Abstract: A gas and steam generator having at least two interconnected combustion chambers wherein water in combination with combustible materials is utilized for creating power for a work operation, each combustion chamber being provided with a reduced nozzle-type outlet for creating great pressures and temperatures within the respective chambers, and each combustion chamber being arranged for receiving combustible materials therein for burning thereof. The initial combustion chamber preferably receives a fuel-oxygen mixture at the inlet end thereof for ignition, with the products of the combustion being maintained at a high pressure and temperature by the restrictive nozzle-type outlet of the chamber. Steam and additional combustible materials are introduced at the nozzle outlet of the chamber for ignition and passage into a next stage combustion chamber whereby additional heat and force is produced for ultimate delivery of great power for a work operation.