Marine steering gear with emergency steering means

An improved marine emergency steering system for controlling a fluid operated marine steering device, the steering device being of the type having a hydraulic steering engine and an actuator for actuating the steering engine, the actuator having a plurality of pressure chambers, and emergency steering means of the type having a hydraulic steering system for passing a hydraulic fluid to the plurality of pressure chambers, the improvement comprising a delivery pump, discharge line means for passing the hydraulic fluid from said delivery pump to the pressure chambers, a check valve mounted in said discharge line means at a location downstream of said delivery pump for checking back flow of the hydraulic fluid in a direction toward said delivery pump, a first relief valve mounted in said discharge line means, said first relief valve being operable to relieve hydraulic fluid from the discharge line means, a steering-directional control valve mounted in said discharge line means intermediate said check valve and the pressure chambers, an oil-charge-directional control valve mounted in said discharge line means intermediate said steering-directional control valve and the pressure chambers, said oil-charge-directional control valve having two working positions and being operable to shift between a first one of said working positions in which fluid received from said delivery pump is passed to the pressure chambers and a second one of said working positions in which fluid received from said delivery pump is not passed to the pressure chambers, oil-charge check valves mounted intermediate said oil-charge-directional control valve and the pressure chambers for checking back flow of the hydraulic fluid in a direction toward said oil-charge-directional control valve, a second relief valve mounted in said discharge line means upstream of said oil-charge-directional control valve to relieve hydraulic fluid from said discharge line means at a set pressure corresponding to a desired charge pressure to forcibly reduce air volume in the pressure chambers, said discharge line means downstream of said steering-directional control valve comprising a first separate line including said oil-charge-directional control valve and a second separate line excluding said oil-charge directional control valve, both of said first and second separate lines being connected to the pressure chambers, and said steering-directional control valve being operable to alternately pass fluid received from said delivery pump through said discharge line means to the pressure chambers indirectly through said oil-charge-directional control valve and directly by by-passing said oil-charge-directional control valve.