live on Center Island in the San Juans. While they love their tranquil digs, they have to make regular milk runs to Lopez Island, a couple of miles away as the crow flies. Gizmo is cool and electric but has limited cargo-carrying capacity, and Maas still has to keep a car on the other end to run errands.

Assisted by brother Alex, Maas backs barge and Fiat down the ramp, powering the barge’s retractable wheels with the car’s front wheels.
“This thing seemed like a good idea at the time,” he said about expending time, money, and creative energy to design and build a car-propelled barge. “I wanted to come up with an electric form of transportation for our bi-weekly shopping trips. As we get older, carrying groceries, 40-lb [18-kg] bags of animal feed, jugs of fuel, etc. in and out of a truck/boat/tractor and up and down dock ramps—almost always at low tide it seems—is getting to be a bigger chore every year. In my mind, the Fiat Barge was the perfect solution. The goal was to not leave the car from the time we got in at our house on Center Island until we got to the grocery store on Lopez.”
Reusing and recycling were also important elements of the project. “The concept is so simple: prepandemic you could buy a used Fiat 500e for $5,000 to $6,000. These cars are lease returns, and while they don’t have great range by current standards (90 miles or so), they are small but with adequate cargo capacity, cheap, reasonably reliable, and an absolute blast to drive.” If a product has more than one purpose, it becomes more useful, hence the grand plan of putting the car not only on its own ferry but also make it propel the ferry—not just on the water but on land as well. Otherwise, why bother?
To show the barge’s scale and complexity, Maas shared its specifications and measurements—8‘ wide by 20‘ long (2.4m x 6.1m), not including ramp and sterndrive. Hull, deck, and bulkheads were constructed from 1⁄2“ (13mm) MDO (medium-density overlay) plywood with 3⁄4“ (19mm) MDO under the car tires. Chine logs, sheer clamps, etc. are Douglas-fir. The hard chines were glassed on the outside with two layers of 9-oz/sq-yd (305-g/m2) E-glass cloth and epoxy.
The main mechanical components of the drive, a MerCruiser Alpha One, Gen 1 sterndrive that was previously used only in freshwater, a BMW X5 differential, and a salvaged BMW driveshaft and U-joints all were found on eBay. He modified the differential for single-axle use. Maas also had to source three separate hydraulic systems: a power unit for the 1“ (25mm) bore double-acting land steering cylinder; a MerCruiser tilt-trim pump for the sterndrive; a Dynamic GP-F25 3.84-cu-in main hydraulic pump for the four Dynamic BMER-2-475-WS-T4 hub motors; and Magister 2“-bore (5.08cm) x 18“– and 16“-stroke (45.72cm and 40.64cm) wheel-lift cylinders made in Ukraine. To balance the hydraulic flow between the wheel-lift cylinders, he used four Brand flow dividers and several valves, including one Prince pressure-relief valve and two Bosch Rexroth counterbalance valves that acted as brakes for the hub motors. The hydraulic hoses were from the Surplus Center, and he got 30 gal (113 l) of vegetable-based hydraulic oil (BioFlo AW32) from BioBlend.
The unusual drive system of the amphibious barge consists of 12“-diameter (305mm) solid-rubber rollers under the Fiat’s drive wheels, which spin a shaft connected to the BMW X5 differential. Maas turned it into a right-angle drive for the sterndrive, which also powers the main hydraulic pump via an attached belt. He said he doesn’t remember the dimensions of the wheels, but he tried to source the widest ATV tires and aluminum wheels at the smallest diameter that had a high enough load capacity.
While the nautical portion “turned out not much more difficult to design and build than I anticipated, land travel with hydraulic hub motors was significantly harder,” he said. “Having only a basic understanding of hydraulic systems, I found that there was a whole world of flow balance valves, counterbalance valves, motor control valves, and on and on that I was almost totally unaware of.” Summoning the relevant shop talents and at least as much perseverance, Maas braved a steep learning curve, “spending enough time and money correcting screwups” until the concept was proven to work and a live demo could be held on the waters of Reads Bay between Decatur and Center islands, for a few mesmerized spectators.

