MMC's Draft Indicator System consists of a series of open-ended pipe probes extending through the hull of the vessel. A gauging head and a pressure-sensing transducer are mounted on the deck end of the pipe probe. The system presents filtered and regulated air via the gauging head to the pipe probe, where it proceeds to clear the pipe of sea water. An attached pneumatic-electric transducer senses the back head pressure necessary to maintain this condition. The transducer then converts this back head pressure, which is proportional to the vessel's draft, into a suitable form for remote display.
While this system is usually used for instantaneous remote readings of the forward and aft draft, additional stations can be located mid-ship to read the hog or sag of the vessel. Optional trim display is available.
The draft display panel (above, left) is bulkhead- or console-mounted to provide readouts to four digits. Draft display can be specified in either feet or meters.
Closed transducer stations (above, center) each require 50 psi of ship's air at 5 cfh, normally from existing deck lines.
The open transducer stations (above, right) each consist of an air filter and regulator, a gauging head, a pneumatic-electric transducer and an electric junction box.