Hull design.

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

togaurd

Member
Joined
Aug 26, 2010
Messages
22
Reaction score
0
Hello,
I have been waiting to get a good start on my 75 smoker craft and looking around for ideas. I don't know why, but I was looking at the hull and transom and realized its not a deep v. I think. At the transom the bottom is not v'd all the way out, it has some kind of downward curve on outsides. This makes two small tunnels that run all the way up to the bow where it rolls out to a semi-v looking bow.

How does this effect the coming rebuild? It won't. I'm just totally knew to boating and I like to know as much as possible about anything I'm wrapped up in.

While reading about hull designs I came across the cathedral hull that was shaped similarly in style. The given examples were on large fiberglass boats, but the tunnels were present nonetheless. There was also another hull design that was close and its strong point was shallow drafts and getting on top of the water fast. I can't remember the name of that hull at the moment, but some of the examples were fast racing boats. Lund is using the IPS design and it looks very similar in the picture I saw of the rear transom.

Not important at all, just wondering.Your probably going to say its a common design on small aluminum boats. I think I'll stop reading about boat design and start striping the boat down. :-#
 
sorry about that.
 

Attachments

  • transom 1.jpg
    transom 1.jpg
    98.8 KB · Views: 1,118
  • bow.jpg
    bow.jpg
    102.5 KB · Views: 1,118
I did some more digging around. Turns out is called the Hydro-lift hull. Well, thats what Smoker Craft calls it. It's reported to get the boat up an plane faster, be more stable in turns and reduce spray.

I wonder how long they have been using it?
 
Looks almost like a tri-hull design. I would guess mid eighties, when there were a lot of fiberglass boats with tri hull designs. Supposed to be a good compromise between stability and speed. Not sure if they worked though, probably more expensive to manufacture.
 
togaurd said:
I did some more digging around. Turns out is called the Hydro-lift hull. Well, thats what Smoker Craft calls it. It's reported to get the boat up an plane faster, be more stable in turns and reduce spray.

I wonder how long they have been using it?

Tri-hulls have bee around for a while. That being said, I have never seen an aluminum one. Also, looking at the transom I would venture a guess that the original transom probably followed the curve of the aluminum and didn't go straight across from gunnel to gunnel as it does now. I would think about replacing the transom with a better pieces of plywood that has been weather proofed. That OSB will not stand up over time. Even if it is water proofed, it doesn't have the consistent rigidness needed to stand up to the flexing of the transom when under power. The flex in the OSB will cause the glued pieces of wood to separate and give way. Just my thoughts.
 
I agree, it does look like a tri-hull. The new Smokers call it a hydra-lift and some other glass boats use something similar under a different name. I'm eager to see how it performs, although I will probably seldom see "cruising" speed. My father n law is letting me use his 1968 Johnson 20. I would like a 35 eventually, but I don't know if the boat will take one.

The transom repair was done before I received it. I knew right away that the OSB wasn't going to stay. They didn't spare the epoxy sealant. Makes for getting the screws out a real nightmare. If I leave the transom height at 20" or take it back to 15"? I know some say make it to match the outboard. My question is would changing the height effect any performance or engineering designs.
 
togaurd said:
... If I leave the transom height at 20" or take it back to 15"? I know some say make it to match the outboard. My question is would changing the height effect any performance or engineering designs.

Regarding your question about the transom height. Yes, it should match the outboard and a mis-match situation will affect performance at least.
IMO, short shafts seem more plentiful especially if you're considering an older motor. Regarding the horse power, I would check and see if has a capacity plate on it. The capacity plate specifies that max weight it can carry and horse power rating. Of course, the plate could be missing and older boats weren't required to have one. In that case, the horse power rating can be calculated. There's post somewhere on this site on how to do this.
Looks like a nice project. I like the hull design. Good luck.
-jasper
 
Thanks. I'll look for the horsepower calculator. Your right, there is no capacity plate on the boat. I have seen some write that it should take a 40 h.p., but I probably will never put one on. I just won't be getting on water that lends itself to going as fast as possible. Will probably hit Lake Michigan a few times a year but only when the wind is out of the south, thats calmest on southern tip.

Going to try and get the transom off and bottom striped this weekend. I would also like to see if the aluminum flat floor is factory or not. I'm almost positive that it is.
 
Horse Power Fromula can be found here.....

https://files.dnr.state.mn.us/education_safety/safety/boatwater/backyardboatbuilders.pdf

Also talks about transom height.....

Outdoorsman
 
Thanks for the link Outdoorsman. I crunched the numbers and came up with 40 hp. That sent me looking at 40 hp tillers. Wow. New ones are crazy$ and older ones tend to be LS or remote or both. I'm going to have a hard time finding one in my price range.
 
togaurd said:
Thanks for the link Outdoorsman. I crunched the numbers and came up with 40 hp. That sent me looking at 40 hp tillers. Wow. New ones are crazy$ and older ones tend to be LS or remote or both. I'm going to have a hard time finding one in my price range.

Where are you located, maybe someone can help you out? I just passed on an older 40hp tiller because it was a short shaft. It was a fixer, but for $75 it was worth a gamble.
 
This site has been a ton of help. I hope my garage empties out soon so I can put the boat in there. Maybe in a couple of weeks.
 
Wow! Two months just flew by and I still have not touched that boat.

To answer my own question, I think the boat is a Smoker-Craft 16' Tri-Fisherman. Now lets see if I can get it the water next spring. [-o<
 

Latest posts

Top