Pedal Powered Boats

I find stick welding stainless easier than mild steel if you have the right rods.

I use stainless nuts ganged or stainless rigid coupling or a combination of them for my hubs. Coupling nuts are also a possibility. These options are heavier than normal tubing and are hard to blow away when welding. The blades are usually made from 40mm wide by 3mm thick stainless flat bar or their close equivalent in imperial size. I would design specifically for the material you can get but this size is close to the right proportions.

The shape is not absolutely critical. The range of performance will be around 80 to 87% efficiency depending on how well you can achieve the foil shape. The 80% would be for a tapered and curved leading edge and a pointed trailing edge. It is not that hard to achieve a good foil because you mark up grind lines to work to. Just takes a bit of time and care. I use a sanding disc for rough finishing and then hand sanding to get really smooth. You can always come back to it after testing anyhow.

The idea of the engine calibration is to get the desired cadence and the power level. I then make the prop to match the engines to the boat. In this regard I could adjust the prop design to suit different engines if needed. Remembering that different thrust will need to be corrected by some constant helm to track straight. The drag associated with this will be small. You could use a single rudder much smaller than you currently have.

There are some photos of a prop on this link showing how they can be fabricated:
http://web.mac.com/cschaffh/iWeb/HPB/HPB Drive v2 Build.html
This was a three bladed prop but a 2-bladed prop would be best if there is no diameter constraint. I doubt that they would be any bigger than you currently have.

Rick W

 

More engine tuning. A perfect day last Saturday. Close to dead calm throughout the morning. Temperature around 20C.

I finally got the cadence sensor mounted on my new frame so the Garmin Edge is now giving me the full data set.

I covered 25km on Saturday in a little under 3 hours. Weed still an issue so a brief stop at either end of the lake to clear the prop. This reduces the average speed but I am getting the muscles used to a bit of exertion again. The bottom bracket is set further out to get legs flatter so some new muscles are being trained. The calves were noticing the change after a couple of hours.

Rick W.

 

Last weekend was spent at Ocean Shores, WA, USA. Saturday morning had a race on Duck Lake, Sunday was a poker paddle.

The race was pretty fun. Unencumbered by a camera or taking photos of other racers, I was ready to fight for first place overall. Unfortunately, a last minute adjustment of the Cadence chain tension proved to be my undoing, as I apparently didn't tighten the eccentric clamp adequately. Very soon after the start of the race the chain started skipping and I had to return to the dock. After running back to the car for the tools, tightening the chain again as well as the clamp, and returning the tools to the car, I started the race over again some 15 minutes after the official start.

It was fun catching the other racers, cheering them on and then leaving them far behind. I ended the race almost exactly an hour after the official start, and in 7th place overall. If I had not had adjusted the chain originally I probably would have finished in first place overall, beating two men in an OC-2 as well as breaking my record from last year. My average speed was about 6.8 to 7, and it seemed that the boat had slightly less drag with the foil rudder as I moved through 7 mph.

The Garmin Forerunner was an excellent tool in terms of keeping me focused on pedaling at a constant rate and moving the boat at a relatively constant speed, without the need to have targets in sight on the course. This year both GPS units were on and recording throughout the race. I have the results posted on my web site but at this moment my ISP is having troubles and it is not connected to the Internet.

My wife took our two kids who are still living at home in the Escapade and raced also. They had a good time pedaling around the course, and my daughter helped pedal on the return leg.

The Poker Paddle was a nice jaunt back through Duck Lake and into the tree lined canals of Ocean Shores. There were a few weeds, reeds and branches, but generally it was a great place to pedal from stop to stop, picking up sealed envelopes containing playing cards.

Between the four of us only my wife managed to get a decent hand, which was good enough to claim a gift certificate to a restaurant in Seattle.

The final event was a cardboard boat race, where teams take sheets of corrugated cardboard, 2 inch packing tape and box cutters and put together some sort of watercraft in an hour. When the hour is up the boats are launched with a single paddler who then tries to head around a buoy a hundred feet or so from the launch point and return.

It was quite fun to watch!

Michael Lampi

 

Mike
It was a very consistent performance. Average certainly seems a little higher than previously. Good result despite the slow start. Nothing like having good engine data. Will help you determine the immediate impact of current if weed is not an issue.

