ALL-ELECTRIC CAT DAYBOAT
BASED ON DutchCraft’s experience building the all-electric, carbon-fibre DC25 monohull, the first of the multipurpose DC25 e-cats is due to be launched in November 2022.
The new 7.76-metre GRP model has already sold 100 units to a European client who runs a charter company.
The low-maintenance all-electric drivetrain means the DC25 e-cat can cruise marine reserves, protected waters and lakes where boats with conventional propulsion cannot – all with zero fumes and noise.
The range of the DC25 e-cat goes up to 65NM at its cruising speed of 6 knots and the boat reaches a top speed of 12 knots with a twin Torqeedo 12 kW propulsion system.
CANDELA ELECTRIC SPEEDBOATS COMING TO NZ
HYDROFOILING ELECTRIC BOATS are coming to New Zealand through a partnership with Next Generation Boats, based in Wanaka.
The first Candela C-7 speedboat will arrive in early April 2022, followed by the bigger C-8 at the end of the year.
Until now no electric motorboat has been able to offer the combination of high speed and long range boaties are used to. Even the best lithium-ion batteries get drained after a very short time of spirited driving.
Stockholm-based Candela has cracked the code to long-range electric craft. Flying on computer-stabilised hydrofoils, Candela’s day-cruiser C-8 and sportsboat C-7 use only a fraction of the energy conventional motorboats use at speeds of 30 knots.
Once foil-borne, Candela’s boats can travel for 2–2,5 hours at a speed of 20 knots and cover 50nm. The on-board computer automatically adjusts pitch, roll and height to account for side winds, waves and people moving around in the boat.
The Candela C-Pod submerged pod-drive is whisper-quiet and the boat is virtually wake free.
The C-8 is Europe’s best-selling electric craft, with over 100 orders for the $520 000, all-carbon fibre day-cruiser since its launch in late 2021.
Next Generation Boats www.ng-boats.com
Sunreef 60 E voted Best Electric
After tallying the votes from more than 10,000 electric boat enthusiasts all over the world and an international judging panel of e-boat experts, the second annual Gustave Trouvé Awards for Excellence in Electric Boats and Boating – ‘The Gussies’ – has announced the recipients of its 2021 honors, recognizing the Sunreef 60 E as Best Electric Sailboat.
The Sunreef 60 E is an all-electric luxury yacht belonging to the Sunreef Yachts Eco range of sustainable catamarans. Besides a reliable and efficient electric propulsion, the Sunreef 60 E stands out with a carbon fibre bimini with in-built curved solar panels, weight-efficient and sustainable finishing materials as well as a non-toxic bottom paint.
The awards recognize the inventors, designers, manufacturers, entrepreneurs and visionaries who are making advances every day to develop clean, quiet, zero emission technologies and designs to reduce reliance on fossil fuel for marine propulsion.
The Duck that wouldn't die
Blue Duck – a 16-foot fantail clinker workboat built in 1895 – received the Innovation Award at this year’s Lake Rotoiti Classic and Antique Boat Show. Yes, you read that right – a 126-year-old boat was recognised for her innovation. She’s electric-powered. Story by Lawrence Schäffler.
Owned by Nelson’s Peter Murton, Blue Duck is no stranger to the Lake Rotoiti show – she’s been displayed there previously and has won various awards. But this year’s gong is a little special because – if the research is accurate – her new propulsion is her second electric system. The first was nearly a century earlier. This latest version marks yet another chapter in an extraordinary life.
The little clinker’s been fitted with numerous propulsion systems over the years but, tantalisingly, the research suggests she was first electrically-powered when big, heavy batteries and equally big, heavy DC motors were only just becoming established in New Zealand.
Murton has owned Blue Duck for about 12 years and makes his living restoring classic boats (more on this in a moment). Saving her and tracing her history, he says, uncovered plenty of scarcely-believable twists and turns. This duck is one tenacious survivor.
