How To Find Gold (and Other Money) With a Dynamic Positioning Control System

Abstract

ABSTRACT An informal account of the first U.S. conversion of a standard tug/supply vessel into a Dynamic Positioned (DP) project vessel. Contains a limited review of deepwater search and recovery and the circumstances leading to the conversion. Concludes with a comparison of costs of chartering an existing DP vessel versus converting a vessel of opportunity. TEXT I had all but forgotten that the modifying of a tug/supply with a DP control system for the Central America Identification Project In 1987 was the first such effort in the United States. I hope to give you some insight as to why and how this occurred. I believe that some of you here today may be able to save a considerable amount of operational money by taking a similar approach when the time comes to select a DP vessel for your future projects. While preparing the original abstract for this presentation, a 9entleman I greatly respect recommended I Include a little of the development of Dynamic Positioning and bits of my personal deep water search aridrecovery experience, in his words, this would add flavor and interest to an otherwise boring subject. I hope he iS right Let me point out for those of You that were not around In "good old days", before DP vessels were readily available, precise stationkeeplng for deep water work was completely dependent upon the shiphandling ability of a vessels master and/or mates. The technique required that a device be placed on the bridge to show the ship handler the vessels actual and real time position In relation to the desired position. In reasonable weather conditions a good shiphandler would have little difficulty using this method to take up and maintain a desired position. [Unfortunately the weather is not always favorable and the level of concentration required to maintain a precise station for long periods of time can be quite exhausting. Under these conditions, as operator fatigue sets in, errors in judgement and reflexes could insidiously creep in with the result that the ship might make a totally unexpected or radical departure from station while equipment was deployed. Such a departure can be very hazardous, even life threatening to personnel. It can also severely damage or bring about the loss of very expensive equipment. Seeking ways to prevent such accidents led, to greater and greater use of automation to augment the shiphandler's capability. You will note that I use the word "augment" as opposed to "replace" the shlphandler. In my judgement nothing can replace a highly-skilled and competent shlphandler. I strongly feel that such an individual must always be the bridge of any deep recovery vessel, including' those with a fu: redundant DP control system. Long before DP vessels became commonplace, I had twice gone through the pressure cooker of attempting to keep a vessel on a very small diameter station by "chasing the X" on a track plotter or TV type display designed by a non-shiphandling electronics technician.