Doodlebugs Latest Project... Engine at front of boat?

[ditchcrawler]

Where are you going to put the propeller with this scheme? Does your boat have a counter stern of appropriate size and shape to accommodate the size of prop which is appropriate for a slow running lump of an engine?

With a hydraulic drive he can match it to run his prop at any speed, even gear up an egg whisk on the back if he wants to

Maybe prop in the rudder

Like several motorised butties

[David Mack]

With a hydraulic drive he can match it to run his prop at any speed, even gear up an egg whisk on the back if he wants to

 

But not necessarily if he is buying whatever hydraulic pump and motor he can find going cheap on Ebay or in a breakers yard.

[waterworks]

 

But not necessarily if he is buying whatever hydraulic pump and motor he can find going cheap on Ebay or in a breakers yard.

Hydraulic pumps have a service life, due to the very tight tolerances internally. Wear means loss of power. A used one from a scrappy would unlikely to be a cost effective option I think. Unless you but it for scrap value and recondition it.

[Doodlebug]

Half of you think it is possible, and half impossible.

 

M latest thoughts are to build a heafty generator using the lister which could easily charge the batteries and run the washing machine.

 

Then once that project is finished convert the boat to electric.

 

Couple of points from the above comments.

 

Firstly when I say I do not want to mess with the steel work what I actually mean is I don't want the boat coming out the water and the work being done for me. Partly expense and partly its no fun.

 

Secondly I know this is not easy and know it might be better to get a different boat. It would have been easier not to stretch it and be easier to get a different outboard. But that is just no fun. I could get an electric outboard and inboard generator. But that is a weekends work. Not a years worth.

 

Lastly you are correct that the steel is totally incorrect for adding an inboard engine. I am actually thinking of using the gearbox and prop on the outboard so that all modifications can be done above the water.

 

So the latest issue (which may need a separate post at some point to keep the topic from straying too far from the post) is what the maximum sized alternator is that can be fitted to a specific horsepower engine. Ideally 5.

 

I think hydraulics are out of the question unless there was a way of running the boat with the 5hp engine and then topping it up for acceleration etc when needed. Can't imagine that is possible without two propellers.

[bizzard]

Flash steam jet propulsion is the cheapest and simplest. All you need is a coal stove and an old drainpipe. phutt phutt.

[Paul C]

Why have you settled on 5hp? It seems incredibly underpowered to me.

[colinwilks]

How about building a miniature push tug? Engine and rudder controlled from present steering position by Morse cables. Save money by licensing your boat as an unpowered butty, plus you could use the tug separately for pootering across to the pub when you simply can't face walking all the way round by the bridge.

[John V]

How about building a miniature push tug? Engine and rudder controlled from present steering position by Morse cables. Save money by licensing your boat as an unpowered butty, plus you could use the tug separately for pootering across to the pub when you simply can't face walking all the way round by the bridge.

 

Yay !!! Opduwer !!! love them !!!

[bargemast]

 

Yay !!! Opduwer !!! love them !!!

 

That certainly would be the easiest and most pleasant solution, and for me that would be a no-brainer.

 

Peter.

[waterworks]

Get a 10 HP Yanmar L100, and build a Diesel outboard engine with a leg and gearbox off an old outboard.

[gazza]

Ditch the outboard powerhead, bolt a hydraulic motor in its place, 2 pot raw water cooled Kubota with a hydrauluc pump nailed to the arse of it in a nice enclosure up the pointy end, job sorted.

 

No faffing with props, forwards and reverse retained, minor mods to the water tank you wanted to use as a fuel tank for water intake, you'd need to house a fuel tank and away you go.

 

No nasty vibrating low revving single cylinder antiques to deafen you and shake your crockery to shit, what's not to like?

[waterworks]

Ditch the outboard powerhead, bolt a hydraulic motor in its place, 2 pot raw water cooled Kubota with a hydrauluc pump nailed to the arse of it in a nice enclosure up the pointy end, job sorted.

 

No faffing with props, forwards and reverse retained, minor mods to the water tank you wanted to use as a fuel tank for water intake, you'd need to house a fuel tank and away you go.

 

No nasty vibrating low revving single cylinder antiques to deafen you and shake your crockery to shit, what's not to like?

