jacquesmm wrote: ↑Thu Nov 15, 2018 1:54 pm
More questions came by email but I want to reply on the forum. Discussions on the forum will help hundreds of readers.
Christers asked about elimination or reducing the size of a cross beam in order to add bow rider style seating forward of the console as in the Hankinson design.
It is not possible.
One of the big differences between the Hankinson and the CT22 is the height of the deck between the hulls (bridge deck). His deck is very low. This provides volume to have a cockpit forward with seating and an enclosed head. That low clearance produces bad slamming under the deck. It can be acceptable for a protected waters boat used with the same program than a pontoon boat. It is unsafe offshore. You can see that very low clearance in the pictures posted above in this thread.
The CT22 has much more bridge deck clearance but it does not leave enough volume to have such a cockpit.
Look at the perspective drawings:
See the box just in front of the console. That is the cross beam we are discussing, the one with a lid.
In the front, the height inside that box is about 6" above the bridge deck!!!
There is no way to bring that down or eliminate it.
Look at the hatches in the foredeck. Those compartments are 17" deep stern side and 10" bow side. That does not leave enough room for seats.
The choice is simple: have a low bridge deck (Hankinson) and lots of comfort but pay a price in blue water ability or have a seaworthy high bridge deck but no extra room for seating.
Anyway, I would never want to sit there in a formed sea, you"ll fly over board.
Seaworthiness or comfort.
That are your choices. It is not an unusual choice, compromises are a major factor in boat design.
The Hankinson and my CT22 are each good designs but for a different program.
The VT650 is another compromise. From what I see, the freeboard is higher, the windage is more than what I like. The bridge deck is lower but not as low as theWild Cat.
That compromise produces enough volume for the bow rider seating but there will be some slamming. Less than with the Wild Cat, more than the CT22.
Thanks for your reply, Jacques. Even if it's not what I wanted to hear, I appreciate it.
However, I don't want to eliminate the connecting cross beams, I understand they have to be there. Please don't take this the wrong way, but why were they/the box put there and not forther forward? By having it where it is, about half the usable space in the boat is taken up by the front deck and the box.
I quite obviously have no NA experience nor experience in designing a boat, which is why every time I ask something I feel retarded. I'm trying to understand why things are done they way they are, but this one continues to puzzle me.
I assume the low height of the forward lockers is because of the sloping of the tunnel ceiling, and that is also why the connecting frame box is placed where it is. Couldn't the front part of the slope be steeper and thus deeper, allowing more internal depth in the cockpit, and possibly also allowing the connecting frame box to moved forward?
With my stated program, I think either of the cats mentioned in the thread could work. I really want to build a CT22, but the way it's laid out, it just doesn't work for me.
I also realize that a standard monohull would be faster and a lot cheaper to build and given the right design, would satisfy all my requirements except being a catamaran. I'm going to have to give this some more serious thinking.
8ft dinghy built in 1992, BBV sufferer ever since.