Abstract: A dual fuel injector for a gas turbine power plant has fuel ducting including gas and liquid fuel ducts which can be removed easily for access to a nozzle of the fuel duct. A separate fluid ducting assembly is attached in the head of each combustor can and has an annular duct, a passage and drillings. The power plant is started on liquid fuel, and runs subsequently on gas produced in a coal gasifier. The flow of air through the duct and passage prevents any unburnt fuel or combustion products from entering the gas duct, and the flow through the drillings prevents carbon build up on face of the injector.