Combustion chamber

A combustion chamber comprising an upstream end wall structure, an inner annular wall structure, an outer annular wall structure spaced radially from the inner annular wall structure,

• the upstream end wall structure comprising an upstream wall and a plurality of heat shields secured to and spaced axially from the upstream wall,
• the inner annular wall structure being secured to the upstream wall, the outer annular wall structure being secured to the upstream wall,
• the upstream wall having a plurality of circumferentially spaced fuel injector apertures, the heat shields being arranged circumferentially around the combustion chamber, each heat shield having a radially outer end, a radially inner end and a fuel injector aperture aligned with a corresponding one of the fuel injector apertures in the upstream end wall,
• the radially outer end of each heat shield having an outer rail spacing the heat shield from the upstream end wall, the radially inner end of each heat shield having an inner rail spacing the heat shield from the upstream end wall, a remote end of the outer rail of each heat shield having a surface abutting the upstream wall, a remote end of the inner rail of each heat shield having a surface abutting the upstream wall,
• the radially outer end of each heat shield having a first plurality of circumferentially spaced apertures extending there-through and through the associated outer rail to direct coolant over the surface of the outer annular wall structure to form a film of coolant, the first plurality of circumferentially spaced apertures of each heat shield extending through the associated outer rail from respective inlets in the surface abutting the upstream wall to respective outlets in a surface of the heat shield facing away from the upstream wall,
• the radially inner end of each heat shield having a second plurality of circumferentially spaced apertures extending there-through and through the associated inner rail to direct coolant over the surface of the inner annular wall structure to form a film of coolant, the second plurality of circumferentially spaced apertures of each heat shield extending through the associated inner rail from respective inlets in the surface abutting the upstream wall to respective outlets in the surface of the heat shield facing away from the upstream wall.