The Electric Boat Thread

[dontsendbubbamail]

How about a description and closeup picture of the lip seal? I would like to understand how you are doing that.

Bubba

[Jeremy Harris]

The seal is just an ordinary nitrile rubber oil seal, as used in cars, trailer axle bearings etc, usually to keep oil in. They work just as well at keeping stuff like water out. I got mine from this ebay seller: http://cgi.ebay.co.uk/12X24X7mm-ROTARY- ... dZViewItem

Unfortunately I can't easily take a close up of the seal now, as I've loctited the screw that holds the prop on, and I'd need to take it off to get a decent picture.

I've been working on a boat design though, making models for a tortured ply canoe. I got the idea from this website: http://www.sloejd-kbh.dk/tema/skibe/Kano_GB/Canoe.html

Here are some pictures of the models I've made so far, the centre one is closest to what I think I'll build:



Jeremy

[dontsendbubbamail]

Now I understand. I thought that you were talking about something you had machined.

Bubba

[12p3phPMDC]

The drive is coming out nicely Jeremy.

Are you going to mount a bearing and a seal
on the bottom of the boat in order to steer unit?
Or are you going to mount like an outboard?

How do you plan on steering the unit, a simple lever arm with reverse steering?

[Jeremy Harris]

Thanks for the compliment. The plan at the moment (it may change!) is to fit the drive leg into a hinged section of the hull at the stern. I want this to look like an unpowered canoe as far as possible, and would prefer not to mount the motor like an outboard for that reason.

I'm aiming to have a narrow transom at the stern, with the sealed box rear triangular stern section, containing the motor, removable. The motor shaft will be inside a sealed tube with steering bearings, probably made from Nylon. The lower part that sticks out the bottom of the triangular stern section will be faired and fitted with a skeg to protect the prop. The motor itself will be well above the waterline hidden inside the dummy stern section.

This arrangement will allow the whole stern section to be pivoted upwards from the top edge of the false transom, allowing the prop to be swung clear of the water for shallows, clearing weed etc. The electrical connections to the motor will be by waterproof connector and I'm planning on arranging for the steering to be connected automatically by a push/pull rocker arm, with the push/pull connections poking through the false transom, well above the waterline. This system will be very like those used to connect flying controls on some removable or folding wing aircraft (a look at some photo's of old carrier aircraft with their wings folded may help show how this works). I could opt for a steering cable, but it'd be one more thing to connect/disconnect when the motor "box" is removed, plus it might limit the hinging movement a bit.

I'm finishing off a 1/8th scale ply model of the canoe at the moment, to see how things may go. Next stage is to build the canoe full scale and see if things work as planned.

Jeremy

[Zoot Katz]

I sure liked the slipper design.

How large a rudder would need to be attached to a canoe?
Seems simpler than steering the prop shaft and no penalty if it only has to be as deep as the skeg or maybe kick up for beaching.

[dontsendbubbamail]

I have been running a 17 lb trolling motor on an 18 foot canoe. Anything extra in the water in addition to the motor causes extra drag. It may be debatable as to how much drag. If there is any wind, it can push the canoe around and make staying on course or turning very hard to impossible unless I put a paddle into the water and use it as a dagger board. A small keel down the length of the boat would be a solution if you don't care about quick turns. I plan to make a bracket to hold the paddle so that I can take it out when not needed.

My vote would be for a removal dagger board and no rudder.

Bubba

[Jeremy Harris]

Zoot, I like the slipper design too, but it's a bit harder to make than a canoe, I think, plus would need a trailer. I'm using the canoe as a starting point, to see how well the motor etc works. If it's a success, then I think I may go for something a big bigger, like the slipper launch, with a fully solar power system. I doubt I'll be able to do more than augment the battery power with solar cells on the canoe, without having ungainly solar panels stuck everywhere. I should be able to mount enough cells on the canoe to get maybe 20 watts of boost though, which will make a significant difference to range, plus allow for solar charging whenever the canoe is sitting idle.

Bubba, Thanks for the tip about the directional stability. I think I'll add a small keel down the length of the canoe, both to fix this and act as a bit of hull protection. I'll carry a paddle as well, so I can use that for any really sharp turns, although I hope that just turning the motor will be enough most of the time.

Jeremy

[dontsendbubbamail]

You may want to consider some kind of remote steering. With my 18 foot canoe, if I sit at the back and tried to steer, the front would stick up in the air and act as a big weather vain. I solved this problem by making a transom that allowed me to put the motor directly behind the canoe. The head of the trolling motor was removed and the wires extended so that I could sit in the middle of the canoe to control the speed. A board was mounted in the place of the head and two ropes tied to the ends so that I could steer from the middle of the canoe.

