In order to figure out where the plumbing needed to go for the aft bunk sink I needed a rough idea where it would go, which is against the wall (non structural bulkhead) I have yet to fit that will also have the doorway into the stateroom. I know where that wall will go so I ran a beam of timber to act as that wall, clamped a door cut out to it to simulate the doorway and that gave me an idea where the steps would run down into the hull. Because of the angle of the wall to the hull (about 45 degrees to centreline) the steps naturally lead you on an angle forward into the hull. This is critical. As are the step heights. It is hard enough climbing up and down them on a boat on the hard, let alone into a hull pitching in a seaway so getting the steps right is very very important. It took me all day to get this right.
First I needed to make some mdf braces upon which anchor the steps temporarily to the hull (they will be glassed in once I am satisfied with their shape, height and position). The kit includes pre cut step treads so as a starting point I used some of these. There are a couple of different shapes, I am not sure why, I didn’t mark them when I cut them from the panels, I am not really following the plans for the furniture as I did not buy a furniture kit so it does not really matter, if their shape works I use them if not I adapt them or make my own from offcuts. I actually found that the shape worked well, it has the angle of the wall already cut into them, also the angle of the cupboards that butt to them on the inside of the hull and allow for the natural angle that I need for the stairs to “work”. By work I mean direct you down them in the most biomechanically efficient way. But I did not know this when I started, the process of setting the steps taught me.
The stairs on a cat or any boat for that matter, often require contortionist like manoeuvring down them. Getting up them is easy as the gap opens up as you climb but coming down is much more difficult. And you need the steps to draw you down them in such as way as to turn you as you go down them so that you naturally avoid hitting the cabin side as you go down them. And because the platform to which the steps jut out from is the angled chamfer panel it is all the more difficult to get the tread heights right, the shape right so as to lead the feet and the body down correctly. I started with the obvious starting point. I centred the first tread on the middle of the chamfer panel. It is aesthetically the best position but the fall from bridgedeck to the first step is about 200mm and the fall from the first step to the next step, which falls right on the chine is about 250mm. But because of the angle away caused by the chine, the further down you put the step the larger the gait needed to hit that next step so although the fall is less the stride is greater.
I experimented with moving this first step up and down but in the end I settled back on the original position in the centre of the chine. It works best and looks best. I used a milk crate to simulate the bottom step but next job is to set the bottom step. This took some time.
At first I could not get down the steps without turning my body as I went down and kind of crabbing down. Going down those steps will become second nature and learned behaviour but for guests that will only experience them every once in a while I want to make them as easy to negotiate as I can. I could not understand why I could not get down the steps easily at first. And then it occurred to me. The position of the bottom step, at this stage a milk crate was not drawing me down the steps correctly. I had it positioned for minimal footprint in the companionway and directly below the step above it. It needed to be forward of the step above it so it turns you down the steps after you have cleared the side deck to cabin side corner with your shoulder.
So next I had to ascertain the correct shape for the bottom step. The milk crate had taught me that my foot wanted to fall out from the hull so another step of the same shape would not do. It would need to be bigger at one end. The downside of this is that it protrudes into the companion way meaning anyone walking from the rear bunk to the ensuite would need to walk around that step that protrudes a long way into the hull. And with any sort of cupboard against the hull outside making that squeeze even tighter. I cut a piece of mdf to what I thought would roughly be the shape I needed. I was pretty close, but the milk crate was not quite the correct height. I split the difference and came out with 2 325mm steps. This wasn’t working. It was just too far to step. But having 650mm fall from the chine step to the sole meant that ideally I need 2 more steps. But this has its own problems. Each step has to protrude out from the step above, it cant just be directly below the step about. And there is not much width in the hull to accommodate this. I worked out a solution. I settled on 250 mm drops for each (from chine to bottom step and bottom step to sole) then I would raise the sole height in this section by 100mm. Problems solved.
After a bit of experimentation with the step shape I had it. I made the duflex step much bigger than the mdf step and slowly worked down with a series of curved lines until I had the shape that would work. I watched where my foot wanted to fall naturally and ensured I did not have my toes over the line when I stepped. I tried the steps over and over until I was satisfied I had it right. I then cut the most appropriate shape. The other consideration I had was the way the aft stateroom door would swing. It was easy to decide it had to hinge to the outside of the hull so that the door did not have to be walked around to get in or out. But it could swing out into the hall or into the room, there is enough space for it to go either way but it would be very cramped inside the stateroom if I put the planed step up into the bunk in place. It will double as a chest for packing clothes or a duffle bag and a seat to sit on to put shoes on or just sit before or after bed. So out was the optimum. In order to swing out I had to be sure the swing of the door would clear the step, so i put a curve in it to accommodate the door swing and the shape worked aesthetically too and also worked ergonomically as a step. All good.
To finish I put timber and panels in place roughly to simulate the furniture that would surround the steps when all of the furniture was in place around it, then retried the steps over and over. When Jo arrived to pick me up I had her try them too. She is much smaller and had no trouble at all clearing the angles and getting down the steps. Getting up them is a breeze for everyone.
It does not seem like much work for an entire weekend but it was a lot of fun and I did spend a lot of time daydreaming about how various walls, steps, doors, sinks etc would work in practice. And not a piece of it was actually glued in yet.