Inside the boat I had to mount the two Graupner 700 turbo C engines to something that would hold them tight, yet something to absorb vribrations and make them able to self-adjust to some degree. In my previous model, I had simply drilled two holes in a wooden beam, and mounted the engines (a pair of 400s) inside those, with some support on the back side. It works, but it is not a very effective cooling method... I sometimes smell burnt wood when I open up the deck of that boat. Oh, well.
In the Tjeld-boat, I wanted something that will make me able to cool the engines more efficiently - obviously there is going to be some more heat generated in this model with these larger engines. Still, though, I stuck to a wooden method. At first, I mounted the shafts, and then measured where the engines should sit. I then, again, found a wooden beam and drilled two holes, a little bit larger than the engines themselves. I then cut the beam in half, slicing it so that each of the two holes were now merely a "crib" for each engine. I then glued this in place, of course taking care to fix it in the right position.
As couplings to the shafts I used some metal pieces joined by a heavy duty piece of rubber, which allows the engines to be a little bit off centre to the shafts. To fasten the engines, I laid a rubber mat in the bottom of each crib, to prevent them from turning themselves around, and then fastened them securely in place using pieces from a Meccano toy set I bought for this purpose. I also use meccano to link the servo to the rudders, and for a lot of other things in the inside of the boat, and I find it to be very efficient and durable.
I bought four lead acid batteries, 12 V and 7,2 Ah. However, I found that I could only fit three inside the boat because of the wheight, there is ample space for plenty more. I placed them just forward of the engines. The speed controllers were fitted just beside the engines, so that the cooling fans I am going to point at the engines will also draw air over the speed controllers, and thereby cooling them as well.
The fans are not in place at this picture, this is just me adjusting the mounting of the engines.
The speed controllers were a pair of Graupner Navy V30R.
The interior after test-fitting everything:
The batteries are fitted inside 3 mm plywood, glued into place and strengthened by pieces from the Meccano set.