Help needed in building the first boat (pedal powered)

Hi all,
An enthusiast here trying to build his first boat and I am very much interested in building a pedal powered boat, something similar to what is shown in the image.

While I do have the knowledge in basic naval architectural principles, not entirely sure where to start with this project. I have tried to search for a plan for this kind of a boat but it resulted nothing. A guidance from designers here is very much appreciated

Thanks in-advance
Shai

 

Welcome to the Forum Shai.

Are you planning on building just one boat for your own usage, or are you hoping to build a series of them and offer them for sale?

I think that you should start by drawing up a 'Statement of Requirements' - this is basically a list of everything that you want the boat to be capable of doing, such as :
how many passengers it has to carry,
any constraints re dimensions (length, breadth, depth),
preferred construction material,
type / location of paddlewheel(s)

Do you have any links for the boat in the photo that you posted above please?

 

Thank you very much for the welcome @bajansailor

To answer your questions,

1. Yes this is for my own use
2. Linked below is from where I have extracted the image
centerforsurfresearch.org/best-pedal-boats

Thank you very much for pointing out the starting point. Would you mind telling what comes after completing the Statement of Requirements?

 

You could then make a start on your preliminary design.
However the more things that you can define in your SOR, the easier it should be - you might well find that after going through your SOR the easiest thing to do might be to simply buy one of the paddleboats shown in your photo above!

How about listing your SOR here, and members of this Forum can maybe help you with it?

Be aware that it is very difficult to build a 'one off' fibreglass paddle boat as per your photo above - you would have to build a plug and a mould first, hence effectively building three boats to get one (and this is just a simplified way of explaining it).
So you would probably be looking at a catamaran hull form with very simple (re shape) pontoons, perhaps with a square or rectangular midships section.
And it might be easiest to then build it in plywood, if you can get marine plywood in Sri Lanka at a reasonable price.

 

Just to second Bajansailor's comments about a statement of requirements. You don't have to think of this as a formal kind of document, its just to help make sure that you consider everything when designing the boat. There are lots of things that might affect the design; in addition to the things that Bajansailor has mentioned, where will the boat be used? Lake, river, sea? (I'd suggest that a pedal powered boat is really only suitable for sheltered water, as human power is very limited, and will not be able to counterract the effect of a strong wind blowing the boat in the wrong direction) Will the boat be transported on land? By vehicle roof rack? trailer? trolley pulled by hand? Will it be kept on the water? on land? undercover? What tools, skills, materials are available to you? The design that you show is for a particular purpose, and there are many other sorts of designs for a pedal powered boat that may well be more suitable, depending on your statement of requirements.

 

2 years ago, Shai, I was in a similar position to yourself. Now I'm coming to the end of my second summer of sailing my pedal powered boat! I only wanted a one person boat for the canal, which is always calm. I was comfortable to use a sheet of aluminium for the hull and had the ability to weld my mechanics for a rear mounted paddle wheel. Yes, you need an SOR stating your use. How many will use the boat, how will you get it to the water etc. You also need to be honest with yourself about your ability to construct whatever you design. I wish you good fortune. I have great fun in my boat and use it often. No home should be without a pedal powered boat.

 

I would just get one of those catamaran paddle boats and then build your pedal system on it.

 

Another quick forming option is to build it in solid works and then 3d print it in sections and make the pieces modular. Gluing them together with epoxy. The programs create pieces that give the ideal 2mm gap between 3d printed pieces for epoxy gluing. Of course each piece would need slotting to snap together with 2, 1mm epoxy coat and most 3d printers are only 2x3 cubes.

 

Curious why you picked that particular design to build, from the many hundreds of examples that are available for study on the internet? These type are fairly commonly rented in the USA. If you can get to a place nearby in the country where you live to rent one, you can try one out to see if it is really what you want. That might help with your SOR, when you realize what you like and don't like, about this one compared to any other boat.

 

@portacruise

Thank you for your reply. Where I live, these kind of boats are not very common. You could only see them at lakes and rivers popular amongst travellers and tourists.

As for the design, I was just browsing through the internet and came across this. Felt it would be easier to model this kind of a design using a CAD tool, as it seems more boxier in shape.

 

@bajansailor @Tiny Turnip

I have come up with the below details for the SOR. How do I go about the preliminery design? I believe I got okay CAD skills and I need to combine these info with the design now.

