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Harnessing the Current to Power Winch Boats

moggill ferry
The Moggill cable ferry crossing the Brisbane River, near Ipswich, Australia (file image)

By Harry Valentine 11-03-2020 06:23:38

Traditional emissions-free boat racing has involved oars and sails. More recently, riders aboard pedal-powered hydrofoil boats competed against oar-powered vessels hydrofoil row-boats. Several years ago, a windmill-powered sailed directly into a headwind and won a trans-harbor sailboat race at Halifax, Canada. That precedent provides opportunity to develop winch-driven boats that sail upstream powered by river current, competing against others of its kind.

Prior to 1980, wind-powered boats sailed the zig-zag path called tacking to sail into a headwind. Then a Canadian physics professor entered a windmill powered one-person boat into a trans-harbor sailboat race at Halifax and sailed directly into a headwind and to victory. The wind-powered three-wheeled “blow-karts” that operate along beaches and in windswept desert regions developed from sailboats. Some blow-kart builders adapted windmills to power the wheels of land vehicles able to travel directly into headwinds. The onboard windmill can also drive a cable-winch to pull a kart across slippery ground. 

The concept of an onboard turbine driving a winch to reel in a cable to move a vehicle can be applied to a boat where the reeled out end of the cable is secured upstream along a river. A waterwheel secured to the boat would use river current to drive the winch to pull the boat upstream. Water has more than 840 times the density of air at room temperature, allowing slow-moving water current to provide tremendous kinetic energy to even a small waterwheel. Like sailing and rowing competitions, winch-boat competitions could attract participants, sponsors and spectators. 

Available Technology

The small-site power generation industry has developed hydrokinetic turbines also known as water windmills that use river (and tidal) current to drive electrical generators. Some builders install these turbines between pontoons that float on water and a secured to a riverbank. There is scope to adapt small hydrokinetic power generation technology to a transportation application where the turbine or waterwheel drives a boat mounted winch connected by cable to an upstream anchor point. For competition, promoters would provide secure multiple anchor points to allow each boats to travel in a separate lane.

People building winch-boats powered by river current would likely have to make modifications to power generation hydrokinetic technology for transportation and competitive racing purposes. The existing technology provides a basis or starting point for further modification and development. While installing hydrokinetic power generation technology at a stationery location along a river or coastal channel requires approval by regulatory authorities, it is legal to connect a rope or cable between a boat and a shoreline along with freedom as to the propeller installed to the boat. 

Scale-Model Winch-Boats

While competitions between scale-model windmill and sail-powered boats would involve much complication, competition between scale-model winch-powered boats sailing upstream and driven by river current would involve less complexity. All boats would have their tethers or cables secured at an upstream location and would line up at a starting line, with a radio-controlled deflector diverting river current around the waterwheel. A one-way freewheel device as used on bicycles would prevent winches from running backwards and hold each boat at the starting line. When the starting pistol is fired, competitors would retract the deflectors as the race begins.

Scale-model winch-boat racing could involve high-school students and competitions could be held at nearby rivers where sufficient water current would activate the waterwheel powered winches. In the case of small boats, nylon fishing line would function well as the towing cable. Building and designing the waterwheel winch-boats would involve teamwork and design ingenuity. Competitors could be required to build their competition boats from recyclable material, with each boat restricted to a maximum width with flexibility on boat length and submerged depth. There would need for separate categories for high school, college and university teams.

One-person Winch-Boat

Many large communities internationally have a race track where on summer weekends, car hobbyists who convert old cars to competition vehicles race against each other. That precedent could be applied to width-restricted one-person winch-boats where teams of hobbyists and enthusiasts, usually mean would build low-cost winch boats over the winter months and enter them into weekend competitions during the summer months. Competitions would occur along sections of rivers where the combination of sufficient river current, water depth, channel width and distance would allow for competitive racing. At some coastal locations, winch-boats could use rip-tides as the energy source.

For safely, each boat operator would wear a life jacket and waterwheels would be enclosed with so as to prevent contact with any person who falls into the water or comes close to a winch-boat. Possible ingenuity around the waterwheel would involve a duct with a larger exit area behind the waterwheel than inlet area ahead of the waterwheel. A valve-flap at the inlet would prevent river current from entering the duct. It would be partially opened to move the boat to the starting line and opened again at the start of the race.

Ocean Channels

Ocean currents and tidal currents flow through many ocean channels and also close to many coastlines. The East River in New York City is a prime example of an ocean channel where winch-boats driven by river current may compete against each other on weekends, should relevant New York City authorities be willing. Tidal currents flow between several islands across the Philippines, between some of the Orkney Islands, between some of the Lesser Antilles, along sections of channel between British Columbia and Vancouver Island, channels around Canada’s Bay of Fundy and at many other locations internationally.

While it may be possible for one-person ocean current powered winch boats to sail against and ocean current, with cable secured by anchor at an upstream location, there may also be scope for a crew to sail a large scale boat. While channels around Canada’s would, at certain times of the day provide energy to provide power to large winch-powered boats with crew onboard, the power of water current in those channels is also notorious for having destroyed several kinetic turbines installed to generate electric power from the regular powerful current.

Commercial Spin-Off

There is potential for commercial spin-off from ideas and concepts developed in competitive winch-boat racing. In New York City, ferry service operates along sections of the East River and sailing against the ocean current that flows through the channels. Depending on location around the world, there would be scope to combine the features of a winch-boat with cable secured at an upstream location, with kinetic ferry technology to sail a diagonal path between points of origin and destination.

At some locations, there may be scope for a winch-boat to operate tourist sightseeing service or function as a mobile restaurant that also offers a short-distance low-speed cruise. If the river current flows at two knots, there may be scope using precedent from winch-boat racing, to develop a large-scale commercial winch boat capable of sailing at four knots.

Conclusions

In a world seeking to reduce carbon emissions, it is likely that competition between winch-boats using river current to sail upstream would attract participants, sponsors and spectators. The range of competition would include home-built, radio activated small-scale winch boats sailing along suitable stretches of rivers and streams to one-person winch boats competing along more energetic channels to large vessels sailing against ocean current. There is potential to transfer ingenuity, innovation and ideas developed in the small boats to larger boats used in commercial service.

Harry Valentine is a regular contributor to The Maritime Executive. 

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.