Jump to content

Can these electric outboards power a narrowboat?


Doodlebug

Featured Posts

I first posed this question in the midst of another topic but now I am planning out my next project properly so looking for points of discussion.

 

What are the pitfalls of using a 86lb trolling electric outboard motor to power a narrowboat.

 

Two of them.

 

I am trying to work out if the idea is feasible. I know they will push the boat but the sticking point is will they push it fast enough.

 

I found this video made by rob bolwell and although I tried contacting him I have had no reply. Anyone know of him?

 

https://m.youtube.com/watch?v=wjA17Fb-WXM

 

It seems to be going at a reasonable speed and our boat appears to be pretty nimble so I suspect it may work better on ours. But this is all speculation and am looking for last minute issues before I bite the bullet and buy some.

 

I don't plan on going on any rivers by the way.

 

Thanks!

 

Doodlebug

Link to comment
Share on other sites

Saw a boat below Atherstone last week being powered by two electric outboards strapped on the back, he was making very slow progress when I saw him.

Edit

Just got the video to load and the set up was identical the boat was blue as well

Edited by ditchcrawler
Link to comment
Share on other sites

Saw a boat below Atherstone last week being powered by two electric outboards strapped on the back, he was making very slow progress when I saw him.

Edit

Just got the video to load and the set up was identical the boat was blue as well

Interesting. Wish I could get in contact with him! When you say slow progress. Do you mean slower than walking pace. I have noticed that our top speed at the moment of 3mph is easily dwarfed by a lot of boats so your idea of slow may be different to mine!

 

With a total of 172lb of thrust you are going to need some serious battery capacity.

Phil

Power source is sorted out. I feel I shouldn't go into detail yet to avoid complicating the topic! My topics usually go off course within a couple of comments!

Link to comment
Share on other sites

I would expect the props to be cavitating all the time, and even if you did get up to any speed, stopping would be too slow to be safe.

 

You can power a narrowboat with electricity but you need at least 10hp available and a decent size prop.

  • Greenie 1
Link to comment
Share on other sites

I would expect the props to be cavitating all the time, and even if you did get up to any speed, stopping would be too slow to be safe.

 

You can power a narrowboat with electricity but you need at least 10hp available and a decent size prop.

See you say that yet we currently have a 10hp engine and I have never maxed it out and usually have it running just over tickover. That suggests 10 is more than enough.

Link to comment
Share on other sites

See you say that yet we currently have a 10hp engine and I have never maxed it out and usually have it running just over tickover. That suggests 10 is more than enough.

 

What size of boat is it?

 

You don't don't want to be holding people up, so you need to get to the speed which is just bellow the bank washing speed, and you need to be able to stop rapidly when going into locks and when coming out in a high cross winds etc. For a 25ton 70' boat I would not have less than 40hp (modern engine), 20hp (60s/70s Lister ST for e.g.) or 10hp (classic old engine) - note that torque is a key factor here.

Edited by Tiggs
Link to comment
Share on other sites

The propellers on those electric outboards are incredibly efficient, well the Minkota ones we used for litter picking on the upper Stort for 7 years in our pick boat Bin Laden were. A 110 amp fully charged battery would last around 3hours but this was with very intensive use, whacking back and forth on full throttle all the time. We also towed a large heavy steel pontoon occasionally which it did pretty well with. We got through 3 motors, 'two were S/H' in that 7 years, they did well considering the bashing they got.

Link to comment
Share on other sites

What size of boat is it?

 

You don't don't want to be holding people up, so you need to get to the speed which is just bellow the bank washing speed, and you need to be able to stop rapidly when going into locks and when coming out in a high cross winds etc. For a 25ton 70' boat I would not have less than 40hp (modern engine), 20hp (60s/70s Lister ST for e.g.) or 10hp (classic old engine) - note that torque is a key factor here.

We weigh 6 ton and are 33ft long. I can easily get the boat going at canal speed just by pulling the ropes.

 

Obviously if someone is catching up with us we let them overtake. And going into locks should be done slow anyway. Never had to put it into reverse and rev hard. I enter locks at tickover then flick it into reverse as we get to the gates - maybe due to being an outboard we have good steering in reverse. I then hop off and tie up.

 

The propellers on those electric outboards are incredibly efficient, well the Minkota ones we used for litter picking on the upper Stort for 7 years in our pick boat Bin Laden were. A 110 amp fully charged battery would last around 3hours but this was with very intensive use, whacking back and forth on full throttle all the time. We also towed a large heavy steel pontoon occasionally which it did pretty well with. We got through 3 motors, 'two were S/H' in that 7 years, they did well considering the bashing they got.

