Originally Posted by SamSam
But most transoms will have knees and/or splash wells that reinforce the transom. Plus they're more robust to begin with.
I have splash wells in the outboard bracket openings. The shape of the pods also come over the gunnels and will be fibreglassed to these for torsion dispersion through the sides of the hull. Internally the pod is bolted through the existing transom which is 40mm thick from starboard right through to port stern, not just individual sponsons. Once it is fibreglassed, I am not worried about the actual pods themselves, I was just hoping for feedback on the thickness of the actual motor transoms. This hull is 3 and 5 mm marine ply with 3 layers of 600gsm bi axial cloth over it. You could hit it with a sledge hammer and it won't crack. It has Kevlar keel strips to prevent cracking of the keel over time beaching etc. I have removed a lot of the internal bracing ( scantlings I have since learned) and rebuilt these and fibreglassed each compartment with 400gsm chopped strand. After I have run the boat in the lake a few times, I will be fibreglassing a 8 mm marine ply deck onto it, followed by a 600gsm biax layer, a horizontal layer of 3mm ply and another layer of 600gsm . I will then inject foam into each compartment.
Considering the draft on first wetting the hull was 200mm, if I can keep the weight down, I anticipate my skinny keels will be able to plane as well as displace well at low speed, making for a comfortable ride. If I need to, I will install a hydrofoil, but time will tell. The boat did not squat with 300kgs on the transom and no bow counter weight at all. I have been looking at some of the keels of high speed light weight cats like the Blackdog Aluminium cats as well as the shapes of the Thundercats used to race in NZ. I think if I can keep the weight down, I'm going to be ok.
This is a great project and I am learning heaps, I have had to change a lot in the last two years it's being going, but that has all been part of my learning experience. This boat is going to surprise a few people and the first draft is a small indication she may actually be something cool.