She was built by the Knewstubb Brothers in Port Chalmers and by 1907/8 was serving as a workboat on the Shotover River, a tender to a gold-working dredger anchored at Maori Point (see photo above).
Museum records show she was initially powered by a Union oil-fired engine, ferrying workers between the shore and the dredger. The dredger, for its part, was an experimental vessel using electricity for the gold recovery process – and there are suggestions that around 1907 Blue Duck (her original name) was eventually retrofitted with batteries and a motor.
Despite her advanced technology, the dredger was a flop and in any event was wrecked when a massive flood washed her downstream. From this point Blue Duck’s trail runs cold and only picks up again in the 1970s when she turns up on Lake Wakatipu, converted to a day-sailer with a gaff rig, cabin, fixed keel and a lump of railway iron for ballast.
In the mid-1980s she sank at her mooring. Some kindly soul salvaged her and took her to Cromwell for a period, before she moved on to Alexandra where she became a garden ornament for a further 15 years.
Murton acquired her when that owner called: “I have a boat in our garden. I think she has a lot of history and shouldn’t be sitting here. She needs to be restored.” So Murton went to fetch her. And yes, Blue Duck was in a bad way, derelict and very weather-beaten.
“But, remarkably for her age,” he says, “most of her kauri hull was OK – though I had to fit new garboard planks, new ribs and recycle the kauri deck. The entire boat had been covered in fibreglass at some point – no doubt to stop the leaks. It looked awful but, ironically, I think the sheathing helped to preserve her. After stripping away the fibreglass I was amazed to discover she didn’t have any rot.”
With her rejuvenated hull he opted to repower Blue Duck with technology from her era – a steam engine. It just so happened that there was a 2.5hp Hasbrouck twin-cylinder steam engine and boiler sitting in his workshop (built by Murton’s engineer dad many years previously).
While this worked well (using the boat’s original 17in x 30in prop) the boiler presented a few safety concerns. These could only be addressed by adding more weight – far too much weight for the little clinker.
The Hasbrouck was replaced by a 1907 two-stroke, single-cylinder 8hp Gray petrol engine. But despite much fiddling and cursing, the Gray proved hopelessly unreliable. It too was abandoned – for a twin-cylinder 8hp Stuart Turner P55 petrol engine. It wasn’t much better.
Eventually, Murton’s son (an engineering PhD student) suggested a more radical solution – a small, 36-volt brushless motor – running that old prop through a 14:1 reduction gearbox. It worked a treat.
Power comes from three deep-cycle batteries (105-amp hours) and the system uses a rheostat for a throttle (it also switches between forward and reverse). The little motor drives the boat to her hull speed – about 5.5 knots – and the batteries are good for about eight hours.
Blue Duck, finally, is back in her element, and relishing the silence.
Timbercraft
The company’s called Murton’s Timbercraft and, as the name suggests, his business covers more than classic boat restoration. He also crafts period furniture from recycled native timbers, though boat restoration/building accounts for 90% of his work.
His marine career began – at age 15 – with the restoration of 14ft clinker, helped by his woodworking teacher. She was powered by a 5hp single cylinder Simplex engine.
Various boat restoration projects followed over the years – mainly for friends – but things really took off when he was commissioned to build a 19-foot John Wellsford Whaler (lapstrake plywood construction) for a friend. “Things just snowballed – all via word of mouth.”
Today, visiting Murton’s Nelson yard is a bit like walking into an open-air maritime museum. Vessels are stationed all over the premises, all awaiting their turn in the workshop. Some are basic repair jobs but most are full restoration projects. The clients are located all around the country.
Among the current stock is the original 12-foot clinker tender from the 1909 scow Te Aroha which operated up on the Kaipara Harbour. The tender is his (not a ‘paying’ job), so will remain hanging in the rafters and until more pressing jobs are out of the way. It has already received new ribs and will be fitted with new planking.