Need a hydraulic oil reservoir, and filter unit, and a hydraulic oil cooler. ( second skin tank possibly )

[gazza]

Need a hydraulic oil reservoir, and filter unit, and a hydraulic oil cooler. ( second skin tank possibly )

Minor details.

 

Bugger having an air-cooled single rattling to death by yer lughole while chugging up the cut.

 

I've got a short tug deck style springer in my mind's eye, everything hidden under it out if sight

[Dalslandia]

Not quite. I was going with (simplified) the idea of using a 200amp motor on the back which most of the time runs using 100amps. A 100amp alternator would be running whilst on the move. That would supply the motor directly unless the motor is off (in locks) when it would charge batteries.

 

Please can you elaborate on your set up. The issue with the hydraulic system is needing a much bigger engine.

 

100 amp at 12V is 1200W but at at 360V it is 36000W

 

Even if a NB use a litre diesel per hour making some 3-4 HP you need more for stopping and going up hill.

1 litre diesel also will make 3 kW electric power.

But efficiency is there to be in the calculations so ad 20%

[Doodlebug]

100 amp at 12V is 1200W but at at 360V it is 36000W

 

Even if a NB use a litre diesel per hour making some 3-4 HP you need more for stopping and going up hill.

1 litre diesel also will make 3 kW electric power.

But efficiency is there to be in the calculations so ad 20%

 

Ahh yes I meant the standard 12v alternators. (though I know they put out a little more than 12)

 

 

Ditch the outboard powerhead, bolt a hydraulic motor in its place, 2 pot raw water cooled Kubota with a hydrauluc pump nailed to the arse of it in a nice enclosure up the pointy end, job sorted.

 

No faffing with props, forwards and reverse retained, minor mods to the water tank you wanted to use as a fuel tank for water intake, you'd need to house a fuel tank and away you go.

 

No nasty vibrating low revving single cylinder antiques to deafen you and shake your crockery to shit, what's not to like?

 

Only the lack of a nice shiny engine! (And would need space for the gear box).

 

 

How about building a miniature push tug? Engine and rudder controlled from present steering position by Morse cables. Save money by licensing your boat as an unpowered butty, plus you could use the tug separately for pootering across to the pub when you simply can't face walking all the way round by the bridge.

 

I must admit I kind of like the idea. But I don't think it counts as a butty unless over a specific number of feet. Ours is 33 so not sure it counts. But its an interesting idea. Not sure my welding skills are quite up to that but might be an interesting project.

[waterworks]

100 amp at 12V is 1200W but at at 360V it is 36000W

 

Even if a NB use a litre diesel per hour making some 3-4 HP you need more for stopping and going up hill.

1 litre diesel also will make 3 kW electric power.

But efficiency is there to be in the calculations so ad 20%

I am hoping that the "uphill" bit was a joke.

 

Please god let it be so !

[waterworks]

Go for a large cocooned generator at the front driving an electric motor outboard ?

 

The major advantage Is you can plug a kettle in, and have brews, while you cruise.

Edited March 9, 2016 by waterworks

[MtB]

I am hoping that the "uphill" bit was a joke.

 

Please god let it be so !

 

 

I took it to mean punching the current on a river...

[gazza]

 

Ahh yes I meant the standard 12v alternators. (though I know they put out a little more than 12)

 

 

 

Only the lack of a nice shiny engine! (And would need space for the gear box).

 

 

 

I must admit I kind of like the idea. But I don't think it counts as a butty unless over a specific number of feet. Ours is 33 so not sure it counts. But its an interesting idea. Not sure my welding skills are quite up to that but might be an interesting project.

What gearbox?

 

Those odd little axiom cars have a two cylinder Kubota in them, as do various lawn tractors/mowers Genny and reefer units. Plenty second hand to be had.

 

Go for a large cocooned generator at the front driving an electric motor outboard ?

 

The major advantage Is you can plug a kettle in, and have brews, while you cruise.

Electric outboards are farty little things, your suggestion is similar to mine but with a lack of grunt.

 

Hydraulics baby, it's the future

Edited March 9, 2016 by gazza

[Dalslandia]

I am hoping that the "uphill" bit was a joke.

 

Please god let it be so !

 

 

 

 

I took it to mean punching the current on a river...

