clutch system that will manage the wire under high load conditions. The advantage is that the wire rope and crawler are protected in these extreme conditions preventing wire breaks and crawler damage. The crawler umbilical that provides power, control and oils to the crawler is stored and managed by the umbilical system comprised of an umbilical winch and powered sheave. This umbilical winch is complete with oil, electrical and optical slip rings to ensure continuous operation during the entire launching / recovery and mining processes of the crawler. The powered sheave is used to ensure that the umbilical remains under tension while spooling onto / off the winch thereby preventing damage and slack turns on the drum.
Mooring Winches
12 computers monitor the MMP crawler from a remote control room onboard the vessel.
down through the opening to the ocean floor. The compensator system detects the moment the crawler touches the sea bed and the Hoist Winch pays out the 140 mm diameter lift wire rope at high speed thereby preventing the crawler from bouncing on the ocean floor. While the crawler is on the ocean floor the compensator system manages the wire rope to accommodate the vessel movement thereby preventing slack wire. Due to the dynamics of the system (vessel motion) the Hoist Winch has a mode of operation that allows for render in the event of the crawler being stuck on the sea bottom or in the event of a snatch on the wire rope due to unusual wave conditions. This is achieved through the introduction of a variable
A four point dynamic mooring winch system has been developed by MMP to ensure that during the launching and recovery of the crawler, as well as while the crawler is operating on the sea bed, the vessel remains on station. Each of the four large capacity electrically driven mooring winches has 2200m of 70mm diameter wire rope and is capable of a line pull of 85 tonnes (top layer). This system allows the vessel to hold steady station on a four anchor spread. Movement within the spread is achieved by heaving in two winches while simultaneously paying out on the other two. The advantage is that the vessel does not have to use its main engines and thrusters during the mining process thereby reducing fuel costs. A further benefit of the system is that it does not require an anchor handling tug to assist with spread laying. The winches have three modes of operation. A tension controlled free wheel or high speed low line pull mode for the laying of the anchors during the deployment of the spread, and a low speed high line pull mode for moving the vessel while on spread. The control station has been optimised and designed to ensure single operator operation from the bridge during spread laying and movement during mining operations.
Marine and Mineral Projects (Pty) Ltd Postal address: Ground Floor Block B Aintree Park Loch Road Kenilworth 7700 Cape Town South Africa Contact: Rodney Norman, Tel : +27 21 763 3965 Fax: +27 21 763 3978 email: Rodney.norman@marineandmineral.com URL: www.marineandmineral.com
A main hoist winch is used to deploy the crawler from the vessel to the ocean floor, through the swell compensating tower.
You don't have Macromedia Flash Player installed.
This content requires the Macromedia Flash Player.
Get Flash
www.digitalwavepublishing.com
www.MarineLink.com
www.vovcha.com