Any idea what power rating?

 

Stupid question but what does S/H mean. Been a long day.m

 

Edit- it means second hand!

Edited by Doodlebug
Link to comment
Share on other sites

And going into locks should be done slow anyway. Never had to put it into reverse and rev hard. I enter locks at tickover then flick it into reverse as we get to the gates - maybe due to being an outboard we have good steering in reverse. I then hop off and tie up.

 

 

What if its really windy (crosswind) or a strong weir? Do you just bump along the armco or potentially get stuck on the weir (ie if going downhill and the wind is blowing that direction?)

 

Also what about winding? I know its a small boat on a big canal but if you want to turn in more places, you'll likely have opportunities with a more powerful engine. Again, what if you want to turn decisively because there's a bit of a crosswind etc? You don't want to be tootling around taking 10 mins, getting blown onto the offside bank, etc etc

Link to comment
Share on other sites

We weigh 6 ton and are 33ft long. I can easily get the boat going at canal speed just by pulling the ropes.

 

Obviously if someone is catching up with us we let them overtake. And going into locks should be done slow anyway. Never had to put it into reverse and rev hard. I enter locks at tickover then flick it into reverse as we get to the gates - maybe due to being an outboard we have good steering in reverse. I then hop off and tie up.

 

 

Any idea what power rating?

 

Stupid question but what does S/H mean. Been a long day.m

 

Edit- it means second hand!

Small one 3/4 hp I think.

Link to comment
Share on other sites

Have a look at this one

 

http://solarpowerednarrowboat.blogspot.co.uk

 

Similar size and weight.

 

Cruses using about 1 1/3 hp. (1Kw)

 

But has a sensible prop size and speed I would have thought. Looks like a much more sensible way of doing a solar powered boat.

 

Having looked up similar, I think the motor is rated at 10Kw but not sure.

Edited by Tiggs
Link to comment
Share on other sites

See you say that yet we currently have a 10hp engine and I have never maxed it out and usually have it running just over tickover. That suggests 10 is more than enough.

10 is fine with a ok big prop

10p is fine with a ok small prop

The prob you get is if or when you get stuck or into trouble. This is when you find out if your engine and prop are upto it.

Some working boats only had around 10 but most of these had a torque and prop far bigger than most still have.

Im far to over proped on tickover i make no wash but catch people up as it still shifts prob about 2mph i often find my self not in gear. But i also have plenty for when i do get stuck.

 

Electric or a by product e.g. genarator type thing with electric drive is the future but the electric motors are still not there yet. 1900 they experimented with electric cars they did about 100 miles, guess what we have pure electric cars they still only do 100 miles.

 

The best way is a small diesel engine running a generator. This gives the best long running fuel economy with high torque and good power.

Edited by billybobbooth
Link to comment
Share on other sites

the simple answer is NO, it is unsafe.

 

I have a 32lb motor pushing a 16ft 600kg launch, it manages canal speeds, and can stop the boat in about 3 boat lengths.

 

for a heavy steel narrowboat, you may get 2 or 3 mph but you will not be able to stop or manouevre the boat safely in a sidewind, a current or an emergency.

 

I have a conventional outboard that comes into use when the batteries and the solar cannot keep up.

Link to comment
Share on other sites

Its not 'starting' that's the problem - yes they would get you going, initially slowly then building up speed.

 

In the 'strong man' competitions a human bean can pull a 35 ton truck - but can he stop it ? (I'm sure you know the answer)

 

Your proposal would be dangerous to you and other waterway users

Link to comment
Share on other sites

the simple answer is NO, it is unsafe.

 

I have a 32lb motor pushing a 16ft 600kg launch, it manages canal speeds, and can stop the boat in about 3 boat lengths.

 

for a heavy steel narrowboat, you may get 2 or 3 mph but you will not be able to stop or manouevre the boat safely in a sidewind, a current or an emergency.

 

I have a conventional outboard that comes into use when the batteries and the solar cannot keep up.

A good point but bear in mind we would have 6 times more power than you have.

 

 

Again I didn't want to over complicate but since emergency stops are an issue - I plan to have the current 10hp petrol (or maybe converted to lpg) engine mounted in position linked with the morso control. When needed the outboard would kick in. Again I won't explain exactly how in this thread but have worked out a way to get it on and in gear within 1 second automatically.

Link to comment
Share on other sites

I first posed this question in the midst of another topic but now I am planning out my next project properly so looking for points of discussion.

