So I have more or less settled on a design for the gantry supports. I will need to seriously bulk out the shape once the main structure is assembled so as to break up the boxy shape it currently has. This is one of the limitations of working with foamcore. You are generally stuck with flat sided shapes (and I am saying generally as I am not certain that you can not curve foamcore...I have been too busy to look it up).
So the photos show the side shapes for the upper and lower portion of this gantry. The gap is intended to give the idea that the gantry can move higher or lower depending on the ship in the cradle. That section will be filled with plastic tubing to represent the hydraulic pistons that make this movement possible. To be clear this piece will not actually be able to alter its height. It is hopefully just going to look like it can.
I have assembled the top support for the gantry and show them assembled and also show a shot of the walkway on top of its supports. The supports are clearly different widths to accommodate the walkway but their attachment points to the walkway will depend on their distance apart once they are on the edge of the elevator. I want these walkways to at least touch the central structure that I have been working on in parallel with this.
And yes I am aware the perspective in the sketch is shot. It is a mess of concepts smashed together and was used to design the card templates that I traced the pieces with. I will scan and post those later in case anyone is interested.