• Dimensions

Height: 2ft
Length: 7ft
Width: 5.5ft​

• Material: Fiberglass
  
• Weight: I am hoping it would be somewhere around 50kg, correct me if wrong
• Carrying capacity: 2 pax/ 220kg (to be on the safe side)
• Propelling mechanism: Pedal operated propeller at the front (the exact location is tbd, trust it would be easier to determine it, once a CAD model is in place)
• Operating conditions: Calm fresh water
• Additional info: hoping to carry it using a trailer when necessary, should have the ability to be taken in and out from water when and where necessary. I got good woodworking/ metalworking skills and have access to the tools.

on a side note, talking about expenses, at this point of time nothing is cheap in the country. Inflation is sky high, many people are fighting for the daily survival. Pretty much all imports are restricted and much like we are heading back to stone age.

@bajansailor What I have gathered might not be alot, but it sure helped me to understand the problem better. Thanks for beaming me light in the dark

@Tiny Turnip you were right, while I was going through the small SOR I have created, I have understood that what I have shown above in a picture might not really be the ideal design for me.

While thanking all for your valuble comments, your further thoughts are very much appreciated @Andrew Kirk @John Rivers

 

I would have a look at some precedents now, which should give you some ideas.
There is a *very* long thread here, which would take a long time to read fully, but would be good to have a look through for inspiration. Pedal Powered Boats https://www.boatdesign.net/threads/pedal-powered-boats.23345/

Are you limited to the dimensions in your SOR? The reason I ask is that a boat of those dimensions will not go very fast, if that is important to you. For speed, a very much longer, narrow hull (with outriggers) would be the way to go. If you wanted a stable platform (for fishing, picnics) perhaps a catamaran would be good. There are numbers of monohull designs in the above thread, too.
The hull can be relatively simple in shape - perhaps a straightforward square cross section.
The drive mechanism will need considerable attention. There are many drives based on bicycle components. You have seen Andrew's stern paddle wheel above, which is particularly suitable for shallow and weedy water.
Rick Willoughby, who set the thread up, is a leading authority on pedal powered boat design. His focus is on efficiency and speed. Have a look on his youtube channel. Some of these boats are the fastest around, but will not be good at load carrying, and will not be very manoeuvrable.
https://www.youtube.com/user/RickWilloughby

 

@Tiny Turnip
I will go through the thread, thanks for the link.

I am not limited to the dimensions I have mentioned. I came up with the numbers (with the aid of some references) as I have a boxier shape in mind (be it a mono or a double hull). Speed is not a concern of mine, I would rather prefer a good stability at slow speeds plus the boat has to be kid friendly as well.

As you rightly said, driving mechanism would need a thorough look as it should not turn out to be a painful experience during the first couple of minutes at least.

And I am planning on a hand-lever to control a simple rudder for maneuvering.

I need to finalize a hull shape, appreciate any leads or means which could guide me to come up with the initial hull shape. A plan would be god given really. (As I have said, I believe I got good CAD and CAE skills and very eager to get to that stage.) Trust the rest can be taken care of, afterwards, step by step (?) @bajansailor @Tiny Turnip

 

• Operating conditions: Calm fresh water
• Additional info: hoping to carry it using a trailer when necessary, should have the ability to be taken in and out from water when and where necessary.

My view is that it will be about practicality and safety, even if high speed is not a consideration, being used in calm fresh water. Unless the river or lake area is very small and protected from the wind, someone (especially children) is likely to drift away if there is significant wind as there won't be enough human power above a certain limit like 10 mph winds. Also, Most trailers cannot be used in Rocky or rough areas of Shoreline, they usually require a paved boat ramp, with the downsides of waiting in line, trailer licensing and maintenance, etc.

FWIW, I have rented that type of pedal boat as well as the propeller driven sea cycle a few decades ago when I was a young and strong man. The seacycle was far superior in requiring less human effort for any particular speed whether it was in smooth calm water, wakes from other boats, or windy days. Rick's boats mentioned in the above link are considerably more efficient than that old seacycle design. Once when I was out on a rental, some of the Paddle Wheel rental boat's passengers had to be rescued from across the lake when the wind caught them.

 

Bro. I'm telling ya. Get one of those stand up paddle cats for about a grand and put a pedal powered propeller with a hydrofoil above the propeller on it. You will be golden.