[Mark in Portugal]

Hi guys;
There are specialty forums for this, but all I get is people who want to sell me new material at 10X my budget.
Really nice looking, but it's not going to happen.

The project; In Amsterdam [Holland] I have a 12 ton 100 year old steel barge I use occasionally for work. Although I only need it rarely, when I need it I really need it.
max speed in the canals is 8mph, distance I need to travel is 3 miles on a charge. 6 would be nice, but the battery cost is another story.

Amsterdam has announced that all vessels must be emission free by 2026. Even now, I'm paying $500 per year penalty for having an internal combustion engine for propulsion.

So, getting to work;
Used forklift motor, 240A 48V, $200 second hand, available now.
pulse width modulated control, new $350, maybe a used one with the motor.

If the motor is 80% efficient [???] it's rated at 12HP. ok for going, a bit light for stopping.

I need some tech info on brush type motors. Amps/ volts / torque / RPM.

How do I achieve short duration overload capability for stopping + turning?
What happens if I gear the motor to turn the prop at 20HP at rated motor speed, then normally reduce that with a pulse width control to keep the rated amps at lower than rated speed?


Next subject;
water cooling.
this will be required even to let the motor run at rated power continuously.
I see 2 ways to do it;
1; add an outer jacket and use glycol solution to cool the motor casing, an intercooler, and 2 waterpumps. The boat already has an intercooler, and the diesel will stay in it for longer transits outside the eco restriction zone.

2; change the motor case for a stainless steel one, with waterjacket.
they're usually just a pipe. I have a lathe. The question that occurs to me is whether the motor needs the magnetic properties of the normal steel tube it's mounted in. 320 stainless isn't magnetic.

I have the time and skill [barely] to do the work.

Because the biggest heat problem is usually the armature windings, I have the idea to add cooling to the shaft; weld a stainless extension and run it through a water chamber.

Does anyone here have any knowledge of this sort of thing?

 

[TUDOR]

Cooling

Can you use a large squirrel cage fan (oversized furnace fan) and duct in cooling air?

The 40 hp table motors at the steel mill where I worked live in an environment that can be as much as 50°C and draw air from the oil cellar at 30°C for cooling. The motors can be operated on as much as a 20% duty cycle

Rule of thumb - 1 hp electric motor = 1.25 hp gas engine

I'm not sure if a diesel equates the same way.

 

[Mark in Portugal]

Cooling is a detail at the moment; speed control, reversibility, and how to match the prop to the motor are what I really need to figure out.
sure, I could add a fan, ducts, etc. But I think it will need water cooling to be successful.

I need about 8 hp continuously; well, for 45-60 minutes, which is the same I suppose.
That's a tough job for a DC motor; most are made for short duty cycles.
This forklift motor is probably prehistoric; the plate picture from the ad is hard to read, and in Italian just for added amusement.

"servizio", [service] appears to read ".53 [or .58] 25%"
I take that to mean duty cycle. 53 could be temperature C?
If we take the amps x volts from the plate, and compare the result to the KW on the plate, the discrepancy would seem to indicate 69% efficiency at 36V, 72% at 48V
So 3.5kw of heat at 48V; that's a lota heat!

Monitoring the heat of the field coils is easy enough, but it's the armature that always melts first.
this motor is not the right motor; but it's 150 euros, $200. The "right" one is $2,000, + $1,500 for the required control.

and another grand for the batteries.

If I buy this motor, I'll probably control it with straight relays, or even a manual lever switch [I'd have to fabricate that]. So it would have 2 speeds, 24V and 48V; and full reverse.
available controls are not able to handle 240A continuously, 150 seems the max [even though they're called 400A controls].

This motor comes with 'the original oil pump', which I take to mean hydraulic pump. so reversing would have been done hydraulically. This is a series wound motor, not designed reversible.
I would have to extract the armature connections; I've done that before with a starter motor.
The starter motor didn't like reversing. it seemed more sparky, and slower. but it did its job.

This way I'd possibly achieve a usable result at a usable cost.

According the plate, the current is equal at different voltages. the power and rpm decreases.

 

[Larry LGT 165]

I can offer no help with the electrical calculations, execpt to sugest a small electric bow thruster auxillery motor up front for steering. They are common here on fishing boats, especially bass boats for tight turning without using the main engine.

Here when a dealer matches a motor to a boat, they take along several props of different pitches and test to find one that allows the engine to reach full rpm on the chosen vessel without labouring.

If you can water cool, running copper pipe along and back just above the keel is common and replaces the need for any type of radiator/fan. A small coolant circulating pump would possibly consume less electrical power than a larger air cooling fan.

You have our interest Mark, as the day will come such regulations are enforced here as well.

 

[Tractor-Holic]

I wonder if instead of one big 12 HP motor,you could use several 12V treadmill motors,I see some rated up to 4.5 HP at the Surplus Center's site ,prices ranging from under $100 to about $200--they are designed for use with variable speed control .

 

[Larry LGT 165]

I wonder if instead of one big 12 HP motor,you could use several 12V treadmill motors,I see some rated up to 4.5 HP at the Surplus Center's site ,prices ranging from under $100 to about $200--they are designed for use with variable speed control .

