Alternate electric propulsion for Chester Yawl.

Builder's Forum
1

I plan on putting a Torqeedo electric motor on the CY with the batteries in the bow, wiring under the floorboards and a remote throttle by the middle seat for the larger motor, or integrated motor/batteries for the smaller ones.
Re-inforcing the transom has been discussed in previous treads, as well as the relative unsuitability of heavy motors due to the need for kneeling on seat by narrow transom in order to start a gas powered engine.

Having said that, which Torqueedo is best suited in your opinion? The Ultralight 403 "Kayak"  Torqeedo does not appear to be suited for the CY. The 503 and 1003 might, but the speed seem un-exciting, based on videos. Of course, rowboat purists will be appalled with my wanting to put an engine, much less wanting power that will propel the boat faster than one could row it. Would a 1003 Torqeedo be suitable? I have seen videos of some Torqeedo motors pushing various dinghies and inflatables ... I also understand that beyond the "hull speed" (whatever that may be for the CY), exponentially more required power only creates more noise, more weight, more cost and hardly any speed improvement. Constructive comments and suggestions are welcome. Thank you in advance.

PS: here are the advertised motor weights/power equivalents with gas engines/thrust specs from Torqeedo:


Ultralight 403 (suitable for kayaks, according to Torqeedo)

Weight: 16.3 Ibs (motor and integrated batteries)

Equivalent to 1.0 HP gas engine.

Thrust: 33 Ibs ISO static thrust (add 50% to Torqeedo figure to compare with trolling motor static thrust)

 


Travel 503:

Weight: 28.4 Ibs (motor and integrated batteries)

Equivalent to 1.5 HP gas engine.

Thrust: 40 Ibs ISO static thrust (add 50% to Torqeedo figure to compare with trolling motor static thrust)


Travel 1003:

Weight 28.4 Ibs (motor and integrated batteries) 9.9 Ibs for motor alone, If batteries separate and put at bow.

Equivalent to 3.0 HP gas engine.

Thrust: 68 Ibs ISO static thrust (add 50% to Torqeedo figure to compare with trolling motor static thrust)

(The ones below do not seem wise in light of the weight at roughly 1/3rd that of the empty hull, hung on the transom ... Of course, batteries at bow would offset the weight and balance challenge)

Cruise 2.0:

Weight: 38.6 Ibs 

Equivalent to 5 HP gas engine.

Thrust: 115 Ibs ISO static thrust (add 50% to Torqeedo figure to compare with trolling motor static thrust)


Cruise 4.0:

Weight: 40.3 Ibs

Equivalent to 8 HP gas engine.

Thrust: 189 Ibs ISO static thrust (add 50% to Torqeedo figure to compare with trolling motor static thrust)

Speeds (not transcribed here are based on 700 Ibs dinghies outfitted with engines).

Sure, there are Minkota and the Electric Paddle motors. What I like about Torqeedo is the brushless motors, electronic management and sealed battery safety features, as well as remotes and gps/speed/battery charge remaining/miles to go, integrated information. This, for a price differential of course, puts the Torqeedo, in my opinion, in a league of its own. Now, I admit to have zero experience, yet with any of those engines.

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For a boat with those lines, designed to be easily driven for good rowing, I wouldn't go over 1 HP. My sailing dinghy, which has nice lines but is fat and squat compared to the CY, hits hull speed with 2 HP.

The only reason I can think of to drive that boat with more than 1 HP is to get through strong wind and chop, but in that case you could just row with the motor on and use muscle power for on-demand boost. The rest of the time you could be saving money and weight with a light motor.

Of the ones you've listed, I wouldn't use one bigger than the 503.

Good luck,

Laszlo

 

 

3

Eric,

Having just watched the Torqeedo videos, I'm of the opinion that even the 503 is overkill for the Chester Yawl. If it was my boat I'd go with the 403. The unexciting performance in the videos is because they are pushing clunkers (inflatibles and clorox bottle fishing kayaks). On a boat designed for easy rowing like the CY, they'll be rockets.

