Hybrid human/electric 2-person catamaran

... and now for something completely different?

This may be silly and completely unworkable, in which case I apologize for the waste of time, and hope you at least find it a little amusing...

Some here may know I've been trying to work up plans for a zero-emissions ferryboat for harbour service... and I've been trying to understand a bit about electric propulsion.

On a completely different tack, I would also, someday, like to have or build another pulling boat for myself, suitable for guest and picnic...

Anyway, I have been reviewing some of the message traffic (1999 to present) among the good folk over at the Human Powered Boats Mailing List - much of their discussion involves highly efficient hull shapes and propulsion systems, and many of the posters are obviously highly skilled with many years of experience.

They have me thinking now, about chucking the old oars, and going pedal/prop. But because I am so ignorant about so much of this, I get to think "outside the box" <grin>... probably way, way, too far outside the box, but anyway.

Here's my last post to the HPV-Boats people (via the eBoaters). Go ahead, it's OK if you have a good laugh...

From: "lockhughes" <felixkc123@h...>
Date: Sat Aug 10, 2002 7:29 pm
Subject: [hpv-boats] Air vs Water props, cadence,transmission efficiencies,faq, etc etc!


Yeooooo eboat folk...
call me crazy, everybody else does. I've been reading up, postings
from the HUMAN POWERED BOAT universe...

Can you think of anyone more interested in hulls and propulsion
efficiencies?

Here's my post to their Mailing List:

To: hpv-boats@i...

Two weeks in the lab can save an hour at the library.
Anon

Thanks to Bob Stuart for this little tag line that I
stumbled across. I've been reading the HPB-boats
archives for the last (ohmygawd) 5hrs... started back
in 1999 and I'm only up to August 2000 so far! ARGHHH!

I started out trying to make notes about some of the
*excellent* posts I have been reading. I wanted to
start this msg by posting some thank yous - but there
were just too many - so, thank you ALL, who have been
contributing to the list over the years.

I'm *supposed* to be working on an electric ferryboat,
but you guys have got me completely off on another
tack at the moment - curse you all, and THANK YOU ALL,
again <smile>

I have an idea (now) for a hybrid HPVessel for two
persons, which I hope is not OT here, because I will
try and address some of the design aspects you good
folk have been considering - stuff like cadence and
transmission losses and weeds and ...

I see air props have been verbotten at events. I
understand concerns about safety. Other than safety,
what other concerns might there be, considering an air
prop vs water? As a long-time sailor, I am aware of
parasitic drag in rigging and topsides,etc., but
wouldn't this drag (air props, *cages*, support
structure) in the air be less than the drag of rudder
and struts, etc in the water, because of the different
densities of the two mediums? I'm guessing too
though, that props in the water are more efficient,
because of that same higher density, of water?

You see, I like that Decavitator!... and yes, I know
the derivation of the boats name! I wonder if the
safety concerns and bans would explain the lack of
apparent interest in this List, or are there other
reasons?

What if the air prop was smaller, and there were two
(or more?) of them, something like this:

http://www.marlec.co.uk/products/prods/rut503.htm

Don't know if all can see that - it's a wind generator
with a smallish propellor with a ring at the prop
tips.

I have read a *lot* of msgs all about problems with
rudder/strut/seal/propellor designs and practical
considerations. If everyone were using air props, I
guess there would be a different set of problems to
face!!!

About cadence, and transmission losses... here's my
thought:

I'd like *my* HPV boat to have an electric dynamo
connected to electric motors driving the air props -
two props at least. You pedal the dynamo and the
energy is transmitted by wires to the motor. Not by
u-joints or shafts or chains. Catamaran configuration.
2 persons, plus picnic. drink holders. Recumbent, so
it's easier to reach stuff like picnic and drinks...
and perhaps to reduce a little windage.

My objective is not some speed record... It's comfort
and distance. Perhaps a 5-6kt cruising speed, with
possible bursts to 10K range in frisky mode.

The electric motors and dynamos I'm talking about here
are one and the same. You spin the motor and it
produces electricity.

I've have been trying to educate myself a bit lately
about electric motors. Today we have available
rare-earth, permanent magnets mounted on a rotor,
inside wire windings. These little (and big)
motor/dynamos have ONE moving part, and are claiming
efficiencies of over 90%. I can buy ones off the
shelf today which will run just fine, fully submerged.

