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by Mike Machnicki - London - England

Going Off Plan ā€“ Part One

About Me

Part One - Part Two

Now comes the scary moment when I start to design to my own requirements, with no training as a marine architect and not even the appreciation of form of an artist. I do however know what I want, and have some technical skills. The assets that will get me through are an over-inflated sense of my own abilities and sheer doggedness honed through thousands of hours grinding through computer code desperately trying to get it working.

Up to now the hull has been built exactly to the plans. Having the correct size and shape is important as it gives the known characteristics the designer calculated. I would have liked to increase the length and width but was unwilling to risk building a boat that may not perform correctly, and may even be dangerous to sail under certain circumstances, though I doubt I have the experience to even know what these conditions would be.

The interior and topsides are a different matter. To start with the boat was designed as a trawler with a fish hold, the description states: "The hold has a surprising 140 cubic feet of volume that will take on a couple of tons of fish or other cargo with ease." Swapping this for living accommodation should not have such a drastic effect. The designer told me the waterline was placed at about half this load, so going out empty the boat would be light and coming in with a full load of fish it would be heavy. I recon the extra structure and equipment would come to about the right weight at about the midpoint, and I can always change stowage of gear to ballast her correctly. Most of the weight is in the engine, tanks and batteries which are amidships and hence in a good location near the centre of balance, but the windage will be increased with the slightly higher and larger pilothouse and the sleeping accommodation forward.

It is a far easier task to follow plans, they tell you not only where to put the wood but what size it is to be and how to join it (what joints to make and fastenings to use). Going off plan means that you will need to consider all of these questions yourself rather than just following instructions, and I have spent many hours trying to figure out how to build the accommodation and the further time on how it should look. This is also to some extent unknown, as a few degrees or inches can make a big difference to aesthetics and the human eye can be very discerning, a big challenge if you want the boat to look right, but aren't sure what right is.

There eventually comes a time to make a commitment and take the first step, but the big question is where to begin? I had considered this many times and finally decided the best place to start was with the scuppers in the transom. I know it sounds strange, but this really was the best place to start. It was a momentous occasion, and one that made my heart beat a bit faster when I started to drill holes in my pristine hull - I didn't count the propshaft tube as a hole in the hull. The good part was that these holes were part of the original design and would decide the height of the cockpit floor, this would need a hatch for access to the rudder stock and quadrant. From here the height of the engine was the next constraining factor, which would give me location of the wheelhouse floor, this would then provide me with the height of the wheelhouse and bit by bit the rest of the structure would follow from these measurements. At least in theory, let's see how that developed over several weeks.

Of course what I haven't mentioned yet is that need to bear in mind all the other systems that will need to fit, (or not - if you get it wrong) within this structure. For the moment I am looking at providing a smooth cockpit floor with scuppers in the transom, with sufficient supports to make it rigid and it also needs to look neat and tidy.

Cockpit support structure, not glued in position yet as access is needed to finish the sides and transom.

As soon as I got the supporting structure made and temporarily fitted the thoughts hit me:

  • What about the hatch to access the rudder bearing?
  • How big will it have to be for the steering quadrant to fit through?
  • How do I make it watertight?
  • What sort of steering will I use and how do I clip it to this structure?
  • Will I be able to connect the exhaust hose?
  • Where can I fit the gooseneck for best maintenance access?
  • Can I put some buoyancy foam in here?
  • Will any of these items interfere with each other?
  • Do I really want the exhaust behind the boarding ladder?
  • What else havenā€™t I thought of?

Then anxiety began to set in and I considered all the other items I was designing and how they would all need to mesh together and support possibly conflicting requirements. It must be noted that this pessimistic scenario of self-doubt was written at a time when I was feeling rather low owing to lack of progress, despite the good weather, this was mainly due to levelling up the trailer and finding no room at the top of my boatshed for the superstructure when I get to that point; difficulty getting into the boat to work due to the height; a longer than wanted walk to get to the garage where the tools and materials are stored - forgetfulness due to age means that I need to make the trip at least twice for each task. Enough of this negative attitude and let's get to work in the bliss of ignorance and sure knowledge that everything will eventually fit somehow.

Wheelhouse levels, looks like plenty of storage space!

Having decided on suitable floor levels, there is a 9.5" step up from cockpit to wheelhouse, good for keeping the water out when the boat is pooped, though I must say with 43" freeboard at the stern that would have to be a bigger wave than I ever hope to meet. The height of the wheelhouse floor is decided by the clearance needed for the engine and this leaves a huge space for tanks, storage of folding bicycles, etc. The other option would be to have the floor lower and have an engine box sticking up, which is both ugly and cumbersome for access to the head and bunks.

View forward. Again looks like plenty of room for shower tray and possibly a flexible water tank. All of these spaces will also have some buoyancy foam installed.

From the wheelhouse there is a step down of 19" (3 steps) to the front of the boat. Assuming the inside headroom is 78" in the centre throughout (less 2" for deck beams supporting the roof), this gives the forward window available height of 19", with a window height of 21" (as the window is raked forwards). I would have preferred to have bigger front windows, this could be done in several ways:

  1. Reduce headroom at the front;
  2. Increase headroom at the rear;
  3. Make the engine space higher;
  4. Make a step for the steering position;
  5. A combination of the above.

Remember the conflicting requirements I mentioned, well these are some of them! Best to sort them out at this stage rather than when the wood has been cut, or even worse glued in place.

So far it looks good in principle, but the acid test is when it's all put together and you walk through it and try using it in rough weather. There are a few minor adjustments I can see at this stage. The step up from the cockpit may need to be two steps. The instrument console is also very high at 59" (78" headroom less 19" step down) so adjustments will need to be made. My inclination is to add a couple of inches to the wheelhouse height and make a 6" step for the steering position, this will also make it easier to exit through the side door. There may also be insufficient headroom going forward, so the first step may need to be cut into the wheelhouse floor.

It all looks good, so at this point lets finish off, in the next article I will see how it works in practice, first jobs are to extend the height of the boatshed and order the framing timber and sheathing ply. I hope to have the shell fully waterproof, if not painted, by autumn so that I can work inside during the winter.


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