ISO 20662:2020

ISO 20662:2020 pdf free.Ships and marine technology一Hopper dredger supervisory and control systems.
4 Components and structure
4.1 Components
A hopper dredger is a self-propelled dredger with its own integrated hopper hold.
An HD-SCS, according to this document, is a basic system for supervising and controlling the dredging operations performed by a hopper dredger utilising sensors, networks, computers, and technologies concerning measurement, communication and automation.
An HD-SCS is an integrated SCADA system that can consist of the following subsystems, based on their functions.
a) STPM/STWC: STPM/STWC monitor excavation process. It should involve the monitoring and control of the suction tube, gantry, draghead, winch, swell compensator and other equipment. The STPM/STWC includes the suction tube vertical/horizontal angle, visor angle, swell compensator position, and valve/gantry state sensors.
b) DSLS: DSLS monitor loading process. It should involve the monitoring and control of overflows, light mixture overboard valve, loading valve and other equipment. The DSLS includes the dredger draught, hopper level, trim/heel, mixture density, mixture flow, overflow position, and valve state sensors.
c) Unloading system: unloading system monitor bottom dumping, rainbow/shore discharging process. It should involve the monitoring and control of the bottom door, split-system pre-dumping door, hopper emptying valve, bow coupling and winch and other equipment. The unloading system includes the bottom door position, pre-dumping door position, and hopper emptying valve state.
d) Dredge pump system: the dredge pump system should involve the monitoring and control of the dredge pump, including pump vacuum and pressure, pump speed, and pump power.
e) Jet water system: the jet water system should involve the monitoring and control of the jet pump, hopper jet water valve, and draghead jet water valve. The jet water system includes the jet water pressure, jet water flow, jet pump speed, jet pump power, hopper jet water valve state, and draghead jet water valve state sensors.
f) Dredge valve system: dredge valve system construction of mixture channel for dredging operation. It should involve the monitoring and control of the dredge valve.
4.2 Structure
The HD-SCS should adopt a multi-layer network structure, including equipment layer, process monitoring layer, and information management layer, as follows:
a) equipment layer: field instrumentation/sensors;
b) process monitoring layer: PLC, signals collecting and processing units, communication network;
c) information management layer: central monitoring and control station.
5 General requirements
5.1 Operating position and control mode
5.1.1 Operating position
The HD-SCS should have local and remote operating positions.
5.1.2 Control mode
The HD-SCS should have the following control modes:
a) manual: manual operation by handle/button/knob and in graphical user interface;
b) emergency: direct operation through hardwire, only for dredging equipment that affects the safety of the ship.
5.2 External communication
The HD-SCS should have communication with a tide-system.
5.3 Diagnostic
When the equipment start and stop control, operation position transfer, or control mode shift operation fails, the HD-SCS can provide diagnostic information to accommodate a safe dredging.
5.4 HMI graphics
5.4.1 Alarm level
In HMI graphics, the HD-SCS alarm level can be set in two colours.
EXAMPLE Red is the highest level alarm, meaning danger; yellow is the secondary level alarm, meaning warning or abnormal condition.
This principle can be applied to all graphical symbols, function-keys, and digital data.
5.4.2 Conventions on graphic colours
The HMI graphic colours can be specified as follows.
a) For HMI graphics, cold tone colours are recommended, and for non-operating graphical interfaces, warm tone colours can be adopted.
b) The colour matching of the HMI graphics should make the flow chart simple and clear with harmonious and consistent colours. It is advisable that the number of colours adopted not be excessive.
c) Colour adoption of the HMI graphics can be in accordance with the specifications in Table 1.
ISO 20662 pdf download.

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