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Having used the PB a few times, I discovered that my original launch plan was not that viable, this being to assemble the boat at the waters edge then put it in bow first & then put the engine on. This works great where you have time & space to do it, but is not so good at busy slipways when that is the only point you could launch from.
So what to do ? Well the obvious answer would be to buy the PB Porta-Dolly, but this looked like an expensive option in the UK & having read various complaints about them & the boat falling off etc I decided that I could do better & for a lot less !
So the home made dolly was born & was a partial success, this was based on some, basic trials in my back garden, which is flat & without the engine. These trials led to a minor embarrassment when first used on the slipway. The original MK1 wheels were smaller & of solid construction, they fitted under the dolly on the other side of the steel axle supports from the current version. They had no vertical support & whilst I had calculated that a steep angle might well tip them under the boat, it had passed my tests in the garden. First use for real & a strong wind, meant that I had to build the boat facing into the wind, which was across the slipway. Everything was fine, until I mounted the engine & tried to pull the boat round so its stern was pointing down the slip, as soon as it started to move across the slip, the downhill dolly tripped under the hull in slow motion. No damage was done, other than to my pride :) Once turned & facing down the slip it all worked fine.
The next problem was getting the wheels off the hull once it was afloat. I had them connected by a length of shock cord & an alloy bracket that clipped over the gunnel, this was to stop them falling off in the water. Unfortunately they were harder to get off than I expected, so instead of just popping the bracket off & expecting them to fall free to be lift on the shock cord, they stayed put ! So I had to roll up my sleeve & plunge my arm into the water to get them off :(
These events prompted the modifications from the MK1 to the new improved MK2 Walker-Dolly below :)
The main structure is that from the MK1, it is 2 pieces of pine plank glued & screwed into a 16" L shape. Then I added 2 small strips one on top of the other to get the right height on the horizontal piece to grip the tube edge & spread the boats weight. I added another piece to the inner edge of the vertical piece, to create the correct angle to leave the wheel vertical. The wheels I bought, they are pneumatic, so spread the load nicely & grip well. The vertical stabiliser arm serves 2 functions, one is to allow the web strap to be connected to the top of it & two to act as a handle to remove the dolly when afloat. The web strap has half a fastex buckle on the end & mates to its other half on the other dolly, just click together & pull the lose end tight to ensure that the dollies will stay in place.
I mount these dollies, so that the wheel axle is in line with the middle of the rear seat, this allows the load to be spread through the hull & stops the support arms flexing. This setup works well with the engine mounted & allows the boat to be assembled by the car & wheeled to the water with ease.
Some people have asked for measurements, so here they are. Above is a JPEG diagram, the Black lines are the dolly, the Blue lines are the measurement extensions & the Red figures are sizes in mm, fitted between the blue lines, or on the end/middle of a red indicator line. The three main wooden parts are all made from 18mm planed pine available from your local DIY store. The axle strut is 6mmx30mm steel bar stock. The wheels I have fitted give 240mm (approx 10") ground clearance when in place.
I have had one comment that the pneumatic tyre would making fitting & removing difficult, this is not the case. Unlike the Porta-Dolly, the Walker-Dolly will not sink ! To install in the water, just place by the side of the hull & push down on the brace until the channel has seated over the side tube, then connect the top strap. To remove after launch, just undo the top strap & push down on the brace & twist to unseat the channel from the side tube. I build the boat, then put the dollies in place next, before adding gear & engine. I have only used this dolly to launch on hard ramps, but it has crossed "car speed bumps" & one ramp has a host of conflicting angles on the way to the slipway & it has worked fine on these, even on bad side angles. I'm fairly happy that this dolly will work on sand & soft or rough ground with no problems.
Below are a selection of pictures with the walker-Dollies mounted on my 10ft boat.
As you can see the Walker-Dolly leaves plenty of ground clearance & spreads the load into the hull over a large area. The under hull shot shows how the Dolly hooks onto the hinge tube of the boat.
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