Is the new rudder any twitchier than the bigger plate from the perspective of dynamic stability?

I am still trying to get some fitness.

Rick

 

At this race I only paused for a moment as I passed the Escapade carrying my family so I could greet them and pick up a tube of sunscreen. Following that I spent a little time applying it while pedaling down the course, which contributed to a slightly slower time for the first part of the race. I felt pretty strong throughout the event, and the general lack of weeds was quite welcome.

The rudder is very sensitive in the forward direction, providing perhaps even more dynamic stability than the plate rudder. There is definitely much less speed loss in sharp turns than with the plate rudder, though I'm not sure it turns as sharply.

In reverse the foil rudder is still nearly useless, unfortunately.

Michael Lampi

 

Mike
You will find the sharp trailing edge on the rudder will cause it to stall at low angles.

Next time you get an opportunity, go slow astern and gradually work the rudder off centre to full lock and then back to centre. You will find the best turning will occur with around 15 degrees. More than this will be worse. If the linkage is in any way sloppy it will be hard to keep the best angle. Jiggling it in and out of stall will increase steering. You soon learn the best point.

Reverse steering can be improved by rounding the trailing edge but this adds a little extra drag going forward.

Rick

 

Up and running

Got the boat on the water today at the rowing course in Carrum. First time with the current fitout nothing broke or cracked, did 4 runs along the course at a comfortable pace and it took 17 min to do the 2km course. Going out with the wind and coming back into the wind the times were almost the same.
Gives me a speed of approx. 7km/hr so room for improvement. Still needs some adjustments with seat position. The rudder is 220mm wide by 300mm deep, on the big side but any smaller and it takes forever to turn.
On the subject of rudders I saw in a book that some of the early destroyers
(1900-1920) had an extra rudder at the bow to make them more easier to handle. How much would an extra rudder at the bow help? When I go backwards the boat turns a lot tighter, would two small rudders with area
smaller than one big one be better?

Ian Cassell

 

Ian
I do not know why it turns better going astern. That is unusual.

The prop shaft strut is quite large and will resist easy turning because it is close to the stern.

Your boat would turn easier with a bow rudder but it would create a tipping feeling. The centre of effort on most rudders is usually well below the centre of gravity of the boat. When you apply initial helm the rudder force and boat momentum produce a rolling couple. If the rudder is on the stern the couple causes roll into the turn whereas at the bow it causes roll out, so initial tendency is to roll you over. The faster you go the more noticeable it is.

Rick W

 

Thought I would revive the thread with some of my weekend activity.

On Saturday I did a couple hours in nice weather. Light breeze from the south had pushed most of the weed up the lake so I was able to get a reasonable average. Only interference was salvaging a fuel powered model boat that had stopped some distance from shore - I claimed salvaged rights but the owner would not think kindly of me given it was worth close to AUD2000.

On Sunday the late model engine, Jeff, had a spin to get some baseline data. Jeff is the current 12 hour cycling distance holder in Australia and wants to try for a record on water. He can hold better than 160bpm continuously over 12 hour period and is working on sustaining that for 24 hours. You will see from attached that he can push along around 11.5 to 12kph at the level.

The other thing to see is how significant a 30kph wind becomes when it is on the nose. It sprung up about 40 minutes in and we called it quits after that. The other feature that is noticeable is the increase in prop slip as the breeze comes up.

So got my endorphin dose and did some alternative engine evaluation.

Rick W.

 

Rick,

The performance I see with you and Jeff pushing your boat doesn't seem to be a whole lot different than the performance I'm seeing with my Cadence.

I suspect that if my boat were the weight it was supposed to be, i.e., low 70 pound range, it would be about as fast as Jeff's performance on your boat with me as the engine on my boat.

All-in-all, I think Gordy Nash's boat (a failed rowing shell design) at 27 feet length is still about the optimum length and configuration for a distance speed record vessel.

You need a longer, weed-free lake.

 

Mike
I was working hard in my effort but Jeff only had one period when he was putting in any real effort.

