Ideas: Twin Paddle Wheel Scow

As found on Youtube and here.  Inspiration for hull and power options.

Introduction
Unlike most other so-called solar-powered boats which in reality run on diesel for more than half of the time, the New Era runs entirely on solar power during normal operation. 
Even during the unusually dark and dismal summer of 2008, the New Era’s solar panels collected all the energy needed to run the advertised schedule of passenger trips on the Caledonian Canal.   
Most people who step on board the New Era do so –at least in part- because they are intrigued by the technology. This section explains how it all works.

 

How the New Era works

The hull

The New Era’s aluminium hull combines high strength with low weight and easy maintenance. Aluminium is also easy to recycle.
The hull, deck house, and fittings were constructed by Seastrike, an established builder of aluminium boats in Walsall near Birmingham.

Aluminium welding is a highly specialised skill. It is a tribute to the builder (which I am glad to pass on here) that the quality of the New Era’s welding seams has repeatedly evoked admiration from passengers who are in the engineering trade.

 

The bow ramp
The New Era has a bow ramp like a landing craft. When lowered onto a slipway, this ramp makes it very easy for passengers with limited mobility to embark and disembark. There is space for up to two wheel chairs on board. The ramp is also ideal for passengers with bicycles. 



Solar power

During normal operation, the New Era is powered entirely by the sun. It uses no fossil fuels and produces no emissions or pollutants of any kind.

The roof of the New Era consists of four solar panels. These solar panels feed into a bank of batteries which store energy for up to 6 hours of cruising.  

There is also an eight horse-power petrol outboard engine which serves as a backup. During the last two years, this engine was started only for periodical checking to make sure it still worked, for crew training, and on one occasion to increase speed and make up for lost time after an unforeseen delay.

 

Electric motors and drive unit
The New Era is primarily driven by two electric motors, each of which drives a paddlewheel at the stern of the boat. The electric motors are quiet, so the predominant sound you hear while under way is the rushing of the water and the plopping of the paddles. 
And finally: The Paddlewheels

Why on earth does this modern (and even somewhat futuristic) boat have paddlewheels like a 19th Century Mississippi steamer? The answer is four-fold:

Reason 1

One of the New Era’s areas of operation is the Beauly Firth; a tidal estuary of which the shallower parts are saturated with bladder-wrack type seaweed. When operating the New Era initially with two electrically-driven propellers, it soon became clear that props and weed don’t make a good combination. The weed tended to clump around the props and render the boat powerless.

The paddlewheels simply brush through the weed and give reliable propulsion even in the thickest of weed-soup.

Reason 2

With a small boat, a propeller has to extend well below the hull to work efficiently; bringing with it the risk of striking underwater obstacles when approaching a landing in shallow and uncharted waters.

In contrast, the stern-mounted paddlewheels do not reach any deeper into the water than the rest of the boat and are protected by the hull. This further enhances the “go anywhere” capability of the New Era.

Reason 3

Contrary to common belief, paddlewheels are very energy-efficient at low speed, because of the minimal slippage between the paddles and the water.

Reason 4

One of the aims of the New Era is to promote solar energy as a viable source of power to get some real work done, like powering a boat.

Two large paddlewheels kicking-up a bit of foam is much better from a demonstration point of view than invisible, inaudible propellers under water; even if the speed of the boat is exactly the same.      

If truth be told there is a fifth reason: I have always been fascinated with paddle steamers from an early age. Alright, the New Era is not quite on the same scale as those old-timers, but to be out on the water with those wheels turning is still a bit of a childhood dream come true.

 

Summary
In the five years since she was built, the New Era has undergone considerable development in her electrical systems and propulsion, while the basic hull and fittings have remained unchanged. The end result is a safe, well-tested, and very capable craft that does everything that was envisaged in the original design. And what is more, the New Era achieves all this without placing any undue burden on the environment.


New Era – Technical Specifications

Dimensions
  • Length: 6 metres (hull only); 7.4 metres with paddlewheel frame fully extended.
  • Beam: 2.2 metres.
  • Draught: Approx. 14cm empty; 20cm at full load.
  • Paddlewheels: 2x 130cm diameter, 65cm wide, 16 blades each;
  • mounted in height-adjustable stern-frame.
Electrical/ mechanical
  • Solar panels: 4×120 Watts polycrystalline from BP Solar.
  • Batteries: 4 to 6 leisure batteries of 12V 70Ah each.
  • Electric motors: 2x Lynch LEM-170
  • Reduction drive: toothed belt + chain.
  • Backup power: 8 HP Yamaha two-stroke petrol outboard.
Accommodation
  • Deck house; seats 1 or 2 crew.
  • Seating; locker benches and foldable seats for up to 8 passengers.
Performance
  • Efficient cruising speed: 2.5 knots.
  • Maximum speed (electric): 3.5 knots.
  • Absolute maximum speed; electric + 8HP outboard: 7 knots.
  • Battery capacity at 2.5 knots: approx. 6 hours
  • Battery capacity at 3.5 knots: approx. 2 hours

 

Originally posted 2012-08-25 06:19:43.

SHARE
A website about Shantyboats and affordable living on the water. More than 800 stories to date, and growing.