In another corner is a 1930s kauri-planked ski-race boat – provenance unknown. “Based on the marks left from the original engine bearers,” says Murton, “I’d say she was first fitted with a WW1 aero engine – and there have been at least three different steering systems.
“She also arrived with an interesting transom. Given the twin exhaust ports we can guess she might have been repowered with a V8 at some stage. There are other mounting points as well, suggesting a different engine mounted further forward. The transom also has a cutaway for an outboard...”
Ulva is a 19-foot clinker built on Stewart Island around 1900 – it’s believed she operated as a ferry, carrying passengers between Ulva and Stewart Islands, and was powered by oars and sails. Tough work in that part of the world!
Murton’s bias to early 20th century vessels is obvious. “I like the era because it represents a part of our maritime history that’s rapidly disappearing. A lot of the old boats meet their ends in bonfires, or are buried under hedges, or left to decay in sheds. I want to help preserve the heritage – and I have the traditional boatbuilding skills to do the work.”
Timber fingerprints
Many of the projects are delivered by an owner with scant knowledge of his boat’s history. “So it often takes some detective work to try to fill in the gaps,” says Murton. “Fortunately for us, timber offers a few clues.
“With many New Zealand boats from that era, you can usually tell where they were built by the timbers that were used – a bit like DNA profiling. Around the upper part of the South Island, for example, builders typically used kanuka for all the knees and natural crooks and stems. Further south, though, they would use more kowhai and rata. Kauri use was widespread throughout the country, so by itself a kauri hull doesn’t help me much.”
Even so, identifying very weathered and aged timber can be difficult, and Murton has on occasion visited the local Woodworkers Guild in Nelson for help, exploring its library and discussing a timber’s grain, texture and weight with the experts.
Though traditional skills such as caulking and scarfing might have been used to bring an old dame back to life, Murton likes to use more modern, robust paints and varnishes to make sure they’re preserved for many more years – “my go-to default is Altex – they make great products.”
For more information visit www.murtons.co.nz
Thrust you can afford
A casual examination of boats in a marina usually reveals a litany of battle-scars – scrapes and dings sustained during tricky berthing attempts. Wind, prop-walk, lack of confidence – they all play a part. A DIY bow thruster can help. By Norman Holtzhausen.
For many boaties returning to the marina after a trip is always fraught. Everyone’s on high alert with a boat hook and fenders at the ready to try and prevent the inevitable crunch with the dock or a pile. Often, shouting happens and fracture lines appear in otherwise watertight marriages.
It can take several attempts to get into a berth. As a result, many boaties lack the confidence to take their boats out on their own and often will relinquish control of the helm to someone after a trip rather than risk disaster. Ideally, they need a bow thruster – but they’re not too easy on the wallet – especially a retrofit project.
So – for a friend’s boat – we decided to explore building a DIY bow thruster. She’s not a particularly big boat – an 8m Marksply GRP launch powered by a 250hp four-stroke outboard. But that single engine combined with relatively high cabin sides (plenty of windage) can make her tricky to manoeuvre, especially in anything other than flat-calm conditions.
The engine delivers a tremendous amount of power if the throttle is shoved injudiciously and it’s also fairly heavy to turn. These factors have led to ‘incidents’ that have left scars on the gelcoat and bends in the railing.
While a small bow thruster would greatly simplify the berthing process, his budget doesn’t stretch that far. Even the smallest thrusters are priced at just under $2,000 and fitting one would incur significant additional costs to modify the hull.
The standard design requires the creation of a bow tunnel to accommodate the propeller and drive mechanism. There are new add-on models from Sideshift which retrofit to the bow outside the hull, but these are also beyond his budget.
ELECTRIC TROLLING MOTOR
One ‘existing’ DIY solution is a modern electric trolling motor. These units have lots of power (thrust), are easily installed and run off the boat’s 12v supply. Some models, such as those from Minn Kota, already have an over-bow installation kit option. Would it be possible to make a bracket to fit a simpler version to the bow? It could be used to push the bow sideways – as required – and lifted clear once the vessel was in open water.