From my own data, V11J is around 1kph faster at the same power level than the Cadence I used in Seattle. It would have been good to do longer comparisons but time did not permit. I think you have made improvements to the rudder since I was in it. I believe your recent times have been better than ever and I expect if you continued to shave weight and optimise things you will be competitive with rowing sculls on the distance events even in good weather. The Cadence is also more streamline for airflow. From my chart you can see the impact of wind no more than 15kph. Jeff's last loop was in very strong wind. I do not have the muscle strength to hold my speed in such wind. Jeff finds 150 to 160bpm not anything strenuous. He would be working over 180bpm for strenuous effort and this would see around 14kph in calm weather. That would be the one to two hour speed.

I was a little surprised at Jeff's heart rate but he has only used a heart rate monitor once before. That was in his 12 hour run and he sustained between 160 and 170bpm for the entire period with one very brief stop. This sort of level would kill me. The reason we did the run yesterday was to get a baseline on the boat so we can estimate what will be possible with the boat by comparing data from his various bike events. He is also working on his water and food intake to go 24 hours.

Jeff is quite young and has only started to think about proper training for long distance events. I expect as he gets to optimum age and with improved training his heart rate will drop for the power level.

V11J is optimised for 12kph. Greg's target speed for the record was 11kph. His average ended up at 10.2kph. If he had sustained 11kph he would have done 264km. My next boat is shorter and a bit lighter. It is all carbon fibre and foam sandwich. I aim for 15kg total.

If you had a world class athlete who can sustain something like 200W for 24 hours then the 28ft boat might work out optimum. Same person in a Cadence would do better than Greg did for sure. Greg's average overall was not a lot over 100W.

Like you, weed is a significant factor from time to time for me. Over the next few weeks I will be looking for a weed free lake. The Murray River does not have the long weed that I have in the local lake. It has got worse in the last couple of years because of drought conditions.

So the Cadence engine is in good shape and could probably get better with proper tuning and the Cadence is already a very good boat but could do better if was made lighter. By the way I have made test panels of carbon fibre and fibreglass sandwich and the comparison on rigidity is staggering.

Rick W

 

Mike
I also took video of Jeff before the wind came up. It was taken as he passed on the second lap. He is doing 11.5kph in the video and heart rate was a bit over 150bpm. You can probably guage from his voice in the attached video it is not a difficult pace for him. He had collected some weed at that stage as well.

I did not ask him to go as fast as he could. I asked that he hold above 11kph but not exceed 12kph. He may be able to sustain 12 or higher continuously but I only wanted a baseline that was good enough to do 250km or so over 24 hours.

Rick W

 

Outriggers as rudders

Started construction on my new boat, a 5m x 300mm beam outrigger. This boat I will sit on top and position the outriggers forward of the cranks, about 1-1.5m forward of midships. What I'm going to try is using the outriggers as rudders, my thinking being outriggers are in the water already so why put another appendage in the water. The pivot point will be controlled by wires or a lever at the seat and the outigger pole fixed to the pivot bracket. The outriggers will be 2m long x 100mm beam and 200mm deep with about 10-20mm in the water, how hard it will be to turn I don't know but at least being summer if I go for a swim it won't matter. The hull will be fully decked in so no problem with water getting in.

Ian

 

Ian
What is the building material this time?

I went out to the Blue Rock Pool today. It was blowing a gale when I left home and the same when I got to the lake.

I mooched along the sheltered shore in the north western corner but even that got a little rough. I could not find the entrance to the river valley. Or more accurately I was not prepared to dodge the dead trees at what I believe was the mouth in the strong winds. Wind was actually strong enough to have me worried about it lifting the boat and rolling me.

So not a good day out. I will look for better weather before I go on another trip looking for a nice lake. Spent three hours driving in total for 5km on the water. Not a good ratio.

Rick

 

New Boat

Rick
New boat is made from plywood and of hard chine construction. Camera has stopped working so can't show any pics at this stage, looks like a new camera. I'm putting the shaft through the centreline and making it a curved shaft. Still early days yet but maybe in the new year it might be ready. Boat dimensions are ,length 5m, beam 300mm at deck, 250mm at chine. Outriggers are 2m long, 100mm beam.
With your search for lakes one I know of is Lake William Hovell, went there a few years ago and it is a great spot. It is on the upper King river south of Whitfield, not a large lake but is for non powered boats only and is in a valley so is sheltered. Camping is not allowed at the reserve but if you talked to Parks Victoria you may get permission. With the drought it is a real problem as there are some lakes that have completely dried up.

Ian