A rotor blade includes an airfoil having a tip plate that extends across an outer radial end. A rim extends radially outward from the tip plate and surrounds at least a portion of the airfoil and includes a concave portion opposed to a convex portion. A plurality of dividers extend between the concave and convex portions to define a plurality of pockets between the concave and convex portions at the outer radial end. A plurality of cooling passages through the tip plate provide fluid communication through the tip plate to the plurality of pockets. A first fluid passage in at least one divider provides fluid communication between adjacent pockets across the at least one divider.