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Propulsion Power


Antrepat

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50 minutes ago, Sea Dog said:

I think you're missing the fact that the typical canal boat burns about 1.25 litres of red diesel per hour. Even if you could halve fuel consumption with a better prop, the annual saving would be too small to justify the expense for the user to buy one. Canal boat props are such a tiny market that there's really no incentive for the manufacturer's to invest. There may be some imperative to improve prop efficiency with electric drive canal boats, but even now that's still a very tiny fraction of an already tiny market. If more efficient propellors do become available for canal boats, they'll be as a result of the R&D for markets other than ours..

I agree apart from the fuel consumption, with the drive for ever bigger engines I think that they use more fuel than the older boats 

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Electric Drive - That is what this is all about. New tech begets new tech. If your prepared ( at the moment ) to pay fortunes for LIFEPO4 battery banks or exotic hand built motors and the associated generators, controllers et al. then prop cost, which you might consider expensive on its own, really is insignificant and yes, like non stick frying pans, the answer may come from other tech endevours.

 

 

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15 hours ago, Sea Dog said:

I think you're missing the fact that the typical canal boat burns about 1.25 litres of red diesel per hour. Even if you could halve fuel consumption with a better prop, the annual saving would be too small to justify the expense for the user to buy one. Canal boat props are such a tiny market that there's really no incentive for the manufacturer's to invest. There may be some imperative to improve prop efficiency with electric drive canal boats, but even now that's still a very tiny fraction of an already tiny market. If more efficient propellors do become available for canal boats, they'll be as a result of the R&D for markets other than ours..

The efficiency difference between a standard prop and a beautiful CNC-machined one will be tiny, maybe a couple of percent at most, because how to design a prop has been well known for many years and everyone uses similar turbine designs because that's already the optimum. For high-speed and high-load multiblade props with much higher power density the difference may be a bit bigger, but we're talking about narrowboat here not nuclear subs or ultra-large ships.

 

There is a radical new tipless prop design being promoted (the blades form a loop) which claims >10% higher efficiency -- these are CNC machined and ferociously expensive, but probably useless on canals because of debris pickup.

 

https://www.mby.com/gear/sharrow-mx-1-tipless-propeller-110120

 

"The only obvious drawback is price. Currently, every MX-1 propeller has to be milled from a solid billet of metal, which helps explain the price of $4,500 for an aluminium MX-1 or $9,000 for a stainless steel one."

 

sharrow.PNG

Edited by IanD
added link to Sharrow prop
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5 hours ago, David HK said:

Electric Drive - That is what this is all about. New tech begets new tech. If your prepared ( at the moment ) to pay fortunes for LIFEPO4 battery banks or exotic hand built motors and the associated generators, controllers et al. then prop cost, which you might consider expensive on its own, really is insignificant and yes, like non stick frying pans, the answer may come from other tech endevours.

 

 

I have that large 36 volts valence LifePo4s battery bank paralleled to give 72 volts, big solar array and 6kw genny, the prop I have works fine.  The gearing and prop must be about right as the motor revs all the way until the last few millimetres of the speed control lever, constant running produces little motor or controller heat.

Honestly an expensive propeller can be wrecked in seconds by picking up a mattress, tyre or large lump of wood.

I have had an electric boat for 4 years and have settled on my current setup, Ian has just ordered one built by Johnathan Wilson and Finesse boats, most of their current production is electric drive so I think that they know what they are doing. 

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45 minutes ago, peterboat said:

I have that large 36 volts valence LifePo4s battery bank paralleled to give 72 volts, big solar array and 6kw genny, the prop I have works fine.  The gearing and prop must be about right as the motor revs all the way until the last few millimetres of the speed control lever, constant running produces little motor or controller heat.

Honestly an expensive propeller can be wrecked in seconds by picking up a mattress, tyre or large lump of wood.

I have had an electric boat for 4 years and have settled on my current setup, Ian has just ordered one built by Johnathan Wilson and Finesse boats, most of their current production is electric drive so I think that they know what they are doing. 

They do, but you still need deep pockets -- not just for the batteries, but add another 10k for an onboard cocooned diesel generator because there are no charging points on the canals...