Our investigation showed that several Minn Kota models could do the job ‘out-the-box’, as they also come with an optional wireless remote control for both steering and thrust. We could install one on the bow and perhaps even add the auto-deploy kit – effectively we could use it instantly for manoeuvring.
The unit remains flat on the deck until required and pushing a button would deploy it into the water. After that, the simple controls make it easy to manoeuvre the boat back into her berth by steering the bow. This is be a great solution for anyone with sufficient budget and/or DIY skills, as installation is pretty simple.
But this option still exceeded the available budget. And we didn’t need full steering control – only a simple, fixed direction solution providing left and right bow thrust. A quick search online to see what other people had done convinced us we were on the right track.
We just needed the right components and a suitable, custombuilt mount. A self-contained and relatively inexpensive electric trolling motor would form the heart of the solution.
WHICH MODEL?
Somewhat confusingly, specifications for trolling motors are usually listed in pounds (lbs) of force, while bow thrusters are listed in kilograms (kg) of force. The recommended model bow thruster for this size boat develops 25kg of thrust force, while available trolling motors range between 18 and 112lb of thrust.
Multiplying kilograms by 2.2 to get back to pounds, we found a 54lb thrust trolling motor would be in the same ballpark as the bow thruster, at 24.5kg of thrust force. So we ordered a mid-range model with the right amount of thrust from Marine Deals for $319.
We also wanted a simple joystick control and could have purchased a ready-made thruster joystick for $169. But in keeping with the low-budget approach we sourced an arcade-game style joystick for $29.90 from Jaycar Electronics.
We purchased the necessary marine cable for extending the controls from the existing motor controller to the helm-mounted joystick. Some boats might need an additional heavy-current power cable to get 12V power to the motor, but in our case we could access suitable power from the anchor winch solenoid in the bow area.
Having secured the trolling motor, the first item on the agenda was making a bracket to hold it securely off the bow. The shaft length is just under a metre while the boat’s bowsprit sits 1.2m above the waterline. We needed a simple bracket which would hold the motor in the right place, while also allowing easy deployment of the unit.
To get the dimensions right we built a wooden prototype in 45x90mm framing timber – easier fabrication – with a view to constructing the final mount in aluminium. The most important factor was making sure it could withstand the twisting motion from the lateral force the motor would exert. We needed a fairly robust structure with at least two mounting points.
We also devised a system to swing the unit over the bow rail for deployment. This reduces the effort of lifting it in place and considerably reduces the risk of dropping the whole thing into the water!
We worked at getting the unit the right distance into the water – the prop needs to be sufficiently deep. Because the motor’s transom bracket can slide up and down on the shaft, we can fine-tweak the final depth.
We chose to err on the side of caution and settled on a slightly too long vertical strut. We cut a ‘hook’ at the top so the bracket fits over the rail and identified where two clamping bolts will be required. These will hold it securely to the rail at the top, and the vertical side of the bowsprit in the middle.
POWER & CONTROLS
We established that the anchor winch’s controlling solenoid (in the bow area) has a direct connection to the battery – good news – we didn’t need any additional highamperage cable. We will, however, replace the lugs at the end of the cable with suitably grunty clips to temporarily clamp onto the solenoid’s power terminals.
At the helm we established the best spot for the joystick control. A space in front of the existing engine control is ideal but we had to keep it clear of the throttle. We also investigated running a cable from the joystick to the bow and identified where we would fit a waterproof (IP67-rated) connector to the trolling motor control unit. This will allow us to permanently install the joystick and cable, and simply plug in the motor when required.
Time for the test. After tying a rope around the motor (just to be safe!) we connected the power cables to a spare battery and twisted the throttle. Success! The bow moved well and the mount handled the sideways force without any issue.