 

Well it is both,

 

If it was written i missed it, but how long is the boat? it is not wrong to have the 8.55 kW motor from Lynch, with 48V you get less losses if generator is in one end and batteries and motor in the other end, unless you go 230 V, on the other hand going 48V generator to 48V batteries might give the least losses

 

http://lynchmotors.co.uk/marine_marine-drive-boats.html

 

Ok 33ft so max Economical hull speed is 7.7 kts or 8.8 MPH, is it a N-Beam? displacement? 8,5 - 9 ton?

Start with that and you have an motor size.

It is the propeller that move the boat, not the engine . motor or generator or batteries. so for best efficiency at that end go with the largest propeller practically that can be fitted. then go for the least losses in the whole system.

 

To go 7.7 kts you need 40 HP, so not realistic, a 8.55 kW or 11.5 HP (imperial) will take you to 5 kts (5.75 mph) open water!

with max 1000 rpm on the prop you will have 16" -17" diameter.

 

A nice canal speed of average 3 mph and you need, (3 / 5,75) ^2,8 = 0,162 x 8,55 = 1,4 kW add some for the narrow canal, say 2 kW,

4 mph and you need ~ 4 kW. the double.

 

To have constant 2 kW you need 2 / 0,9 = 2,22 / 0,8 = 3 kW or so from generator.

At 4 mph you need 5 - 5.5 kW or a 6 kVA generator, if you don't want to take the energy from the batteries.

 

Charging at max 25% of the batteries size give you a 20 kW bank (AGM batteries can be charged in 4-6 hours)

20 kW at 48V ​ is 400+ Ah and the bank weight 480 kg 8 x 60 kg PC1800-FT Odessey, but i guess you can go with half of that.

4 x 60 kg,

214 Ah -190 Ah (20-10h rating) 48 * 214 Ah = 10,3 kWh ~ 8 kW useable

 

If you go 5 MPH you need 5,8 kW at the propeller ~ 6.5 kW from the generator and batteries, if the generator give 5 kW you need 1.5 from the batteries, and can go 5 hours at that speed on 4 PC1800-FT batteries.

 

You can also go 4 hours at 3 mph just from the batteries.

 

If you want a proper motor for show. laser scan one and have it 3D printed :-)

 

A modern cocooned diesel generator and solar panels ...

 

​

Edited March 9, 2016 by Dalslandia

[FadeToScarlet]

Harbourmaster large outboard with a Petter-McLaren PD2. A classic engine in an outboard, as fitted to some "river" class boats in the 50s/60s.

[Paul G2]

 

 

 

Well it is both,

 

If it was written i missed it, but how long is the boat? it is not wrong to have the 8.55 kW motor from Lynch, with 48V you get less losses if generator is in one end and batteries and motor in the other end, unless you go 230 V, on the other hand going 48V generator to 48V batteries might give the least losses

 

http://lynchmotors.co.uk/marine_marine-drive-boats.html

 

Oh 33ft so max Economical hull speed is 7.7 kts or 8.8 MPH, is it a NBeam? displacement? 8,5- 9 ton?

start with that and you have an motor size.

It is the propeller that move the boat, not the engine . motor or generator or batteries. so for best efficiency at that end go with the largest propeller practically that can be fitted. then go for the least losses in the whole system.

to go 7.7 kts you need 40 HP, so not realistic, a 8.55 kW/ 11.5HP (imperial) will take you to 5 kts (5.75 mph) open water!

with max 1000 rpm on the prop you will have 16-17" diameter.

 

a nice canal speed of average 3 mph and you need, 3/5,75^2,8= 0,162*8,55= 1,4 kW add some for the narrow canal, say 2kW,

4 mph and you need ~4 kW. the double.

 

to have constant 2 kW you need 2/0,9= 2,22 /0,8 = 3 kW or so from generator

at 4 mph you need 5-5.5 kW or a 6 kVA generator, if you don't want to take the energy from the batteries

 

charging at max 25% of the batteries size give you a 20 kW bank (AGM batteries can be charged in 4-6 hours)

20 kW at 48V ​ is 400+ Ah and the bank weight 480 kg 8x 60 kg PC1800-FT Odessey, but i guess you can go with half of that.

4x60kg 214-190 Ah (20-10h rating) 48*214=10,3 kWh ~8kW useable

 

If you go 5 MPH you need 5,8 kW ~6.5 kW from the generator and batteries, if the generator give 5kW you need 1.5 from the batteries, and can go 5 hours at that speed on 4 PC1800 batteries.

