Pages

Sunday, October 26, 2014

Building a 40' steel Pilothouse sailboat. Puzzle.













- Boat design and building are like putting a puzzle together.

- But it has to be assembled in a certain manner to achieve the expected end result. Usually referred to as the "Design Spiral", but more about that later. To put a boat together requires a lot of time, patience and not to be lazy and afraid about checking, checking, and also about double-checking. The best way to save precious expensive time is to start with a very clear statement from the client about function, purpose, destination, proposed budget, and any other provisions that might alter the almighty weight of the vessel. I have seen too many times where you start for the client with a Colin Archer and end up with a daysailer! It is crucial to narrow down early into the project The Choice. Trade-offs and options will come soon enough. To illustrate, I am presenting L'Oceane 40', an Offshore boat with all the characteristics of a proper yacht with a look that demands respect. Respect of the sea being foremost in the delivery.

- It always starts with a drawing, and as mentioned above a good description of what is expected. If given a free hand as far as the overall boat, it is important to nail down the type of accommodation plan as soon as possible. Yes, many boats are designed from the inside-out as shown with the shoe boxes production so prevalent these days, and this one is no exception except for the fact that by design the look can be rendered much better. The sketch arrived and surprisingly only a few changes where made from the original. A separate shower, more space in the forward cabin, and a modification to the table in the cockpit. Also a little later, the inboard rudder was switched to a transom-mounted blade with a skeg, the easier way to install a trim tab for the wind vane part of the installation. 

- Fail to plan, plan to fail as they say. So, a project starts on paper or rather nowadays with computer-aided design programs. For L'O. the size was limited to 40' to avoid regulations over the 12M. limit. The envelope with the beam and the draft define her main characteristics. The draft is always a big decision making. In this case, a steel boat and no specific concern about shallow water, I felt comfortable with a depth of 6'-3" -1.9M. to achieve the stability and performance required.


- You would expect to see a fin with a bulb at the bottom. Well, you see with a steel boat it is imperative to keep the ballast low but also to be able to keep within the foil fuel and water, sometimes batteries and pumps. Therefore I avoid bulbs that would implicate a thin upper shell. They are also a b.i.t.ch to build and there is nothing better than a well-drawn foil from top to bottom. I favor a trapezoidal profile because the design brings the lead further forward and benefit of a longish top for added volume capacity. 

- A far as the lines plan. Again, one has to adapt the shape to the material medium employed. With a metal boat, I favor three options. Developed chines; developed round bilge or the origami method which I call Imagiro.


- I started by looking at different boat shapes to get the feeling about proportion for a new hull, particularly in terms of beam, freeboard, and displacement to get the grasp of the subject, I run Rhino (a 3-dimensional program) at a very early stage.


- I choose the radius bilge system, where the hull is divided into three panels per side, all developed for easier construction. Still one has to bend to the curvatures, but the plates lay down with little persuasion


- The modern method of construction calls for CNC cutting files. The builders of today yachts more often than not, do not have the room for lofting the hull full size and even the skill required to lay down the architect's Lines Plan. Nesting the pieces is an efficient way to maximize the use of plates.








- The hull is built upside down on a strong back. The combination of frames and stringers are clearly shown in the pictures. On MBCC models, especially built with metal, I favor a conic stem shape, keeping sharp at the waterline but wide at the deck to augment the volume with a short overhang. The bow is a busy place and more feet room is considerably safer.






- Time to turn the hull over. Not a simple operation as you can imagine. Now the work can start on the deck. Actually more complicated and detailed with the added Pilothouse. This aspect of the design was introduced right of the bat and I spend a lot of time trying to fit and define the character of it on a relatively small hull which was to have an enclosed helm station and a settee berth over a double cabin. The owner liked the look of the windows being tilted forward as seen on certain Dutch boats and over here, seen on trawlers and fishing vessels in the Northwest Pacific region. This presented a challenge. I choose to add corner windows to cut down on the bulk of the superstructure.

- The cockpit is 8' long and contains the steering wheel with console and folding table. Originally with an inboard rudder, I was planning to have the helmsman seat made part of the transom as shown.


- Turning to the interior, view of the pilothouse, and the installation of insulation. Good visibility is provided all around by the large windows and further forward with portlights.

Time to get the boat out for sandblasting.  



She sure looks like a U Boat right now.


- Time to turn to the Interior.

- The Accommodation plan started by sending me an original sketch. It is important as mentioned before to be well aware of what is going on in the mind of the customer. It is my job to separate the wheat from the chaff. Having a boat floating on her lines is a great achievement and it starts by having your 3D's head focused on the whole boat.

 
- In true Pilothouse fashion, the boat can be steered from the inside. There a full-fledge settee berth on the port side. What cannot be seen in this picture is the double cabin down below, also to port and underneath the sitting area. The galley is next, notice the U shape which is a better layout for cooking at sea. Aft of the bulkhead is the access door to the aft cabin.











- Looking aft is the door to the toilet, equipped with a separate shower. A very necessary feature in my mind. The companionway is offset to starboard and with the engine under the pilothouse, there is access from the top and through a side door.

- Forward of the Head. A small desk is all that is required when the navigation is controlled from the pilothouse.




- The saloon is self-explanatory and can seat a fair amount of people around the folding table. As seen with this happy family. A skylight gives plenty of light to the forward cabin. There is also anther one over the Galley area.


- The conclusion is: this is a lot of boat for a restricted size of 40', inside and out. Time to go back on deck.



- On a relatively short length, to place a full pilothouse on deck is a challenge. It did not turn out too bad. The number of windows helps along with the roof curvatures.






A few deck details.

- The owner insisted on having a wooden mast, along with the boom and bowsprit made of the same material. He also stipulated that the spar be no longer than 50' overall. I spread the Sail Plan accordingly and this worked just fine.



Finally sailing after 2 years of hard work.














2 comments:

  1. I'm looking forward to more posts on this wonderful design.

    ReplyDelete
  2. I have added a few more photos on "Puzzle".

    ReplyDelete