 

Even including fuel saving an electric boat doesn't make sense financially today, people are getting them for other reasons like silent cruising or wanting to be greener, especially if charging points do appear in the (how distant?) future.

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1 hour ago, IanD said:

They do, but you still need deep pockets -- not just for the batteries, but add another 10k for an onboard cocooned diesel generator because there are no charging points on the canals...

 

Even including fuel saving an electric boat doesn't make sense financially today, people are getting them for other reasons like silent cruising or wanting to be greener, especially if charging points do appear in the (how distant?) future.

Its cost me a fair amount of money about 7.5k the old engine paid for the batteries and I think 5k for the rest covers it, its not a system like yours but it works well, my labour if it was in the equation would put the costs up substantially. My old electric motor will sell on Ebay know doubt so I am happy with system now. I am hoping that the genny gets little running as even on HVO it creates pollution but its good to have that backup 

6 minutes ago, TheBiscuits said:

 

Ye cannae change the laws of physics!

 

 

Lol 15 in parallel twice and then in series, it was early and I wasn't thinking to well ?

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1 minute ago, peterboat said:

Its cost me a fair amount of money about 7.5k the old engine paid for the batteries and I think 5k for the rest covers it, its not a system like yours but it works well, my labour if it was in the equation would put the costs up substantially. My old electric motor will sell on Ebay know doubt so I am happy with system now. I am hoping that the genny gets little running as even on HVO it creates pollution but its good to have that backup 

Of course if you use secondhand bits and DIY ("free" labour) like you did it'll be cheaper, the same applies to a diesel propulsion system. But an electric propulsion system (with a generator) still costs a lot more than a diesel one, regardless of whether it's new or secondhand/DIY, there's just a lot more stuff in it and some of it is just plain more expensive and complex than a diesel.

 

The costs are coming down as batteries/motors/electronics get cheaper (largely driven by BEV), but there's still a big difference. A large part of this is because you really need a generator, on a narrowboat solar isn't enough in the winter or for long consecutive days of cruising, and a decent built-in quiet marine generator is expensive and always will be. If/when charging points become widespread this won't be needed, by then battery costs will have dropped too and so and electric will be cheaper than diesel -- but that's a long way in the future...

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3 hours ago, IanD said:

The efficiency difference between a standard prop and a beautiful CNC-machined one will be tiny, maybe a couple of percent at most, because how to design a prop has been well known for many years and everyone uses similar turbine designs because that's already the optimum. For high-speed and high-load multiblade props with much higher power density the difference may be a bit bigger, but we're talking about narrowboat here not nuclear subs or ultra-large ships.

 

"The only obvious drawback is price. Currently, every MX-1 propeller has to be milled from a solid billet of metal, which helps explain the price of $4,500 for an aluminium MX-1 or $9,000 for a stainless steel one."

 

 

... and these sort of responces have been seen whenever new and expensive tech hits the market. Lots were said about horse against car, IS happening about ICE vs electric when a Tesla has a crash.  As regards expense, then of course a precision one off hand made by robot is going to be loads more than a simple item made with 19th century tech. BUT as Henry Ford might have said, " wait till I get my shit in one sock and the prices will tumble."

 

You have a good argument for now, but now is not where we are going and the ICE is out , even on the canals, in the not to distant future which, if it is to be really economical, just like a modern Euro X diesel, is going to need tech to be economically available and just because something never has doesn't mean it never can.  Love to have this discission at your local Frog and Trumpet when I return to the motherland and get the boats built.

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13 minutes ago, David HK said:

... and these sort of responces have been seen whenever new and expensive tech hits the market. Lots were said about horse against car, IS happening about ICE vs electric when a Tesla has a crash.  As regards expense, then of course a precision one off hand made by robot is going to be loads more than a simple item made with 19th century tech. BUT as Henry Ford might have said, " wait till I get my shit in one sock and the prices will tumble."

 

You have a good argument for now, but now is not where we are going and the ICE is out , even on the canals, in the not to distant future which, if it is to be really economical, just like a modern Euro X diesel, is going to need tech to be economically available and just because something never has doesn't mean it never can.  Love to have this discission at your local Frog and Trumpet when I return to the motherland and get the boats built.

