An arrangement (10) for delivering gases from combustors (15) to a first row of blades. The arrangement (10) includes at least an upstream flow path (60) including an aft first side wall (64) and a downstream flow path (62) including a forward second side wall (66). A convergence junction trailing edge (40) is defined at a downstream terminal edge (41) of the first side wall (64), and the second side wall (66) converges toward the first side wall (64) in the direction of the convergence junction trailing edge (40). An impingement sheet structure (78) is located between and provides impingement cooling air to the first and second side walls (64, 66). Openings (88) provide a cooling air passage between the first and second side walls (64, 66) and provide a flow of post impingement air into the gas path at the convergence junction trailing edge (40).