:ditto:Now there's a good thought. You could mount them on a couple old outboard motors with the gas engines removed.

Separate batteries, separate turning for steering if required, props already in place, forward neutral and reverse, and you could leave the original drive system completely separate for when you are out on open water.

.:thThumbsU

 

[mda2000]

If you went with the outboard lower units, that would allow you to handle reverse in gearing, not in reversing the motor. The only issue I could see with that is the mechanical losses in the direction change before connecting to the prop.

How are you planning on connecting a prop to the motor? Long straight shaft similar to a mud motor or something more similar to an outboard lower unit? 12HP seems like a very small motor for a 12 ton boat but I know you are working with what you have.

I like your motor control idea using relays. I think I'd add a middle circuit of 36v for "cruising". I'm thinking once you are up to speed, you could drop down to 36v and maintain your speed but keep some heat out of the motor.

As far as circulating water, I would try a pipe pointed toward the bow as a pickup then pipe it where it needs, and dump out at the stern. Just trying to come up with a way to keep pumps, etc out of the mix if possible. I think when you are headed down the waterway, the force of water should be enough to push the water in the pipe up (depending on how far up is).

 

[Mark in Portugal]

a small electric bow thruster auxillery motor up front for steering.

I installed a bow thruster on my large boat; but I've managed this one for 20 years without one, and there is no budget for that.
Alright, I'm just going to say it; I'm really very good at handling this boat.

I wonder if instead of one big 12 HP motor,you could use several 12V treadmill motors,I see some rated up to 4.5 HP at the Surplus Center's site ,prices ranging from under $100 to about $200--they are designed for use with variable speed control .

That's the US! over on this side, that's not going to happen.

:ditto:Now there's a good thought. You could mount them on a couple old outboard motors with the gas engines removed.

Separate batteries, separate turning for steering if required, props already in place, forward neutral and reverse, and you could leave the original drive system completely separate for when you are out on open water.

The stern of the boat is too high for an outboard; and with the rudder there's no way to mount one without some serious butchering, which would terminate my historic boat permit that allows the boat to stay in the city at all.
Also, in Europe I've never seen cheap old anything.
Separate batteries? NO NO NO! less batteries is what I want!
This boat steers with a great big tiller.

If you went with the outboard lower units, that would allow you to handle reverse in gearing, not in reversing the motor. The only issue I could see with that is the mechanical losses in the direction change before connecting to the prop.

How are you planning on connecting a prop to the motor? Long straight shaft similar to a mud motor or something more similar to an outboard lower unit? 12HP seems like a very small motor for a 12 ton boat but I know you are working with what you have.

I like your motor control idea using relays. I think I'd add a middle circuit of 36v for "cruising". I'm thinking once you are up to speed, you could drop down to 36v and maintain your speed but keep some heat out of the motor.

As far as circulating water, I would try a pipe pointed toward the bow as a pickup then pipe it where it needs, and dump out at the stern. Just trying to come up with a way to keep pumps, etc out of the mix if possible. I think when you are headed down the waterway, the force of water should be enough to push the water in the pipe up (depending on how far up is).

Prop to motor will be probably be with a big cogged belt, that will allow gear ratio too.
36V would be nice, but would require dropping out 2 batteries, or having a complex arrangement of 12, or a complex arrangement of 2V cells. If 24 is too low, and 48 too high, I'll switch back and forth, or just go slower.
Also, this doesn't have to be built all at once; if it really bothers me, I can always change.
6 batteries could give 24 or 36 or 72 [momentary overspeed for stopping]
There will have to be a pump or two. tried and tested, I have enough experimental stuff going on already.
tricky part is keeping the armature cool. I haven't thought of any practical way to monitor it spinning in there.
12HP is about the largest possible electric before costs head into the stratosphere. Bigger motor need bigger current, which is bigger batteries, bigger charger, etc.

Sailing and mooring up while holding the camera in one hand;

 

[mda2000]

tricky part is keeping the armature cool. I haven't thought of any practical way to monitor it spinning in there.

I'm not 100% sure about this, but have you thought about having a hole drilled through the armature shaft to run coolant? It would be tricky to connect something to it because whatever connector you use would have to be able to seal while spinning.

 

[Larry LGT 165]

I'm not 100% sure about this, but have you thought about having a hole drilled through the armature shaft to run coolant? It would be tricky to connect something to it because whatever connector you use would have to be able to seal while spinning.

No real need to cool the rotor, as oil cooled stators are common in motors. May need a small pump and heat exchanger to water.

Mark, "THEY" are the ones changing the rules, not you. Surely they would allow some modifications to your older boat to meet the new standards.

EDIT: Do you have access to a dry dock. Can you cut a hole in the underside of the hull and install a jetski drive. No props or driveshafts to interfere with the rudder, just need your electric motor to power the drive..

 

[DL-North]

This interesting.
What are you pushing the boat with now?

Some thoughts,

Here old treadmills are readily available FREE, any number of small (1-4? hp) DC motors could be had. And they come with controls also.
The guys over on a Old Wood Working site re-purpose them for drill and lathe work.