We're not disagreeing here -- as I keep saying electric is expensive now but the cost is dropping, however as long as you need a generator (no widespread charging points) I can't see how it can ever become cost-competitive since a marine generator costs more than a marine diesel engine even before you add on the batteries and the rest of the electronics. Yes it's the future (more eco-friendly etc), but cost is an obstacle to widespread adoption, and this will only be fixed with charging stations.

 

The cost of the Sharrow prop is high now because it's not mass-produced, the article says exactly that, and it will come down assuming it succeeds in the market. But I'm not sure the higher efficiency will compensate for it being way more prone to picking up canal debris on the loops -- this usually slides off a normal prop especially with a burst of reverse, but I can see it getting stuck with the Sharrow, meaning far more frequent visits to the weed hatch. Looks beautiful though...

 

I'm a fan of new technology (used appropriately!) which is why I'm having an electric (OK, series hybrid) boat built, but I also recognise the disadvantages and especially the cost at the moment...

Edited by IanD
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2 hours ago, peterboat said:

I have that large 36 volts valence LifePo4s battery bank paralleled to give 72 volts, big solar array and 6kw genny, the prop I have works fine.  The gearing and prop must be about right as the motor revs all the way until the last few millimetres of the speed control lever, constant running produces little motor or controller heat.

Honestly an expensive propeller can be wrecked in seconds by picking up a mattress, tyre or large lump of wood.

I have had an electric boat for 4 years and have settled on my current setup, Ian has just ordered one built by Johnathan Wilson and Finesse boats, most of their current production is electric drive so I think that they know what they are doing. 

I would love to have the details of your propulsion because we are in the middle of doig the design work on the boats. How many batteries , amps etc. How big is your solar and how much does it contribute to charging and domestic loads. How fast is your charge to full from 50% on your 8kW gene?  I have so many questions. Maybe I can give a whatsapp number annd we could become digital pen pals!

 

I have said I am not a fan of the Lynch motors either 48 or 72v models but that comes from an academic standpoint reading data not an experience one. Such high kW rates and for what.?The experienced posting on these forums before, of a widebeam cruiser ( was it yours? ) shows you never get near the amount of the rate. I think 3.3kW to get 3mph. I would thing a 10kW motor with good torque would be more than enough for a cruising narrowboat and widebeam also. You only need full beans on short occassions starting off or manouvering to a stop or to take speed off quickly.

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as the owner of a lightweight camping cruiser with electric propulsion on the Thames, the biggest benefit and the raison d'etre from my viewpoint is the silent progress as opposed to a vibrating tonky tonk that just ruins the whole experience.

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1 hour ago, David HK said:

I would love to have the details of your propulsion because we are in the middle of doig the design work on the boats. How many batteries , amps etc. How big is your solar and how much does it contribute to charging and domestic loads. How fast is your charge to full from 50% on your 8kW gene?  I have so many questions. Maybe I can give a whatsapp number annd we could become digital pen pals!

 

I have said I am not a fan of the Lynch motors either 48 or 72v models but that comes from an academic standpoint reading data not an experience one. Such high kW rates and for what.?The experienced posting on these forums before, of a widebeam cruiser ( was it yours? ) shows you never get near the amount of the rate. I think 3.3kW to get 3mph. I would thing a 10kW motor with good torque would be more than enough for a cruising narrowboat and widebeam also. You only need full beans on short occassions starting off or manouvering to a stop or to take speed off quickly.

Torque as such is irrelevant for a boat because prop load goes up as rpm^2, what matter is that the motor (geared or direct drive) and prop are matched to get rated power at rated rpm.

 

10kW should be OK for canals (even emergency stops), but is probably a bit low if you ever want to go out onto rivers (especially the Ribble Link) -- the industry seems to be converging on 15kW/20hp as the right-size for a "go-anywhere" standard-size narrowboat, the commercial systems are all 48V/50V to avoid high-voltage regulations and because 48V inverter/chargers and batteries are widely available.

