My boat build is officially (almost) finished! When I launched my first incarnation of my home designed, pedal powered boat I’d painted it all nicely. Unfortunately I had to try many different versions of all kinds of parts of the boat so it ended up looking rather battered. After several successful trips, including using a big pedalling force to test durability, it was time to tidy things up. I’m hoping for continued reliability now I’ve learnt so much about the boat and have painted parts in 2 colours. The metalwork is silver and the interior woodwork and paddle wheel are red. I still need to sand and revarnish more woodwork but apart from that it’s complete. I had a few surprises during my development, not least of which was how strong the pedal and drive mechanism needed to be. I managed to retain the components but had to add lots of bracings which, whilst not elegant, have had the desired effect. The pedals push and pull long connecting rods to turn the paddlewheel but apart from that the 2 ends of the mechanism are mounted independently and use the strength of a longitudinal timber to hold them at the correct spacing. I hope, probably next spring, to take the knowledge I’ve gained to build a mark 2 version which will use a steel structure from front to back to eliminate possible flexing. I’d also make the gunwales (top sides of the hull) less fussy and set the long connecting rods wider apart for more shoulder room for the pilot. Since I’m now confident that I won’t be sinking the boat on calm waters I won’t bother with the front foam filled flotation chamber. Today I sailed for 3 energetic miles to see what I felt like after a boat based workout.
The boat soon picks up speed and can be pedalled gently, taking similar effort to walking. At this level speed is probably still over 2 mph. Applying more effort does up the speed but you need an exponential rise in work rate as speed increases. As a cyclist I enjoy putting the work in so today tried different amounts of force applied to the pedals. I worked at a medium effort but it didn’t make me breath more than a fast walk would do. I counted my cadence (rate at which the pedals turn) and found it to be 31 rpm. This seems like a wall. It’s easy enough to reach nearly 30 rpm but impossible to get much beyond 30. What does happen, though, is that the resistance in the pedals builds massively. It’s like climbing a hill by bike in too high a gear. The muscles feel it but the lungs don’t. I sailed towards Liverpool for over half an hour to Ellerbeck boatyard before turning round. I’ve added a new pad to the seat and only on the return leg did I start to shuffle around for comfort. I noticed my breathing was increasing somewhat but nowhere near what I’d experience on a mountain bike ride. I pushed harder on the return leg but analysing on the app. Strava revealed that my efforts made no discernible difference to my average speed. Since the activity is muscular more than aerobic I decided to slow my pedalling and reduce the effort for the last few minutes. I could not only feel a little cramping in my calves but could see a deep dent in the muscle as the muscle contracted to a knot. The cramp didn’t develop into anything debilitating and I pulled the boat out of the water to take the pictures.
I could gear the paddlewheel down with a chain and sprocket arrangement but think that around 4 meters of greasy chain would be far less appealing than my long metal connecting rods. I intend to pace myself on future trips to give me valuable exercise. It may be less aerobic than cycling but I could tell from the feel in my leg muscles that there are some real training benefits to turning the pedals at such a low cadence. I believe that I’ve identified that I may be using too low a cadence in my cycling so will do some studying and see if I can improve my technique. This has been revealed to my by boating. Who’d have imagined that? I’d covered 3 miles, measured via Google Earth, in just over an hour.