This system feature has been designed to give the crane operator information on hook position and movement. This is especially useful when the hook is not in his line of sight i.e. working sub-sea or "blind".
Anti-2-Block prevention is done by constantly monitoring the hook position. The system may give pre-warning when the hook approaches the limit, outputs may force the hoist to be set in "creep speed". The system uses absolute encoders not requiring any parts in the boom tip, reducing potential dropped objects.
Monitoring the hook position, a programmed "rope end" can be set to prevent the rope paying completely off the drum or to stop the pay-out at a programmed position, max lowering.
Rope and/or Hook speed is monitored and pre-warning on speed may assist the operator to maintain control of the hoisting motion
Boat sector warning
If the crane is equipped with an Automatic Overload Protection System (AOPS), defining the Boat Sector is important to set crane control logic. The Hook Position will be monitored defining the Boat Sector as programmed, below the facility cellar deck.
Slew and Hook Position Sensor
The Mipeg Slew Operation Monitoring System (OLM) and Hook Position System (RSI) are using the same sensor. The digital encoders are engineered into the winches or slew system and will pick up the rotation of a shaft. The encoder is an absolute encoder which means that the position/measurement is not affected by power loss. As soon as power is re-established, the precise position will be pick-up even if the sensor is moved or rotated during the power loss.
This shaft/pick-up point may be a direct coupling or a geared/linked shaft to a load hoist winch or a boom hoist winch to monitor Rope Speed and Direction calculating the Hook position. Used as a Slew Angle Sensor, the unit is directly coupled or geared/linked to a shaft which gives a slew ratio to monitor the crane rotation of its axis.
All sensors may be supplied to suit standard marine environment or hazardous condition,zone 1 (Class 1 Div 1).
|Sensor Type||Protection||Operating Temperature||Certification|
|Absolute Encoder, aluminium housing, SS shaft||IP 66/67||-30 to + 70 degrees C||Safe area application|
|Absolute Encoder, aluminium housing, SS shaft||IP 66/67||-40 to +70 degrees C||Ex d Atex/IECEx zone 1|
|Absolute Encoder, Stainless Steel||IP 66/67||-40 to +70 degrees C||Ex d Atex/IECEx zone 1|
|Rotational Encoder, safe area||IP 66||-40 to +75 degrees C||Safe Area|
|Rotational Encoder, zone 1||IP 66||-40 to +75 degrees C||II 2 G/D EEx d IIC T6|