The number of UMS ships has increased rapidly over the past few years. Control systems are much more reliable now than they were when first applied to ships. Educating the crew to understand control functions is now undertaken by most shipowners. More ships will, in future, be fitted with remote-control systems as a means of reducing crews.
Nowadays, however, far more UMS ships are in operation. Crews have grown familiar with the systems and training is more prolific. In the immediate future more owners will adopt UMS, not only as a means of cutting crew to a minimum and thus cut operational costs, but also for reasons of safety.
Remote-control systems. As a number of remote-control stations may be installed, operation must only be possible for one station at a time. There should be no misunderstanding as to which station has control at any time one time, thus there should be continuous indication at all the main control stations showing which one has control. When control is transferred from one station to another, a warning must be given. Only one station which has taken control must acknowledge the fact.
There must be means by which the propulsion machinery can be stopped from the bridge, regardless of whether another station is being operated. Any orders activated from the bridge are to be indicated in the control rooms.
Indicators of the speed and direction or rotation of reversible engines, or the propeller pitch and speed of rotation must be fitted on the bridge. Additionally, an independently-operated stand-by control should be provided in the engine room. It must be able to override the remote control system.
For diesel plant with fixed-pitch propellers the fuel supply and direction of engine rotation should be effected by a single control lever. The controls must operate the machinery in a time sequence acceptable for the engines, and able to shut-off the fuel supply if the desired and actual direction of rotation of the engine and the cam-shaft position does not match.
In addition to alarm indication for the lubricating oil system, the system must be able to shut down the engine if lubricating (lube) oil is lost. The circuit and sensors for this function must be additional to the alarm circuit required.
On the bridge, both audible and visual alarms are to operate and indication given when the speed of the main engines is to be reduced due to the following fault condition: high scavenge air temperature, oil mist detected in crankcase, low piston coolant outlet flow, low piston coolant pressure, also for low cylinder coolant pressure if on a separate circuit.
Where the lube oil cooling water and oil fuel booster pumps are not driven by the main engine, the standby pump is to start automatically if the discharge pressure from the working pump falls below a predetermined value.