A flat stern canoe would be my first choice even if it is not as efficient as a double end canoe. A well behind the rear seat is my second choice. My third would a transom like I have.

It is really cool as to how close you can get up to wild life with this setup. I have been cruising up a river and come within 25 feet of a heard of deer drinking from the river and not spooked them.

Bubba

[John in CR]

Jeremy,

One thing to keep in mind with steerable thrust is that you want to build a stable canoe, since the thrust when turning will also try to make it flip. Of course batteries in the bottom will help counter that effect, but be careful with that high output RC motor.

John

[vax]

I'm designing 5m electric/wind hybrid catamaran boat for some time now. This involves laser cutting plywood sections (0.5m distance) and filling the gaps with foam. Further I plan sanding it to right shape and finishing with epoxy resin.
Next step is taking negative mould.
It's modelled in SolidWorks, so I can easily transform it into laser cut files (*.dxf).
Motors will be dual 600W geared, from Chinese scooter. Direct shaft drive.
Otherwise I think it will have conventional sails (I happen to have them already), and perhaps ability to recharge batteries from props spinning when it's on sail power.
Or, maybe using wind turbine instead of sails?

[paultrafalgar]

Sorry, nothing electric here, but I thought you might like to see:
http://www.hydroptere.com/~hydropte/_en ... 624#centre

[John in CR]

Vax,

It looks like you've got a lot of efficiency robbing surface area in those keels. I'd suggest taking a look at Bernd Kohler's anti vortex panels, which replace keels using a very small wetted surface area and use 0 additional draft for the basic hull shape in total contrast to traditional keels. see http://www.ikarus342000.com/Looseends.htm .

John

[Jeremy Harris]

Like the hull shape, Vax, but I'm with John on the wetted area from the keels causing a load of added resistance. I've been reading up on this stuff over the past few weeks, mainly the work done by some of the good human powered boat people. They get a bit fanatical about reducing wetted area, as their "motor" power is very limited.

There's some good software about that allows pretty accurate modelling of performance. I'm still trying to get to grips with the rather awkward interface, but Michlet does seem highly regarded. Modelling your hulls in it, with and without the keels, would show what the effect was.

I'm just about done with my hull design, it's not dissimilar to your cat hull in some ways, a sort of cross between a canoe and a skiff, made from tortured ply. I'm currently building what I hope will be the last model, an eight scale version in 1/32" ply, to make sure the panel shapes I have are properly developed. Putting pseudo 3D bends into plywood can produce some really nice looking hull shapes I've found, plus it's a pretty easy building technique.

Jeremy

[Lock]

Rick just posted another youtube vid. From the post:
"This is a long slender pedal boat with an electric drive. The motor is a Turnigy SK 600W permanant magnet synchronous motor with 3-phase supply from a two small 12V batteries. The boat topped out at 10kph (5.4kts) while drawing 200W from the battery."

[John in CR]

Lock,

Thanks for sharing but I'm sure Jeremy as well as myself want to build electric boats that are useful. Make the hull in the clip longer and it's likely to go faster on the same 200W. I'm looking at building a 1000-1500lb cat that can handle another 1000-1500lb of passengers, and is sturdy enough to be comfortable 30-40miles out in the ocean, and will achieve 6-7 knots (the high end of trolling speeds for sailfish, marlin, tuna, and mahi, which a prevalent here "in season") using only 1200-1500W.

John

[BMI]

Hi to all you guys who are interested in large electric boats.
I thought I would post some info on an e-boat project here in case anyone is interested.
I am in the middle of a project where we are converting a 50 foot racing catamaran to all electric drive. This will be the most technologically advanced electric boat in the world when it is finished due to the advanced battery diagnostics and monitoring capabilities. It will be powered by three 5kW Power Pod retractable electric motors. We are just waiting for the motors to arrive from the US any day now. The 48V 240Ah battery bank is already at the boat yard waiting to be installed.
The boats' batteries will be recharged by solar panels, back-up diesel generator and re-generation (when the boat is under sail power in strong winds).
The boat has been entirely stripped out now in preparation for fitting of batteries, motors and all associated electrics.
As you can see from the below photos of the boat in its current state the boat looks pretty bare.

I will be happy to provide updates as to progress if there is interest here. There will be a full featured article appearing on this electric boat in at least two major boating/alternative energy magazines which will show to those involved in the boating industries what is currently achievable with regard to electric boat technology.

[Lock]

Lock,
Thanks for sharing but I'm sure Jeremy as well as myself want to build electric boats that are useful.

Hi John. Understand!