Or a bit more $$, trolling motors, older versions w/o GPS are modestly cheap.

If you're only adding small motors, I'm not sure I'd spend much time on fancy cooling, and if you used trolling motors it's a non-issue.

A set of bow thrusters would give much greater control. (but maybe you don't have stiff wind of current in those canals)

 

[Mark in Portugal]

Dan; we already covered those things above.

"They" don't give a toss about my ugly old historic boat; funny thing though, the tourists used to love it. 'Ooh look, a typical Dutch guy and his typical Dutch dog!'
Dog wasn't Dutch either of course.

The stator is air cooled; duty cycle at full power is short. If I water cool the outer case, that will absorb some heat from the middle too, but probably not enough.
Yes, I did think of drilling the shaft; thinking is as far as that goes.
I have another idea, which I could actually achieve; weld an extension to the rear of the shaft and run it through a water jacket. a lot of heat will bleed along the shaft and dissipate into the water. that requires just 1 seal.

The existing shaft and prop work just fine; there is really no need [or budget] for more.
Importantly, I can reach down from the stern to pull plastic bags out of the existing prop.

 

[Larry LGT 165]

Please tell us more about this interesting craft Mark. What do you use it for, or transport on the deck?

What's below deck, just the engine, any equipment siorage or personal accommodations?

Do you just stand on deck and steer with the tiller?

Thanks.

 

[DL-North]

I didn't see where either were discussed.
And you still haven't said what you are pushing it with now.

If you only need 8-10 hp, that's not much if you use DC motors.
You could easily have 3 or 4 belt driving a common shaft.
As for belts, 2 x 3/8" or 10 mm vee belts would easily handle 10-12 hp, depending on belt speed.

And trolling motors, bolt 3 or 4 to the rudder and your done, and no cooling problems.

And more pics and details please.

Dan; we already covered those things above.

 

[Mark in Portugal]

It's a classic Dutch utility sailing barge called a 'Westlander', about 100 years old, riveted steel on steel.
I bought the boat in 1982; it had a square steel cabin on it and we lived in it for 7 years; no rent in the middle of the city.
Couldn't get away with that anymore, and we bought a bigger boat with a permanent mooring I needed a workboat, so I cut the square cabin off and welded the flat deck on it; keeps the water out.
I bought a Mercedes OM636 36HP diesel [1965], and steer with the original tiller.

I keep my tools and workclothes in there, it airtight containers. Also scaffolding, stepladder, paints I use to maintain my houseboats.
Now we live in Portugal, and when I travel to Amsterdam it's a mobile work platform.
I often have to take ships to shipyard, and I bring the workboat too. Last time I was there, I used it to travel 10 miles to the city and back many times, since having a car there isn't practical.
I could do the journey on a bicycle in the same time, but while I'm there I work 14 hour days and don't need more fatigue.
One houseboat I have has to get under a very low bridge to get out for maintenance. I built it with a removable rear cabin, about 10' square and weighs a ton.
I have a crane come and lift it off, set it down on my workboat. I've done this many times now, always a show.
I could survive without the workboat, but it would be expensive.

 

[Larry LGT 165]

Great pics Mark, and sounds like a great lifestyle too.

The clearance under the old arched bridge is a real eye catcher. Hope the water level in the canals is stable.

Thanks,

 

[DL-North]

Mark,
That is really cool, and you have quite the operation there.

 

[steddy]

Any thoughts of harvesting the powertrain out of an electric golf cart (or two)? Reversible, variable speed, speed controller, 36 or 48 volt. I'm not sure how much horsepower/torque they have, but some of them are fairly peppy from a standstill, and they're pretty darn heavy for their size.

 

[Mark in Portugal]

The water level in the canals is highly engineered; it's usually stable within a few inches. the boat is made to clear the bridge and will do so unless there's unusually high water.
Back in 1999 I needed unusually low water to slip a boat under a bridge; I was told to call the control center.
They were able to give me accurate predictions for a week; rainfall, wind and tide dictates how much water they plan to release, which they can only do at low tide.
In Dutch, 'tide' and 'time' are the same word.
They told me they were going to drain a lot of water on December 31, in case the millennium bug crashed their systems. All I had to do was find a tug captain willing to work on new years day, 2000.
He wasn't the most skilled. still, we did it.

Golf carts; sure, if I found one. or three. Mostly anything I find second hand here in Portugal is crazy overpriced, and utterly worn out. When in Holland I don't have time and I don't have a car to hunt for things.
Also, golf cart is a lightweight thing. Forklift is industrial. Heavy, serious.
This big old forklift motor is offered at a decent price.

 

[Mark in Portugal]

oil cooled stators are common in motors. May need a small pump and heat exchanger to water.

I've been thinking about this.
Have you any experience of oil cooled DC motors?
I'm wondering if it could be oil filled, if the commutator + brushes would be ok in oil or if a seal would be required to keep those parts dry [that would be difficult].

What kind of oil? how full should such a motor be? what about froth, mechanical resistance?