So for my little HP cat, I'm guessing an efficiency of
81% between the pedals and the prop? I'd introduce
bicycle gears that I can shift, so there's some more
loss there too...

But otherwise, it'd be an almost solid state
propulsion system? No shaft seals, u-joins, gear
boxes.

... and no rudder. With a little electronics, I
would steer the boat by changing the speeds of the
props. These little electric motors will spin in
*reverse*, if the current is reversed. So now, I'm
backing up, and turning within a boats length if I
wish, just by twiddling the joystick - yeah, I'm
steering and reversing by joystick.

With this configuration, the weedy lagoons around
here would not be so problematic.

Now I fear I'm getting a little offtopic so *snip*
here if you think so...

You guys bring up cadence. And how two persons
need to be "sync'ed", or - de-coupled, if they're of
different strengths (or temperments <grin>)

So at this point, I introduce a little bit more
electronics, and a battery. If the two pedalers are
driving separate dynamos, then they are free to pedal
at whatever speed they wish. If the pedaling isn't
smooth, doesn't matter, `cause the electric smooth out
the power by the time it gets to the prop.

If the plan is to go for a leisurely cruise, the
one pedaler or both can still pedal at frisky speed -
and STORE their power for later, in the battery. In
picnicing mode - boats pulled up on the shore - if
there's some wind, the props turn into wind
generators, and STORE wind energy. Tired on the water
and taking a break from pedaling? Props spin in the
wind again.

Anyway. I'll stop here. I would appreciate any
feedback, very much!!! I'm probably wildly over or
under estimating some simple fundamental law of
physics or the state of current technology <pun
intended>... I was *supposed* to be an engineer at one
point. Went to University, but discovered I couldn't
drink enough to ever succeed as an engineer <smile>

Regards, and thanks, one more time

Laughlin Hughes
http://groups.yahoo.com/group/QCYCTender/

[end of my post to the HPV-Boat folks]

EBoaters? Any thoughts? am I crazy?

by the way, if you read over their posts for the last few years, you
will find TONS, and I mean TONS, of FASCINATING STUFF, about hull
design and construction, rudders and props, etc etc. as it relates to
small and highly efficient boats, by a lot of VERY KNOWLEDGEABLE
PEOPLE!!!

http://www.ihpva.org/pipermail/hpv-boats/

Lock

ps... If you're curious about the reference to "Decavitator", check
this out:
http://lancet.mit.edu/decavitator/
and don't overlook the videos, like this:
http://lancet.mit.edu/decavitator/video/recordRun.better.mpg

 

Lock;

Be careful of manufacturers efficiency claims. Efficiencies of "over 90%" are typically at optimum conditions, full load, low temperatures, ... Your results may vary. Before you get too far along, you might want to verify that you can actually achieve these results at the speeds that you intend to operate and without a cooling with liquid nitrogen.

Cheers;
Mike Schooley

 

Thanks Mike. I'm on the lookout now for a couple of used PM motors from Black&Decker electric lawnmovers, and a 5' prop. Just something to play/learn with onshore - but may come in handy on hot days? Gonna steal the neighbours kids wading pool, set up a test "bench" to measure thrusts, etc.

Trying to read up on (air) props at present. I would be looking (eventually) for motor/dynamos optimized for the rpms,thrust,etc.
I would need - might end up winding my own or commissioning something (LRK's?) Have the plans (and a cheap source for rare-earth PMs) for a d-i-y Savonious rotor wind gen, which sorta ties in anyway.

Boat specs look like this todate:
200lb boat, approx.10ft. beam x 18ft lgth. (including 2 dynamos, two motors, four batts and picnic!), 300lb crew, so 500lb. all up, and can be disassembled for storage. Twin, 5ft. props port and starboard, at the stern. Beams and supports, windsurf carbon spars.

(Debating bow or stern for the props - bow would be cleaner air, and might be nicer on hot days, but harder to light cigarettes <grin>)

See my msg to Ted for more odd ideas re hull construction:
http://boatdesign.net/forums/showthread.php?s=&threadid=784

Cheers
L
ps

dang... there go the plans for the airconditioning.

 

I believe I may already have my drivetrain:
(stolen from the Yahoo Group "Power-Assist")

well, I'm still gonna look around for those B&D electric lawnmower
motors - I have enough bicycle parts to make the test buggy.

