Welcome to Gaia! ::

Depends on what sprue you use. Wargames Factory's sprues can get quite small, and that's what I use for rungs.

I'll have to explore the stairs idea...

Nice!
The other day I took apart on iPod dock for parts and it has a metal mesh across the top and was thinking something like that would be great for a bridge surface, maybe you could find something like that? I'm making a foot bridge out of it right now, so I'll post that as soon as it's done as well.


EDIT:
After fiddling with what I had, I ended up making an Engineer's Bridge; you pull the turret off of a tank and replace it with a simple pneumatic system that deploys and recovers such a bridge. I know that both parts don't match too well, but that's from only having thee cross-sections in the larger one. I like to think it makes things looked slimmed down to lighten the weight as well.

I'll finish it once I have a tank to mount if on and have the proper angled pieces to replicate the sturdier bottom piece.
I also have something new to contribute to this thread! As I'm starting a Chaos army, Company of Misery, I decided to chuck a few things together. at this point I still have some arms and pauldrons to assemble and then fill the gaps with just enough sprue to connect the spikes to the frame. Otherwise, probably paint them all to look like Ultra Marines and have TONNES of blood running down from them.