The barge’s complex hydraulics control panel that operates valves and pumps can be operated from the open driver’s side window.
He also had to learn how to disable or disconnect the sensors that would prevent the Fiat’s drive wheels from turning while the rear wheels were still. Someone on the Fiat 500e online forum suggested pulling the 70-amp fuse for the power steering, which did the trick. At the premiere, Maas drove the Fiat onto the barge at his house, the rig making its way to the launch ramp, a good half mile away, and out onto Reads Bay to motor around at about 6 knots, courtesy of the Fiat’s wheel power. Had he gone across to Lopez, he would have made it to the store without ever having to get out of the car. “At least we could come close enough to that to see that with a bunch more time, money, and effort we would eventually get there,” he said.
“At that point it became apparent that this amphibious barge was never going to meet my goal of making a vehicle that was reliable and easy to use. The rear-wheel steering and the wide wheelbase made driving down our narrow dirt roads way more challenging than was acceptable. I decided to pull the plug on the project [because] every test run would present new difficulties, usually hydraulic.” It also became apparent that the electric Fiat 500, while compact and fun to drive, is too heavy at 3,000 lbs (1,360.78 kg), which is 1,000 lbs (453.6 kg) more than the same model with an internal-combustion engine. On top of that, Maas calculated that he added about 600 extra lbs (272.16 kg) of machinery and fluids to the barge plus additional freeboard to the hull to keep the ocean out. “It was really asking too much of the hydraulic-drive system,” he concluded and decided to let go of his creation.
That’s the end of the first chapter, because the Fiat Barge has already embarked on another career at the Marine Maintenance Technology Center of Skagit Valley College in Anacortes, Washington. Last summer, department chair Mike Beemer and instructor Art Hebert, who had heard about the barge, went to Center Island to inspect it at Maas’s shop and bat around ideas for its future use as a training aid to teach their students about hydraulic systems.
They liked what they saw, and with the nod from the school to accept it as a donation, the path was clear to pick it up on a late summer day at the Center Island dock, where Maas was waiting for the transfer of ownership. Using the Fiat as propulsion, he drove the barge down the ramp and then turned it around to offload the car before Beemer and his crew could tow the empty barge to Anacortes, where it instantaneously became a topic of conversation.
“When we hauled it out at Cape Sante Marina and set it on our trailer, there were a dozen people around, wanting to hear about it,” Beemer remembered the scene that hinted at its value as an advertising prop. “We’re going to take it to the next Anacortes Boat Show and the Waterfront Festival with a car on it and raise it up and down, let people ask questions, and put Skagit Valley [College] stickers all over it.”

The barge at Skagit Valley College’s Marine Maintenance Technology Center in Anacortes, Washington,
However, the barge’s true calling is as a training aid for the hydraulics class taught by Matt Mardesich, the school’s engines and mechanical instructor: “One of the big challenges with our hydraulics program is building training aids at the school that are meaningful [and] actually perform work. You can have a cylinder go or a motor run, but unless it’s really pulling something, showing strain, and doing the work, it’s not real for the students. [The barge] has five or six actuators, and it was plumbed in a fairly complex way with lots of different valves. First, students will be mapping it, drawing a schematic of what’s going on, then actually running it. If we [install] pressure gauges and flow meters at key points, they can see the fluid power running through the system, not to mention the fun of driving this thing around the parking lot.”
Since Maas did not want to part with his electric Fiat, the barge needs a new vehicle to provide motive power. A former student’s small Mazda or a well-used Geo Metro might do the trick, albeit using fossil fuel. Another option for strictly shore-based demonstrations that don’t require powering the outdrive could be a stationary power pack or a stand-alone engine to operate the hydraulic pump.
For now, the barge is going into storage until the current cohort of two-year students enters the spring semester and takes the marine hydraulic systems class, earning five credits. This presents a chance for local high schoolers who are enrolled in a building-construction program to get in on the barge act, fabricating a temporary roof structure and trusses every 2‘ (610mm) on center to prop up the vessel on its keel for shrink-wrapping. “There’s so much teaching and learning with this thing,” Beemer concluded.
As for Maas, he said he’s “generally happy to have the Fiat Barge gone,” and expressed satisfaction about the college finding it useful. It freed up space on his premises for a new boat already taking shape—a 19‘ (5.79m) foil-assisted, stepped-hull, electric-powered catamaran using surplus carbon, S-glass, and Carbon-Core plastic honeycomb panels. Look for a report in one of our upcoming issues.
Skagit Valley College Marine Technology Center, 1606 R. Ave., Anacortes, WA 98221, USA, tel. 360–766–6282.