military bidge boat the transom has no angle what is the best way to attach outboard?

I have a military bridge boat that is 19 feet long 7 feet wide and 24 inch deep at the transom. Plus the transom is 90 degrees.
These boat were designed to be a float bridge. 2 boats bolted together by the transom and bridge road bed attached on top. If you have seen the movie "kelly's hero's" starring Clint Eastwood they drove a tank over one.
The problem I have is: What is the best way to put a motor on the back with such a steep angle and height.
I have attched some pictures from a Vietnam web site that shows 2 50 horse power motors on it.
Thank you for your idea's

 

Well, first of all, welcome to bd.net

Most outboards you find now will probably be set up for a transom raked aft around twelve degrees, give or take a few degrees. Sterndrives are in the same ballpark; jet drives are generally available in 0 or 5 degrees.

Depending on the outboard, its lowest trim setting might give an acceptable thrust line (ie, near parallel to the bottom) with the current, 0-degree transom. Other outboards might trim out too much even fully tucked in. If that's the case for your chosen setup, probably the easiest solution would be to fabricate a setback bracket at a suitable angle, bolt it to the transom, and clamp/bolt the outboard to the bracket. In steel this could be done for less than a hundred bucks if you can cut/weld it yourself; fibreglass is also an option. This way, you don't compromise the original boat (esp. its structural integrity) at all, and you have more freedom to optimize the motor placement.

 

Welcome aboard!

A setback mounting bracket is probably your best bet, allowing you maximum flexibility. Matt has summarized the details very well.

Good luck with your project.

 

Does it have the M-60 on it, Cool!