From the original post:

The canoe I'm planning to build is the Selway Fisher Raven on this site: http://www.selway-fisher.com/Opcan16.htm. It's a ply, stitch-and-glue, open canoe. It seems to need around 40 watts or so to travel at 3.5 to 4 kts. It's maximum hull speed is about 5 kts, but it would need around 200 watts to reach it. My plan is to build a cruising boat that I can use to travel inland waterways and lakes at normal paddling speed, hopefully with some solar cells to augment range and allow charging when not moving.
The finished canoe should look like a scaled-down version of a typical Victorian electric river canoe like this one:

Make the hull in the clip longer and it's likely to go faster on the same 200W. I'm looking at building a 1000-1500lb cat that can handle another 1000-1500lb of passengers, and is sturdy enough to be comfortable 30-40miles out in the ocean, and will achieve 6-7 knots (the high end of trolling speeds for sailfish, marlin, tuna, and mahi, which a prevalent here "in season") using only 1200-1500W.
John

Understand. My interest in eboats is mostly about 40-passenger water taxis:
http://groups.yahoo.com/group/QCYCTender/

Here is a thread you might get a kick out of:
http://www.boatdesign.net/forums/hybrid/solomon-technologies-electric-wheel-electric-motor-propulsion-systems-676.html

...I got my first electric scooter "by accident" as a way to educate myself a bit about batteries and controllers and charges and electric traction generally. Had no idea what I was getting into (meaning not so much the tech but the politics.)

tks
lOCck

[John in CR]

Hi to all you guys who are interested in large electric boats.
I thought I would post some info on an e-boat project here in case anyone is interested.
I am in the middle of a project where we are converting a 50 foot racing catamaran to all electric drive. This will be the most technologically advanced electric boat in the world when it is finished due to the advanced battery diagnostics and monitoring capabilities. It will be powered by three 5kW Power Pod retractable electric motors. We are just waiting for the motors to arrive from the US any day now. The 48V 240Ah battery bank is already at the boat yard waiting to be installed.
The boats' batteries will be recharged by solar panels, back-up diesel generator and re-generation (when the boat is under sail power in strong winds).
The boat has been entirely stripped out now in preparation for fitting of batteries, motors and all associated electrics.

I will be happy to provide updates as to progress if there is interest here. There will be a full featured article appearing on this electric boat in at least two major boating/alternative energy magazines which will show to those involved in the boating industries what is currently achievable with regard to electric boat technology.

BMI, yes definitely keep us posted on progress. Out of curiosity, did you slip a digit on the battery capacity, because that's only 11kwh of capacity, or 45 minutes of runtime with the three 5kw motors at rated capacity? For the 10m cat for which I'll soon kick off construction, my back of the napkin capacity plan is 15kwh. That is without any solar panels in the budget. What is the maximum output expected from your PV panels under optimum sun?

John

[Lock]

Beauty boat BMI! Who was her designer please (Shuttleworth?) Will you still be racing her? I understand the daggerboards as max. efficiency for racers, but if I were cruising her I would move to centerboards... (old Tornado sailor here)
tks
Lock

[BMI]

Hi to all you guys who are interested in large electric boats.
I thought I would post some info on an e-boat project here in case anyone is interested.
I am in the middle of a project where we are converting a 50 foot racing catamaran to all electric drive. This will be the most technologically advanced electric boat in the world when it is finished due to the advanced battery diagnostics and monitoring capabilities. It will be powered by three 5kW Power Pod retractable electric motors. We are just waiting for the motors to arrive from the US any day now. The 48V 240Ah battery bank is already at the boat yard waiting to be installed.
The boats' batteries will be recharged by solar panels, back-up diesel generator and re-generation (when the boat is under sail power in strong winds).
The boat has been entirely stripped out now in preparation for fitting of batteries, motors and all associated electrics.

I will be happy to provide updates as to progress if there is interest here. There will be a full featured article appearing on this electric boat in at least two major boating/alternative energy magazines which will show to those involved in the boating industries what is currently achievable with regard to electric boat technology.

BMI, yes definitely keep us posted on progress. Out of curiosity, did you slip a digit on the battery capacity, because that's only 11kwh of capacity, or 45 minutes of runtime with the three 5kw motors at rated capacity? For the 10m cat for which I'll soon kick off construction, my back of the napkin capacity plan is 15kwh. That is without any solar panels in the budget. What is the maximum output expected from your PV panels under optimum sun?

John

Only the two outboard motors will be used for normal cruising. The central motor is designed as a manoevring motor so will not be used for most of the time. We expect to get a good hour of motor run time from two motors at leisurely cruising speeds.
We haven't worked out how many solar panels we can fit yet but I will let you know when we get to the stage of deciding.

[BMI]

Beauty boat BMI! Who was her designer please (Shuttleworth?) Will you still be racing her? I understand the daggerboards as max. efficiency for racers, but if I were cruising her I would move to centerboards... (old Tornado sailor here)
tks
Lock

I am not sure who the boat was designed by originally but will chase up the details for you and will let you know. I am only the battery supplier and electrical engineer on the project. I am designing the electrical systems for the boat for the electric conversion (both power and data). As far as the original boat design goes I will ask the boat's owner next time I speak with him.

