How Positioning Sensors Are Installed on a Cutter Dredge: The Rudee Inlet II
The Rudee Inlet II is owned by the City of Virginia Beach, Virginia.
This is a description of the installation of the positioning system that provides heading, position and depth of the dredge to the Hypack software. The dredge is an Ellicott Series 970 Dragon model. Working along with the Hypack system is a dual-antenna GPS system from CSI Wireless that provides heading and position of the dredge. The depth tracking system is an A2TS Vertical Angle Sensor from US Digital.
A2TS Angle Sensor
The A2TS is installed in a box mounted on the starboard side of the dredge ladder well above the water line. The cable for this sensor is a standard phone line cable or as in this installation, a CAT-5 cable with eight wires. Of these, only six are used. The black and yellow wires are not used. A standard six-wire phone crimp can be used to replace either end of the cable.
The other end of the cable is connected to the US Digital connector in the cab of the dredge near the power supply. This end of the connector is attached to the serial connector #2. The A2TS connector on the shelf has a power supply that is plugged in to the UPS (Uninterruptible Power Supply).
CSI Vector GPS
The CSI Vector GPS unit uses three antennas to provide position and heading. Two of the antennas are used to provide position and the third antenna is used to receive RTCM corrections from a Coast Guard station so that the position is more precise. On the Rudee Inlet II, the antennas are located on the roof of the dredge cab. The arrow marks the direction of the dredge. The GPS unit in the picture attaches to the computer using PORT A on the GPS unit and Connector #1 on the computer.
The GPS receives power from the 24 VDC power supply that is installed in the cab of the dredge.