By shifting the telegraph lever from FULL AHEAD to NAVIGATION, a gradual acceleration program is activated; the program is adjustable and enables the engine to reach navigation RPM's in the desired lapse of time.
If any fault occurs during gradual load take-over the engine load increase is interrupted; the engine stabilizes at the value reached at the moment in which the fault occurred and remains in that condition until the fault disappears.
Automatic resumption of power increase takes place according to the preset gradient.
If one of the stand-by causes persists beyond a given time the device automatically starts decreasing the load, beginning from stand-by position and persists until its determining cause disappears. The decrease may occur according to two adjustable speeds which are automatically selected by the programme as a function of the seriousness of the fault.
The following are some of the anomalous conditions which determine the limiting and safety functions described above:
- fresh cooling water high temperature at the outlet of each cylinder;
- cylinder exhaust gas high temperature versus average value;
- cylinder exhaust gas mean temperature;
- thrust bearing, journal bearing, stern tube bearing, crosshead bearing, and big end bearing high temperatures;
- cylinder average high temperature, piston cooling fluid low flow rate;
- engine luboil high temperature;
- fuel injectors cooling fluid flow failure.
Emergency
Shield push-buttons are provided both on Bridge and ECR. By means of these push-buttons some safety and protection facilities may be excluded (RPM reduction, torque limitation, acceleration gradient, engine power manual limitation).
If a "crash stop" is affected in this condition, the admission of starting air takes place at a number of RPM's higher than required for normal reversal and the RPM set-point, as well as positioning limit of the fuel oil lever are automatically brought to a third emergency level.
If said emergency starting RPM's are not reached within a certain limit, the air valves close and a starting failure alarm is displayed.
To repeat the "crash stop" operation, the operator must reset the engine telegraph on STOP position and then set the desired number of RPM's.
