9 - Steering gears

Abstract

Publisher Summary Ships, from at least the 1950's have been fitted with automatic steering, making helmsmen redundant for deep-sea passages. After the required course is set, the automatic steering maintains direction, correcting any deviations occurred because of weather. Some problems had been experienced with the early versions of automatic steering systems while changing from automatic to manual steering and vice versa. Since then, automatic steering has improved and electrical control of the steering gear has now become the norm—with hydraulic telemotors being used. Support for the bearing is provided by framing beneath the steering gear deck. Bearing occurs over a period of time, and allowance is made in the construction of the steering gear for a small vertical drop of the rudder stock. The steering gear itself also imposes a limit on rudder movement, but with the hydraulic oil loss and the ship stopped in heavy weather, there may be severe damage to the gear. The tele-motor has become, on many vessels, the stand-by steering control mechanism, used only when the electric or automatic steering fails. The gear pump output and therefore rudder movement, is controlled by a floating lever, one end of which is moved by the control motor (or tele-motor), and the other end by the movement of the tiller. The hunting action of the floating lever is no longer required as the normal control of the steering gear from the bridge is by electric signal. When the steering gear has attained the required rudder angle, the electric feedback unit connected directly to the rudder-stock cancels the input signal to the control amplifier and the steering gear is held at that angle until another rudder movement is required.