 

Be careful that a lot of electric drive systems (especially the cheaper ones) can't sustain the headline power for more than a short period of time, fine for an emergency stop but the last thing you want is the controller to cut power back when you're going upstream on a river...

 

Typical power when cruising strongly depends on exactly how fast you're going, a reasonable assumption is 3kW on a normal canal, 1kW when passing moored boats, zero in locks -- if you work out how many hours you spend doing each you can do a power audit. The biggest solar panel array you can fit on a narrowboat (6x380W panels) will give you an average of about 9kWh/day in summer and 1.5kWh/day in winter -- Peter does better but he's got a wideboat with far more roof area ?

Edited by IanD
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6 minutes ago, IanD said:

We're not disagreeing here -- as I keep saying electric is expensive now but the cost is dropping, ..

 

I'm a fan of new technology (used appropriately!) which is why I'm having an electric (OK, series hybrid) boat built, but I also recognise the disadvantages and especially the cost at the moment...

Can I put a smiley face here?  :)  

Our design on paper and because I live and work in the Far East where we have really cheap stuff through TaoBao etc .... and the quality problems too if your not carefull, is slanted towards the best cheapest option with quality any where because we  have a special contemporary design for a unique use and a budget we should stick to.  Guys, Midland is not going to get nearly a grand for a macerator toilet, when I need 4 for my project and I can get less estheticly designed last century options at a quarter of the price (UK sorced) delivered to my door.   Not getting a / aa premium veneered ply because exterior b/bb (UK souced) is just as good. Which brings me to propulsion.

 

My original post was more "throwing it out there" and I am gratified that ya'll have responded in that spirit. I see reason in some things where before I has questions.  To OUR propulsion design we really want to go the electric route on space issues primarily. However, going the LIFEPO4 route, shiny Blue Electric Boxes and tiddly Lynch motors would mean we would never complete the fit out. So as we stand its Clacium LA 230amp 12v in a 4p 4s config, Its a 1/4 to 1/3rd cheaper than Lithium and can last a real long time if you treat them right because they are built like tanks for the mining industry.. Pair with the aforementioned 10kW motor, which the data sheet from the original build tests says that should enough. Solar, as much as I can get and a suitable generator. Was pleased to see here that 8kW may be enough. A lot cheaper.  The power system will be controlled by those new fangled Off Grid Solar contollers that do everything 4 expensive Blue Boxes do because we have to have a high 230 load due our kitchen requirement ( we have to hot feed 20 people twice a day ) and lots of pumps, 24v stuff and bow thrusters in a 57ft hull form. 

 

We want to be as 21st century as possible but like the prop answers, have to be practical as well.

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2 minutes ago, David HK said:

Can I put a smiley face here?  :)  

Our design on paper and because I live and work in the Far East where we have really cheap stuff through TaoBao etc .... and the quality problems too if your not carefull, is slanted towards the best cheapest option with quality any where because we  have a special contemporary design for a unique use and a budget we should stick to.  Guys, Midland is not going to get nearly a grand for a macerator toilet, when I need 4 for my project and I can get less estheticly designed last century options at a quarter of the price (UK sorced) delivered to my door.   Not getting a / aa premium veneered ply because exterior b/bb (UK souced) is just as good. Which brings me to propulsion.

 

My original post was more "throwing it out there" and I am gratified that ya'll have responded in that spirit. I see reason in some things where before I has questions.  To OUR propulsion design we really want to go the electric route on space issues primarily. However, going the LIFEPO4 route, shiny Blue Electric Boxes and tiddly Lynch motors would mean we would never complete the fit out. So as we stand its Clacium LA 230amp 12v in a 4p 4s config, Its a 1/4 to 1/3rd cheaper than Lithium and can last a real long time if you treat them right because they are built like tanks for the mining industry.. Pair with the aforementioned 10kW motor, which the data sheet from the original build tests says that should enough. Solar, as much as I can get and a suitable generator. Was pleased to see here that 8kW may be enough. A lot cheaper.  The power system will be controlled by those new fangled Off Grid Solar contollers that do everything 4 expensive Blue Boxes do because we have to have a high 230 load due our kitchen requirement ( we have to hot feed 20 people twice a day ) and lots of pumps, 24v stuff and bow thrusters in a 57ft hull form. 

