The T5 shock tunnel will be used as a high-enthalpy testing facility to complement the work done in the low-enthalpy quiet tunnels. In T5, the heating of the driver gas is achieved by adiabatic compression with a heavy piston in a compression tube. The piston is driven by compressed air from a secondary reservoir. The compression tube internal diameter is 300 mm and its length is 30 m. The shock tube is 12 m long and has 90 mm internal diameter. The piston mass is 120 kg. The nozzle exit diameter is 300 mm. The overall length of the facility is 51 m. The facility provides a steady flow for 1 and 2 ms, depending on the reservoir enthalpy. Since this corresponds to typically 30 “flow times” (length of model divided by free-stream speed), it is sufficient to achieve a significant period of steady flow. The range of reservoir specific enthalpy achievable in T5 is 2-20 MJ/kg, with a reservoir pressure range of 10-90 MPa. The facility operates with a 0.3 m exit diameter.