 

You can also go 4 hours at 3 mph just from the batteries.

 

If you want a proper motor for show. laser scan one and have it 3D printed :-)

 

a modern cocooned diesel generator and solar panels .

 

​

 

I'm not quite sure what all of your made-up math symbols stand for, but if you use the alt codes shown below you can use the correct math symbols and it'll make your post way prettier.

 

Link to alt code web site. They have alt codes for just about any symbol you can think of.

 

ETA - Well, darn, the alt codes are in a table that refuses to copy here, but follow the link and they are all there.

Edited March 9, 2016 by Paul G2

[Dalslandia]

 

I'm not quite sure what all of your made-up math symbols stand for, but if you use the alt codes shown below you can use the correct math symbols and it'll make your post way prettier.

 

Link to alt code web site. They have alt codes for just about any symbol you can think of.

 

ETA - Well, darn, the alt codes are in a table that refuses to copy here, but follow the link and they are all there.

 

Thank you Paul.

most of the math did I not write down, they was only visible in the calculator for some sec. all the math symbols is correct. but i can make it more visible.

the symbols used is those that is used in excel files

 

¼ (just testing)

Edited March 9, 2016 by Dalslandia

[Doodlebug]

 

 

 

http://lynchmotors.co.uk/marine_marine-drive-boats.html

 

Ok 33ft so max Economical hull speed is 7.7 kts or 8.8 MPH, is it a N-Beam? displacement? 8,5 - 9 ton?

Start with that and you have an motor size.

It is the propeller that move the boat, not the engine . motor or generator or batteries. so for best efficiency at that end go with the largest propeller practically that can be fitted. then go for the least losses in the whole system.

 

To go 7.7 kts you need 40 HP, so not realistic, a 8.55 kW or 11.5 HP (imperial) will take you to 5 kts (5.75 mph) open water!

with max 1000 rpm on the prop you will have 16" -17" diameter.

 

A nice canal speed of average 3 mph and you need, (3 / 5,75) ^2,8 = 0,162 x 8,55 = 1,4 kW add some for the narrow canal, say 2 kW,

4 mph and you need ~ 4 kW. the double.

 

To have constant 2 kW you need 2 / 0,9 = 2,22 / 0,8 = 3 kW or so from generator.

At 4 mph you need 5 - 5.5 kW or a 6 kVA generator, if you don't want to take the energy from the batteries.

 

Charging at max 25% of the batteries size give you a 20 kW bank (AGM batteries can be charged in 4-6 hours)

20 kW at 48V ​ is 400+ Ah and the bank weight 480 kg 8 x 60 kg PC1800-FT Odessey, but i guess you can go with half of that.

4 x 60 kg,

214 Ah -190 Ah (20-10h rating) 48 * 214 Ah = 10,3 kWh ~ 8 kW useable

 

If you go 5 MPH you need 5,8 kW at the propeller ~ 6.5 kW from the generator and batteries, if the generator give 5 kW you need 1.5 from the batteries, and can go 5 hours at that speed on 4 PC1800-FT batteries.

 

You can also go 4 hours at 3 mph just from the batteries.

 

If you want a proper motor for show. laser scan one and have it 3D printed :-)

 

A modern cocooned diesel generator and solar panels ...

 

​

 

Thanks for this - but are the calculations for the overall speed not rather fast? We travel at walking speed using the 10hp which is about 3mph or 4kmh.

 

We weigh 6.5 ton if that helps?

 

Will work through the calculations and see if I can come up with anything further.

[Doodlebug]

Update: Had a further thought on this. Just exploring the hydrolic route for a bit.

 

What stops there being two pumps and two engines. One large vintage engine doing about 5hp and another small engine like a yanmar (or even the old outboard engine) doing between 5-10hp.

 

Both could be connected to the motor. At tickover the 5hp engine would be driving the prop and when power is needed the other engine could kick in and give it a boost.

 

This diagram probably explains it better.

 

Also (a sill question) but can a hydrolic motor be used as a pump? I.e. can I buy two motors and just put them either end to ensure they match up ok?

 

https://drive.google.com/file/d/0B7TNhOlxZL71XzljbW5rakp3TXBrT05pdUJMS1JIS3pqNlk0/view?usp=sharing