Making an architects plan chest, how can I strengthen the drawer?

[Eif]

I am going to make a large plan chest from plywood, I am just working out how to make the drawers. As the width would be roughly 1000mm and depth 700mm to accomodate A1 paper. Does anyone know how a drawer this wide would usually be strengthened to prevent the bottom of the drawer from buckling?

I was thinking of using a muntin however, I would need the inside bottom of the drawer to be completely flat, so as not to buckle the paper that would sit inside, any help would be greatly appreciated.

 

[peter-harrison]

You could just reinforce the bottom underneath with a bit of hardwood glued in?
Or use thicker ply for the drawer bottom.
I took apart a whole load of map drawers from the Royal Geographical Society many years ago. They were made with 3/8" birch ply bottoms.
By the way, I think your concern may be misplaced. The force exerted by a maybe 50mm high stack of paper won't be that much per square inch, and will be evenly distributed, and will therefore not have a tendency to twist the drawers. I would happily make drawers like that with 6mm ply bottoms.

 

[ChaiLatte]

Over the 1000mm dimension, make the bottom slightly arched. It will not harm the paper but will contribute to the strength. You could similarly make your munchkin slighly arched, as well as choosing the plywood direction so its strongest direction is across the longer span. You could take inspiration from how acoustic guitars are built and braced.

 

[Jacob]

Give it extra support with a central runner under it. Tongued or housed into the front rail with glue and screws. Supported at the back, various ways.
Or just stiffen from underneath with a glued on strip in place of muntin, as per peter's suggestion above. And I agree, probably not that necessary.