In search of Boat Design Help

I am in need of fiberglass boat design help. Please let me know if interested.

 

Welcome to the forum, @Bukmaster9. I'm interested, at least to start talking. How can I help you? Send me, if you wish, a personal message for more details.

 

@TANSL I cannot find how to send a PM... my apologies.. I just signed on to this forum. you can reach me by email bukmaster9@gmail.com or welcome to send me a PM


Thanks

 

Hi Bukmaster - would you like to tell us a bit more about your design project please?
We would all be very interested - even just a brief overview would suffice if you do not want to disclose too much detail at the moment.
Although if you do give some details, and explain what your problem areas are, you can be guaranteed to get lots of different opinions re how you should go about solving your problems!

 

My plans are to stretch a 24’ to 27’ fiberglass boat … I will add the length to the stern.

Here is the link to the boat I am stretching. It is a 24’ boat. I am getting an older hull and taking out the floor and stringers. The boat will be stripped down to just the hull skin. Then I am adding 3’ to the stern end. I have included a couple pictures of one that is pretty much exactly like I will be doing.

My concerns are for the performance of the new stretched hull in stability and handling. I also need to know how to distribute the weight for especially the fuel tank and the 45 gallon bait well. I appreciate you help


2400 RENEGADE | Radcliffe Boatworks http://radcliffeboatworks.com/post/5/2400-renegade.html

 

So you are already in process of adding the three feet, going on the above picture ? What are those alcoves at the transom intended for ?

 

No I am not in the process yet. The pictures are of a project that was done a couple years ago by another guy. He used the exact 24' privateer hull I intend to use. The two acloves on the sides are for trim tabs and the one in the middle is a tunnel drive ( suppose to help the boat get on plane quicker in shallow water when the motor is trimmed up).

 

Here is a picture of that boat finished. He said it rides very well. But before I get started I would feel more comfortable with naval engineering opinions. Most importantly I need advice on the weight distribution on the interior... the fuel tank (125 gallons), bait well (45 gallons) , 3 batteries, and positioning of the center console are all of specific concern. A calculated approach is what I am seeking , prior to starting . And any other tips are welcomed

 

You need someone who is familar with planing boats, not just the larger displacement vessels which most naval architects work with.

 

One of the blessings of planing hulls, is that typically they are not overly sensitive to weight distribution, lengthways. Reason for that, is that the area of greatest dynamic lift, is at the leading edge, and if you shift weight forward, that will be accommodated to some extent, by the leading edge moving forward. Ditto shifts of weight rearward, the leading edge being further back, and the lift further back as well. So far as your rather substantial fuel tank is concerned, the obvious place is around the middle of the boat, that way an emptying fuel tank will have least impact on trim.

 

I'm at a loss to understand the rationale with those trim tab recesses, a tab on a flat transom would do the same or better job, so what's that all about ? If it's to avoid a catch point for fishing lines, then I think the outboard motor might eclipse that, somewhat.

 

Bukmaster, the above photos are impressive - but could you post some showing the current condition of your boat please?

I presume that you will install new stringers in the same position as the old ones?

Re the extension, will you just follow the natural curves of the hull, or will it be a 3' parallel section added on?

I have seen quite a few boats here, of all shapes and sizes, some fibreglass, some wood, where they have added extensions on the back.
Your length to beam ratio will increase, but not by a lot. You probably will not need extra power for the stretched version, compared to the 24' length.
As Mr E says, try to locate your heavy items, and especially the consumables like fuel, at or near the longitudinal centre of buoyancy of the boat.

What type of power are you planning on installing on your boat?
Re that abrupt change of section in the tunnel, I would have thought that this would just generate a lot of turbulence?
I cannot see why it is needed, especially so if you have an outboard engine on a bracket standing off the transom.
Are you planning on building a similar tunnel, along with similar alcoves for the trim tabs?

 

@bajansailor I don’t have the hull yet. I am trying to do as much as I can now so when I get the hull the project can take off running
Yes I will install new stringers in same position
I plan to put the 350 Suzuki outboard
That’s the first time I have seen a tunnel like that. A buddy of mine knew what it was , i guess he has seen them. I don’t need it necessarily . I am not planing on putting the trim tab recesses
I really would like someone on here to help me get this thing in some software but I guess from what you all are saying its not really necessary.

 

The step in the middle would be next to useless in getting less draft, it is too short. What is the normal treatment with the flats boats, to get more engine height ?

 

I am probably the victim of a profound professional deformation but I would try to find out some things, be clear about some things, before starting the reform. The 10% variation in length is not a small thing, it can influence not only the speed / power of the boat but its stability. I would like to know the position of the ship's center of buoyancy after modifying, but before modifying it. It would be prudent to calculate how the transom should be to properly support the new motor and if I need to fit some b rackets to reinforce it. The fuel tank and bait well are big weights that should be distributed among various reinforcements that, at worst, now do not exist ..... Anyway, check and define some things before starting. This is my opinion which, as always, is debatable.