Yes, she will still be racing. This is why we are waiting eagerly for the motors to arrive. The plan is to mount them on some kind of hinged panel so they can be lifted completely out of the water by a hoist/pulley system so as to not cause any drag while the boat is racing.

[John in CR]

Beauty boat BMI! Who was her designer please (Shuttleworth?) Will you still be racing her? I understand the daggerboards as max. efficiency for racers, but if I were cruising her I would move to centerboards... (old Tornado sailor here)
tks
Lock

Lock,
Before installing any daggers or keels, look into Anti Vortex panels first. Less surface area so less drag, require no more draft than the hull itself, more effective because they reduce the water vortices that create drag and wake. Look at Bernd Kohler's work he has generously shared in the links on the right half of the page at http://www.ikarus342000.com/Looseends.htm

BMI,
Since it's a refit not a build, I assume that for the PV panels you aren't going with the ones that can be built right into the deck and walked upon. That's the route I'd love to go, if it wasn't so darn expensive. ie a craft covered almost entirely in PV above the waterline would be great. Add in about 1000lbs of lithium batteries, reefable wingsails for more efficient sailing with improved maneuverability (including reverse under sail), plus a nice size wind turbine for battery charging without sun or the need to be under way, and then you've got a near ideal boat.

I assume you plan to use BMI lithium cells. What is special about the BMS mentioned in your first post?

John

[BMI]

Beauty boat BMI! Who was her designer please (Shuttleworth?) Will you still be racing her? I understand the daggerboards as max. efficiency for racers, but if I were cruising her I would move to centerboards... (old Tornado sailor here)
tks
Lock

Lock,
Before installing any daggers or keels, look into Anti Vortex panels first. Less surface area so less drag, require no more draft than the hull itself, more effective because they reduce the water vortices that create drag and wake. Look at Bernd Kohler's work he has generously shared in the links on the right half of the page at http://www.ikarus342000.com/Looseends.htm

BMI,
Since it's a refit not a build, I assume that for the PV panels you aren't going with the ones that can be built right into the deck and walked upon. That's the route I'd love to go, if it wasn't so darn expensive. ie a craft covered almost entirely in PV above the waterline would be great. Add in about 1000lbs of lithium batteries, reefable wingsails for more efficient sailing with improved maneuverability (including reverse under sail), plus a nice size wind turbine for battery charging without sun or the need to be under way, and then you've got a near ideal boat.

I assume you plan to use BMI lithium cells. What is special about the BMS mentioned in your first post?

John

The type or number of solar panels which will be used hasn't been decided as yet.

There is a ferry here in Sydney Harbour which is absolutely covered in solar panels. It is called the "SolarSailor" and you can see it on the manufacturers website here- http://www.solarsailor.com/
When you see the boat close up it sure stands out from all the other boats with all the solar panels which cover her.

Yes, our boat will be powered by BMI batteries. Originally the boat was going to be fitted with more than half a ton of Trojan lead acid batteries. Then the owner of the boat looked into the capability of the BMI packs and decided on them instead. The total battery weight of BMI packs comes in a little under 200kg so is less than half the weight of the original Trojan battery bank for the same effective battery capacity.
The BMI batteries don't have a BMS but a VMS instead. There is a basic explaination of the VMS here-
http://lithbattoz.com.au/index.php?page ... iagnostics
The VMS allows for a laptop computer to be plugged in to a dedicated battery diagnostics panel mounted socket fitted in the boats instrument panel. The internal voltages of every cell in each of the battery packs can be displayed on the PC and errors for over charge, over discharge and over temperature are logged as is the total number of full accumulated battery cycles. The batteries have the ability of performing an automatic self check up to twice a day. If any cell in any battery is found to be out of specification or requires attention in some other way an SMS text message can be sent to the boat's owner or an email sent alerting him/her of the need to check the battery in question. Therefore the owner of the boat could be on the other side of the world many miles away from the boat and will know at all times of the condition of all the batteries in his/her boat.

[Lock]

Gawd I love that Solar Sailor. Hadn't checked their site for a long while now. Nice to see developments and growth (apparently) in the offing for them. Didn't see any pics of the "real" Solar Sailor at first, just computer renderings of future stuff, so my fav Solar Sailor pic:

SolarSailor.jpg (52.42 KiB) Viewed 1914 times

John, tks for the link to Kohler's Anti Vortex work. Very interesting and will read later. Love the idea of built in swim platforms (smile)

...and I still say BMI's project is a Shuttleworth
Lock