Thanks for the comments and welcoming messages!
Yes the basic principle is to use the heat from the coals to generate the steam and to cook the meat. Very important is to have a safety valve otherwise your whole pressure vessel can go boom! Hehehe, I will post Pics as soon as I get some time.
I will try to get the video on youtube as well. And will see what i can do in the way of posting the blueprints for this. One of the issues in South-Africa is that our power supplier is very iffy, thus the getting a power failure mid Braai can be catastrofic, and starting the generator just for a rotisserie seems wastefull (since fuel is also very expensive), hence the steam-spit was born.
Off to work I go!