Laszlo

 

4

   I intend to use a trolling motor on my Yawl and don't see the need to beef up the transom. I will probably have to make a filler for the sculling notch, but that is all. I suggest that you give it a try first, if there is any flexing of the transom then go ahead and add structure. 

  If you add a battery access hatch to the bow seat be sure you have an airtight seal so you don't lose your flotation in case of capsize. 

  The Yawl is so easily driven that a little thrust should go a long way and one might be able to use relatively smaller batteries than expected. I want to try mine with a 33lb thrust troller and a pair of batteries small enough to fit into the rowing seats. If the range is adequate I can figure a way to attach them to the seats. We want to use this combination to explore slot canyons in Lake Powell from our houseboat, so being able to travel 8 or 9 miles loaded with two people and two dogs is essential. 

   Please keep us all informed of your results and progress, I for one, am very Iinterested to see how this works out.

5

   Thank you, Lazslo for your suggestions! I chuckled at your reference to "pushing Clorox bottle fishing kayaks" ... And I hear you loud and clear lol.

i will be calling Torqeedo and look more closely at that 403. I have a friend in TX who has dual  2.0 on a 16' plastic bass boat. This is apples and oranges as far as the propulsion task goes but at least I will get his feedback on operating a Torqeedo motor.

 

thanks, again Lazslo and I will report back with my decision/experience when I settle for one particular model and get to use it.

 

cheers,

Eric 

6

   I plan to use a 45 lb trust max model with the digital maximizer built in.  I'm not planning to hang it on the transom.  It will be mounted right where the skeg is supposed to be with a shaft hole and pvc pipe sleeve up through the middle of the rear seat.  It will only go up and down in positioning and will rotate for sterring.  For launching, shallow water, or rowing without electric I will rasie it up against the hull bottom getting most of the prop out of the water.  When electro motoring I will lower it about 6  to 12 inches.  The battering 24 size will under the center rowing seating.  The seat will need to be a little bigger than the stock one.

I let you know how it goes - still building now. 

Rink

 

 

7

   Lazslo, Chester and Rink,

 

Thank you all for the input. See my plan, above. I will keep the forum posted as to my final decision and more importantly as to the results. Of course, I look forward to reading about your experience, too. 

 

Happy rowing/motoring!

Eric

8

Finally got my boat on the water.  It floats!  I modified the skeg area to add the motor. When I row with two people up front - theres no motor prop drag.  When I motor  with just me it drags a little hard to see it in this photo though.  45 lbs thrust moves the but well at just 50% throttle eith two on board.  For rowing I still need practice.  I plan to do motor electric sailing so I give performance reports later.

9

   I keep my Chester Yawl on a lake here in Germany close to the Toqeedo guys. As one of these fine gentlemen sails with me I got to try out the Travel and the Ultralight. The later is just perfect. At 100 - 120 W it moves the boat with 3.4 kn. Full throttle you get up to 4.5 - 4.7; but it does drain the battery faster. I modified the Prion mounting and just keep the battery ( or two) in the open boat with the controls as we like to move around in the boat. I have a Herreshoff coquina-style steering line running through the boat. Let me know if I can give you more information.

Ralph

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   Just a note. I noticed Rink's boat above does not have any numbers. In Florida once you put mechanical propulsion on the boat it requires registration. You might want to check into your own state requirements.

11

   Ralph,

I would be interested with your torqueedo experience on a CY

Mine is going well with standard rows, but sometimes, it could be safe to get an engine in some locations (eg venezia) and allows to cover more distance.

What is your autonomy at 3kn without wind and flat water?

Many thanks in advance

Emmanuel

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   https://picasaweb.google.com/116491750727644503626/Fall2014?authkey=Gv1sRgCO_e24Ts1sqPbw

 

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   Hi Emmanuel,

Sorry for the late reply but had some issues with my account. 

Above you find some pictures of my boat.  

Our lake ( Starnberg ) is 12 nautical miles long and one battery gets me from one end to the other easily at 3.5 knt. The second one brings me home with energy to spare. 

The bigger torqeedo is quite an overkill and you have to fit an awkward tiller extension unless you have someone sitting on the bow. 

Ralph

14

   Many thanks Ralph, it gives me good understanding on what is possible