 

What are the pitfalls of using a 86lb trolling electric outboard motor to power a narrowboat.

 

Two of them.

 

I am trying to work out if the idea is feasible. I know they will push the boat but the sticking point is will they push it fast enough.

 

I found this video made by rob bolwell and although I tried contacting him I have had no reply. Anyone know of him?

 

https://m.youtube.com/watch?v=wjA17Fb-WXM

 

It seems to be going at a reasonable speed and our boat appears to be pretty nimble so I suspect it may work better on ours. But this is all speculation and am looking for last minute issues before I bite the bullet and buy some.

 

I don't plan on going on any rivers by the way.

 

Thanks!

 

Doodlebug

Those 86 pound thrust Outboards draw 58 AMPS at 24 volt IIRC,that is a massive drain on a Battery bank.

 

CT

Link to comment
Share on other sites

True true. But my topics usually go off on tangents.

 

If I explained the complex version people would say it's too complicated to work. Thing is that it's a very simple system but with a back up component for every aspect of the design.

 

If I explain the simple version people say "what if"

 

It's like me questioning whether direct drive is a danger to canal users - what if you break down and can't stop? What if you run out of diesel. Or the rudder breaks?

Those 86 pound thrust Outboards draw 58 AMPS at 24 volt IIRC,that is a massive drain on a Battery bank.

 

CT

Desperately trying to stay on topic but Power comes from an engine in the front.

Link to comment
Share on other sites

the simple answer is NO, it is unsafe.

 

I have a 32lb motor pushing a 16ft 600kg launch, it manages canal speeds, and can stop the boat in about 3 boat lengths.

 

for a heavy steel narrowboat, you may get 2 or 3 mph but you will not be able to stop or manouevre the boat safely in a sidewind, a current or an emergency.

 

I have a conventional outboard that comes into use when the batteries and the solar cannot keep up.

How did a horse stop a boat? or manoeuvre in a side wind?
  • Greenie 1
Link to comment
Share on other sites

Hi Doodlebug,

good to read you've got a new project planned.

If you want a decent electric outboard, you'll find out that they don't give them away, but it may be a good and green solution for the future.

These electric outboards are known worldwide and seem to be very reliable.

I've only seen one in action on a 25ft yacht that an American guy was traveling with in France, he was very happy with his and said that he didn't regret not having his petrol-outboard anymore at all.

 

http://www.torqeedo.com/en/products/outboards/travel

 

Peter.

Link to comment
Share on other sites

I bought a Minn Kota Genesis from the USA. 24v 74lb thrust. Just the motor unit. I.made a stainless shaft and a mount for it and wire it to a 60a PWM controller (generic Chinese £13)

 

I found a second hand motor but available new from USA for £300 incl shipping.

 

http://pages.ebay.com/motors/link/?nav=item.view&id=252370793047

 

Minn kota did make a 12v "3HP" model but the letters stand for HiPower not HorsePower.

 

My 24v unit pulls up to 45a so that's around 1hp equivalent I think.

 

I use it on a heavy 14ft GRP launch. I think two of these would push a small Nb but you are looking at about 60+ amps draw continuously I reckon. You will need good batteries.

 

Torqeedos are a bit dodgy - more of an expensive toy with a high speed remote control aircraft motor driving through a planetary gearbox. Burnout issues. Minn Kota are direct drive heavy slow running motors.

 

 

The idea of the Torqeedo was to get a small inflatable to plane with an electric motor. Minn kota are built down to a price but they are specifically designed to push heavy boats slowly.

 

I put a Kipawa prop on mine. Good thrust and good in weed.

 

The 24v 74lb and above are the large 4 inch motor unit which is a different beast from the usual minn kota motors one sees ')

Edited by magnetman
Link to comment
Share on other sites

A good point but bear in mind we would have 6 times more power than you have. and probably 20 times the boat weight = 20 times the momentum.

 

 

Again I didn't want to over complicate but since emergency stops are an issue - I plan to have the current 10hp petrol (or maybe converted to lpg) engine mounted in position linked with the morso control. When needed the outboard would kick in. Again I won't explain exactly how in this thread but have worked out a way to get it on and in gear within 1 second automatically. if you have a seriously sized narrowboat a petrol outboard won't be adequate for stopping either, unless it is a heavyweight turning an 18" prop (is there such an animal?). you'd better explain further to convince the doubting Thomases that your proposal is practical and reliable.

How did a horse stop a boat? or manoeuvre in a side wind?

I don't know - you tell me.

 

but then they weren't operating at the same speed or in the same circumstances as found on canals today.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.