Abstract: A system for measuring the force exerted on two or more hydraulic jacks, each carrying the same load. The system comprises for at least each of the main chambers of the jacks, a sensor to measure the pressure of the hydraulic fluid and a calculation member making it possible to calculate, from the electrical signals provided by the sensors, the total force exerted on the set of jacks. The system is particularly applicable for detecting the force exerted on the jacks for actuating the jib of a crane.