<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#ffffff" text="#000000"> Thankyou muchly Ron.  If I may take this unribbed (at this point) laminated and curved board a step further then.  What if you add to the mix : <blockquote>1: align the grain of the panel perpendicular to the bridge. 2: rib cross grain to equalize stiffness. </blockquote> Do you think it would be strong enough with  a standard thickness to do the job then ? Would you expect to be able to use less ribbing then usually ? Cheers RicB Ron Overs writes: If you are thinking about the application of a laminated panel without ribs, this wouldn't have sufficient stiffness to support the downbearing load if the panel thickness was a standard nominal thickness (say between 7-9 mm). A panel on its own would have insufficient sectional depth to achieve the stiffness required. If you were to use a thicker panel, at some point you would achieve a satisfactory stiffness but the overall mass of such an assembly would greatly exceed the mass of a conventionally ribbed panel of normal thickness. One of the principal structural benefits of the ribs is that it gives the overall assembly a sufficient sectional depth that the panel and ribs can, together as a unit, provide the necessary stiffness. I'm not suggesting that a laminated panel wouldn't have a higher stiffness than an equivalent thickness solid panel. It certainly would, but not enough to support downbearing in its own right. If you find this hard to believe just laminate a little section for you own investigation. Best, Ron O. </body> </html>