A turbine blade includes an airfoil defined by a pressure side outer wall and a suction side outer wall connecting along leading and trailing edges and form a radially extending chamber for receiving a coolant flow. A rib configuration may include: a leading edge transverse rib connecting to the pressure side outer wall and the suction side outer wall and partitioning a leading edge passage from the radially extending chamber. The rib configuration may also include a first center transverse rib connecting to the pressure side outer wall and the suction side outer wall and partitioning an intermediate passage from the radially extending chamber directly aft of the leading edge passage. The intermediate passage is defined by the pressure side outer wall, the suction side outer wall, the leading edge transverse rib and the first center transverse rib, and thus spans airfoil between its outer walls.