Cheers

Lock

 

You mentioned using Bicycle gears?
Do you mean like Deraileur gears?
Not sure I can see the point of that. gears on bikes are really only for hills, to handle large differences in speed (Uphill vs down hill)
In the water you obviously wont have any hills, and the difference in speed between cruising and flat out is only double at most.
I would have thought that you should just set up a ratio that works comfortably at about 60-80 rpm for the pedaler.
Anyone any other ideas on this?

 

Hi Mat

yeah, a guess I did!.. Andreas mentions a 1:16 gear also (fixed, I *guess again*)

Andreas - you assume I have some idea of what I'm tapping about <smile>...
I am, however, tapping about using *air* props, not a water prop. So I was *guessing* that the speed range of the props would be much, much greater than a water prop? Like... 860 times as great roughly?
I'd love to be able to get rid of any gears, really.

Lock

 

Just a couple more links for this thread?

Here's a commercial hybrid human/electric pedal/paddle boat (water paddle wheel rather than a water or air prop):

http://www.2californiablonds.com/energydeluxepedal.htm

and here's a little video of a (semi-?) commercial (?) pedal-powered one person catamaran with an air prop:

http://www.angelfire.com/trek/boat/XTREK3.WMV

as I understand the scuttlebutt, the maker sold off a limited production and is "negotiating with investors", last heard of...

Lock

 

Hey - here's an air prop electric propulsion system that takes this one-man vehicle to over 30kts at a sprint (on land).

Spotted at the National Electric Drag Racing Assoc's "Nationals" event, yesterday:

http://alan.batie.org/photos/nikon/020901_nedra/

Will find/tap with this gentleman, find out about rpms, etc etc. Looks like 4 batts in the stern.

Lock

 

I just wanted to use the pic to illustrate the little "test-bench" I want to play with on deserted island roads this spring... For the record, re the "craft" in the pic:

It's a "Wind Wagon" by Bill Bruder. Some more details:
He hit a speed of 39.17mph on Monday. Had to "throttle back" at 39+ `cause his frontend was going airborne.
(A record speed though, for Bill.)
It has a 62" ultra lite prop built by IVO prop.
36volt golfcart motor running at 48V but "capable of more".
The current motor is series wound.
About 2500 RPMs
The rig dry weighs 247lbs. plus Bill.
4 batts, 48 V NAPA Orbital Deep Cycle Marine

He did three runs down the track and about 30 min. of
himself and others driving it plus cooling people off
during photo shoot. This was on one charge.

Bill figures at 3 to 6 mph he can most likely go two hours on one charge - but he has never tried a distance run (!)

He says it runs well at lower rpms also.

Cheers

Lock

 

Given up on water props...

Here's another air prop boat (hope, at least, some here find this a little amusing):

http://www.tricrides.com/flyboat.htm

cheers
Lock
http://groups.yahoo.com/group/QCYCTender/

 

I saw one of those operating in Sardinia I think- it was way cool and flew very well!

 

*BUMP*

Ahoy all. Long time since alongside here.

Just wished to add/update this thread... from 2002.

Can't say us humans have evolved much in this time, but battery-electrics vehicles and vessels sure have. Can you say "LiFePO4"? <smile>

Anywhoo, the subject is human-electric hybrids and air props for boats...

OK, electrics, but with a human assist... so, on the electrics side of things:

As the internet moves to audio-visual, more of the content is video, so here are a couple of videos that illustrate what folks are up to w/electric air props:
Two videos of a "Razeebuss" in action:
http://paraglidetv.com/video/paramotor-general/razeebuss-aircrafts-1er-deco-moteur/index
http://paraglidetv.com/video/paramotor-general/new-electric-paramotor-razeebuss-aircrafts/index

Hey, if you sail, I'm w/you. These things sound like food processors! But in flight they have to worry `bout chopping lines and legs... On the water, we can afford larger/slower/quieter props.

There is a yahoo group where these bleeding edge fliers hang out:
http://groups.yahoo.com/group/electricPPG/

So, while I am embroiled these days with lubbers that don't understand what personal electric vehicles are about, I haven't forgotten the really important parts of the world (the wet bits...)

Fair Winds and Following Seas

Lock Hughes
human-electric hybrid

 

*bump*