A turbine blade comprising: a hollow airfoil, platform, and integral dovetail; said airfoil including opposite pressure and suction sides (20,22) extending in span from root to tip and in chord between leading and trailing edges (24,26); said tip including first and second ribs (36,38) extending outwardly from a tip floor along said pressure and suction sides (20,22), respectively, and joined together at said leading and trailing edges (24,26); and a cascade tip baffle transversely bridging and integrally joined with said first and second ribs (36,38) above said tip floor to partition said tip chordally into corresponding tip pockets on opposite sides of said baffle, wherein said tip baffle is spaced aft from said leading edge along both said first and second ribs (36,38) to define a forward tip pocket directly behind said leading edge, and said baffle is disposed obliquely to the camber line and disposed relative to said leading edge to transversely distribute flow streamlines in a cascade aft over said baffle toward said trailing edge, wherein said forward tip pocket diverges in width aft from said leading edge, and wherein said first and second ribs (36,38) and tip baffle are coplanar in elevation above said tip floor and fully surround said tip pockets, and wherein said baffle is concave forward toward said leading edge where said baffle joins said first rib and said baffle is convex forward toward said leading edge where said baffle joins second rib, and said baffle is convex aft toward said trailing edge where said baffle joins said first rib and said baffle is concave aft toward said trailing edge where said baffle joins said second rib. a hollow airfoil, platform, and integral dovetail; said airfoil including opposite pressure and suction sides (20,22) extending in span from root to tip and in chord between leading and trailing edges (24,26); said tip including first and second ribs (36,38) extending outwardly from a tip floor along said pressure and suction sides (20,22), respectively, and joined together at said leading and trailing edges (24,26); and a cascade tip baffle transversely bridging and integrally joined with said first and second ribs (36,38) above said tip floor to partition said tip chordally into corresponding tip pockets on opposite sides of said baffle, wherein said tip baffle is spaced aft from said leading edge along both said first and second ribs (36,38) to define a forward tip pocket directly behind said leading edge, and said baffle is disposed obliquely to the camber line and disposed relative to said leading edge to transversely distribute flow streamlines in a cascade aft over said baffle toward said trailing edge, wherein said forward tip pocket diverges in width aft from said leading edge, and wherein said first and second ribs (36,38) and tip baffle are coplanar in elevation above said tip floor and fully surround said tip pockets, and wherein said baffle is concave forward toward said leading edge where said baffle joins said first rib and said baffle is convex forward toward said leading edge where said baffle joins second rib, and said baffle is convex aft toward said trailing edge where said baffle joins said first rib and said baffle is concave aft toward said trailing edge where said baffle joins said second rib.