 

We want to be as 21st century as possible but like the prop answers, have to be practical as well.

I have PM'd you my number David around at the moment but going out shortly and then for a meal later

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57 minutes ago, David HK said:

Can I put a smiley face here?  :)  

Our design on paper and because I live and work in the Far East where we have really cheap stuff through TaoBao etc .... and the quality problems too if your not carefull, is slanted towards the best cheapest option with quality any where because we  have a special contemporary design for a unique use and a budget we should stick to.  Guys, Midland is not going to get nearly a grand for a macerator toilet, when I need 4 for my project and I can get less estheticly designed last century options at a quarter of the price (UK sorced) delivered to my door.   Not getting a / aa premium veneered ply because exterior b/bb (UK souced) is just as good. Which brings me to propulsion.

 

My original post was more "throwing it out there" and I am gratified that ya'll have responded in that spirit. I see reason in some things where before I has questions.  To OUR propulsion design we really want to go the electric route on space issues primarily. However, going the LIFEPO4 route, shiny Blue Electric Boxes and tiddly Lynch motors would mean we would never complete the fit out. So as we stand its Clacium LA 230amp 12v in a 4p 4s config, Its a 1/4 to 1/3rd cheaper than Lithium and can last a real long time if you treat them right because they are built like tanks for the mining industry.. Pair with the aforementioned 10kW motor, which the data sheet from the original build tests says that should enough. Solar, as much as I can get and a suitable generator. Was pleased to see here that 8kW may be enough. A lot cheaper.  The power system will be controlled by those new fangled Off Grid Solar contollers that do everything 4 expensive Blue Boxes do because we have to have a high 230 load due our kitchen requirement ( we have to hot feed 20 people twice a day ) and lots of pumps, 24v stuff and bow thrusters in a 57ft hull form. 

 

We want to be as 21st century as possible but like the prop answers, have to be practical as well.

LA cells are cheap and can have long life if they're robust (e.g. traction cells) and treated properly, but the big problem is preventing sulphation which means regular charging to 100% capacity and then equalising -- which on an electric boat means running the generator regularly for several hours after they're "full" (and getting to 100% is slow anyway), this can easily double your generator running times, not good for lifetime or noise (or fuel consumption).

 

They're specified to be fully recharged overnight in applications like fork lifts (and mining) to achieve the specified lifetimes -- if you're regularly moored up with shore power for charging this is much less of a problem, but it is a real issue if you plan to mostly rely on solar or a generator while out on the canals. It's why most people nowadays are using LiFePO4, they just don't have this problem, but they do need a proper BMS to control charging and monitor the cells.

 

Also beware that most "calcium LA" batteries are not intended for the kind of repetitive heavy traction loads that you get with electric propulsion, they can have very short lifetimes when used like this because the plates shed active material and fall to pieces. Maybe the ones you intend to use are different, but you need to really check the specifications carefully because most "industrial" use is very different to most "traction" use.

 

Or I suppose if the LAs are cheap enough in China you can just throw them away if they die from sulphation or heavy use... ?

Edited by IanD
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Just now, David Mack said:

There was a radical square bladed prop design being promoted a while back. It has since sunk without trace

.

The difference is that the Axiom prop was a combination of BS and hiding the fact that in order to be better in reverse than a conventional prop it was worse in forward gear.

 

If you go and read the links about the Sharrow prop it does appear to be a genuine advance in prop efficiency, with both theory and test data to prove it.

 

If it does offer the advantages claimed for ship-scale props then I suspect it will be a huge success, saving even a few percent of fuel is the Holy Grail for shipping companies and this promises to do better than that.

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14 minutes ago, David Mack said:

There was a radical square bladed prop design being promoted a while back. It has since sunk without trace

.

When I converted mine I just cut down the original prop, it was to big for the diesel engine before so I removed an inch of it carefully and it now spins to maximum rpm, I gave it a nice polish for good measure ?

I had a look at those Sharrow props but 4.5 to 9k in dollars sort of stopped me, mine seems to work ok

Edited by peterboat
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