the"new" great gate

Does somebody know the description of the new Main gate of Minas tirith. I heard it was made of Mithril and steel this time, but i need to know more then that. I would like to know its new structure in as much details as possible so I can make a image of the gate for my new web site. I've been searching all over the web to find a description of the new gate but i didnt find anything helpful for me. Maybe some wise tolkien fan could help me.

PS does somebody know where to find a movie-pic from the gate so I could see how they made the old gate in Jacksons movie. (this might help me imagen the structure of the new gate...)