This is a paIR OF 3/4 inch plate fender panelS used to handle docking ferries.
The unit has six inch square formed channels as ribs.  The picture 
shows two panels lacked together ready for welding.
   THe question is which way will the panels distort??
The two vertical tube ribs are already welded together except 
they are not welded to the panels.  All welding is to be continuous
1/4 inch fillets.  
   Are the mating plate surface going to be concave or convex?
Randy