Outboard for Storm 15

[George Whiteside]

Good morning all. I hope that one of you can help me. A friend of mine is building a Storm 15. I would like to buy him an outboard motor for it and am thinking of the Honda 2.3HP, which comes in long and short shaft versions. Is it the short shaft version I need please?
Alternatively, any recommendations on suitable outboards would be welcome.
Thank you

[Terry Cross]

Hello George
 Welcome to the forum .
We have owned “IONA” a Storm 15 for over 3 years, built by Bob Jennings and featured on the forum May 2006.
On completion Bob could not bring himself to cut a hole in the hull to accommodate the outboard and we are glad he did not.  We sailed “IONA” for a few months,  mostly on lakes, and could not see the need for an outboard.  However when we were about to visit the Swallow Boats “raid” at Teifi Boat Club in 2008 we decided to try an electric outboard on an outrigger.  It did the job OK but when not in use we found it obtrusive  when sailing.
       In Sept 2009  I decided to try an electric outboard on a bracket attached to the rudder. This proved very effective and have used it numerous times but only on inland waters. I am planning to use this system on the sea with a larger motor.
See on the forum "Electric outboard on "Iona"(a Storm 15)"
What I am trying to say is  the Storm 15 is a sailing boat and rarely needs a motor and  I think a hole in the bottom will cut the hull speed by about 11/2 knots.  The decision is up to your friend

Terry Cross  “ IONA “

[Gareth Curtis]

Hi Terry,

I too am nearing completion of a storm 15. There is no way on earth after 3 years of toil that I am cutting a hole in the bottom, it's no-where near pefect but I made it and I can't bear to cut a whole in it now!!!

I have read your thread on electric engines and many more on other sites, I don't want a petrol engine anyway because of the smell / fumes alone.

My problem is that I want to take my kids sailing and it's all coastal sailing where I live. an outboard rightly or wrongly gives me a sense of security that I can get out of a difficult situation should I need too.

Have you used you electic motor in such a situation?

When I went to visit matt last, he showed me the electric motor he had fitted into a rudder for a storm 15, he was less than enthusiastic about it and suggested it would be better to simply clamp it on the side when needed?? He suggested that there was too much drag??

My current plan is to take it slowly and rely on oars first of all and see where I go from there.   

Gareth

[Jeremy]

I've seen the rudder mounted motor that Nick and Matt built.  I think the reason it may not have performed as well as hoped might be to do with the prop.  I've done a lot of work over a period of nearly two years of building an efficient electric propulsion system, although in my case its going in to my electric version of Winsome.

I did consider using one of the cheap electric outboards, but realised quickly that they weren't very efficient so I didn't bother looking into them in more detail.  However, one chap over on the Boat Design forum has done some interesting (and cheap) experiments with making them more efficient, with very good results.  Take a look at the posts in my "Efficient Electric Boat" thread made by Denny Wolfe, starting from this one: http://www.boatdesign.net/forums/boat-design/efficient-electric-boat-27996-15.html#post302305 .  It may well be that a standard electric outboard simply modified in the way that Denny describes, will prove to be up to your needs.

I wholeheartedly agree with your wish not to cut a hole in the hull!  I am modifying my approach to fitting the electric drive unit so that it fits through what amounts to a rudder stock tube, rather than have it fitted in a big well.

Jeremy

[Peter Williams]

We have a Storm 17 with an outboard well, though we also have a blanking plate which almost fills the horrible gash in the hull.  We also have an electric outboard which is way too difficult to install in the well - you'd have to drop it tight down to clear the rudder, and you couldn't keep it canted in the well and still be able to steer the boat.

So just out of interest, we tested it clamped to the gunwale about as far back as we could, but (obviously) turned through nearly 90 degrees and locked in place.  You can get the angle just right so that this has a neutral effect on the steering, and then use the tiller.  The boat did over 4 knots flat out (I calculate about an hours running on a 110AH 12V battery, though much longer at 2.5 knots, I reckon)

Practically, though, this isn't much good to us for two reasons:

1.  There's no-where handy to put an outboard inside the cockpit or under the foredeck and:

2.  There's no where very convenient to put the very heavy battery other than just forward of the mizzen mast in a battery box.  And the captain claims that this affects the trim of the boat.

If we could figure out where to stow the battery, I'd still like to find a way of seriously re-modelling the outboard so that I can raise and lower it through the well.  Still pretty awkward, though.

[Terry Cross]

Hello Gareth
At the Teifi  “raid“  we used an electric outboard (35lb thrust) on frame protruding over the side, level with the aft bulkhead.  It worked perfectly, took us out of the estuary, against the tide, and up to the start line at about 3 knots. We had a heavy battery stowed near to the aft  bulkhead  which   was very obtrusive, as was the outboard when it was switched off and tilted.
After the “raid” it brought back from the finishing line to the jetty without any problems   
The next day, as we were launching off the beach, we decided to dispense with the outboard.

Last year my son Paul used “IONA” in Scotland  (featured on the forum) and it was from his experiences that I decided to experiment with the outboard on the rudder.
I have made a number of mods. since the article on the forum, the main ones being:
1 Using  two smaller batteries stowed forward of the centreboard case  (moving the  weight forward and easier to handle)
2 Fitting a plug & socket ( to get rid of the crocodile clips connecting the motor)
3 I found it very difficult to lean over the back to raise or tilt the motor so I fitted a clamp near to the bottom of the shaft, ran a line from it through the pivot and through a jamming cleat on the tiller. This enables me to easily lift the motor clear of the water when sailing.  Which, I hope, answers your second question about drag. There is,nt any!
I hope this helps you.
We have made a number of other mods. Center mainsheet through jamming cleat, Removable thwart (ideal when rowing or running downwind single handed), a removable seat forward of the center board case (covers batteries and ideal for crew to slide across instead of standing up

Terry Cross “IONA”

[Terry Cross]

Gareth

 PS   We are taking Iona on her holidays to Weymouth at the end of the month. I will let you know how the motor performs on the sea.
Terry

[Jeremy]

Since writing the post above in reply to the original question, Denny Wolfe has posted some photos of his electric outboard, fitted to his Arctic Tern (pretty similar to a Storm 15) on the Boat Design forum.  His post is here: http://www.boatdesign.net/forums/boat-design/efficient-electric-boat-27996-28.html#post381261 and might be worth a read if you're looking at a cheap outboard option, albeit with a little DIY.

Denny took an off-the-shelf Minkota electric outboard, replace the standard, very inefficient, propeller with a cheap model aircraft one, added a fairing around the tubular leg to reduce drag, added a fairing around the prop hub and replaced the standard horribly inefficient resistive speed control with one from an RC model.  The result looks pretty good to me.

Jeremy